A few more warnings have resulted in the Midland CWA since I switched over.  I’ll blog about the most recent.  By 2300 UTC I noticed a line of deep convection moving northward through Brewster County, TX.  Unfortunately, this area was on the far southern end of our domain today, so I didn’t get HWT specific products until some of the potentially severe portions of these cells may have already been ongoing.  Anyway, as you’ll notice, MRMS MESH and HSDA data were indicating potentially severe hail with this line of storms between 2250-2258 UTC.  I had to use the KMAF reflectivity data to produce the warning (to see the extent of the line of convection).  Nevertheless, you’ll notice that the MESH was as high as about 2 inches in the extreme southern portion of the image.  HSDA data at the time was showing a line of categorical giant and large hail.

These data prompted me to issue a warning, which went out at 2304 UTC.  The following image shows the resulting polygon.

Any reports so far?  No…I’m not real sure to expect any either, but we’ll see.

Kris

LAPS CAPE fields rather quickly caught onto the idea that the northern LBB/southern AMA area would be dominated by cooler, more stable surface air as a result of outflow from the earlier supercells southeast of Lubbock.  The most instability is limited to the far western portions of the CWAs.

The MRMS products were a big help in this case being able to look at multiple radars since my storm was right near the radar as depicted in the image below.  (Wesely)

The Height of the 50dbz core went above 30,000ft agl, which was a trigger for issuing the warning. The 4 panel product below made the process easier in two ways. First the storm was near the radar and so having a 50 dbz echo core height product that took into account multiple radars was extremely helpful as the local office radar was unable to see the top of the storm. In addition, you could just look at the one screen and see the 50 and 60 dbz core height quickly without having to look through multiple slices of an adjacent offices radar to find the height of these cores.

The MESH and HSDA algorithms below both provided lead time for the quarter size hail that fell 11 miles north of Amarillo at 2236Z. The multi radar aspect of the MESH algorithm also made it easier to use than having to look at an adjacent radar to see the top of the storm. The HSDA is not multi radar and thus there were some limitations with this algorithm for the storm near Amarillo due to the close proximity of the storm to the radar.

Cloud Top Cooling (CTC) did a nice job of showing that convection was really trying to break out in Amarillo’s County Warning Area (CWA). There were numerous cloud top cooling signatures beginning at 20z. The first 50dbz echo reached the ground at 2146z. So it took awhile but eventually the storms overcame the cap and became severe (See image of CTC below).

Jeremy Wesely

Some HCA detections in the east (right most storm) are occurring within areas of non-uniform beam filling from the first storm (and most likely the second storm).  Forecasters should be wary of identifications within these regions and shows the need for investigation of the base variables in addition to using the algorithms for diagnosis of storm severity.

–KO

The images below show a 4-panel display of the height of the 50dBZ echo above -20C (top left) and above 0C (bottom) right, and the height of the 60dBZ echo above -20C (top right) and above 0C (bottom right).  This time represents the time of the highest MESH values (~3.0in) and indicates the 50dBZ core was over 26k ft above the -20C isotherm and the 60dBZ core was nearly 20k ft above the -20C isotherm.  About an hour later this storm began to collapse with the eastern storm becoming dominant.

This is the corresponding MESH image corresponding to the top image.

At 2132 UTC the HSDA on the eastern storm showed a hail core (indicating giant hail) from the 0.5 degree slice up through the 4.0 degree slice (~30k ft).  This corresponded well with the rotating updraft.  The MESH at this time (not shown) showed 2.83in.

Just for you, Kristin! See? I was paying attention. 🙂

On a 4-panel with MRMS Sfc Z, Sfc Vil, and others.

Trace tool was used on upper-left panel and indicated how the flashes increased quickly with severe storm over Dickens, Kent, and Stonewall counties in SE LUB’s CWA.

Admittingly, the latter 5 min occurred while I was creating the image, etc, so didn’t redo my centroid there, just the zig-zag bad data.

Martello

So, with ongoing and potentially severe thunderstorms in the Midland area, I decided to move to Midland!  Well, not really, but virtually.  =)  So, we’ll see how well the MRMS, HSDA and other products work here, and if the pattern recognition I developed on the previous two days will work well here.  Now, I am expecting a dearth of reports way out here in west Texas, unless they have some cameras strapped to a rattlesnake or a jackrabbit.  Anyway, after transferring over, and getting products set up as quick as I could, I quickly issued my first warning based mostly on the MESH and 60 dBZ reflectivity values at -20C.  This warning was issued for the affecting the western portions of Loving and the far northern portions of Reeves Counties.

Following is a four panel of various MRMS parameters and the 0.5 degree HC.

Notice that the MESH product in the lower left no longer indicates sever hail, however, the 0.5 degree HC algorithm clearly shows some giant hail signals.  This storm had undergone recent weakening and the MESH 30 minute accumulation had indicated severe size hail within the previous 30 minutes.  The severe hail still may had been reaching the ground by the time I was able to load up the data.  So, I went ahead and issued the warning.  We’ll see if we get any reports from this storm…but I’m not too positive.

Kris

KLBB radar reflectivity really ramped up 2115Z and MRMS Low-Lvl Rotation Track also indicated increasing in intensity of the low level mesocyclone. See images below. Low-Lvl Rotation Track Prog was used for the TOR warning.

Though the low-level circulation was increasing and ramping up, it wasn’t “gate-to-gate” on the SRM just yet at 2115Z on KLBB.  Nevertheless, OUN_WRF indicated high 0-1KM SRH forecast values in the next hour on the order of 300-400 m2/s2 where the dangerous part of the storm was headed, thus went straight to a tornado warning due to the conducive environment. (See below images).

We still continue to watch our northern counties below the old MCS outflow boundary, as the air is only slightly cooler, shallow, and remains conditionally unstable with extremely backed easterly surface winds.

Wow, what a day.  My favorite (due to being more comfortable and the type of storms) ALL WEEK!!

Martello/Zimmerman

I’m pretty excited about the 4 products displayed below. We have displayed below the 50 and 60 dbz echo top products as well as the height above -20C of the 50 and 60 dbz echo. These products allow for quick analysis and use of the Donovan method of determining hail size. Many offices in the central plains look closely at the heights of the 50 and 60 dbz echoes in warning decision making. Therefore, these tools are extremely beneficial for both initial warning decision making on whether to go with a warning or not. They also help to give confidence in increasing the projected hail size as these 50 and 60 dbz cores grow well above previously established basic severe level thresholds of the day.  The storm depicted in the image below had golf ball size hail reported with it.

Wesely