EWP2012 Week 2 Summary: 14-18 May 2012


The National Oceanic and Atmospheric Administration (NOAA) Hazardous Weather Testbed (HWT) in Norman, Oklahoma, is a joint project of the National Weather Service (NWS) and the National Severe Storms Laboratory (NSSL).  The HWT provides a conceptual framework and a physical space to foster collaboration between research and operations to test and evaluate emerging technologies and science for NWS operations.  The Experimental Warning Program (EWP) at the HWT is hosting the 2012 Spring Program (EWP2012).  This is the fifth year for EWP activities in the testbed.  EWP2012 takes place across five weeks (Monday – Friday), from 7 May through 15 June.  There are no operations during Memorial Day week (28 May – 1 June).

EWP2012 is designed to test and evaluate new applications, techniques, and products to support Weather Forecast Office (WFO) severe convective weather warning operations.  There will be three primary projects geared toward WFO applications this spring, 1) evaluation of 3DVAR multi-radar real-time data assimilation fields being developed for the Warn-On-Forecast initiative, 2)  evaluation of multiple CONUS GOES-R convective applications, including pseudo-geostationary lightning mapper products when operations are expected within the Lightning Mapping Array domains (OK/west-TX, AL, DC, FL), and 3) evaluation of model performance and forecast utility of the OUN WRF when operations are expected in the Southern Plains.


Week #2 of EWP2012 occurred during 7-11 May.  NSSL and the GOES-R program provided travel funds for four forecasters from the NWS: Brian Carcione (WFO, Huntsville, AL), Stephen Kearney (CWSU, Memphis, TN), Julia Ruthford (WFO, Charleston, WV), and Todd Dankers (WFO, Denver, CO).  Other visiting participants this week included Dave Carlsen (Environment Canada), Bob Aune (UW-CIMSS), Wayne Feltz (UW-CIMSS), Jordan Gerth (UW-CIMSS), Lori Schultz (UAH), and Chad Gravelle (GOES-R NWSTC liaison, Kansas City, MO).  Overall the weather pattern was exceptionally quiet for this time of year as a large ridge dominated the central US.  Nevertheless, southern stream disturbances  brought convection to the Rio Grande Valley eastward into Florida.  And northern stream flow over the ridge allowed short-wave troughs to deliver convection from the Western Great Lakes to the East Coast.

Photo:  1)  Jim LaDue (NWS/WDTB), 2)  Chris Siewert (CIMMS/SPC/GOES-R), 3)  Lori Schultz (UAH), 4)  Chad Gravelle (GOES-R NWSTC liaison), 5)  Julia Ruthford (WFO, Charleston, WV), 6)  Todd Dankers (WFO, Denver, CO), 7)  Jordan Gerth (UW-CIMSS), 8)  Stephen Kearney (CWSU, Memphis, TN), 9) Kristin Calhoun (CIMMS/NSSL), 10) Bob Aune (UW-CIMSS), 11) Brian Carcione (WFO, Huntsville, AL), and 12) Gabe Garfield (CIMMS/WFO Norman, OK). Photograph by Greg Stumpf (CIMMS/NWS-MDL).


14 May:  SC early, and then Central FL.  SW TX was also briefly worked.

15 May:  Western VA, Eastern IA, and Central FL all had marginal storms.

16 May:  Hailers in VT and Upstate NY.

17 May:  A marginally-severe event across eastern FL, GA, and SC.



NSSL 3DVAR products were quite useful as judged by the majority of forecaster comments.  But there were a few drawbacks.   The following are specific comments:


  • Ten km divergence was extremely useful.  Somehow when the colorscale turned red (10 ^s-1), it seemed to precede severe weather.   On May 16, 10 km divergence turned red 20 min before the first report of large hail.  It also was useful at far ranges from radars.  NSSL may actually adjust so that max divergence at upper levels would be used, or storm top divergence would be added.
  • Updraft helicity was extremely useful too.  But it was more the trend that was important.
  • Updraft strength was used with success.  The team that covered the NWS Burlington, VT CWA storms on May 16 noted values of 12 – 16 m/s preceded severe reports.


  • 3DVAR had problems depicting the rear inflow into a bow echo northeast of Albany, NY on May 16.
  • Beam blockage issues in Burlington’s area possibly produced spurious updrafts.
  • There was little calibration with respect to identifying what horizontal winds at the lowest levels could be associated with severe winds at the ground.


  • Would’ve liked cross-sections and information on elevation of max vorticity and updraft strength.
  • What can be done about visualizing 1 km wind?  Fabricating 1 km wind and making comparison to ground reports is desirable.  Preferred something in addition to wind barbs.  Would’ve liked isotachs on wind barbs.
  • Forecasters would like to go up in MRMS product height levels like all-tilts does with PPI elevation scans.
  • No one compared the 3DVAR maximum vorticity  to the MRMS azimuthal shear product.


There were no events within the OUN WRF domain this week.

Multiple-Radar / Multiple-Sensor (MRMS)

Everyone was in agreement that the MRMS products were quite useful in depicting storm intensity trends at higher frequency than traditional radar data.  Here are some other remarks below:


MRMS was very good in quantifying trends azimuthal shear without having to worry tilts.

  • MRMS was complimentary to 3DVAR in highlighting first indications that a storm was going severe.
  • Could see MESH, and 60 dBZ height products trend upward before single radar features.
  • It was good in figuring out if warning should be continued.
  • Liked using height of 50 dBZ above -20 and -10 C, especially for lightning anticipation.
  • Accuracy was good in MESH though perhaps with a somewhat high bias.  That may be due to lack of perfectly placed reports.
  • MRMS Helped validate base data.
  • Most common products:  height of 50 dBZ above -20C & -10C,  MESH.
  • Update frequency seemed good, not too frequent, not too noisy.


  • Could see a forecaster just warning when a 50 dBZ echo reaches above a certain temp level.


  • Thought a negative in the volume browser was having NSSL 0.5 km vs 1 km split into different grids.
  • Need good training to calibrate  forecaster to strong values within MRMS products.
  • MRMS needs to be imported into FSI
  • Forecasters would like to go up in MRMS product height levels like all-tilts does with PPI elevation scans.

GOES-R SimuSat:

The simulated satellite imagery was useful to visualize model output, and sometimes scarily accurate given the storm-scale model was run almost 24 hours before the experiment time.  Here are some comments below:


  • Couldn’t live without it?   Thought it was amazingly useful tool for evaluating model convection.  WRF runs were quite accurate.
  • The product was useful in figuring out whether to go to Chicago or Davenport on Tuesday.  Would we have made those same decisions looking at QPF?


  • Didn’t recognize that the output was tuned to GOES-R instruments and not current GOES.  This was especially true with WV imagery.  It looked very different compared to obs.


  • Would it be better to have a somewhat different colorscale.
  • Would like simusat in GFE because that’s where the grids are being produced.  Would also like a cloud base image (the cloud base is not satellite but camera view).

GOES-R Nearcast:

The Nearcast product was often used by forecasters mostly before they were consumed by warning decisions.  Both CAPE and delta-Theta-E were used most often.  Here are a few comments below:


  • Really liked the CAPE product.  Qualitatively it was highlighting the areas needed for closer inspection of convective potential.
  • Noticed CAPE did differ from delta-Theta-E in places.
  • Noted the good job nearcast products diagnosed the outflow interacting with the seabreeze and then having the storms initiate there later.
  • There were good delta THTE gradients in Arkansas


  • Nearcast products didn’t depict the Hudson Valley instability maximum as well as RAP data, or just looking at surface dewpoint observations.
  • None of them liked the signs of delta THTE changing from one day to the next.  Credibility was lost a bit.

GOES-R CI (UAH, UW Cloud top cooling)

Both tools received mixed reviews but mostly positive.  Forecasters found that they were useful at most times.  Though sometimes, the CI product didn’t detect CI for various reasons (e.g., cirrus, other unknowns).   Here are specific comments below:


  • Thought that adding the strength of signal color scheme was a significant improvement to the UAH CI tool.
  • The cloud top cooling product detections were better correlated with potential severity than the UAH CI detections.
  • Would like to pull in these products into the NWS pilot projects.


  • Had to stop from associating high UAH values with intensity.   Be wary of missed expectations with products.  This potential for confusion could be reduced with good training.


  • Would like to include it into the pilot project in Charleston. 


While we used the LMA a couple times, there was not enough action to get a good feeling for what values constituted timing for using for warning decision.  The case study showed jumps in the first hour of initiation.  This product was a bit lost within all of the other products.

There are more GOES-R feedback details on the GOES-R HWT Blog Weekly Summary.


The following comments were made by the forecasters as they recalled their memories of using AWIPS2 in HWT experimental warning operations:

  • Paraphrasing the forecaster’s thoughts, If they could use up-arrow keys to ascend model layers or any 3-D grid, that would be great!
  • FSI should add 3-D visualization for MRMS or 3dVAR.
  • Julia would like to be able to contour image and overlay contours on other images.
  • Julia experienced difficulty with keeping AWIPS2 up and running more so than others.  Her failure rate for issuing warnings was 25%.
  • AWIPS2 was great for loading any data on CONUS scale and zooming in as far as WFO-scale could do in the past.


We were short on logistics discussions but a few points came out worthy of note:

  • Training day was great!  But still struggled on the first days.
  • Would like training delivered a few weeks ahead of time.  Took training in smaller chunks than time allowed.
  • Couldn’t get an admin shift added for the last minute.
  • There are the usual WES issues.  Some offices have operable WES machines while others do not.
  • Thought a quick reference guide would be good.


Jim LaDue, EWP2012 Week #2 Weekly Coordinator

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EWP STATUS FOR 18 MAY 2012: 9am-12pm SHIFT

EWP STATUS FOR 18 MAY 2012: 9am-12pm SHIFT

Friday is our end-of-week debriefing day, and we do not conduct real-time operations.  The schedule:

900   Webinar prep and dry run in WDTB Conf. Room (presenters only)

1000-1140  End-of-week debriefing in NSSL Dev Lab (forecasters, scientists, guests)

1140-1200  Break

1200-1300  “Tales From the Testbed” Webinar in WDTB Conf. Room (presenters, facilitators, guests)

1300  End of operations for the week, forecasters travel home.

Jim LaDue, EWP2012 Week #2 Coordinator

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Daily Summary: 2012-05-17

Today’s scenario developed roughly as expected with storms in both the Jacksonville and Melbourne CWAs.  However the Melbourne CWA experienced enough of an inactive period that Todd and Stephen decided to go to a canned case.  As they did two storms with quasi-supercell characteristics developed west of Daytona Beach and drifted southeast.  Brian and Julia were both in the Jacksonville CWA, but with only the remnants of the outflow-driven multicell moving south through Jacksonville, I suggested that Julia could monitor Melbourne’s CWA.  She began to do so but quickly ran into an overload situation as she attempted to monitor the new products, issue severe thunderstorm warnings for the entire CWA, and special marine warnings, all while CAVE periodically crashed.  I should’ve had her just issue warnings for the two storms approaching Cape Kennedy so that she could have more time using the new products.

Product evaluation:

Todd and Stephen appreciated the GOES sounder nearcasting CAPE on the same 4 panel as the simulated satellite imagery, real-time IR and VIS, and lightning data.  They noticed the storms struggling the most where CAPE was least across the central peninsula. There was also a well defined theta-E gradient with maximum values across Jacksonville’s CWA, dropping toward the south.

With the early storm north of Jacksonville, Todd and Stephen noticed the midlevel vorticity picking up on the storm along with midlevel updraft strength worked well in depicting the intensifying storm.

The UAH CI product at flagged a severe storm warned at 2145 UTC as early as 1945 UTC with the UW CTC picking up on it at 2045 UTC.

It’s useful to note that SPC’s slight risk area in SE CO and SW KS had only one report as of 0000 UTC.  SC, GA and northeast FL was the most active part of the country.

Jim LaDue:  EWP Week 2 coordinator

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Update: 2012-05-17 2230z

Todd and Stephen are going through the 2010-05-19 case in OUN. I decided to let Julia relocalize to MLB as convection is intensifying in the northern CwA. One of the storms west of Daytona beach is sporting a three body scatter spike and 3dVAR updraft of 15m/s


Jim LaDue. EWP Week 2 coordinator.

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Update: 2011-05-17 11:30z

I ave Todd and Stephen the opportunity to exit MLB and try out a case since convection was appearing to remain weak in their area. They went for it and the case is being set up.

Brian and Julia are still in warning mode in JAX with a southward moving multicell riding an outflow boundary.

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JAX – ThetaE Gradient

Noticed an interesting diagonal differential heating sort of boundary in across northern Florida where the next round of convection appears to be initiating.  It show up well on the nearcast as s thetaE gradient and is now showing up on Vis and CI products…if this end up being the focus of more critical convection later in the afternoon this could be a really good application the nearcast product.  There was a similar looking (though not sure if it was the same cause) feature when we were MLB two days ago that was where the bigger stuff triggered.  Waiting to see….

JAX – 3D Var vs Dual Pol

Here is an good example of 3d Var picking up on a strengthening storm and some mid level rotation.  The top 4 panel 3 d var from 1905 and the second is radar from 6 minutes later.  The updraft strength, updraft helicity and updraft velocity products show a strong signal while the mid level storm relative velocity images (3 and 4 degree scans especially) have good rotation developing.  Not much at low levels (images not shown) but nice example of 3-d Var pick up and highlighting mid level rotation.  One additional feature that would be very good to have in the 3d var data is something that shows the height of max updraft helicity.  Built a 4 panel to compare all tilts radar (top two panels) to 3-d var updraft helicity and storm top (10 km) divergence as they seem to be good parameters to for finding rapidly intensifying/severe storms and will have to see how it works for the next storm.  Below is an example of the procedure with interesting gravity wave like features from the previously dissipating storm but nothing much firing yet to see how it works.

Interestingly there is a red (94%) and a few other CI detections in the vicinity of the ‘gravity wave’ looking things.  Curious to see how they build…

Outlook: 2012 May 18

Today’s situational environment remains little changed from our expectations yesterday.  An upper-level low has moved in from the Gulf yesterday to South Carolina today.  Deep, moist convection (DMC) has already erupted around the perimeter of the upper low.  To the south, unusually strong mid-level flow continues along the central Gulf to the FL peninsula.  With plenty of moisture resident over FL, and southwesterly low-level flow, it appears we have a good juxtaposition of shear and CAPE in a climatologically unusual location.  Supercells are likely, especially where the shear is strongest from St. Augustine and south.  However the question of the day is expected coverage of DMC.  The coolest air aloft resides close to the upper low meaning that northern FL would see the steepest lapse rates and least inhibition.  Early DMC in southeast GA helps confirm this thinking.  Further south, the air aloft is warmer and coverage is expected to be less.  We’ll also have to rely on the initiation of the west coast seabreeze to help provide the strongest low-level forcing to overcome the greater inhibition to the south.  The eastern seabreeze may help to provide enhanced low-level shear but the poor boundary-relative convective steering layer flow will limit residence time of any incipient DMC in its lifting zone.  While some time may lapse before we get mature storms in the central FL peninsula, whatever storms that form could turn into supercells, especially if they latch onto the enhance shear along the eastern seabreeze. Damaging winds and large hail are possible with these storms though an unusual intersection between outflows and seabreeze interaction may enhance low-level vertical or horizontal vorticity enough for a tornado.

At this time, Todd and Stephen have localized to MLB while Brian and Julia are covering JAX.

Jim LaDue: EWP week 2 coordinator

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EWP Daily summary: 2012 May 16

We focused operations in both the Burlington, VT and Albany, NY CWAs ahead of a strong upper-level storm and cold front.  Stephen and Todd started issuing warnings with the help of MRMS MEHS product in northern Lake Champlain at 1820z.  Shortly afterwards (1915 Z) Brian and Julia issued a SVR warning in Herkimer county, NY following indications of a three-body scatter spike and dual-pol hail signatures.  Neither the MRMS or 3DVAR showed strong storm indications.  But Brian noticed storm top divergence > 9.5 s^-1 in the storm top.  Both storms produced hail ~1″ in diameter but no wind reports.  Ten minutes later, the UW CTC showed large negative values in eastern Hamilton County, NY as the storm continued east.

Both teams kept issuing severe tstm warnings as the storms continued east and new ones developed west of Albany.  The BTV team noticed that CI was useful for areas where outflow initiated new storms far enough away from old thunderstorm anvils.  They also liked using the 3DVAR vertical velocity.  One severe storm with a MEHS of 2″ showed updraft strength of 14 m/s at 2018 UTC over Essex County (BTV’s area).  They also noticed max updraft preceding max reflectivity by up to 20 minutes.  Meanwhile Todd and Julia focused on peak storm top divergence in 3DVAR.  Todd believed that product actually helped with lead time before reports arrived. The Albany team thought the MRMS azimuthal shear, and the 3DVAR updraft vorticity was useful in identifying intensifying storms.  They also found the nearcast theta-e differences successfully flagged the ridge of instability going up the Hudson Valley.

As the action wound down in BTV, Todd and Stephen worked with the CI team on flagging new convective initiation along the tail end of the front in northeast Arkansas.

Some limitations came out too.  Julia found that the 3DVAR barely perturbed the flow around a bow echo east of Saratoga, NY.  So she used traditional radar interpretation to assess the storm.  The Albany team would also have liked a quick cross-section ability.  Julia issued a flash flood warning but didn’t use the new products in the decision-making namely because she had no familiarity with how they may be used for that kind of product.

The Albany team also had issues with CAVE and Warngen with occasional crashes and slowdowns.

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EWP STATUS FOR 17 MAY 2012: 12-8pm SHIFT

EWP STATUS FOR 17 MAY 2012:  12-8pm SHIFT

Prospects for active real-time operations appear to be diminishing a bit.  However, there are two possibilities for operations.

The first would be in FL as the southern stream flow and continuing small short-wave troughs move across the peninsula.  Little cap and high moisture will initiate convection quite early should the diurnal heating be allowed.  Today, thick cloud cover restricted heating.  It’s more likely that there will be less deep cloud cover and solar insolation will be stronger. The southern stream flow may be strong enough to organize any convection into sustained multicells or perhaps a short duration supercell.  In fact the SREF guidance suggests a good possibility of supercells, especially in southern FL including the Keys.

The second area would be along the coastal Carolinas just like in the past few days.  The odds for organized convection would strangely enough be less than in FL owing to lower mid-level winds.

Most likely we may focus the two teams on FL if two CWAs are active with convection.  Given the lack of convective inhibition and plenty of local forcing mechanisms, we’ll start again with an early shift.  Should the area be on the subsident portion of an upper-level wave, we should be ready to activate a case in DRT mode.

Shift time will be 12 – 8 pm.

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