We used MRMS data during storm interrogation and decided to warn for a storm over far northeast New York and far northwest Vermont. As early as 1812z the MESH was indicating hail just over 1 inch while the height of the 50 dbz echo above -20c was over 5000 feet. Warning decision was not made until after 1820z after looking at KCXX radar data. 1 inch hail reports were received from about that time. Attached is a 4 panel showing the Max Expected Size of Hail (MESH), heights of 50 dbz echo above -20C, and reflectivities at the -10C and -20C levels.
Lightning activity has been prevalent in the FL-LDAR domain today and the ltg jump alg has detected multiple jumps in range of the domain. Scale_0 seems to be the most stable at keeping the storms ID’s unique while scale_1 seems to be dealing with lots of mergers/splits.
In the past half hour (2230-2300 UTC) at least 3 jumps have been detected at scale_0: cell IDs: 31025 @ 2242 UTC, 31107 @ 2245 UTC, and 31184 @ 2248 UTC (additional jumps likely occurred prior to this time).
Storm clusters at scale_0 at 2242 UTC. Cell 31025 was the primary storm of interest in the testbed.
The main cell of interest for forecasters in the HWT operating in the MLB domain has been #31025. 3DVAR products depicted increases in max updraft and vorticity as early as 2230 when the domain was re-centered over the storm. The storm maintained its strength through over the next half hour and the forecaster opted to continue the warning at 2256 UTC (the first TOR warning issued in the HWT was at 2225 UTC, see the forecaster post associated with these warnings for more info). The screenshots below from AWIPS2 include lightning, 3DVAR, MRMS & KMLB radar data for this event:
AWIPS2 screenshot 2245 UTC. Top left: 3DVAR max updraft composite; Top right: MRMS Refl @-10C, pGLM lightning flash extent density, & 1-min NLDN CG data; bottom left: MRMS MESH; bottom right: 3DVAR updraft helicity and 2 km winds
At the time the tor warning was issued in the HWT:
AWIPS2 screenshot @2257 UTC: Top left: pGLM flash extent density and 1-min NLDN CG data; top right: pGLM flash initiations & Tor warning; bottom left: refl @-10C; bottom right: KMLB 0.5 deg refl
Even as the clusters have become a bit more muddled, the storm tracking algorithm has seemed to maintain a good handle on individual clusters at scale_0, though some of the cell ID’s have changed…
WDSSII image at 2324 UTC: Left: Refl at lowest altitude and lightning flash contours; right: scale_0 storm clusters overlaid on pGLM flash extent density.
SHAVE is also operational today over this same area… current reports include 1 in hail and high wind:
SHAVE data between 2200 and 0000 UTC in the Kennedy Space Center domain. Gray H circles correspond to no hail, green H circles 1 in hail, and blue W circles severe wind. Reports include 1 in hail piled against side of house & dents to truck.
Technical difficulties of note: the KML images are not currently updating on the webpage, but should be back up in the next day or two; it is also possible that cron job notification of a python script stopped running mid-day on 2 May 2012 and data between 2 May and 14 May, may need to be reprocessed to assure that jumps occurred within the network range.
A storm cell over Volusia County, Florida apparently ran over a sea-breeze front and developed a lot of rotation. A hook echo on the reflectivity and strong gate to gate shear was quite evident on Melbourne’s radar. We had been monitoring MRMS data including reflectivities at -10C and -20C. Looking back at Convective Initiation, there was a strong signal at 2154z.
Twenty minutes later the satellite picture and NLDN lightning data looked like this:
MRMS data at 2224z showed 57 dbz echoes at the -10C level.
By 2225z, velocity data from Melbourne’s radar compelled us to issue a tornado warning. Time from the first Convective Initiation signal to issuing the warning was 30 minutes.
After issuing the warning, we got the 3DVAR domains set up properly and here is a screen capture of the 2km vorticity and winds for the storm of interest.
Here is a four panel of various 3DVAR data for the storm at 2230z.
At the top of the hour, the storm was still quite organized, and a second tornado warning was issued.
The first warning of the week was issued by the MLB team for a storm just northwest of MLB. The MRMS and 3dVAR shows some indication of rotation with that storm between 3 and 6 km.
Updraft helicity and merged azimuthal shear layers and units are different. How does one compare between the two?
Despite strong indications from the NSSL-WRF SimuSat imagery, convection in the DVN CWA has stayed rather benign. The NSSL-WRF appears to have overestimated the low-level prefrontal moisture.
SimuSat Imagery at Top, IR Imagery at Bottom, valid 2100 UTC 2012-05-15
The GOES-R NearCast Theta-E Low vs. Mid-Level Theta-E image indicates very little destabilization ahead of the front (in fact, it actually indicates increased stability). This is consistent with surface dewpoints in the 30s and 40s reported ahead of the front.
GOES-R NearCast Theta-E Difference valid 2030 UTC 2012-05-15
There have been a few cloud-to-ground lightning strikes just to the northeast, and the 3DVAR and MRMS data have helped to monitor the convection across multiple CWAs and on the edges of multiple radars.
3DVAR Analysis of Reflectivity, Updraft composite, 30 Minute Updraft Accumulation, and 1km/10km Divergence, valid 2120 UTC 2012-05-15MRMS Surface Merged Reflectivity, -20C Reflectivity, VIL, and MESH valid 2114 UTC 2012-0515
