Wednesday, January 16, 2019

The great government shutdown - day 27

I'm now furloughed for 27 days with no end in sight.  Instead of developing courses, improving the EF Scale, thinking about the next generation of warning services, I'm at home growing increasingly concerned about how to weather this crisis.  I do have other things to keep me busy.  I'm still a meteorologist, and thus plan to keep my skills active, just through other means, such as this blog site.  I'm also Chair of our local Scout Pack and the Pinewood Derby is coming up, along with other activities.  I decided to see what working out 5 days a week does for me; I'm already noticing significant improvement.  I help with my wife's proposal writing, and my son's homework.  But I miss my other family at the Warning Decision Training Division, and I especially miss the interactions of my colleagues.

I'm beginning to see the potential of a war of attrition as federal employees lose hope that the government is a safe place to have a rewarding career.  I'm also seeing the level of demoralization increase as people see how indifferent the administration is to the welfare of its employees.  How can anyone working in the shutdown agencies not be demoralized when the president retweets whacko editorials calling for federal employees to just quit?  I certainly hope that somebody cares and values the work that we do.   

 To this, I answer that people do care.  I know how highly the emergency management community cares about the National Weather Service.  They do every time the National Weather Service works with emergency management to prepare for big weather events like fires, blizzards, severe weather and hurricanes.  I'm sure anyone looking to take their business to the next level cares that the Securities and Exchange Commission works.  I'm sure the flying public cares that there are no delays in airport security and that air traffic controllers aren't distracted by how they're going to pay their bills.  So far I've talked about the front face of the government, those employees that have to report to work in a shutdown.  

They may be what the media talks about or what the public sees on a daily basis, but they are supported by a foundation of government employees that provide everything from research, administrative support, training, and more.  They are the ones that are furloughed.  Without them, everything will crumble.  For my part, I'm one of those that provide training the National Weather Service forecasters.  The forecasters consider what I do to be absolutely essential, and therefore I consider my job essential to the success of the National Weather Service.  It's not just me, however.  I work with an entire division devoted to training the NWS.  We have cooperative institute research associates and contractors.  None of the federal employees can do our job without their help.  They're simply not expendable, like some commodity.  They are professionals that become indispensable.   As this shutdown continues, I fear that the foundation will start to give away as employees lose hope, or have to find other means to make ends meet.  

For this reason, I wrote my senators expressing my grave concerns about the lack of interest in our welfare at the top.  I wrote from my perspective.  There are millions of other perspectives that our elected officials need to hear about.  My letter is on top, followed by the responses of Senators Lankford and Inhofe below.   The responses are a bit canned and they differ in content.  But I hope you find some encouragement and if anything, some motivation to write your representatives and keep writing.  


Dear Senator Lankford and Senator Inhofe:

My name is James LaDue and I work for the National Weather Service's (NWS) Warning Decision Training Division.  My division's work is to develop courses and training on warning decision making to all forecasters in the National Weather Service.  The types of warnings for which we conduct training include those related to severe thunderstorms, tornadoes, winter storms, flooding, and other hazards. The courses that we teach provides an important foundation for the success of the NWS in providing warnings to protect life and property.  
The job I do is not just work but a passion of mine.  I am the kind of person that looks forward to pushing the latest science into the operations of the NWS.  Today my colleagues and I are unable to carry out our training because of the shutdown.

Now I weigh in on this shutdown with this letter as a private citizen.  With no hope for a budget agreement any time soon, this shutdown is likely to become the longest in history.  Consequently, this shutdown will likely produce larger and larger negative outcomes for our country as it continues to drag onward.  Our division cannot educate incoming NWS employees on warning decision making until the shutdown is over.  This is already causing a delay on the date in which our students will be trained to issue warnings.  Even among the trained NWS staff, I'm already hearing of the stress and uncertainty impacting forecast and warning operations in the NWS.  There is only so much time left before we will start to see these impacts badly affect the communities they serve.

Some of that is because many of my colleagues only have so much savings.  And the rest is likely from a loss of feeling secure.   My new federal employee colleagues are living with minimal savings or in high cost of living areas and cannot go on without pay after missing even a couple checks.   Others have had events in their lives that have dwindled their savings and are now living closer to the edge of insolvency.  All of us are shouldering the burden of increasing stress, not knowing when payment will come.  We know sacrifice for country but practical matters of needing funds will begin to dominate everyone’s concerns.  While creditors may show some leniency, they also have only so much patience.

While these issues come with every shutdown, this one has been accompanied with an excessive encroachment of politics into the federal workforce.  I’m concerned about the posturing on both sides of the issues surrounding the budget impasse, especially the recent attempts to politicize federal employees.  I don’t want to call out specific incidents because I think you’ve heard them too but I can if prompted.  Like all federal employees, I work especially hard to make sure that my activities are as apolitical as possible.  We are taught that every year when we must renew our ethics training.  The politicization of federal employees by politicians to further their causes only serves to threaten our culture of ethical service and it must stop. To do so I implore the Senate to participate with the House to end this shutdown now so that the politicians do not attempt to further damage the apolitical nature of the federal workforce.   Leave the politicians’ work to stay with the politicians by keeping the government open.  

If we are to restore proper perspective of putting country before party, I implore the Senate to work with other branches of government to modify how appropriations are done so that federal employees and the people they serve don't suffer the consequences of budget disagreements.   We are an embarrassment to ourselves and to every other country.  No other country I'm aware of shuts down their government because of a budget impasse.   I'm sure there are options to allow the government to continue functioning while budget disagreements are resolved.   Needless to say, I've heard quite a few interesting options that I would love to share, though I'm sure you've heard of them.  However, I'm sure you and your colleagues have reasonable options that can be considered in an amendment to the appropriations process. 


Response by Senator Inhofe first

Dear Mr. LaDue:

Thank you for your correspondence regarding the recent government shutdown. As your voice in Washington, I appreciate being made aware of your views.

The President sent his budget proposal for fiscal year (FY) 2019 to Congress on February 12, 2018. This past June 2018, the Senate Appropriations Committee passed all twelve appropriations bills out of committee in a bipartisan manner. Of these twelve, nine have passed out of the Senate, and five have been signed into law by President Trump. These five enacted bills comprise over 75 percent of our government’s total discretionary funding for FY19. As a result, federal agencies like the Department of Defense and the Department of Veterans Affairs have been funded and will continue to operate without interruption. 

 The remaining seven funding measures that have not yet been signed into law were operating under a short-term continuing resolution until December 21, 2018. Due to dire security concerns on the U.S. southern border, the President made a commitment to increase border security funding and build a barrier at the border. Following the December 21 funding expiration, President Trump chose not to sign the pending funding measures because of their insufficient funding for border security. And, unfortunately, due to Democrats’ unwillingness to negotiate with our President, legislation appropriating funding for the federal agencies that fall within the jurisdiction of these seven funding measures expired with the continuing resolution on December 21, 2018. 

The current shutdown is a burden on many Americans who faithfully serve our nation, and I am disappointed Democratic leaders have thus far not taken seriously the issue of border security. However, I am hopeful Democratic leaders reverse this obstruction and we reopen the government. As a member of Congress, one of my primary responsibilities is to ensure the safety of my fellow Americans. As such, I support President Trump’s effort to fully fund border security. 

Proposals are currently circulating within Congress that would reopen the government but fail to providefull funding for a border wall—these simply defer a problem that we can no longer avoid. Our borders desperately need security. Insufficient resources allow thousands of immigrants to illegally enter the U.S. each year, and many of these illegal immigrants are involved in drug trafficking, human trafficking, and other crimes. Democrats, many of whom have supported satisfactory border funding in the past, are choosing to prolong the government shutdown by refusing to acknowledge the importance of this funding, which is in the best interest of all Americans. While I will continue to work to see that the federal government is reopened as soon as possible, I am committed to ensuring our southern border is secure. 

Furloughed workers who may need assistance during this time can visit the Office of Personnel Management’s (OPM) website here for guidance regarding how to operate under a funding lapse. Additionally, Congress recently passed S.24 - the Government Employee Fair Treatment Act, which ensures that backpay is provided for federal employees affected by the shutdown and allows employees required to work during the shutdown to use leave time. President Trump has agreed to sign this legislation.

Thank you, again, for contacting me regarding this issue. I look forward to supporting a solution that both provides border security funding and reopens important government agencies. If you are interested in keeping up with my work in the Senate, I encourage you to sign up for my online newsletter by visiting: https://inhofe.senate.gov/newsletter/sign-up 


Sincerely,

James M. Inhofe
United States Senator

Response by Senator Lankford


January 15, 2019

Dear Mr. James LaDue, 



Thank you for contacting me about the federal government shutdown.  I appreciate your involvement in such an important national issue.

As you are aware, the federal government is currently partially shut down, a carryover from the end of last year.  The U.S. Constitution states that before federal tax dollars may be expended, Congress must first enact a law giving permission for those funds to be spent.  Congress is required to fund the federal government with the passage of 12 appropriations bills by the end of fiscal year, which runs through September 30th

Over the past 12 months, Congress agreed on five of the 12 appropriations bills to fund most of the government including Defense, Veterans, Education, Health, Energy, and more.  However, there were major disputes with the remaining 7 bills, most of which centered around the issue of border security.
The President requested, months ago, more federal funding for additional border security, including constructing more fencing and using additional technology along parts of the southern border.  Our nation already has more than 700 miles of fencing, but some of it is old and in need of repair.  Our office has been notified by border agents that there has been a significant decrease in the number of illegal immigrant entries since new fencing, constructed or replaced using $1.7 billion toward border security from the previous appropriations, has been placed in some areas.  Border security has not always been and should not be a partisan issue.  I support securing our southern border by adding technology, staff, and fencing where needed.  National security should remain a top priority for Congress, and border security is a necessary part of it.
During a federal government shutdown, the entire government does not completely shut down.  Essential services, national security, transportation, and safety functions continue to operate.  Programs that are funded with mandatory funds (eg. Social Security, Medicare, Medicaid, etc.) are not affected by a government shutdown.  But there is tremendous cost financially and personally when the government shuts down since every agency without funding must cease new operations, workers are furloughed, contracts have to pause, grants stop, etc.  Again, in this case about 75 percent of the government is funded, but the other 25 percent are feeling the consequences like not receiving their paychecks.  I have spoken to many great federal workers and contractors that are frustrated and financially hurting during this shutdown.  This is unacceptable.
I have worked to end the shutdown politics and to propose a requirement that places the greatest burden on Congress and the White House when annual funding has not been completed.  In addition, I’ve worked on a separate proposal that would keep the government open when Congress and the President cannot reach a funding agreement by the fiscal deadline.  To force compromise and agreement on funding, it would include a series of weekly 5 percent cuts to congressional and White house funding.  This is designed to dramatically ramp up pressure on decision makers to reach a funding agreement.  This concept holds federal operations harmless while forcing Washington to do its job and carry out its constitutional responsibilities to fund federal operations.
believe that if Congress is unable to meet the appropriations deadline that the government should automatically and temporarily be funded at the previous year's levels.  Executive branch cabinet members should not travel and Members of Congress must remain in D.C. until all negotiations are finished.  The American people and federal employees should not be held hostage because Congress did not properly do its job.  This bipartisan proposal will encourage congressional accountability.
I have also worked to develop major budget process reforms for Congress.  We still operate under the 1974 Budget Act, which was created just after Watergate.  It has always been a bulky process and has only worked as designed a total of 4 out of 44 years since it was enacted.  Our three-step budgeting process and 12 appropriations bills process is not used anywhere else in the world.
We should reduce the number of appropriations bills to pass every two years to no more than four bills.  We should mandate floor debate for greater transparency.  We should conduct more oversight hearings, and we should completely rework the Congressional Budget Office process.  Currently, I have about five other Members who are actively working with me on this budget redesign.  I will continue to work with Members from both sides of the aisle to get the changes we need to fix this broken process that favors the status quo and spending more.  I recently spoke on the Senate floor to discuss my proposals to prevent government shutdowns.
Congress can also consider a continuing resolution (CR), which continues last year's funding into the current fiscal year and kicks the can of responsibility further down the road.  A CR is better than a government shutdown, but it is also a terrible way to fund the government.  Simply copying last year’s priorities into this year gives no oversight, no opportunity for change, and no certainty.  Also, new contracts cannot start under a CR since there is no certainty for the future of any program.  Congress has used 178 CRs to fund the government since 1977.  Congress has not followed the correct annual process to fund the federal government since fiscal year 1995.  While not every CR is bad, it is certainly not as good as individual spending bills that have more input and greater transparency.  A little sunlight is a very good disinfectant for government waste.
As I continue to serve on the U.S. Senate Committee on Appropriations and the Senate Finance Committee, I will fight for responsible federal spending and a long-term solution to our national debt.  I will also continue my work as a member of the U.S. Senate Homeland Security and Governmental Affairs Committee as we work to fix the nation's broken immigration system.
I hope this information is helpful.  Please feel free to contact me again or sign up for my e-newsletter via my website at www.lankford.senate.gov for more information about my work in the U.S. Senate for all of us.


In God We Trust,

James Lankford
United States Senator
 

Friday, January 11, 2019

The Port Orchard, WA tornado of Dec 18, 2018

The strongest tornado in Washington State since 1986. hit the town of Port Orchard, a suburban-style town about 40 mi west of Seattle and east of the southern Olympic Mountains.  This story from KOMO nicely summarizes what happened.
https://komonews.com/news/local/storm-survey-team-heads-to-gauge-damage-from-port-orchard-tornado

According to the NWS Seattle office, the tornado produced EF2 damage to homes in a neighborhood and also a storage facility. While the tornado track was relatively short, it was as wide as 300 yards.  This event is the latest in several notable fall and early winter tornadoes that have occurred in western WA and northwest OR in recent years and is similar in strength to one that formed in the Pacific Ocean and came ashore to strike Manzanita, OR in October of 2016.




Where did this tornado come from and was the threat predictable?  Tornadoes are exceptionally rare in this part of the world; on average, only 1-2 occur in western Washington in a year. So there are not very many cases in which to build a rich repository of cases in which to build an analysis of common tornado-producing patterns.  This means we have to depend on detecting the ingredients favorable for producing tornadoes.  The tough part of this is that we don't know all the ingredients for tornadoes and even if we did, some may require observations that just aren't available to us on an operational basis.  Even in the traditional tornado alley, it's difficult to determine what exactly happened to create tornadoes in any one event. 

This case is no different in its marginal characteristics and didn't express the kind of predictability that operational meteorologists depend on to make a confident forecast.  The Storm Prediction Center only forecasted general thunder in their morning and midday severe weather outlooks.  This is, after all, the time of year when cold upper-level systems combine with the mild Pacific Ocean sea surface temperatures to generate instability, and this day was a classic case.   Enough instability to generate convection is one thing, but a tornado friendly environment? SPC isn't anticipating one.  The base situational awareness of forecasters and the public would likely be starting from a relatively low point.

But I don't think this event was undetectable, nor even unpredictable, and we have surface observing networks, model analysis, GOES data, and especially a WSR-88D not too far away.  Some of these data suggest that it would be possible to ramp up situational awareness quickly when the evidence appears to show that the morning forecast was understating the threat.  Let's assume the first indications that the environment may be favorable for tornadoes comes from the behavior of the storms themselves.

The first indication likely appeared from the development of the first detectable radar-observed signatures of rotation aloft.   By far, of all storm types, supercells provide the precursor signatures with the most predictability.  Squall line mesovortices can provide some predictability but with less lead time.  And nonmesocyclonic tornadoes (aka landspouts) often provide no precursor signatures from radar at all.  So, in this case, was there evidence of a supercell responsible for this tornado?

Here is the KATX WSR-88D radar loop for the two hours leading up to the tornado.  This four-panel loop started near noon PST (labeled here 1:59 pm CST in the reflectivity panel).  The parent cell of the tornado first appeared around an hour later, or 1 pm PST near Skokomish, WA.   Already the half degree velocity appears to show some positive shear.  Another 27 minutes had to pass, or by 1:32 pm PST  before the radar indicates that the parent cell strengthened enough to produce a real mesocyclone signature with a rotational velocity of 40 kts (This lesson on WDTD's home page describes a mesocyclone and how to measure rotational velocity).  At about the same time the differential reflectivity showed the onset of high Zdr values accompanying the reflectivity core.  The half degree beam from KATX centered around 1.2 km above the radar.  High Zdr values in high reflectivity most likely show large raindrops.  But at the next elevation scan up, around 2.1 km, the same high Zdr values appeared at this time and here the surrounding values dropped.  The Quillayute, WA sounding that morning showed the melting level around 1.4 km.   This was likely a Zdr column, a common sign of an updraft transporting liquid droplets above the melting layer.  These two features, updraft, and a mesocyclone persisted for 30 minutes with only minor fluctuations as the storm approached Port Orchard.  A cell with a persistent mesocyclone and updraft fits the description of a supercell.  The only feature not readily apparent is the absence of some kind of hook echo or a low-level reflectivity notch.   I'm not surprised we don't see these features since this storm was quite small, both vertically and horizontally. 




A four panel loop from the KATX WSR-88D covering the two hours prior to the Port Orchard tornado.  The panels start with reflectivity (upper left), base velocity (upper right), correlation coefficient (lower left) and differential reflectivity (lower right). 



A radar loop over the two hours leading up to the tornado from the WSR-88D KATX.  The reflectivity appears in the upper left, base velocity in the upper right, differential reflectivity (Zdr) in the lower right, and correlation coefficient (CC) in the lower left.


The Quillayute, WA sounding from 2018 Dec 18 12 UTC.
Were these signatures worthy of a credible tornado threat?
Accoing to the latest tornado warning guidance quick guide, 25% of mesocyclones with a rotational velocity of 40 kts are associated with tornadoes.  This is pretty high, and achieves the highest skill if the decision is made to classify this mesocyclone as tornadic when it reaches this rotational velocity. But there is a significant disclaimer.  The guidance makes no mention of the environmental conduciveness to creating a tornado.  Plenty of atmospheres can produce supercells but with no capability to generate a significant tornado threat.  While the guidance was taken from environments with tornado watches, was this environment worthy of seriously considering this guidance?  Well, the morning sounding shows a few signs that say yes, and a couple that gives me pause.

The left chart shows the probability of a mesocyclone being tornadic with a given low-level vortex signature strength presented by low-level differential velocity in m/s (LLDV) or rotational velocity in kts (LLRV).  The right panel indicates the Heidke Skill Score should the decision be made that the given mesocyclone is tornadic as a function of LLDV and LLRV.  The sources of information come from a 2003 Tornado Warning Guidance (TWG), a WDTD study, and Smith and co-authors in 2015.  The purple filled circle with a black border represents the rotational velocity of the Port Orchard mesocyclone at 1332 PST.

First, the good signs. The most favorable sign was a rather impressive 35 kts of bulk wind difference in the lowest 3 km above the surface, 21 kts in the lowest one kilometer (bulk wind difference is a very simplified representation of a more proper shear measurement).  Even more impressive, the shear direction sharply bent clockwise almost 90 degrees at roughly one km.  The hodograph looked quite similar to that of many tornado-producing profiles found in multiple composite studies.  The low-level 'sickle shape' of the hodograph permits a large amount of streamwise vorticity to be ingested into any convective updraft that manages to form. Two authors, John M. Esterheld and Donald J. Giuliano, studied the association between the low-level shear orientation and the storm-relative low-level wind and the categorization of supercells from nontornadic to significantly tornadic.  That angle is what's called the critical angle, and a value of 90 degrees would lead to having all of the horizontal vorticity represented by the shear to be streamwise.  The critical angle appeared to be the nearly 90 degrees for the Quillayute sounding.  

On the other hand, the feature giving me pause was that the thermodynamic profile barely showed any instability.  One representation of instability, CAPE, only yielded a meager 134 j/kg, and that's the maximum version available based on the morning sounding at Quillayute.  This amount was well below anything that the tornado warning guidance can offer as enough to generate a strong enough updraft for a supercell.  I would be looking for more before considering a reasonable prospect to generate a strong enough updraft.  The only positive attribute to the thermodynamics was that the low-level lapse rate was somewhat high, or in other words, there was not much convective inhibition.  But the presence of the storm in the afternoon surely pointed to more instability being available to the south and east of the Olympics than what the sounding showed.    Sure enough, the Regional Atmospheric Prediction (RAP) model painted a more unstable picture with nearly 280 j/kg of uncapped CAPE using a 100 mb deep mixed layer parcel from a 22 UTC analysis at a point near the storm's location.  A 100mb layer may be asking a lot for a storm who's depth was only 6 km.  Thus I checked the surface-based CAPE and it was 490 j/kg.  Perhaps the optimal layer from which a parcel may be drawn would be in the lowest 50 mb, but I think you get the picture that adequate CAPE appeared to be available.

The RAP sounding near Port Orchard valid 2018 Dec 18 22 UTC.  

The 0-3 km bulk wind difference and the storm-relative helicity in the 0-1 km and the 0-3 km layers were higher in this RAP sounding than for the Quillayute sounding.  Though the critical angle was less the component of the low-level shear oriented perpendicular to the 10 m storm-relative flow was still quite high.   And perhaps it's quite likely that the actual hodograph shape may have had a higher critical angle.  BTW, the critical angle, and the strength of the lower level shear really point to the fact that the streamwise vorticity was quite high.  Any mechanism to tilt such vorticity would readily produce a low-level mesocyclone, even for storms not deviating to the right.  The last severe storms conference in Stowe VT featured several studies of different types that indicated that we should pay more attention to streamwise vorticity.  As an aside, we appeared to be circling back to this parameter since it's importance in producing mesocyclones was first studied by Robert Davies Jones in the early 1980s.

Okay,  I only showed two sounding points, and one was from 12 UTC.  But what was the spatial pattern of the environment capable of producing supercells and tornadoes?  According to the 1-hour forecast of the 21 UTC RAP, Supercell Composite Parameter (SCP), most of western Washington State, and offshore areas had the potential for supercells.  The only area not favorable was located in the northeast Olympic Penisula and north, where both the deep layer vertical wind shear and CAPE were lacking in the RAP analysis.   The SPC formulation of the Significant Tornado Parameter (STP) was below 1 in all areas except for coastal Oregon where CAPE was high enough to keep the parameter above 1.  The RAP sounding above showed that the mixed layer CAPE likely brought down the STP to 0.2 but the fixed layer STP, which depends on surface-based CAPE, was higher.  Again, sometimes mixing the lowest 100 mb of the atmosphere may be too much to ask when we're talking about a shallow convective layer such as this day.  This even was not the first time that a significant tornado developed with barely any effective layer STP but higher fixed layer STP.

Above, the 21 UTC 1 hr RAP forecast of fixed layer Supercell Composite Parameter overlaid with 850 and 500 mb winds.
Above, the 21 UTC 1 hr RAP forecast of fixed layer Significant Tornado Parameter.

Thus returning to the question of whether there was enough information to issue a tornado warning.  I would say that there was.  Some events are completely undetectable and thus deny us the luxury of engaging in 20/20 hindsight.  But this one left enough to show that we can engage in this activity.

The KATX radar was fortunately close enough to depict a supercell with a mesocyclone strong enough to have perhaps a 30% chance of a tornado provided the environment supported the possibility of tornadoes.  The morning Quillayute sounding and the afternoon modified RAP analysis sounding showed hodograph profiles, sufficient CAPE, and low enough CIN to be favorable for tornadoes.  I won't even consider whether the boundary layer relative humidity was sufficiently high.  The environment had high relative humidity in the lowest 3 km and all soundings showed dewpoint depressions of only a few degrees at the surface.

Sometimes we need a little convincing that what appears to be favorable ingredients for rotating storms actually produced something elsewhere.   Well, it appeared this supercell was not the only one in the area.  The Multi-Radar/Multi-Sensor (MRMS) depicted another mesocyclone track in the Pacific that occurred a couple of hours earlier.
The MRMS rotation tracks product accumulated over six hours ending at 23 UTC 18 Dec 2018. A strong mesocyclone track appeared offshore west of the mouth of the Columbia River.  The other, southeast of the Olympics.
 More importantly, back to the question of the longer range outlook, was there any signal in the NWP guidance from earlier in the day that ought to be reconsidered? Well, the 12 UTC SPC High Resolution Ensemble Forecast (HREF) system did predict correctly that there would be plenty of CAPE, or at least a few hundred joules per kilogram, as the multi-panel display shows around the time of the tornado.  The HREF also showed that convective cells would be plentiful according to the 11-hour paintball plot of >40 dBZ reflectivity valid for the same time.


The HREF surface-based CAPE member plot valid 18 Dec 2018 22 UTC

The HREF paintball plot of reflectivity > 40 dBZ from each member, valid 18 Dec 2018 22 UTC

The HREF even showed that the fixed-layer sigTOR parameter would have an up to 30% chance of exceeding 1.  However, most of the high probabilities were close to the coast where the CAPE was the highest.  What happens inland was fracturing and lowering of probabilities.  While not zero, it would be hard to have any confidence of a significant threat, at least significant enough to warrant a tornado outlook from the 12 UTC runs.  And the updraft helicity forecast showed only one short-lived, low-value, plot in southwest Washington – hardly the kind of result that would promote anyone to raise the risk level.
The HREF probability of fixed-layer sigTOR parameter exceeding one, valid 18 Dec 2018 22 UTC
The HREF four hour ensemble maximum 2-5 km updraft helicity ending 19 Dec 2018 00 UTC
So while the morning guidance didn't impress, there was reason to be on the watch for that rare event. The HREF shows CAPE and a nonzero probability that sigTor values exceeding one.  The environment appeared to exceed expectations by just enough to allow more than one storm to produce a significant mesocyclone, one of those with a confirmed tornado, and the other not known due to its location.



Tuesday, August 21, 2018

The tornado wind measurement of 19 August 2018 in Inola, OK

Here's an interesting observation the Inola, OK mesonet site recorded after a tornado passed near or overhead.  The 2 meter, 3 second wind gust observation wound up being higher than that located at10 m.  The tornado responsible for this wind observation developed just southwest of the mesonet site, then struck a farm a mile to the northeast before moving on several more miles before dissipating.  Overall, this tornado was rated EF1 based on the damage to some barns and trees.

An infographic of the tornado track and the reported mesonet wind gusts from the Inola tornado of 2018 August 19. (courtesy of NWS Tulsa)
This event would seem to confirm that tornadoes can produce stronger winds very close to the ground and shows that tornado wind environments don't adhere to the log normal vertical wind speed profile assumed during larger, straight line severe wind storms.  While this rare measurement at two levels seem to confirm that tornadoes produce stronger winds below 10 m, there are some things I heard from several knowledgeable people in the mesonet program that may suggest the difference in wind gusts may be due to differences in instrumentation.   I contacted Chris Febrich, James Hocker, and Cindy Luttrell at the Oklahoma Climate Survey, the organization in charge of the Oklahoma Mesonet.  They mentioned that the 2 m anemometer is a standard wind cup while the one at 10 m is an RM Young propeller vane anemometer.  While not immediately obvious, their hypothesis suggested that the RM Young 10 m anemometer was not directed into the wind when the strongest gust arrived.  A possible reason for this was that the wind shifted rapidly with time and that the RM Young at 10m may not have turned into the wind in time to sample the full speed of the peak gust. A propeller vane anemometer isn't likely to sample the wind at full speed unless pointed directly into the wind.  And some time is needed for the vane to respond to a new wind direction.  Conversely a cup anemometer isn't sensitive to changes in horizontal wind direction.  Chris sent these few wind direction observations to highlight his concern.

171 degrees at 20:36
267 degrees at 20:37(moment of peak gust)
289 degrees at 20:38

Now, a vane anemometer is designed to completely reorient into a new wind direction in a much faster time interval than implied by these measurements.  But we are talking about a small tornado and so the changes in direction may have happened much more quickly.

Chris also pointed out that the mesonet record contains no instances where the 2m wind gust exceeded the 10m at the same place and time.  Within that period of record were four other mesonet sites struck by tornadoes.

So this doesn't put cold water on the possibility that stronger winds occurred at 2m vs 10m but it may mean we cannot use this case to show otherwise.  Still, these are interesting observations which align well with the observed damage from this tornado.  The link below gives you a drone-based view of the tornado path from where it passed through the mesonet site and then to the northeast to a farm residence.  
The peak wind speed at 2m altitude is quite consistent with the damage incurred to the farm that can be seen in the drone footage and also witnessed by Scott Peake that you can see in his video link below.

These kinds of observations don't come by very often, and when they do, it's most likely courtesy of a field project such as TWIRL (Tornadic Winds: In-situ and Radar observations at low Levels) operated by the Center for Severe Weather Research.  The teams in this project deployed portable surface stations into tornadoes to measure winds at 1m above the ground  while mobile radar teams measured the winds overhead.   The TWIRL project successfully deployed surface stations into two tornadoes, the 2018 May 9 Sulphur, OK tornado and the 2018 May 24 Dodge City area tornadoes.  Neither tornadoes had measured winds at 1m exceeded the wind speeds measured by nearby radar.  However, efforts to simultaneously measure winds at low and high levels in previous field programs, like VORTEX2, netted examples where winds measured at 10 m above ground exceeded the radar observations at higher altitudes.  And another event occurred where a serendipitus, and somewhat scary, encounter by a CSWR team produced very high resolution profile of winds where the maximum measured was only 3.5 m AGL.

So why the fuss about whether the strongest winds are at low vs higher levels?  It's because engineers design buildings to withstand a certain level of winds  tuned to a reference level of 10m (the kind measured at most airports) over 3 second durations and then assume the winds are weaker below that level and stronger above.  This wind profile is called a log normal wind profile.  So for example, engineers would typically construct a building able to withstand a 3 second long gust of 90 mph at 10 m above ground where they would assume the wind at 3 m above ground would be perhaps 75 mph, and a wind at 100m above ground would be stronger.  But the evidence shows tornadoes produce wind profiles that don't follow the log normal profile. And the result could be stresses on buildings that greatly exceed that produced by a standard log normal profile.  But to what level tornadoes deviate from the log normal profile is something we don't know.  Wouldn't it be nice if we did?  Then we could have a better idea of how to design buildings with improved tornado resistance.  The only way to find out is with more observations in a tornado boundary layer.  That's why even serendipitus observations are important.

BTW, I am a Chair of a standards committee for the American Society for Civil Engineering (ASCE) that seeks to put the guidance in wind speed estimates into a document that includes not only anemometers and radars but also wind speed estimates from the EF Scale, tree-fall patterns, remote aerial measurements and building forensics.  Hopefully soon we'll also include a section on photogrammetry such as what could be derived from Scott's video above.

Sunday, December 31, 2017

The Strong Great Lakes Mesovortex of 30 - 31 December 2017

One of the strongest lake-induced mesoscale vortices I've seen struck Marquette, MI yesterday with 60 mph wind gusts and an amazing longevity as it survived a passage over the UP of Michigan and then dropping straight south down the long axis of Lake Michigan last night to eventually make final landfall midday today on the Michigan, Indiana shoreline. The Great Lakes produces numerous vortices during its convective lake effect season, ranging from small misocyclones less than 4 km wide documented by a study by Steiger and co-authors in 2013, to 4-50 km mesoscale vortices documented by Laird and co-authors in 2001. Some misocyclones have been reported to have caused winds strong enough to break tree limbs along the Great Lakes shorelines possibly as they've intensified into weak tornadoes. But I have not heard of the larger vortices being strong enough to do the same kind of damage.  

These vortices can produce impacts when well-behaved snow bands suddenly take sideways departures to visit areas not predicted to receive snowfall. This one produced impacts even in an area well-accustomed to lake effect snow. The snowfall rate and high winds shut down at least one state highway where an accident shut down US-41 south of Marquette. An employee at the NWS Marquette shot two pictures of the event, one of the main convective band associated with the mesoscale vortex approaching them and then a few minutes later, a whiteout.


A tweet showing US-41 shut down due to whiteout conditions and an accident.

A picture, taken from the NWS Marquette, MI, shows the main convective band approaching shore to the north.




The peak wind gusts reported reached 60 mph near Marquette as the convective band on the western flank of the mesoscale vortex passed over the station.  The surface map provided by NWS Weather and Hazards Viewer.


As the mesovortex passed to the south and into Lake Michigan, residents around the Grand Traverse Bay tweeted pictures of funnel clouds, certainly representing tornado-like vortices. I'm not sure where these waterspouts were located relative to the mesolow but they may have been within a few hours of its passage.  It goes without saying that the mesolow was ripe with vorticity and the available convection to help concentrate into misocyclones and perhaps even weak tornadoes.



https://twitter.com/NWSGaylord/status/947266131450105861/photo/1

The impacts continued down Lake Michigan although perhaps in an unexpected way. The lake effect band plaguing the south shore of Lake Michigan for some hours quickly weakened before the arrival of the mesovortex, potentially providing a narrow window of unimpeded travel. However the arrival of the mesolow meant that snowbands reoriented themselves and reached areas not expected to experience lake effect given prevailing synoptic scale wind direction. The east-west band slapped a broad section of the southern lake Michigan shoreline with rapidly dropping visibilities and enhanced winds capable of causing brief whiteouts. While the shoreline didn't see the 60 mph winds from yesterday's Lake Superior landfall, they were certainly strong enough to simulate the wintertime equivalent of a thunderstorm but with the extra benefit of whiteout conditions and added ice cover on road surfaces.




A video loop of the Northern Indiana WSR-88D showing the impact of the mesolow on the location and behavior of the snow bands.


Maximum wind gusts from today's mesolow landfall in southern Lake Michigan.  Image courtesy of the Weather and Impacts display from the NWS.



This mesovortex event provided a platform to showcase two amazing advancements in meteorology. The first is the major upgrade in our GOES. The recent launch of GOES-16, and its placement as the eastern operational satellite provided a spectacular rapid update loops of the development and intensification of the mesolow over Lake Superior. the last minute explosion of convection that the canvassed the northern view from the NWS MQT office was well-captured one one-minute intervals from the satellite, manifested as rapidly expanding and glaciating anvils, similar to a summer thunderstorm. The satellite captured smooth ribbons of lake effect cloud streets converging into the mesolow from the north and east. The Marquette WSR-88D complimented the satellite by showing the internal structure of the mesolow and the strong winds whipping around its western flank.



The next day the new GOES captured another convective explosion just offshore of Lake Michigan's southern shore. The satellite explicitly showed the new convection convert from bright liquid water clouds to mostly ice the same way it did for summer thunderstorms.




The second showcase was the eerily accurate prediction by the NAM, NAM 3km and the HRRR models from even two days in advance. This amazing success was partly courtesy of the excellent analysis of the low pressure in advance of the arctic front over Lake Superior from the day before it intensified. But the models could take advantage of the excellent lake temperature and ice cover analysis, as well as the model advancements that allowed them to accurately depict the structure and motion of the mesolow.


NAM 3 km surface temperature and wind analysis from the night before the mesolow formed and intensified before hitting Marquette.

As an example, the 3 km NAM from the previous night accurately depicted the strong winds on the mesolow's western flank approaching Marquette during the middle of the day. It may have fallen short of the peak observed wind speeds but it certainly was good enough to show that a sudden onset whiteout conditions could be possible. And then in even more spectacular fashion, the same model run moved the mesolow down the axis of Lake Michigan.   


NAM 3 km 16 hour forecast surface winds and sea level pressure from 00 UTC Dec 30.




This persistent scenario depicted by the models prompted at least one NWS office to draft up a forecast and publish headlines announcing the mesolow's arrival a day ahead.



Finally, this mesolow has many of the characteristics of a tropical cyclone and polar lows.  It intensified over relatively warm waters of Lake Superior while a deep convective layer allowed for more intense concentration of the loose low pressure into something much tighter than I've seen before.  A deep convective layer for this time and place is only about 3 km.  The center of the low was surrounded by warm air, of 19-20 deg F, not the single digits or below zero readings from inland.  Perhaps the strong warming was partly courtesy of strong sensible heat fluxes when the mesolow began to intensify. It's a feedback process that can help explain the genesis of tropical cyclones.  In this cold environment, the process can only go so far.  Yet we're not talking about a cat 5 potential environment, just one strong enough to do what we've seen here.

A model sounding over Lake Michigan near the mesolow depicting the 3 km convective layer and vigorous vertical motion (horizontal orange lines).  Image courtesy of COD and SHARPPY.



Laird, N. F.L. J. Miller, and D. A. R. Kristovich2001Synthetic dual-Doppler analysis of a winter mesoscale vortexMon. Wea. Rev.129312331, doi:https://doi.org/10.1175/1520-0493(2001)129<0312:SDDAOA>2.0.CO;2.  Link

Laird, N.F., L.J. Miller, and D.A. Kristovich2001Synthetic Dual-Doppler Analysis of a Winter Mesoscale Vortex. Mon. Wea. Rev., 129312–331,https://doi.org/10.1175/1520-0493(2001)129<0312:SDDAOA>2.0.CO;2 

Linders, T. and Ø. Saetra2010Can CAPE Maintain Polar Lows?. J. Atmos. Sci., 672559–2571, https://doi.org/10.1175/2010JAS3131.1 

Steiger, S.M., R. Schrom, A. Stamm, D. Ruth, K. Jaszka, T. Kress, B. Rathbun, J. Frame, J. Wurman, and K. Kosiba2013Circulations, Bounded Weak Echo Regions, and Horizontal Vortices Observed within Long-Lake-Axis-Parallel–Lake-Effect Storms by the Doppler on Wheels. Mon. Wea. Rev., 1412821–2840,https://doi.org/10.1175/MWR-D-12-00226.1 

Sunday, January 22, 2017

Rare and dangerous high risk of tornadoes in GA and FL


I haven't seen tornado outbreak environments like this in some years.  The latest Storm Prediction Center (SPC) outlook still has a high risk for severe storms including long-track significant tornadoes for portions of south Georgia into north Florida.  The last time that a high risk was issued by the SPC was almost three years ago according to Skip Talbot's Facebook post, and possibly no high risks have been forecast into the Florida peninsula.  Now storms are starting to form along and ahead of a cold front in the western FL panhandle and north along the GA, AL border.  Newer storms are firing up along the cold front south into the Gulf.  These should be of interest to anyone concerned about their safety which should include especially the high risk zone.

Later, more isolated storms will fire to the south and threaten the Florida peninsula.  While they may be more isolated, the environment will also support the potential for strong tornadoes.  The risk may not be high for Tampa, Orlando and Melbourne, but if you're unlucky enough to be in the path of a potentially tornadic storm, assume it'll produce significant tornadoes putting you at risk.



Areas north of the high risk may not see an obvious environment supportive of tornadoes because of the widespread rain in southern Georgia.  However this system is unusually far to the south, and our collective experience, limited.  Thus I suspect that even western to central Georgia may see a tornadic threat as the surface low deepens dramatically to something rarely seen in central GA - up to five standard deviations below normal for this time of year.  Outside of hurricanes, the sea level pressures will be very low down into FL as well.  As a result low-level winds will be strong and that means that if you're experiencing a cloudy, cool rainy atmosphere now, that may change quickly to one favorable for severe weather very quickly.   Residents in the Huntsville, AL area on the super tornado outbreak day of 2011 can relate to that.  Temperatures were in the 50's all afternoon and then in the last hour, jumped to near 70 deg F quickly followed by a mile-wide long-tracked tornado.



Furthermore, the probability that any one supercell will produce a significant tornado currently stands in the 15% range according to research by Smith and Thompson and Marsh of SPC in the last few years.  Get used to those numbers being extremely high.  As cases are gathered and return intervals calculated, you may see them as rather unusually high.  More importantly is that these numbers will go up from here as the day progresses.  The key thing to consider is that area hodographs feature large storm-relative helicity, very humid atmosphere (in an absolute and relative sense) and lots of buoyancy for thunderstorms to grow uninhibited, as seen from this sounding from the HRRR in the FL Panhandle ahead of the storms.


Bottom line, if your sheltering location is dusty, or cluttered, clear it now!