1930z FWD

Latest GOES R- LAP algorithm trends indicating increasing instability and moisture across the CWA to the south of a fairly stationary warm front across Oklahoma.

Highest instability/moisture exists across se portions of the CWA…tapering to moderate across nw portions of the region. (Fig 1&2)This matches fairly well with model progs. But this enviromnment is being advecting nw based on s/se flow low-level flow. Model analysis indicates strongest deep layer shear values will be across nw portions of the cwa (around 40kt)…with marginal values across se portions (25 kt). Combined shear/instability fields indicate highest potential for organized severe weather will be across NW half of the cwa this afternoon…with more isolated threat farther se. In general large hail and wind threat are supported by the high instability and adequate to strong shear. Tornado threat exists as well based on modest low-level helicity and shear values.

LAP Data for Mesoanalysis

The LAP data provided useful information for analyzing the current environment in the Lubbock CWA (and surrounding region) as well as trends in the data. Precipitable Water and CAPE are two great examples.

The PW image shows the approaching dryline from New Mexico with increasing PW out ahead of it. A loop of the data shows increasing values from MAF CWA north into very southern portion of  LUB. A similar trend is seen in the CAPE values with max values of 2500 to 3000 well to the south.   The 12Z KMAF Sounding (below) shows the low level moist airmass. When modified it indicates CAPE Values approaching 3800.

Expect the best chance of severe storms will be the Eastern portion of the LUB CWA as conditions continue to destabilize this afternoon and dry line progresses eastward.

-snowstrm

LUB Early Analysis

Lubbock CWA not experiencing severe convection at beginning of shift, but departing cells observed to the north and northeast.  Based on mesoanalysis, will also watch MAF and ABQ CWAs for emerging storms that could be mature in the LUB area.

CI gave a useful signature for developing storms in Pecos Co TX, and Roosevelt Co NM.

For example.  Roosevelt Co storm first acquired a probability of severe (albeit small 7%) at 1906Z.  CI first passed 50% at 1815Z.  By time of writing (1940Z) it had trended down.

At 1950 two areas have CI >60%, Dickens Co and Briscoe Co.

AMA 12Z sounding was not judged to be representative.  Based on modified MAF sounding 3800 SBCAPE can be achieved, also represented by RAP mesoanalysis.



-Holaday

Daily Summary: Week 3, Day 1 (May 18, 2015)

Forecasters operated in Lubbock and Midland CWA's.

- Bill Line, SPC/HWT Satellite Liaison

NUCAPS

- Nice supplemental sounding to have midday/ early afternoon

- Its nice to be able to adjust it

-

GOES-R CI

- A lot of mixed results yesterday

- It didn’t pick up well on development in some places, but better in others

- In midland area, it did real well for us

- For large storm with tor, 86% percent before it developed. 

- 60% probability has best score for initiating convection

- In convective situation, it is important to know when that first initiation will occur, even if it isn’t severe to start.

ProbSevere

- It lets you sort the storms quickly, it shows you trends in storms

SRSOR

- Over Northeast outside of our area

Lightning jump

- Mouse-over and have trend-line/meteogram pup-up with readout

Pickles 5/18/2015 23z

Utlility of Lightning Jump Detection algorithm in providing situational awareness on total lightning increase.

At 2241z…LJDA…detected a 3 sigma jump with the storm of concern. (Fig1)  At that time ENTLN data reported 177 cloud flashes…only 9 of which were CG. (Fig2)  Then at 2250z ENTLN reported 351 flashes…4 CG. (Fig3) The LJDA provided good situational awareness on this doubling of total lightning count and subsequent intensification. which based on 65-70 dbz reflectivity at 25000 ft was valid. (Fig 4) The other interesting note…is that most of the lightning was IC and not CG. CG data would have told you very little about this storms intensification.

Fig1.

Fig2.

Fig3.

Fig4.

MAF lightning jump

Reeves County supercell yielded useful lightning jumps on a few occasions.

Approximately 21:20Z jump of 2 sigma preceded severe hail reports.

A 21:45Z jump came ahead of pronounced inflow notch, right turn and tornadic behavior.  At this point fluctuations in the level continued to produce  some jumps that stood out, but the storm was already clearly severe.  Pictured is 22:32Z, along with path.

– Holaday

Storms Develop in MAF

Convection developed in MAF CWA. Convective initiation probability exceeded 50% approximately 30 minutes before storms developed over Jeff Davis County.

Range from MAF radar is a limiting factor for storm analysis in this part of Texas. Subject had awareness of this due to Radar Quality Index (shown here as overlay on visible satellite).

This underscores the utility of GOES-R based products to the forecaster.

Modest jump in lightning also observed, may be examined in another post.

CIMSSPWRET imagery

Additional convective development continues late this afternoon mainly along the sharp CAPE gradient in southwest Texas.

ENI LJDA Sigma Values Not Matching Time Trend Flash Data

The ENI time trend flash data for a storm in sern NM did not seem to indicate the 7 sigma jump in strikes seen in the  LJDA. The LJDA had a 7 sigma jump indicated at 2235Z, however the time trend trace does not seem to warrant that value.

Lightning Jump with Pulsing Storms

The Lightning Jump Detection Algorithm showed sigma values of 2 to 5 with some storms in the Western Portion of Norman’s CWA. Immediately after each jump there was a corresponding downward spike in lightning as seen in the Earth Networks time series below. This shows the pulsing nature of these storms.


The lightning detection color codes are helpful, but it would be nice to overlay these on radar to easily match up with cells. Perhaps make the shading translucent.