New Warning Help

While watching the storms redevelop…I utilized a screen with the -20C MRMS data, the ProbSvr model  and the ENI thunderstorm alerts. I had a TimeSeries on another plot as well.

2258Z.. Focus on the pink circle in the middle. This is where it first pulsed from 27-74%.

2300z the ProbSvr pulsed to  82%

2302Z…ProbSvr was 82% and I saw the -20C reflectivity jump to 62dbz.

at 2304Z… probSvr was 95%

The SVR went out at 2306. And ProbSvr remained at 95%.



I could have look at this a little earlier and probably warned at 2302 looking back. But for the record, once I looked at it.. all I did was look at the display that is in the screen captures and only went through the all tilts once. So in reality.. I would have had to maybe wait a scan or two in all tilts to process before issuing. Where here, with the MRMS data and ProbSvr I was confident issuing quicker than I would have with legacy abilities.



Lauren

ProbSvr Helping Warning Expiration

I utilized ProbSvr again today to help me to determine whether or not to let a warning expire or continue it. I also have the -20C MRMS height under this and that has also helped. My warning was supposed to expire at 2245z. I skipped a few screen captures for the sake of time/space.

2234Z ProbSvr was still at 90%

2238Z.. ProbSvr is down to 77%

At 2240Z…ProbSvr down to 75%

Here at 2244Z…probsvr is down to 74%

Although these probs are still fairly high.. the trend down was enough to let me expire it and the trend continued after expiration.



Lauren

ProbSvr with Warnings

Here is an interesting example of ProbSvr ramping up while looking at 4 storms.

2214Z. ProbSvr is picking up four cells. This is the first scan where the two right cells have pulsed. Earlier, this could be a situation where we weren’t sure which storms would pulse back up. Seeing this helped the LUB office issue the severe you see here.

2216 shows both right cells increasing some more.

2220 shows them combining so it’s hard to say which storm is stronger now.

2224 and we issued the southern severe.

At 2232 Z reported quarter size hail.

The ProbSvr showing the difference in the cells helped us see which ones needed the focus of attention. It caught the high probs on the southern storm before the warning went out with a higher lead time for the hail. Again, it is to note that when the two storms combined, that may be why it spiked up because the northern storm was stronger at an earlier point.



Lauren/mahal

ProbSevere and experimental warnings

Our forecast teams in Midland and Lubbock have been coordinating on experimental severe thunderstorm warnings, as storms blew up under a moderate cirrus shield (Figure 1). ProbSevere has served to increase confidence and prompt warnings, where the probability jumps up quickly.

Figure 1: ProbSevere, MRMS composite reflectivity, and HWT experimental warnings.

For instance, in the northernmost two warnings, a forecaster in Midland shared with me that the probability jumping from 9% to 35% in a few scans gave him enough confidence to pull the trigger on an experimental warning in this high-MUCAPE moderate-shear environment. Golf ball and quarter-sized hail have been reported in several of the southern warnings.

-Cintineo

NUCAPS vs Observed RAOB

Today we got a special sounding at 18Z from KMAF to compare with the 19 Z NUCAPS sounding at roughly the same location. The NUCAPS sounding was able to pick up on the stable layer above 850 mb, although the NUCAPS sounding did have it a little higher. Also, after modifying the boundary layer T/Td in the NUCAPS sounding, MUCAPE values were very comparable between the two.

19Z NUCAPS

18Z KMAF

NUCAPS Sample

Sample image with lowest levels adjusted to match the surface observations.

-Champion

ProbSevere in Utah

Though far outside of our forecasters' CWAs of operation, a lone storm in southern Utah gradually increased in ProbSevere probability. It was 50% at 19:12Z (Figure 1), then fluctuated between 30% and 50% until 19:26Z when it reached almost 60% (Figure 2), and rapidly rose to 76% (Figure 3) and then 91% at 19:32Z (Figure 4), when it was warned by the National Weather Service. No reports have been received yet.

Figure 1: ProbSevere, composite reflectivity, visible reflectance, and NWS severe weather warnings at 19:12Z.

Figure 2: ProbSevere, composite reflectivity, visible reflectance, and NWS severe weather warnings at 19:26Z.

Figure 3: ProbSevere, composite reflectivity, visible reflectance, and NWS severe weather warnings at 19:30Z.

Figure 4: ProbSevere, composite reflectivity, visible reflectance, and NWS severe weather warnings at 19:34Z.

-Cintineo

CI Sample

The images show a small break in the cirrus across Eddy County.  The CI picked up on this for one scan before the cirrus moved back in.  A storm did form there.  The 40% for this one scan was underdone due to some cirrus contamination.

1845 Z (above)

19Z (above)

1915Z (above)

1931Z (above)

-Champion

Missed CI

Cirrus clouds may have impacted the CI algorithm (click to animate):

Note that the developing convection is evident on the visible satellite.

This convection is associated with >35 dBZ echoes (click to animate):

There is a possibility that the infrared satellite may be weighted too heavily during the day time because it is clear on the visible data there was convective initiation.

Here is what the infrared satellite observed (click to animate):

Note the dense cirrus across the area, which likely impacted the CI algorithm.

Mahale

LUB Mesoscale 19Z Forecast

Current sfc conditions in the LUB CWA are generally characterized by temps in the M/U 70s and Tds U50s/L60s. GOES sounder information shows moisture advection to our west pooling along the Rockies in NM.

19Z GOES Total PW

Recent satellite/radar trends show CI occurred just prior to 19Z in SE NM. CAPE values over CWA via GOES sounder are AOB 100 J/KG, but are expected to increase through the day.

GOES 19Z CAPE

Model guidance suggests that ML CAPE values will not be very impressive (max AOB 500 J/KG), with 0-6 km bulk shear AOB 30 kts through 00Z, but shear values are expected to increase after 00Z as wind field strengthens. MU CAPE values AOA 1000 J/KG especially over our southern zones appear likely…with MU CAPE AOA 2000 J/KG also possible. Overall, expect large hail and severe wind gusts to be main threat through the early afternoon. Tornado potential appears low, especially through the early afternoon.

ERTEL