The SPC is forecasting ...tornadoes large hail and damaging winds over parts of eastern texas northern and western louisiana as well as southern and eastern arkansas this afternoon and tonight.... Please read the latest public statement about this event.
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SPC AC 181948 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0248 PM CDT TUE MAR 18 2008 VALID 182000Z - 191200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS EAST TX...SRN/CNTRL AR...MUCH OF LA... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE SLGT RISK FROM CNTRL TX TO WRN KY... LARGE SCALE FORCING APPEARS TO BE STRENGTHENING ACROSS SRN TX PER RECENT INCREASE IN CONVECTION ALONG ADVANCING WIND SHIFT FROM NEAR AUS...SWD TO NEAR CRP. LATEST THINKING IS THIS ACTIVITY WILL SEE A MARKED INCREASE OVER THE NEXT FEW HOURS AS STRONG UPPER SPEED MAX...H5 IN EXCESS OF 100KT...BEGINS TO EJECT ACROSS SOUTH TX TOWARD THE LOWER MS VALLEY. GIVEN THE LINEAR STRUCTURE THAT HAS ALREADY DEVELOPED IT APPEARS A DAMAGING SQUALL LINE IS BECOMING INCREASINGLY LIKELY. SHEAR PROFILES ARE VERY IMPRESSIVE ACROSS THE WARM SECTOR BUT MARGINAL MID LEVEL TEMPERATURES/LAPSE RATES ARE SUPPRESSING THE INSTABILITY OVER AN OTHERWISE SUFFICIENTLY MOIST ENVIRONMENT. MID DAY SOUNDINGS FROM LCH/SHV/LZK ALL SUPPORT STRONG/DEEP ROTATING UPDRAFTS. HOWEVER...THERE IS SOME CONCERN THAT STORM MODE ACROSS THE WARM SECTOR MAY PRIMARILY BE LINEAR ALONG SFC WIND SHIFT. EVEN ALONG THE INCREASING SQUALL LINE SHEAR PROFILES CERTAINLY SUGGEST EMBEDDED SUPERCELLS AND TORNADOES. ONE INTERESTING NOTEWORTHY TREND ACROSS THE WARM SECTOR HAS BEEN THE RECENT DRYING...BUT SUBSTANTIAL WARMING...ACROSS ECNTRL TX/NRN LA/SRN AR WHERE DEW POINTS HAVE DRIED INTO THE UPPER 50S. THIS DEEPENING/DRYING BOUNDARY LAYER MAY ACTUALLY SERVE TO ENHANCE THE DAMAGING WIND POTENTIAL AS SQUALL LINE ADVANCES INTO THIS AIRMASS. LATER THIS EVENING FORECAST SOUNDINGS STRONGLY FAVOR SUPERCELLS AND POSSIBLE TORNADOES ACROSS THE MODERATE RISK AREA AS HIGHER MOISTURE RETURNS NWD INTO THE ARKLATEX REGION. IF DISCRETE SUPERCELLS CAN DEVELOP A FEW STRONG TORNADOES ARE ALSO POSSIBLE. STRONG FORCING WILL SHUNT LARGE CONVECTIVE SYSTEM EAST ACROSS AR/LA INTO MS/WRN TN/KY DURING THE OVERNIGHT HOURS. DAMAGING WINDS ARE THE GREATEST SEVERE RISK WITH THIS ACTIVITY...ALTHOUGH ISOLATED TORNADOES ARE CERTAINLY POSSIBLE. ..DARROW.. 03/18/2008 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z