Ok, well we’ve gotten some recent cloud-top cooling amounts from clouds in Randall County, TX.  Cloud top cooling rates as low as -17C/15 min were observed in Randall County as the outflow boundary moved across the area, as indicated in the image below.

Also, notice the rather distinct theta-e ridge still present and extending into Randall County. per the LAPS data (image 2 below).  We’ll see if these products allow for an appropriate focus and help predict likeliest locations for eventual development.

Watching for potential development SSW of current supercells over Floyd, Dickens, and King counties to the NE. CTC shows potential. Cirrus anvil across the NE CWA will likely inhibit any CTC effectiveness.

Unfortunately, GOES_CIMSS Nearcast (either E or W) data did not extend further enough east across the LUB CWA to be effective with this event. (see 2030 UTC CIMSS W projection below).

If the Garza area was to develop quickly, the OUN_WRF project indicates 0-1KM SRH to 200-260 m2/s2 which mean environment would be favorable for rapid rotation and potential tornadoes like earlier storms to the north.

We continue to monitor development closely.l

Martello/Zimmerman

Slide 1: 1855Z Based on Donovan method we would be issuing a severe thunderstorm warning when the 50 dbz core reached 26,000 to 28,000ft based on a freezing level of around 10,000 to 10,600ft agl. This would have been enough for me to issue a thunderstorm warning at 1855z.

Slide 2: 1858Z HSDA shows large hail for the 1st time.

Slide 3: 1902Z MESH indicates 1″ hail for the 1st time.

Slide 4: 1918Z The -20C level gets a 60dbz return for the 1st time.

Summary Verification: Our 1st quarter size severe hail was reported at 1923Z with the first Golf ball size hail report at 2004Z. There was lead time no matter, which method or combination of methods would have been used on warning for this storm. The MRMS products did offer a quicker diagnostic overview of the storm than having to look at multiple height scans as we commonly do with the Donovan method.

Wesely

Strong convergences initiated northeast of Lubbock, TX near Floydada in Floyd County.  CTC product caught -16-17K/15 min around 18:15 UTC on this storm. Tornado warning was issued 19:21 UTC which resulted in 1 hr/6 min lead time if you had warned initially off the CTC projection.

CTC product W/Visible Satellite

The OUN_WRF progged Surface Merged Reflectivity Composite also nailed the point of storm initiation around 1900 UTC(See image below).

Below is the 1900 UTC 2.5KM Theta-E image clearly indicate moisture converging near the point where this supercell developed up through Floyd and Brisco counties northeast of Lubbock. Also, the wind fields verify that there was like good moisture convergence in this same area.

Some of the MRMS (MESH/30 min MESH swath) and HSDA (0.5 degrees showing potential for large hail as well) real-time data gave quick indications that this atmosphere was volatile and showed the storms potential with little latency at 1900 UTC.

This storm has already produced quarter-size hail at 1923Z and a few land spouts (weak tornadoes).

Well, there’s a severe thunderstorm down in the Lubbock CWA and all is quiet here on the northern front…way down south in the TX panhandle that is.  Anyway, an outflow boundary has moved across the area and appears to be settling in west-central portions of the TX panhandle so far.  The image below shows the latest GOES-15 Vis image combined with the 2.5km LAPS theta-e (1845 UTC).  METAR observations are laid atop the image (1900 UTC).  Hopefully, you can notice the reddish colors in the southwest part of our CWA just south of the Amarillo area.   A strong theta-e ridge extends from the Lubbock area into the southern portions of our area per the LAPS data.  So, we’ll be watching that area and the leading edge of the cu field in assoc/w the outflow for development.

Kris

Texas panhandle is the area of main focus for the first part of this afternoon. Analyzing CI, as seen below, indicated development was expected to quickly form by 19z.

Image 1 – CIMSS CTC prior to CI around 18z.

Image 2 – Cloud Top Cooling at the time of CI over the central parts of Texas panhandle around 1815z. Values right around -17oC.

Image 3 – Vis sat around 1815z, with CI. Vis at 1845z shows the explosion of the storm in the panhandle, with the CTC product thus providing around a 30 mins lead time.

Image 4 – With the radar products unavailable at this time, using MESH and probability of severe hail to show the development of the storm to severe levels.  The CI on CTC developed around an hour prior to the MRMS products reaching severe levels.

The WRF simulated satellite image forecast for 23 UTC (top) compared well with the observed IR satellite (bottom) with respect to the mid-level boundary location across Indiana.  However, it did not handle to convection well which formed over PA.  Instead it showed more convection east of the higher terrain across MD and northern VA.