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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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 afternoon everyone!
The Storm Prediction Center has issued a MARGINAL risk for severe thunderstorms for tomorrow.  The office will be closed, so please refer to the SPC homepage link further on in the synopsis.

The Storm Prediction Center (SPC) has issued a MARGINAL risk for severe thunderstorms in the current DAY 1 Outlook: FROM NORTH TEXAS EASTWARD ALONG THE NORTHERN GULF COAST…

…SPC SUMMARY…
Isolated severe storms will be possible today and tonight from parts of the southern Plains eastward into the northern Gulf Coast states.
SPC DAY 1 SEVERE THUNDERSTORM OUTLOOK (LINKED)

TORNADO PROBABILITY

Probability of a tornado within 25 miles of a point.
HAIL PROBABILITY

Probability of one inch diameter hail or larger within 25 miles of a point.
DAMAGING THUNDERSTORM WIND PROBABILITY

Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.

The following is the current CSU – MLP severe weather forecast map:
CSU – MLP DAY 1 FORECAST (CLICK FOR LARGER IMAGE)


DAY 1 PROBABILITY CONVERSION TABLE

SPC DISCUSSION
…Texas east to the Florida Panhandle…
An upper-level low over NM will move east generally along the Red River/TX-OK border through tonight, as a surface cold front from central TX east across central MS/AL moves slowly south. Thunderstorm coverage is expected to increase this afternoon across portions of central/eastern TX within a zone of low-level warm advection and aided by increasing large-scale ascent with time. Modest MUCAPE north of the front and sufficient shear for organized updrafts will result in the potential for large hail with a couple of stronger storms. Closer to the front over central/east-central TX thunderstorms are expected to develop through this afternoon, with the potential for a couple of supercell storms with large hail/damaging gusts as the primary severe hazards. Some potential for a brief tornado may also exist given sufficient low-level shear within the frontal zone.

Thunderstorm coverage is also expected to increase farther east along the front later today and tonight as moisture/buoyancy increases. Deep-layer shear will remain supportive of organized storms, including isolated supercells, with the risk for large hail and strong/severe gusts. Some risk for a tornado will remain through the overnight hours in the vicinity of the front, where modestly-increasing low-level flow will contribute to sufficient low-level shear.

A term / value during low buoyancy (CAPE below 1000) and high shear called SHERB (Severe Hazards in an Environment with Reduced Buoyancy) is used to indicate where the best probability could be for tornado activity.  While the NADOCAST site is down, I’ll continue to post these.  Values of 1.0+ indicate where the tornadic activity may have the best probability.
EFFSHERB 12:00 NOON CST MAR. 08 – 6:00 P.M. CST MAR. 08



Based on my analysis of the severe weather indices, the forecast calls for a marginally unstable atmosphere.  At the time of completing my analysis, some isolated thunderstorms were ongoing.  I expect the onset of the strongest storms to initiate between 12 NOON CST and 1:00 p.m. CST.  Forecast indices suggest the main threats to be isolated large hail and damaging thunderstorm winds / gust.  Based on shear and EHI values, some tornadoes could most likely occur, however given the limited MLCAPE and EHI values below 3.0, tornadoes should remain in the EF0 – EF1 intensity.

Regarding EHI values, I have been listing minimum and maximum values for each outline area of where the weakest values and stronger values are located.  In this synopsis, I am including a 0 – 3 SRH map from the NAM 3KM model so you may get an idea where the minimum and Maximum EHI values would be located.

Indices were analyzed from the NAM 3KM, HRRR 3KM, CIPS DETERMINISTIC, SPC SREF, and CSU – MLP model guidance.

The following were the forecast parameters and indices analyzed this afternoon, with the max. values pertaining to the MARGINAL outline.  Bear in mind, indices recorded below are for the time of peak intensity.  Some indices meanings are posted below the indices themselves, and the NWS page containing a more extensive explanation can be accessed further on in the synopsis:
SBCAPE: 250 – 750 j/kg-1
MLCAPE: 250 – 500 j/kg-1
MUCAPE: 500 – 1500 j/kg-1
SRH 0 -1 km: 150 – 300 m2/s2
SRH 0 -3 km: 300 – 800 m2/s2
SRH EFFECTIVE: 100 – 300 m2/s2
L. I.: -1 to -3
SCP: 1.0 – 6.0
STP: 0.0 – 0.2
0 -6 km SHEAR: 65 kts – 75 kts
EFF. SHEAR: 55 kts – 65 kts
MID LEVEL LAPSE RATE: 7.0C – 8.0C
DEWPOINT: 51F – 68F
EHI: (MINIMUM) 0.5 – 1.25 (MAXIMUM) 0.9 – 2.5
TOTAL TOTALS INDEX: 50C – 53C
K INDEX: 31 – 36C
SWEAT INDEX: 450 – 500
THOMPSON INDEX: 32 – 39
CRAVEN – BROOKS INDEX: 10,000 – 20,000

CAPE

ENERGY HELICITY INDEX

K INDEX

TOTAL TOTALS INDEX

STORM RELATIVE HELICITY

LIFTED INDEX

SWEAT VALUES

THOMPSON INDEX

Craven SigSvr Parameter:
The simple product of 100mb MLCAPE and 0-6km magnitude of the vector difference (m/s; often referred to as “deep layer shear”) accounts for the compensation between instability and shear magnitude. Using a database of about 60,000 soundings, the majority of significant severe events (2+ inch hail, 65+ knot winds, F2+ tornadoes) occur when the product exceeds 20,000 m3/s3.
A little fact on SRH values and tornadoes from NOAA / NWS

A little fact on SRH values and tornadoes from NOAA / NWS
Storm Relative Helicity (m² s^-2)
SRH (Storm Relative Helicity) is a measure of the potential for cyclonic updraft rotation in right-moving supercells, and is calculated for the lowest 1-km and 3-km layers above ground level. There is no clear threshold value for SRH when forecasting supercells, since the formation of supercells appears to be related more strongly to the deeper layer vertical shear. Larger values of 0-3-km SRH (greater than 250 m² s^-2) and 0-1-km SRH (greater than 100 m² s^-2), however, do suggest an increased threat of tornadoes with supercells. For SRH, larger values are generally better, but there are no clear thresholds between non-tornadic and significant tornadic supercells.

STP ( Significant Tornado Parameter) EXPLAINED:
A majority of significant tornadoes (EF2 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 (Supercell Composite Parameter) 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.

The following are the SCP (Supercell Composite Parameter) and STP (Significant Tornado Parameter) forecast maps from the NAM 3KM and HRRR 3KM model.  Generally, the higher the values and brighter the color, indicates a greater probability of strong thunderstorm and / or tornadic activity over an area:
NAM 3KM SCP FORECAST 12:00 NOON CST MAR. 08 – 9:00 P.M. CST MAR. 08, 2025

NAM 3KM STP FORECAST 12:00 NOON CST MAR. 08 – 9:00 P.M. CST MAR. 08, 2025

HRRR 3KM SCP FORECAST 12:00 NOON CST MAR. 08 – 9:00 P.M. CST MAR. 08, 2025

HRRR 3KM STP FORECAST 12:00 NOON CST MAR. 08 – 9:00 P.M. CST MAR. 08, 2025

NAM 3KM STORM RELATIVE HELICITY FORECAST MAP

Please use the following maps, which should update automatically, for Mesoscale Discussions and Convective Watches.  You may have to refresh your browser, or click on the graphics.  I have provided the SPC homepage link below, so you may get the updated information regarding any changes to the outlook:
https://www.spc.noaa.gov/classic.html
SPC MESOSCALE DISCUSSIONS (CLICK IMAGE FOR UPDATES)

SPC CONVECTIVE WATCHES (CLICK IMAGE FOR UPDATES)

IF A TORNADO WARNING IS ISSUED FOR YOUR AREA, IMMEDIATELY TAKE STURDY AND SAFE SHELTER
The following sites will explain most of the severe weather and tornado values listed above, 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 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)

NWS DOPPLER RADAR LOOP (LINKED, CLICK RADAR MAP)

RAP RADAR (CLICK IMAGE THEN GO TO LOOP DURATION AND PICK LENGTH OF LOOP, THEN CLICK RADAR SITE)
CARIBBEAN RADAR (CLICK IMAGE TO ACCESS ANIMATION)

You may direct any questions by contacting me personally, ANYTIME, at: [email protected]

Have a blessed evening!

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