Layer PW Gradients Helpful With Placement Of Storms In KY and TN.

Below is the 4 panel LAP Layer PW product at 2100 UTC. The total PW image in the upper left, and the 700-300mb layer PW in the upper right, were showing a plume of PW from eastern KY into south central TN.

The MRMS 0.5 degree reflectivity image below shows a broken line of showers and some storms from eastern KY into north central TN. This corresponded to the backside gradient of PW described above. These gradients are a good way to find more favorable areas for convective development. JJW

LAP Underestimating CAPE A Bit - Still Gave A Reasonable Estimate.

The upper left image shows LAP CAPE, with the cursor readout in a small area of CAPE in clear skies in northern MS. The value was around 262 J/kg, which seemed a little low, compared to the modified NUCAPS soundings and Prob Severe model output around 400 J/kg. The CAPE values elsewhere were in the 150-300 J/kg range in the Memphis CWA. Still, it gave a reasonable idea of how much CAPE was present. Perhaps the lack of clear sky data (see upper right image) may have lead to the slight underestimate. JJW

WV/IR 1-minute Imagery Loop

Just a little loop for your enjoyment...

SRSOR 1-minute IR imagery overtop 1-min WV imagery. This allows you to see the active convection and cold cloud tops as well as the mid to upper level moisture.

~Lilly Miller~

Surge of Cool, Dry Air seen in the AMV's

The CI and Severe CI algorithms had some false detects within this loop (top two panels) where convection didn't end up firing both along the convective line and southwest of the line.

The Atmospheric Motion Vectors (in the bottom left panel) showed the surge of low level dry air really well wrapping in from the northwest. As the dry air approached Florida...it helped cut off the convective activity along the southern end of the line.

~Lilly Miller~

Useful Products for TV Mets

It has been a great experience seeing the different products perform this week during the experiment.

As the TV meteorologist in the group, I have seen what could be useful during the preparation of the forecast and during the weathercasts.

The three products that stand out to me are: Prob. Severe Model, Lightning Jump Detection Algorithm, and the 1-minute GOES imagery.

Most of the time we have to be careful with what we show our audience because it might be too much for them to digest and understand, which we don't want to happen. The weathercast is supposed to be easily understood by everybody.

As long as we explain what we are showing, I believe the Lightning Jump Detection Algorithm and Prob. Severe Model could easily be integrated into our radar software to show these features on air that could give our viewers ample lead-time with severe t-storms. I am hoping WSI can bring these features into their software with future builds.

Last, the 1-minute satellite imagery would look really good in HD and be another tool in our back pocket to track subtle features that might be missed with our current 15-30 satellite updates.

-BW

Convection struggles...

Isolated convection continues to simmer across central and eastern portions of the MEG CWA and over points east and northeast.  GOES LAP PW shows the greatest concentration of low topped storms focused within richest total layer PW values near 0.90" and corresponding 900mb PW near 0.30".  Given continued limited moisture expect isolated convection will continue to struggle with minimal severe threat expected through the remainder of this afternoon.

19Z GOES LAP PW and MRMS Composite Reflectivity

Tornadotod

NUCAPS Plan View 497mb Temperatures - Good Snapshot of Values But Has Several Data Void Areas.

This is a plan view image of the NUCAPS 497mb temperatures, with the cursor readout showing -17.95C values, at 1800 UTC, in the middle of the Memphis CWA. There are several data void areas, so this image may not help to assess all areas for temperatures at this level. However, it does give an idea of the temperatures at this level at 1800 UTC. This could benefit the mesoscale analyst in assessing temperature profiles and the expectation for continued development of showers and a few storms. JJW

KTBW Laps versus NUCAPS Sounding

The 18Z NUCAPS Adjusted Sounding came in drier than originally thought. But taking a closer look at the LAPS Layer PW data...the drier sounding makes sense. At a clear air retrieval point bout 15 miles off of the coast of Whitney Beach, FL showed ample moisture at low levels but much drier air at mid and upper levels. The total layer PW according to LAPS was 1.7" but the NUCAPS sounding indicated a TPW value of 1.3". Drier air was noted in WV imagery so perhaps the actual PW value is somewhere in the middle.

~Lilly Wood~

CI Provides Lead Time on Cell Just South Of Memphis.

Below in the upper right is the CI product. The cursor readout shows a value of 58% with a cell just southeast of the city of Memphis in Shelby County at 1945 UTC.

The radar image from KNQA below shows the cell with 41 dBZ at 2003 UTC exiting far southern Shelby County. This provided about 18 minutes of lead time for the 35 dBZ-plus echo. This made sense, as the modified NUCAPS sounding (not shown) showed a little more than 400 J/kg of CAPE in that area, ahead of the pre-frontal surface trough. JJW

GOES CI strikes again...

While waiting for convection to pop further west closer to the low level  instability gradient, GOES CI provided an excellent prediction with 1915Z output indicating 65-70% probabilities over the central CWA.

1915Z GOES CI

21 minutes later, MRMS Composite Reflectivity echoes above 35 dBZ have developed over central portions of the CWA collocated right where GOES CI had its higher probs.  Excellent!

1936 MRMS 0.5 km MSL Composite Reflectivity

Tornadotod