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ENHANCED SEVERE THUNDERSTORM RISK FORECAST SYNOPSIS…ISSUED APR. 04, 2022…8:40 P. M. EDT

6 min read

Disclaimer:  This site is not affiliated with the National Hurricane Center, Hurricane Hunters, Storm Prediction Center, or National Weather Service.  ALL forecasts herein are the result of my analysis, (to which you will see me at times, insert excerpts from various agencies due to the nature of the importance of the information) and I am solely responsible for the content.  As ALWAYS, follow the National Hurricane Center, National Weather Service, and your local Emergency Management officials for emergency decisions.  In addition, this is strictly a FORECAST OFFICE.  I CANNOT make decisions regarding travel plans, etc.  My purpose, is to provide you the information, based solely on information I analyze, and the accuracy of the information at hand of the time of analysis, so you may make informed decisions.
(T. F. “Storm” Walsh)

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Please be aware, even though I do not post every night, rest assured I am continuously monitoring various areas for any significant weather.  I will be taking Sundays off (family time), unless we have active systems that may be posing a threat (i.e. Tropical, Winter Weather, Coastal Storms, etc.).

I will reiterate, my forecasts are based on the available information at the time of analysis, and are only as accurate as the information analyzed and the solutions provided.

Good evening everyone!

I am going to try and make this forecast short and to the point.   Given the work week, when I post in the evenings, the synopsis on any given night, will be for the day 2 outlook.  This is why I mention for my readers, to use the SPC website link so they may view the outlook when it becomes day 1, as conditions can change overnight.

The Storm Prediction Center (SPC), has issued an ENHANCED RISK OF SEVERE THUNDERSTORMS in the current DAY 2 outlook: FROM THE SOUTHERN MISSISSIPPI VICINITY EAST-NORTHEASTWARD TO THE GEORGIA/SOUTH CAROLINA COASTS…
…SPC SUMMARY…
A broad area of severe-thunderstorm potential will exist across portions of the southern and southeastern U.S. on Tuesday, especially from the central Gulf Coast vicinity into central/southern Georgia and southern South Carolina. A swath of damaging wind gusts and several tornadoes are possible.
Outlook-category-descriptions

SPC DAY 2 CONVECTIVE OUTLOOK (LINKED TO OUTLOOK TEXT)
day2otlk_1730
TORNADO PROBABILITY
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 – EF5 tornadoes within 25 miles of a point.
day2probotlk_1730_torn
HAIL PROBABILITY
day2probotlk_1730_hail
DAMAGING THUNDERSTORM WIND PROBABILITY
day2probotlk_1730_wind
Based on my analysis of information contained in the current SPC DAY 2 Outlook, in the western most portion of the ENHANCED risk area, a fast moving, bowing MCS (Mesoscale Convective System), will be starting out at the beginning of the forecast period.  The SPC suggests that damaging winds and a tornado potential should be the main risks.  Analysis of the NAM – WRF from F5 DATA, and the NAM 3km suggests this occurs at approximately 11:00 a. m. EDT.  As we begin to get into early to late afternoon, instability will increase.  Moderate CAPE values, Lifted indices, 0-1 km helicity, etc., will lead to the system once again transform into a well organized linear band, which should produce QLCS (Quasi Linear Convective System) type tornado circulations along with some possible embedded supercells.  Based on some of the severe and tornado indices I analyzed this evening, I cannot rule out the possibility of the SPC upgrading a small area of the ENHANCED risk area from MS. to a portion of AL. to a MODERATE risk.  The STP indices I analyzed yesterday evening, have weakened sightly, however still remain on the strong end.

The following indices were analyzed this evening, regarding the mentioned models:

SBCAPE: 1500 – 2000 j/kg
MLCAPE: 500 – 1500 j/kg
HELICITY: 0 – 1 km: 250 – 400 m2/s2
L. I.: -4 to -8
EHI: 2 – 4
VGP: 0.4 – 0.8
STP: 4 – 9

STP EXPLAINED:
A majority of significant tornadoes (F2 or greater damage) have been associated with STP values greater than 1, while most non-tornadic supercells have been associated with values less than 1 in a large sample of RAP analysis proximity soundings.

SCP EXPLAINED
A multiple ingredient, composite index that includes effective storm-relative helicity (ESRH, based on Bunkers right supercell motion), most unstable parcel CAPE (muCAPE) and convective inhibition (muCIN), and effective bulk wind difference (EBWD). Each ingredient is normalized to supercell “threshold” values, and larger values of SCP denote greater “overlap” in the three supercell ingredients. Only positive values of SCP are displayed, which correspond to environments favoring right-moving (cyclonic) supercells.

VGP: The VGP (Vorticity Generation Parameter) is meant to estimate the rate of tilting and stretching of horizontal vorticity by a thunderstorm updraft. Values greater than 0.2 m s-2 suggest an increasing possibility of tornadic storms.

The following sites will explain most of these values, and will give you an idea of what to expect:
ENVIRONMENTAL INDICES AND PARAMETERS NWS
https://www.weather.gov/lmk/indices

THE WEATHER PREDICTION
http://www.theweatherprediction.com/severe/indices/

The following outlined maps from F5 DATA NAM – WRF model indicate where the model solution indicates where the strongest indices for  severe weather and tornadoes will occur.  Analysis of indices suggests the severe threat to initiate around 11:00 a. m. EDT, through 11:00 p. m. EDT 03/05/22.  Based on the NAM – WRF, and NAM 3km model, indices begin to move offshore and slowly weaken. 
F5 DATA NAM – WRF 11:00 A. M. EDT BEST TORNADO PROB
f5.torn.11am
2:00 P. M. EDT
f5.torn.2pm
5:00 P. M. EDT
f5.torn.5pm
f5.torn.5pmtwo
8:00 P. M. EDT
f5.torn.8pm
f5.torn.8pm.2
11:00 P. M. EDT
f5.torn.11pm
f5.torn.11pm.2
The following NAM 3km animations indicate the locations and strength of the forecast STP (Significant Tornado Parameter) index, and SCP (Supercell Composite Parameter) index.
NAM 3km STP ANIMATION (11:00 A. M. EDT APR 05 – 11:00 P. M. EDT APR 05)
nam-nest-se-sig_tor-1649095200-1649160000-1649214000-80
NAM 3km SCP ANIMATION
nam-nest-se-supercell_comp-1649095200-1649160000-1649214000-80Please use the following maps for all days, which should update automatically, for Mesoscale Discussions and Convective Watches.  You may have to refresh your browser, or click on the graphics.  I am also providing the SPC homepage link, so you may get the updated information regarding any changes to the outlook:

SPC MESOSCALE DISCUSSIONS (CLICK IMAGE FOR UPDATES)
Valid MD Image
SPC CONVECTIVE WATCHES (CLICK IMAGE FOR UPDATES)
Valid WW Image
SPC HOMEPAGE LINK
https://www.spc.noaa.gov/classic.html
IF A TORNADO WARNING IS ISSUED FOR YOUR AREA, IMMEDIATELY TAKE STURDY AND SAFE SHELTER

The following NWS Watch / Warning map will provide local NWS information for your area.  Click the image, then once it refreshes, click on your area of interest to view any special weather statements, hazards or advisories for your area.
NWS WATCH / WARNING DISPLAY (LINKED…CLICK MAP, THEN YOUR AREA)

WSI DOPPLER RADAR LOOP (LINKED)

RAP RADAR (CLICK IMAGE THEN RADAR SITE)
You may direct any questions by contacting me personally, ANYTIME, at: twalsh22000@yahoo.com

Have a blessed evening!

T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST

 

palmharborforecastcenter

2022-04-05 00:40:07

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