Severe Thunderstorm Warning 95, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
300 PM CST SUN MAR 26 2000

RATHER COMPLEX SURFACE PATTERN ACROSS THE AREA THIS AFTERNOON.
OUTFLOW BOUNDARY FROM EARLIER CONVECTION IN NORTHERN OKLAHOMA RUNS
FROM NORTH CENTRAL OKLAHOMA... INTO NORTHERN PART OF OKC METRO
AREA... AND THEN INTO EAST CENTRAL OKLAHOMA. WIND SHIFT ACROSS THE
BOUNDARY HAS BECOME LESS DEFINED... ALTHOUGH ENHANCEMENT OF CU FIELD
STILL EVIDENT NEAR THE BOUNDARY. EVEN THOUGH SURFACE WINDS HAVE BEEN
SOUTHWEST ACROSS CENTRAL AND SOUTHWEST OKLAHOMA THROUGH THE
AFTERNOON... SURFACE DEWPOINTS HAVE MIXED OUT VERY LITTLE...
IMPLYING SOME DEPTH TO THE MOISTURE. LIFTED INDICES HAVE CLIMBED TO
MINUS 10 OR MORE OVER PORTIONS OF CENTRAL OKLAHOMA. IF CONVECTION
DOES OCCUR... DEVELOPMENT OF STORMS SHOULD BE FAIRLY RAPID.
MEANWHILE... SURFACE TROUGH OVER WESTERN OKLAHOMA... WILL CONTINUE
TO PROGRESS EAST AND INTERSECT THE REMNANTS OF THE OUTFLOW BOUNDARY.
BELIEVE OPPORTUNITY FOR THUNDERSTORMS OVER CENTRAL AND NORTHERN
OKLAHOMA WILL BE PRIMARILY THROUGH THE MID EVENING HOURS...
LINGERING TO AROUND MIDNIGHT IN THE SOUTHEAST ZONES.

MEANWHILE... COLD FRONT IN SOUTHERN KANSAS IS EXPECTED TO MOVE
ACROSS THE AREA OVERNIGHT AS A STRONG UPPER WAVE DIGS INTO THE
MIDWEST. THIS WILL KICK UP NORTHERLY WINDS TONIGHT... BEFORE THEY
START TO DIMINISH BY MONDAY AFTERNOON. FEW CLOUDS EXPECTED WITH THE
FRONT ACROSS WESTERN PORTIONS OF OKLAHOMA AND NORTH TEXAS... WHILE
CLOUDS OVER THE CENTRAL AND SOUTHEAST SECTIONS SHOULD BE GENERALLY
GONE BY MONDAY MORNING. PROGRESSIVE UPPER TROUGH OFF THE BAJA COAST
IS EXPECTED TO MOVE QUICKLY EAST... BRINGING ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS TO THE AREA ON TUESDAY. SERIES OF QUICK
MOVING WAVES FOLLOWING BEHIND WILL MAINTAIN A THREAT OF SCATTERED
SHOWERS AND THUNDERSTORMS INTO THURSDAY. MILD TEMPERATURES TO
CONTINUE INTO MID WEEK... BEFORE HIGHS COOL DOWN INTO THE 50S ON
THURSDAY.

PRELIM. NUMBERS...

FCSTID = 32
OKC   48  70  45  71 /  30   0   0  40
HBR   46  72  46  73 /   0   0   0  30
SPS   51  74  49  80 /   0   0   0  30
GAG   40  70  43  70 /   0   0   0  30
PNC   45  68  44  70 /  30   0   0  40
DUA   51  72  45  74 /  30   0   0  40

.OUN...
OK...NONE.

TX...NONE.

OKZ004>048-050>052-TXZ083>090-262100-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1230 PM CST SUN MAR 26 2000

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND EARLY TONIGHT ACROSS PORTIONS OF CENTRAL OKLAHOMA. THE SLIGHT
RISK AREA IS MAINLY EAST OF A LINE FROM MEDFORD TO KINGFISHER TO
WAURIKA.

DISCUSSION...A SURFACE TROUGH OF LOW PRESSURE IS MOVING INTO WESTERN
OKLAHOMA AT MIDDAY.  THIS TROUGH IS AHEAD OF A MORE SIGNIFICANT COLD
FRONT WHICH WILL MOVE SOUTH FROM KANSAS AND SWEEP ACROSS OKLAHOMA
TONIGHT. AHEAD OF THE SURFACE TROUGH...SOUTH TO SOUTHWEST WINDS AND
DEWPOINTS INTO THE LOWER AND MIDDLE 60S ARE COMMON OVER MUCH OF
OKLAHOMA. BEHIND THE TROUGH...WINDS TURN TO NORTHWEST AND DEWPOINTS
DROP INTO THE 30S AND 40S. THIS TROUGH MAY ACT AS A FOCUS FOR
THUNDERSTORM DEVELOPMENT THIS AFTERNOON...AND IS EXPECTED TO LIE
FROM MEDFORD TO WAURIKA BY MID AFTERNOON.  ALTHOUGH WINDS AHEAD OF
THE TROUGH ARE SOMEWHAT VEERED WITH WIND DIRECTIONS FROM THE
SOUTHWEST...ENOUGH CONVERGENCE MAY DEVELOP TO INITIATE THUNDERSTORMS.

ANOTHER POSSIBLE FOCUS FOR THUNDERSTORMS IS A RESULT OF MORNING
CONVECTION WHICH OCCURRED ACROSS NORTHERN OKLAHOMA. THUNDERSTORMS
LEFT BEHIND AN OUTFLOW BOUNDARY WHICH RUNS FROM ALVA TO FAIRVIEW TO
NEAR OKLAHOMA CITY AT NOON.  CONVERGENCE ALONG THIS BOUNDARY IS ALSO
NOT THAT STRONG...BUT AS THE SURFACE TROUGH TO THE WEST INTERSECTS
THIS BOUNDARY...AN AREA OF ENHANCED LOW LEVEL FORCING IS EXPECTED TO
DEVELOP SOMEWHERE NEAR OKLAHOMA CITY.

AS AFTERNOON HEATING PROGRESSES...THE ATMOSPHERE IS EXPECTED TO
BECOME MORE UNSTABLE AND A FEW SEVERE THUNDERSTORMS ARE POSSIBLE.
THE MAIN SEVERE WEATHER THREATS ARE EXPECTED TO BE LARGE HAIL AND
STRONG WINDS. THE SEVERE WEATHER THREAT WILL SHIFT TO EASTERN
OKLAHOMA THIS EVENING. SPOTTER GROUPS AND EMERGENCY MANAGERS ACROSS
THE SLIGHT RISK AREA SHOULD BE PREPARED FOR POSSIBLE AcCTIVATION THIS
AFTERNOON AND EARLY TONIGHT.

DLF