All Sky Severe Environment

Mesoscale analysis is MUCH improved with ALL SKY products. It gives the forecaster a great visual of where moisture advection is occurring in the layered products.  In addition, CAPE and Total PW highlight the more unstable regions with intensifying storms from overlaid region radar data. 

-Jake Johnson

NUCAPS Modified Sounding Analysis

Wichita Falls tornadic environmental data using NUCAPS Modified Sounding.  NUCAPS sounding surface data had temp/dewpoint of 73/68, looking at surface obs temp/dewpoint range near the NUCAPS point sounding was 74-76/69-70.  Therefore modified numbers were in the ball park.



NUCAPS 700-500mb Lapse Rate Gridded Product did a decent job with mid lapse rates across southwest Oklahoma showing a favorable environment for severe thunderstorms.

GOES-W & GOES-E GLM comparison

Looking at GLM for GOES-W in Full Disk (L)  and GOES-E in meso sector (R) the flash extent density and average flash area compare well to one another. Max FED values were 62 and 64 fl/5-min respectively. They also showed similar overall footprint with even the smallest flash values. Parallax is obvious with the peak  values separated by ~15 mi at this longitude.



GLM FED from GOES-W full disk (UL), GLM FED from GOES-E meso sector (UR), 10.3 um from GOES-W full disk (LL), 10.3 um from GOES-E meso sector (LR)

-- S Coulomb

Dryline Evolution Using PW

Favorite application of the LAP Precipitatable Water is the low level from the SFC to 900 MB as a good proxy to dryline evolution. It very clearly highlights how it developed through the day.

Watch the dryline in West Texas

South Beach

GLM lightning "jump" prior to tornado spinup

GLM showed a lightning increase (5 fl/min @ 20:39 to 12 fl/min @20:44) prior to tornado report and TDS signature at 20:56. Once the circulation weakened the lightning rate also dropped back to 5 fl/min. The min Flash Area kept a consistent look as the updraft moved east-northeast.



--SCoulomb

ProbSVR

ProbSVR time series graphs with the online version continues to be one of my favorite for tracking trends.  Uncertain how to display this cleanly in AWIPS II? 

- Jake Johnson

ProbTor Jump

ProbTor jumped from 37% to 74% over an 8 min period with the circulation over SW MO as a TDS became evident and a tornado was reported.



--SCoulomb

Visible and GLM for developing supercell

Two supercells developed in far southwest Oklahoma along 0-3km CAPE gradient.  At 1957Z ProbSVR Hail 10% Wind 39% Tor 3%, then 6 minutes later at 2003Z ProbSRV Hail 63% Wind 75% Tor 5% on the southern storm.  GLM Total Optical Energy in lower left image performed well with the increase in lightning activity for both supercells. 

-Jake Johnson

ProbSevere Suite Helping on Busy Severe Weather Day

A very active severe weather day continues over the NWS CWAs our teams are covering today (OUN, TSA, SGF).  A couple highlights from quick discussions with forecasters relate to ProbSevere suite of products:

• ProbTor is especially useful to draw attention to storms that might be rapidly increasing their tornadic potential, especially when busy interrogating many storms and issuing warnings.
• ProbHail on a storm over southern OUN CWA was indicating 75% probabilities, but the MESH was low biased (under an inch).  The storm was reported to have produced golf ball sized hail.  The forecaster viewed the high ProbHail value as a demonstration of the value of additional information included in the ProbHail model.  (The forecaster suspected low MESH due to updraft tilt, which is a known source of low bias.)
• One forecaster changed the ProbSevere double contour threshold from 3% to 10% given the very favorable environment for tornadoes in his CWA today (SGF).  The customizability was viewed very positively as that changed greatly decluttered his display.
• ProbTor jumps are proving very useful in highlighting storms with rapidly increasing tornadic threat (e.g., a storm in the SGF CWA had ProbTor jump from 37% to 74% in 8 min as the storm developed a TDS and had ground reports of tornadoes).

-J. Sieglaff

Underwhelming ProbHail

ProbHail on the storm in southwest MO seemed to be too low based on other derived parameters (MESH/Hail Index) and storm structure. ProbHail was consistently 70-75%. It was explained that the hail cape (~750 J/kg), the EBShear (47kt) and lightning (29 flash/min) were relatively lower than one would expect given the environment. Justin showed the parameter space for each of the ingredients and how they were weighting down the overall ProbHail due to the ratios being <1.



-- SCoulomb