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)

For those who have donated to my site, your help has been greatly appreciated.  If you are not aware, donations to my site help pay for subscriptions to sites I use as well as software updates, which provide all the models and information used in my forecasts.  To donate, please click the DONATE button to the right side of the page, or on the graphic of the dog.  Any help you provide is immensely appreciated!
DONATIONS ACCEPTED AND APPRECIATED

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 day everyone!
The forecast center is closed on Sunday’s

The SPC has introduced a MARGINAL risk for severe thunderstorms in the DAY 2 and DAY 3 outlooks:
DAY 2

DAY 3

CSU – MLP AND NSSL ML DAY 2 PROBABILITIES

CSU – MLP AND NSSL ML DAY 3 PROBABILITIES



CURRENT DAY 1 SEVERE WEATHER OUTLOOK
The Storm Prediction Center (SPC) has issued a MARGINAL risk for severe thunderstorms in the current DAY 1 Outlook: ACROSS PORTIONS OF THE SOUTHERN PLAINS…

…SPC SUMMARY…
Isolated strong to severe thunderstorms could produce hail and gusty winds this evening into the overnight hours across portions of the southern Plains.

SPC DAY 1 SEVERE THUNDERSTORM OUTLOOK (LINKED FOR OUTLOOK TEXT)

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.

CSU – MLP DAY 1 FORECAST (CLICK FOR LARGER IMAGE)

NSSL ML DAY 1 PROBABILITY


DAY1 PROBABILITY CONVERSION TABLE

SPC DISCUSSION EXCERPT:
…Southern Plains…
An upper trough this morning over southern CA/eastern Pacific to the west of Baja California will move east into the southern Rockies by early Saturday morning. Strengthening south-southeasterly 850mb flow is forecast to advect richer moisture northwestward from the Hill Country (50s dewpoints) into parts of west TX northeastward into western/central OK. Steep 700-500 mb lapse rates sampled at 12 UTC this morning in Midland, TX (7.7 deg C/km), will aid in the development of 500-1200 J/kg MUCAPE as the moist plume gradually moistens/heats today. Forecast soundings shows strong to very strong effective shear (50-70 kt), which will support storm organization.

Initially, isolated storms are forecast to develop on the northwest periphery of moisture return over parts of northwest TX late this afternoon. As the upper trough approaches the region this evening into the overnight, a more extensive southwest to northeast corridor of convection is expected. One or more clusters will likely evolve into linear bands and move east-northeastward near an eastward-moving Pacific front and from prior storm-generated cold pools. One of these linear clusters seems likely from parts of the Permian Basin vicinity into northwest TX tonight as deeper large-scale forcing for ascent pivots into the southern High Plains. A predominately hail risk with the strongest storms this afternoon/evening will probably transition to a mix of hail/wind potential during the overnight as the storm mode becomes more linear. Strengthening low-level warm-air advection over OK tonight will favor primarily elevated strong to locally severe storms capable of a hail risk into perhaps as far north as southern KS during the pre-dawn hours on Saturday.

The following maps are from NADOCAST for tornado and hail probabilities.  The outlined region in the tornado probability map indicates a .1% (<1%) probability.  
12Z NADOCAST TORNADO PROBABILITY 

12Z NADOCAST SIGTOR PROBABILITY (CLICK FOR LARGER IMAGE)

12Z NADOCAST HAIL PROBABILITY (CLICK FOR LARGER IMAGE)

12Z NADOCAST SIGHAIL PROBABILITY (CLICK FOR LARGER IMAGE)

Based on my analysis of the preliminary severe weather indices, the forecast calls for a marginally unstable to borderline moderately unstable atmosphere at the moment.  Indices indicate severe thunderstorms may be possible during the early evening, into the overnight hours. The main severe risk as of analysis this morning appears to be isolated hail, based on lifted indices, bulk shear and steep mid level lapse rates.  DCAPE values of 700+ j/kg-1 indicated isolated damaging wind gusts may occur as well within the 5% wind / gusts outline.  While CAPE values are mostly within the marginally unstable range, based on bulk shear, maximum 0-3km SRH values, and veering winds with height, isolated brief tornado activity (EF0 – EF1) could occur within the area of maximum indices.  The strongest forecast indices and parameters should occur within the central and southern portion of the 5% HAIL outline, an isolated area over north central OK., and within the darker shaded 0.1 and 0.15 outlines in the NSSL ML map. 

Based on analysis of model animations, the current outlook, and analysis of indices, the strongest convection and indices should occur approximately between 6:00 P.M. CST FEB 13 – MIDNIGHT, with some activity continuing into the early morning hours.  Rain and general thunderstorms could initiate by 3:00 – 4:00 P.M CST.  Please visit the SPC homepage via the link provided for any changes to the forecast today.
CAPE VALUES FORECAST

DEW POINT FORECAST

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

The following were the forecast parameters and indices analyzed this morning.  Bear in mind, MAXIMUM 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: 500- 1200 j/kg-1                  
MLCAPE: 500 – 1250 j/kg-1                   
MUCAPE: 500 – 1250 j/kg-1                
SRH 0 -1 km: 50 – 100 m2/s2               
SRH 0 -3 km: 100 – 275 m2/s2        
SRH EFFECTIVE: 100 – 200 m2/s2          
L. I.: -1 to -4                                                   
SCP: 1.0 – 4.0                                          
STP: 0.1 – 1.1 
0 -6 km SHEAR: 60 kts – 80 kts                  
EFF. SHEAR: 50 kts – 70 kts                        
MID LEVEL LAPSE RATE: 7.0C – 8.5C   
DEWPOINT: 55F – 59F                                    
EHI: 0.6- 1.5                                     
TOTAL TOTALS INDEX: 49C – 50C                     
K INDEX: 22C to 34C                                          
SWEAT INDEX: 435 – 485                          
THOMPSON INDEX: 23 to 38      
CRAVEN – BROOKS INDEX: 10,000 – 25,000    

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
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 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 6:00 P.M. CST FEB. 13– 6:00 A.M. CST FEB. 14

NAM 3KM STP FORECAST 6:00 P.M. CST FEB. 13– 6:00 A.M. CST FEB. 14

NAM 3KM RADAR SIMULATION 6:00 P.M. CST FEB. 13 – 6:00 A.M. CST FEB. 14

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, TAKE IMMEDIATE SAFE AND STURDY 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 links will connect you to the Excessive Rainfall probabilities and River Flood Outlook:
EXCESSIVE RAINFALL
https://www.wpc.ncep.noaa.gov/qpf/excessive_rainfall_outlook_ero.php

SIGNIFICANT RIVER FLOOD OUTLOOK
https://www.wpc.ncep.noaa.gov/nationalfloodoutlook/index.html

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 forecasts, 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)
WUNDERGROUND RADAR SUMMARY MAP (CLICK FOR UPDATES)

PRECIPITATION TYPE (CLICK TO ACCESS ANIMATION FEATURE)

CARIBBEAN RADAR (CLICK IMAGE TO ACCESS ANIMATION)

You may direct any questions by contacting me personally, ANYTIME, at: twalsh22000@yahoo.com

Have a blessed day!

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