Severe Thunderstorm Warning 337, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
153 PM CDT MON JUL 22 2002

COLD FRONT CURRENTLY EXTENDS FROM NORTH OF KAY COUNTY SW INTO
NORTHWESTERN PARTS OF FA.  PRE-FRONTAL TORCH HAS WARMED TEMPERATURES
INTO UPPER 90S/100S EARLY THIS AFTERNOON.  WINDS AHEAD OF FRONT WILL
LIKELY BACK SOMEWHAT WHICH WILL HELP INCREASE CONVERGENCE ALONG
FRONT THIS AFTERNOON/EVENING.  EXPECT BEST CHANCE FOR STORM
DEVELOPMENT TO BE ALONG AND BEHIND FRONT FROM ROUGHLY SWO SOUTHWEST
TO NEAR CSM.  TEMP/DEWPOINT DEPRESSION WILL BE IN THE 30 TO 40 DEGREE
RANGE SO SOME OF STRONGER STORMS WILL HAVE POTENTIAL FOR
STRONG/DAMAGING WINDS. WITH LOSS OF HEATING LATER IN THE EVENING
THINK THAT BEST CHANCE FOR OVERNIGHT STORMS MAY BE ACROSS WEST
CENTRAL/SW OKLAHOMA WHERE BETTER LOW LEVEL CONVERGENCE IS FORECAST.

GOING INTO TUESDAY FOCUS FOR STORMS WILL BE ACROSS CENTRAL AND
MAINLY SOUTHERN PARTS OF FA.  COLD FRONT/WIND SHIFT IS EXPECTED
TO SITUATED NEAR RED RIVER VALLEY TUESDAY AFTERNOON.  WILL KEEP
IN SLIGHT CHANCES CENTRAL AND CHANCE POPS SOUTH.  WILL ALSO
GO MORE WITH FWC NUMBERS AND CURRENT FORECAST FOR HIGHS.

SURFACE RIDGE WILL CONTINUE TO SHIFT TO THE EAST ON WEDNESDAY
AS SURFACE LOW ASSOCIATED WITH UPPER STORM SYSTEM MOVES INTO
NORTHERN PLAINS.  COLD FRONT/SURFACE TROUGH TO THE SOUTH
WILL ALSO BECOME LESS DEFINED.

GOING INTO EXTENDED PERIOD...UPPER RIDGE IS FORECAST TO BE CENTERED
OVER CENTRAL ROCKIES ON THURSDAY.  HOWEVER...MRF AND ECMWF LOWER
HEIGHTS ACROSS THIS AREA GOING INTO FRIDAY WITH APPROACH OF
TROUGH NEAR PACIFIC NW.  TWO MODELS DIVERGE ON SOLUTION AFTER
THIS POINT WITH ECMWF DEVELOPING MORE OF A TROUGH ACROSS WESTERN
US.  THIS EVENTUALLY PUTS AREA IN SOUTH TO SOUTHWEST FLOW ALOFT
WITH LEE TROUGH.  MRF FORECAST MORE RIDGING OVER SOUTHWESTERN
STATES AND WITH TIME BUILDS RIDGE OVER WESTERN STATES GOING INTO
NEXT WEEK WITH FRONTAL PASSAGE MONDAY/TUESDAY.  WITH LEE TROUGH
MAY ADD IN SOME SLIGHT POPS SATURDAY/SUNDAY AFTERNOON FAR WEST
AND ALL AREAS MONDAY FOR POSSIBLE FRONTAL PASSAGE.

SIX
PRELIM NUMBERS

OKC  71 91 69 92 /  40 20 20 10
HBR  71 92 69 95 /  40 30 20 10
SPS  73 94 72 96 /  20 30 30 20
GAG  65 89 64 93 /  30 20 10  5
PNC  69 89 67 92 /  30 20 10  5
DUA  74 94 71 94 /  10 30 30 20

.OKC...
OK...NONE.
TX...NONE.

OKZ004>048-050>052-TXZ083>090-222000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1200 PM CDT MON JUL 22 2002

THUNDERSTORM OUTLOOK...
SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS NORTHERN OKLAHOMA THIS
AFTERNOON...AND ACROSS MUCH OF OKLAHOMA AND NORTH TEXAS TONIGHT.
ISOLATED SEVERE THUNDERSTORMS MAY OCCUR...BUT NO ORGANIZED SEVERE
WEATHER IS EXPECTED.  IF ISOLATED SEVERE THUNDERSTORMS DO
OCCUR...THE PRIMARY THREAT WILL BE STRONG WINDS.

DISCUSSION...
A COOL FRONT WILL MOVE THROUGH NORTHERN AND WESTERN OKLAHOMA THIS
AFTERNOON. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE
FRONT. THERE IS SUFFICIENT INSTABILITY TO ALLOW SOME OF THESE
THUNDERSTORMS TO BE STRONG OR BRIEFLY SEVERE...BUT WEAK WINDS IN THE
ATMOSPHERE WILL MAKE ORGANIZED SEVERE WEATHER UNLIKELY.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT TUE JUL 23.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...70 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...10 PERCENT.

OTHER HAZARDOUS WEATHER...
NO OTHER HAZARDOUS WEATHER IS EXPECTED THROUGH TONIGHT.

THE NEXT SCHEDULED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AT 7 AM
TUESDAY.