Lightning Jump Algorithm – Page 2

ProbSvr gives good lead time

Posted in GOESR, Lightning Jump Algorithm, Live Blogs, ProbSevere on April 20, 2016 by Kristin C.

Looking at the use of prob severe in providing lead time. At 23:36z a report of ping pong ball size hail.

Analysis of prob severe and lightning jump 20 minutes before at 23:16z , shows the probSvr displaying 91% chance of severe, 46kts shear, MU cape 947, Mesh 1.07″, Growth rate strong: glaciation: strong, flash rate 28/min and 1 signa jump.

20 minutes later at 23:36z: 90% chance of severe, 49 kts shear, Mu cape 1157, Mesh 1.93″, Growth rate:strong, Glaciation: strong, 0 signa. ( however, jump did stay at 1 during 20 min duration.)

One report of ping pong ball size hail at that point.

Prob severe may be a good factor in issuing an early warning for a severe storm.

-thunder

Eastern Amarillo CWA Storm

Posted in GOESR, Lightning Jump Algorithm, ProbSevere, Total Lightning on April 20, 2016 by Kristin C.

While we are watching storms in the Lubbock CWA, I kept an eye on a storm over the eastern portion of Amarillo CWA, near I-40. The ProbSevere was 25% at 2308 UTC and jumped to 84% by 2314 UTC as MRMS MESH and total lightning flash rates jumped significantly (also the effective bulk shear was rather high in the mid/upper 40 knots). The ProbSevere values continued to increase into the 90% range. A 1.00″ hail report was received at Interstate 40 at 2325 UTC and after the report was received, a severe thunderstorm warning issued. The good lead-time for this storm can be attributed to all predictors of ProbSevere–strong satellite growth rates, strong satellite growth rates, increasing lightning in a highly sheared environment and MRMS MESH over 1.00″.

NOAA/CIMSS ProbSevere contours and MRMS composite reflectivity valid 2308 - 2332 UTC 20 April 2016. — NOAA/CIMSS ProbSevere contours and MRMS composite reflectivity valid 2308 – 2332 UTC 20 April 2016. (click for animation)

-Sieglaff

Storm Southeast of LBB’s RDA

Posted in GOESR, Lightning Jump Algorithm, Live Blogs, ProbSevere, Pseudo GLM on April 20, 2016 by Kristin C.

Storm development has occurred southeast of the Lubbock, TX RDA in the Texas Panhandle. While initially the all-tilts reflectivity looked promising, PROBSvr continued to indicate marginal severe potential. Combine this with no significant lightning jump and low flash density on the PGLM array, the decision was made to hold off on a warning for now.

Severe storm near KSJT

Posted in Lightning Jump Algorithm, Live Blogs, ProbSevere on April 20, 2016 by Kristin C.

Severe storm near KSJT (J-Money):

Lightning jump product gave a nice heads-up (on the order of about 10 minutes) to developing severe storm. Prob Severe values were also fairly high and steady-state leading into rapid intensification.

ProbSevere and MRMS reflectivity at -20C

First Warning in San Angelo CWA

Posted in Lightning Jump Algorithm, ProbSevere on April 20, 2016 by Kristin C.

A thunderstorm developed along a residual outflow boundary/stationary front southwest of San Angelo Wednesday afternoon. The forecaster group issued an experimental severe thunderstorm warning based on lightning jump data, ProbSevere output, and all radar tilts examination. Figure 1 below shows a loop of 0.5 degree KSJT reflectivity and ProbSevere contours. ProbSevere first exceeded 50% at 1952 UTC, 60% at 2002 UTC, and 80% at 2012 UTC. The experimental data along with all radar tilts analysis helped forecasters increase lead-time and confidence in issuing a severe thunderstorm warning. After the warning was issued the storm again experienced a lightning jump and ProbSevere values maxed at 100%, with MRMS MESH over 3.00″.

KSJT 0.5 degree reflectivity, NOAA/CIMSS ProbSevere contours and experimental severe thunderstorm warning polygons valid 1948 - 2016 UTC 20 April 2016. — KSJT 0.5 degree reflectivity, NOAA/CIMSS ProbSevere contours and experimental severe thunderstorm warning polygons valid 1948 – 2016 UTC 20 April 2016.

-Sieglaff

Mesoscale Analysis as of 1830z

Posted in Lightning Jump Algorithm, Live Blogs, Mesoscale Discussions, Pseudo GLM, Total Lightning on April 20, 2016 by Kristin C.

J-Money Mesoscale Analysis as of 1830z:

Two regional short-wave features to note in the 700-500 mb layer this afternoon, as per water vapor imagery and meso-analysis data. The leading system was near the TX/LA border and pushing east, with associated storms being heavy rain producers, given saturated, weakly sheared environment. Houston LMA and flash rate density products show a fair amount of lightning as well.

Through 19-22z, better convective potential may shift to central/south TX, as a subtle 700 mb short-wave over west TX moves in. This may interact with a decelerating outflow boundary in the vicinity. Layered PW data depicts the leading edge of mid-level dry air and presumably steeper lapse rates as well. Main question is can strong 700 mb cap shown on 12z KDRT sounding be overcome. Time will tell. Maybe 19z NUCAPS could help later today?

Severe storms Ramping up Pecos into Terrell county

Posted in Lightning Jump Algorithm, Live Blogs, ProbSevere on April 19, 2016 by Kristin C.

ProbSvr at 99%/ Radar showing 70% DBZ, in twin storms south Pecos co. Radar jump 2 sigma.

Decided to warn on both storms with two separate warnings.

KMAF 0.5 reflectivity 0013 UTC and severe warning polygons (yellow)

4panel at 0008 UTC of ProbSevere (top left), lightning jump (top right), visible (bottom left) and IR (bottom right)

ProbSevere, Lightning Jump warning

Posted in Lightning Jump Algorithm, Live Blogs, ProbSevere on April 19, 2016 by Kristin C.

Analysis of storm at 21:32z shows 86% svr prob, growth moderate, glaciation weak. Lighting jump was huge at 8!

DBZ reflectivity is at 63. Even though glaciation is weak. Storm shows characteristics of large hail. Decide to issue warning for hail at 21:52z. Beat actual CWA warning by a few minutes.

Lightning jump a precursor to large hail?

Posted in Lightning Jump Algorithm, Live Blogs on April 19, 2016 by Kristin C.

Sudden lightning jump and Prob Severe enhancment in northern Pecos county, TX. Given thermodynamic/shear environment, large hail seems probable. -J-Money

LJA and Severe CI

Posted in Lightning Jump Algorithm, Live Blogs on April 19, 2016 by Kristin C.

Thunderstorms finally beginning to develop across Pecos County in west Texas as midlevel shortwave trough continues to slowly apprach the area. Recent development has seen a 8 sigma jump in lightning activity across south-central Pecos County.

Lightning Jump scale 0, from 2124 to 2136. 5 min NLDN CG flashes also plotted.

Severe CI actually peaked at 64% for this storm…

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Spring Experiments & Beyond

Category: Lightning Jump Algorithm