Good day everyone!
Quite a bit to discuss today. The Storm Prediction Center (SPC) Norman OK. has issued a MODERATE risk for Severe Thunderstorms for this afternoon into tonight for portions of AR…NRN LA…NWRN MS…SRN/ERN MO…WRN TN…SRN IL…WRN KY…EXTREME SWRN INDIANA…
A SLIGHT risk of Severe Thunderstorms has been issued for LOWER MO/OH VALLEY REGIONS TO E TX…TN VALLEY AND PARTS OF MS DELTA REGION…
From the SPC OUTLOOK Text:
MULTIPLE ROUNDS OF SEVERE TSTMS WITH LARGE HAIL…DAMAGING GUSTS AND A FEW STG TORNADOES ARE POSSIBLE IN AND NEAR MDT-RISK AREA TODAY AND TONIGHT.
The SPC has issued the following Public Severe Weather Outlook (PWO):
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK
0407 AM CDT THU APR 03 2014 …
SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF THE OZARKS REGION TO PARTS OF THE MID-SOUTH AND LOWER OHIO VALLEY THIS AFTERNOON AND TONIGHT…
The NWS Storm Prediction Center in Norman, OK is forecasting the development of tornadoes, large hail and damaging winds from the Ozarks region to parts of the Mid-South and lower Ohio Valley this afternoon and tonight.
The areas most likely to experience this activity include:
most of Arkansas
southern and eastern Missouri
Elsewhere, severe storms are also possible from the mid-Mississippi Valley to western Ohio and southwestward to central Mississippi, eastern Oklahoma and southeast Texas.
A strong disturbance 3-7 miles above ground will move northeastward out of the Four Corners and Rockies today, causing winds to strengthen over the outlook area.
As that happens, a cold front will overtake a dryline from north to south across parts of eastern Kansas, Missouri and eastern Oklahoma.
When the front and dryline encounter sunshine-heated and richly moist air to their east, thunderstorms should erupt and become severe, with help from that increase in surrounding winds. The greatest threat for very large and damaging hail will be with the early, western storms in Missouri and Arkansas this afternoon and evening, while the damaging-wind hazard will ramp up this evening and possibly overnight in the Mississippi Valley.
Tornadoes–some strong with EF2 or worse damage–also are possible. A separate band of severe thunderstorms, also offering tornado and severe-wind risk, may form tonight over parts of the Mississippi Delta region–in and near the southern part of the moderate-risk area. State and local emergency managers are monitoring this developing situation.
Those in the threatened area are urged to review severe weather safety rules and to listen to radio, television, and NOAA Weather Radio for possible watches, warnings, and statements later today. ..Edwards.. 04/03/2014
Based on analysis of the 12Z Upper Air Soundings from around the risk areas, initial parameters and indices are already indicating a very unstable atmosphere from FWD, OUN, and SGF for samplings…with CAPE Values ranging from 2000 – 3000 j/kg, Lifted Indices -5 to -10, Supercell Composite Parameters 16.7 – 24.9, and Significant Tornado Parameters 3.1 – 5.7
These values have a tendency to decrease approaching the Moderate risk area, HOWEVER…THESE CONDITIONS WILL MOVE EASTWARD as we get into the afternoon hours. Albeit as of the time of the soundings, a strong CAP, or CINH (Convective INHibition) was in place over the areas noted, the CAP will be broken over the MODERATE risk area by around 1:00 p.m. CDT, with CINH values < -50 to zero.
The following are some forecast indices and values within the MODERATE risk area for this afternoon:
SBCAPE: 2000 – 3000 j/kg
MLCAPE: 1000 – 1500 J/KG
Lifted Index: -8 to -10
Totals Totals Index: 52 – 56
Showalter Index: -6 to -4
EHI: 2 – 3
CRAVEN BROOKS INDEX: 30,000 – 50,000
SWEAT INDEX: 400 – 425
MID LEVEL LAPSE RATE: 7.5 C/km
K INDEX: 25 – 35
SFC Theta-E: 340k
SEVERE WEATHER INDICES CARTS
Based on analysis of the most current available information obtained through the following models (GFS, RAP, ECMWF, and NAM – WRF) using F5 DATA Severe Weather Software, the greatest tornado threat appears to be in, (concurring with the SPC tornado probability map) the 15% and HATCHED AREA. The HATCHED AREA indicates where the probability of EF2 – EF5 tornadoes will have the tendency to occur.
This is inline with the RAP and NAM – WRF modeling which indiates STP of >1 with probabilities of EF2 – EF5 tornadoes higher within the circled areas.
ALL of the models are pretty much in agreement of storm initiation beginning around 1:00 pm. CDT through 4:00 p.m. CDT…in other words, this is when the modeling expects the worst of the severe weather to take place. Albeit the threat should begin to diminish around sunset, conditions will be in place for a severe threat to continue into early evening further east in the risk areas.
Based on consistency in both severe weather indices modeling over the past 48 hours, and SPC outlook forecast upgrade…this office…erring on the side of safety and public awareness is issuing the following:
BASED ON CURRENT AND FORECAST SEVERE WEATHER PARAMETERS, BARRING ANY UNFORESEEN CHANGES…THIS EVENT HAS THE POTENTIAL TO BECOME A PDS (Potentially Dangerous Situation) WITHIN THE MODERATE RISK AREA.
Residents within the risk areas, especially the MODERATE risk area, should closely monitor this developing situation throughout the day, and into early evening, and should monitor NOAA Weather Radio, LOCAL NWS OFFICE Statements and Warnings, and Local Media updates.
IF A TORNADO WARNING IS ISSUED FOR YOUR AREA…SEEK SHELTER IMMEDIATELY!
The following maps and graphics are linked for you to retrieve up to date information regarding this Severe Weather event. Just mouse over them and click.
I will try to be on later this afternoon to post updated information to social media sites. PLEASE check this site often, as added updates will not email or inform you as a new post.
Have a blessed day and STAY SAFE!
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST / SEVERE WEATHER SPECIALIST
MEMBER WEST CENTRAL FLORIDA AMS
OFFICIAL SKYWARN SPOTTER (ADVANCED)