Today, we started operations in the Albuquerque (NM), Midland (TX), and Lubbock (TX) county warning areas.  An early-morning mesoscale convective system left an outflow boundary over west Texas.  While the atmosphere recovered in its wake during the afternoon, storms developed in the less-capped/higher-terrain to the north.  In this convective episode, multicell clusters were the dominant mode, and the Albuquerque forecasters (Mike Dutton and Jeff Garmon) issued several warnings (a few hail reports were received).

In the Midland and Lubbock CWAs, the onset of convection was delayed, compared to the expectations derived from the OUN WRF and HRRR forecasts.  As a result, the decision was made to move the Lubbock forecasters (Ty Judd and Tim Tinsley) to the Amarillo CWA to assess the 3DVAR products in storms that approached the area from Colorado.  However, after only a short while, the storms decreased in intensity, prompting a move back to the Lubbock CWA.

By 6:30 p.m., convection developed in earnest in the southeastern portions of the Albuquerque CWA, promising to move toward the Midland and Lubbock CWAs.  The Midland forecasters (Steve Nelson and Randy Skov) issued multiple severe warnings for multicells and supercells.  The Lubbock forecasters issued a few warnings for left-movers that originated with the Midland convection.

-G. Garfield, Week 5 Coordinator

Today, we started operations in the Memphis (TN), Huntsville (AL), and Tulsa (OK) county warning areas.

In the first two CWAs, an ongoing mesoscale convective system prompted several experimental warnings.  Forecasters Steve Nelson and Ty Judd operated in the Memphis CWA;  in this CWA, the primary experimental platform was the 3DVAR system.  Forecasters Randy Skov and Jeff Garmon operated in Huntsville, AL, where their primary experimental platform was the Lightning Mapping Array.

In Tulsa, forecasters Mike Dutton and Tim Tinsley evaluated the convective initiation (CI) products.  Unfortunately, CI never occurred.  This prompted a move to the San Angelo (TX) CWA, where ongoing multicellular convection allowed for an evaluation of the OUN WRF, in addition to the 3DVAR and base radar products.  Several warnings were issued, but with little verification (presumably, owing to the sparse population of west Texas).

Shortly thereafter, convection exited the Memphis CWA prompting a move of those forecasters to the Jackson (MS) CWA.  Several warnings were issued for storms within the original mesoscale convective system.  The Jackson forecasters continued to evaluate the 3DVAR products, in addition to the base radar products.

Finally, convection in the Huntsville CWA diminished to the extent that a switch was in order.  The decision was made to transfer the Huntsville forecasters to Birmingham, to follow the convection that they had monitored in the Huntsville CWA.

-G. Garfield, Week 5 Coordinator

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

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.

Today was one of those days where we ended in somewhat different locations than we intended.  Following the morning forecast, we had Stephen and Brian focus on Blacksburg, VA’s CWA while Todd and Julia took on Sterling, VA and the LMA site.  We were enthused about the possibility of severe multicells in both areas given the deep, rich moisture, decent CAPE and about 30 kts of deep layer shear.  However, the storms that formed remained weak with only a few lightning events per minute.  Apparently the weak lapse rates only become worse, likely because the area was on the subsident side of a weak wave lifting into New England.

After a couple hours of failed attempts at vigorous Deep, Moist Convection (DMC).  Brian and Stephen moved to the Davenport, IA CWA to sample DMC in a weak CAPE, steep lapse rate layer with 25 kt 3 km winds along a cold front.  Initiation was painfully slow as the environment was marginally conducive to DMC.  Yet by 6:30 pm storms intensified just enough to produce severe winds just south of Davenport.  3DVAR showed a good example of wind augmentation at 1 km around the south side of one small multicell just before the wind reports.  It also showed convergence from what appeared to be a gust front.  The base velocity 0.5 deg scan from KDVN showed the downburst in more detail.

Meanwhile we noticed that the Melbourne, FL area had a large pocket of strongly unstable, and unworked air surrounded by active outflow boundaries slowly converging on the CWA. Todd and Julia shifted to Melbourne and set up for a better than expected event.  They issued a severe thunderstorm warning for rapid development just northwest of Melbourne.  The LMA showed rapid increases in lightning rates up to 20 fl/min I believe.  Meanwhile 3dVAR showed some rotation around 5 km MSL.  The CI product from UW highlighted some of the initial phases of that thunderstorm.  Later on, one of the storms near Titusville began to rotate.    Soon KMLB base velocity showed a strong azimuthal shear and a tornado warning was issued.  3dVAR had a gap between two domains that prevented early detection until the 3dVAR northern domain was shifted south.  The 3dVAR will need to be redone for a later case review.  Meanwhile the UW CTC product didn’t flag the storm as it developed.

The IA case is a great example of a weak CAPE, marginally convective event with severe winds.  The MLB case is a good severe GOES-R mini scenario for AWOC.

Jim LaDue:  EWP week 2 coordinator

We started today in Wilmington, NC and San Antonio, TX.  However the CI products were having issues with dense high clouds in NC and we subsequently shifted focus to Melbourne, FL to track convection approaching Orlando.  As we shifted, two supercells formed near Myrtle Beach, SC.  We were initially frustrated but a new tornado warning was issued west of Palm Beach, and the far southern county of Melbourne’s CWA.  Unfortunately the storm evolved into a nonsevere state before we shifted localizations there.  Meanwhile strong supercells developed west of Del Rio and tracked southeast on the Mexican side of the border.  As the thunderstorms grew upscale in Mexico  a spectacular haboob evolved that caused the UAH CI product to track a few cold pixels.  Some were cumulus above the haboob while one of the tracks may have been triggered by the dust as it swept over a mountain range or by a cumulus cloud.  Elsewhere, storms north of San Antonio were too weak to issue warnings.

Thus with the lack of warnings, the teams concentrated on inspecting the products and writing blog entries.

Jim LaDue, EWP2012 Week#2 Weekly Coordinator

Our forecasters operated as Corpus Christie, TX (CRP) and Brownsville, TX (BRO).  Our CRP forecasters got most of the warning work today, as all of the severe storms stayed north in their CWA.  They issued many TORs, and some SVRs.  Our BRO forecasters spent more time monitoring CI and nearcast data for evolution of the environment.  They issued one SVR on a storm coming out of Mexico, but it died before reaching the U.S.  Details are in the forecasters live blog posts.  Here is the current SPC reports map:

Greg Stumpf, EWP2012 Week #1 Coordinator

The marginally-severe event predicted for the southeastern coastal U.S. panned out pretty much as expected.  We operated all day as two WFOs:  Charleston, SC (CHS) and Jacksonville, FL (JAX).  Each of our teams issued several SVR warnings.  One notable storm developed behind the first squall line and passed close to the KCLX radar, with a decent low-level notch and BWER.  All of the storm reports received were of (speed unmeasured) wind damage consisting of one or a few downed trees (with no diameters given!).

Greg Stumpf, EWP2012 Week #1 Coordinator

We operated in 5 different WFOs today, although out “bread and butter” was the Brownsville, TX (BRO) area, where several large supercells tracked across their CWA.  However, since they were mostly over open terrain, there were very few reports.  This is where we kept our MRMS domain most of the day.  Simultaneously, we had another team working the El Paso, TX (EPZ) WFO, concentrating on storms mainly in southern New Mexico.  These storms were mostly non-severe, except for one golfball hail report.

After dinner, we salavaged some storms in Midland, TX (MAF), and in Florida, hoping for the some PGLM action.  Both areas received no severe reports.  Here’s is the pretty meager storm report map:

Greg Stumpf, EWP2012 Week#1 Coordinator

Our first day for EWP2012 so our teams operating an MCS with embedded severe cells in the San Angelo, TX, (SJT) and Austin/San Antonio, TX (KEWX) WFOs.  The storms were moderately severe with low coverage. Mostly 1-1.75″ hail, a few wind damage reports, and one tornado report near Llano, TX.  Our teams issued a few SVR warnings, as they were adapting to the new experimental products.

Greg Stumpf, EWP2012 Week #1 Coordinator