MESOSCALE DISCUSSION 0260
NWS STORM PREDICTION CENTER NORMAN OK
1117 AM CST MON MAR 17 2003
AREAS AFFECTED...N CNTRL/NE TX
CONCERNING...SEVERE THUNDERSTORM POTENTIAL
VALID 171717Z - 171945Z
POTENTIAL FOR SEVERE THUNDERSTORMS WILL INCREASE ACROSS PARTS OF
NORTH CENTRAL/NORTHEAST TEXAS THROUGH THE AFTERNOON HOURS...WW
MAY BE NEEDED WITHIN NEXT 2 TO 3 HOURS.
ISOLATED CONVECTION HAS INITIATED SOUTHWEST OF THE DALLAS/FORT
WORTH AREA WITHIN THE PAST HOUR. THIS APPEARS TO BE WHERE LOW-
LEVEL WARM ADVECTION HAS BECOME MAXIMIZED...IN WAKE OF UPPER
TROUGH OVER THE GULF OF MEXICO...AND AHEAD OF MID-LEVEL SHORT
WAVE TROUGH WHICH IS BEGINNING TO SHIFT OUT OF THE SOUTHERN
ROCKIES. AS EASTWARD PROGRESSION OF UPSTREAM SYSTEM CONTINUES
NEXT SEVERAL HOURS...STRONGER LOW-LEVEL WARM ADVECTION REGIME
WILL PERSIST/ DEVELOP SLOWLY NORTHEASTWARD ACROSS THE
DALLAS/FORTH WORTH AREA INTO NORTHEAST TEXAS.
IN RESPONSE TO LARGE-SCALE FORCING FOR UPWARD VERTICAL MOTION...
CONVECTIVE ACTIVITY IS EXPECTED TO INCREASE IN COVERAGE/INTENSITY
...WITH STRENGTHENING MID-LEVEL FLOW BECOMING SUPPORTIVE OF
SUPERCELLS. LARGE HAIL APPEARS TO BE PRIMARY SEVERE
THREAT...WITH A FEW DOWNBURSTS ALSO POSSIBLE. A GRADUAL
NORTHWARD RETURN OF LOW-LEVEL MOISTURE INTO PARTS OF NORTHEAST
TEXAS...ACCOMPANIED BY INCREASING SURFACE HEATING MAY CONTRIBUTE
TO MORE FAVORABLE LOW-LEVEL THERMODYNAMIC ENVIRONMENT FOR
ISOLATED TORNADOES TOWARD 21Z.
..KERR.. 03/17/2003
ATTN...WFO...SHV...FWD...OUN...
