Tornadoes and Hail in Texas, September 19, 2001

TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AMARILLO TX
440 PM CDT WED SEP 19 2001

MID TO UPPER LEVEL MOISTURE STREAMING NORTHEAST OVER THE SOUTHERN
ROCKIES AND SOUTHERN HIGH PLAINS THIS AFTERNOON AS LOW-LEVEL
MOISTURE WAS BEING PULLED NORTH ACROSS WEST TEXAS AND INTO SOUTHWEST
KANSAS...IN ADVANCE OF A DEVELOPING DRYLINE IN EASTERN NEW MEXICO.

ISOLATED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED TONIGHT PRIMARILY
NEAR BANDS OF LOW-LEVEL CONVERGENCE STRETCHING FROM SOUTHWESTERN
KANSAS INTO SOUTHEASTERN COLORADO...AS WELL AS ACROSS THE CENTRAL
AND SOUTHWESTERN TEXAS PANHANDLE. THUNDERSTORMS WILL LIKELY RECEIVE
ADDITIONAL LIFT OVERNIGHT FROM STRENGTHENING LOW-LEVEL WARM AIR
ADVECTION PATTERN/ISENTROPIC LIFT.

DRYLINE TO TIGHTEN UP ON THURSDAY AS IT PUSHES INTO THE CENTRAL
TEXAS PANHANDLE. ISOLATED THUNDERSTORMS AGAIN POSSIBLE THURSDAY
AFTERNOON...MAINLY ACROSS THE EAST. HOWEVER...COLD FRONT WILL PUSH
SOUTH INTO THE OKLAHOMA PANHANDLE THURSDAY EVENING AND THROUGH THE
TEXAS PANHANDLE BY LATE THURSDAY NIGHT. FOR NOW WILL INTRODUCE
SLIGHT CHANCE POPS FOR THURSDAY NIGHT...BUT LATER SHIFTS MAY HAVE TO
INCREASE POP VALUES AS MOIST UPSLOPE FLOW STRENGTHENS BEHIND FRONT.
ALSO...MID LEVEL SUBTROPICAL MOISTURE WILL HANG AROUND AS WELL WITH
BANDS OF EMBEDDED VORTICITY. LAST SEVERAL SHORT RANGE MODEL RUNS...
PARTICULARLY ETA/AVN...HAVE INDICATED BEST CHANCE FOR PRECIPITATION
TO BE SATURDAY AND SATURDAY NIGHT...PRIMARILY AS A RESULT OF
STRONGER PASSING TO THE NORTH OF THE AREA. THEREFORE...RAISED POPS
FROM SLIGHT CHANCE TO CHANCE. UPSLOPE COMPONENT EXPECTED TO PERSIST
THROUGH REST OF THE WEEK...SO NO CHANGES TO SUNDAY FORECAST OF SLIGHT
CHANCE TSRA.

IN THE EXTENDED...UPPER LEVEL FLOW WILL CONTINUE TO VEER...
PRACTICALLY BECOMING NORTHERLY BY EARLY NEXT WEEK. THIS MAY AID
ANOTHER WEAK COLD FRONT TO PUSH SOUTH ACROSS THE AREA BY SUNDAY
NIGHT/MONDAY. UPSTREAM FLOW WILL BE STRONG ENOUGH TO SPILL OVER THE
NORTHERLY FLOW...ALLOWING RIDGE TO DEVELOP OVER THE CENTRAL U.S. BY
MID WEEK...RESULTING IN A WARMING TREND.

.AMA...
TX...NONE.
OK...NONE.

JH

OKZ001>003-TXZ001>020-192200-

TEXAS/OKLAHOMA PANHANDLES THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE AMARILLO TX
320 PM CDT WED SEP 19 2001

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS ALL OF THE
TEXAS AND OKLAHOMA PANHANDLES THIS AFTERNOON AND THIS EVENING.

A WARM...MOIST...AND UNSTABLE AIRMASS IS IN PLACE ACROSS THE
PANHANDLES THIS AFTERNOON. A SURFACE LOW PRESSURE TROUGH ACROSS
SOUTHEAST NEW MEXICO AND SOUTHWEST KANSAS WILL MOVE SOUTHEAST INTO
WESTERN SECTIONS OF THE PANHANDLES THIS AFTERNOON...AND WILL CONTINUE
MOVING SOUTHEAST THIS EVENING AND TONIGHT. CONVERGING WINDS ALONG THE
TROUGH WILL LEAD TO THE DEVELOPMENT OF THUNDERSTORMS. DUE TO THE
INSTABILITY ALREADY IN PLACE...STORMS WILL HAVE THE POTENTIAL TO
STRENGTHEN QUICKLY. SOME OF THE STRONGER STORMS COULD BECOME SEVERE.

THE THUNDERSTORMS ARE EXPECTED TO MOVE SOUTHEAST INTO PANHANDLES.
THE MAIN THREATS FROM THE STORMS WILL BE LARGE HAIL...DAMAGING
WINDS...AND HEAVY RAIN. THE TURNING OF WINDS WITH HEIGHT WILL
SUPPORT ORGANIZED STRONG TO SEVERE THUNDERSTORMS...BUT THE WIND
SPEEDS AT THE MID LEVELS ARE EXPECTED TO REMAIN BELOW THOSE NEEDED
FOR TORNADO DEVELOPMENT.

SPOTTERS AND EMERGENCY MANAGEMENT OFFICIALS ACROSS THE TEXAS AND
OKLAHOMA PANHANDLES SHOULD REMAIN ALERT FOR POSSIBLE ACTIVATION THIS
AFTERNOON OR THIS EVENING.

COCKRELL