Good evening everyone!
Another round of Severe Weather is on tap for the weekend.
The Storm Prediction Center (SPC) Norman, OK. has issued a SLIGHT risk of Severe Thunderstorms from NRN KS/FAR SRN NEB NEWD TO NRN IL/SRN WI…in the DAY 2 OUTLOOK
Based on the current information contained in the outlook, I concur at the moment with the main threat being hail and damaging thunderstorm winds, based on analysis of forecast severe weather indices. Based on my analysis this afternoon of forecast indices from F5 DATA Severe Weather software, the 12Z GFS and NAM – WRF output indicate indicates mainly mutli cellular to squall line type development, with the 2 exceptions being further south in the risk area, or, if the CAP can be overcome. The latter COULD occur should forecast daytime heating become sufficient enough. Analysis of forecast indices and parameters indicate the best probability of severe weather development to lie within the outlined areas of both the GFS and NAM models, and initiating around 3:00 p.m to 7:00 p.m. CDT. The LLJ (Low Level Jet) is forecast to strengthen during the early evening, and some discrete cells could be elevated, and become organized to produce large hail.
Albeit parameters can change between now and tomorrow afternoon, the premise is, that instability / lift will be greater than shear, leading to the more prominent threat of Hail and Damaging Straight Line Winds. I copied a limited list of forecast indices, so those who wish, may compare them to the indices int he following charts.
SELECT FORECAST INDICES
SBCAPE: 1500 – 2000 j/kg
MLCAPE: 1000 – 1500 j/kg
Lifted Index: -6 to -8
SWEAT Index: 375 – 450
Showalter Index: -6 to -4
MOKANSCAN SEVERE INDICES
THE WEATHER PREDICTION INDICES CHART
I will try to have an update tomorrow morning sometime, and will most likely be sometime after the 12Z Upper Air soundings are posted for within the risk area.
The SPC has also issued a SLIGHT risk for Severe Weather for THE SOUTHERN PLAINS/OZARKS TO THE MIDDLE/LOWER MS RIVER VALLEY…in the DAY 3 Outlook:
Have a blessed evening!
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST / SEVERE WEATHER SPECIALIST
MEMBER WEST CENTRAL FLORIDA AMS
OFFICIAL SKYWARN SPOTTER (ADVANCED)