Flash Flood Warning 45, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
300 PM CST SAT NOV 16 1996

LINE OF TSRA APPROACHING NW ZONES ATTM ALONG OUTFLOW BOUNDARY FROM
THIS MORNINGS STORMS IN WRN OK/KS. HAVE HAD A FEW SVR REPORTS ALONG
THIS LINE...BUT MORE WIDESPREAD THREAT APPEARS TO BE HEAVY RAINFALL
AND POSSIBLE FLASH FLOODING. WILL BE ISSUING FFA FOR TONIGHT FOR
ALL EXCEPT ZONE 77 AS NEW GRIDDED DATA SHOWING THE BEST VERTICAL
MOTION AND HIGHEST QPF ALONG THE NRN COUNTIES. EXPECT WIDESPREAD 1-
2 INCH AMOUNS WITH LOCAL AMOUNTS UP TO 4 INCHES.

12Z PCGRIDDS96 DATA CONTINUES TO SHOW EXTREMELY HIGH HELICITY
VALUES FROM 00-06Z TONIGHT WITH CAPE VALUES FCST TO BE 100-500
J/KG. THESE CAPES SEEMS LOW COMPARED WITH CURRENT OBSERVED LI/CAPE
VALUES AND OBSERVED SVR REPORTS TO OUR WEST. WILL KEEP MENTION OF
SVR POSS IN ALL ZONES.

MOS TEMPS LOOK GOOD WITH SOME DISAGREEMENT IN FIRST COUPLE PERIODS.
LEANED TO WARMER TEMPS IN THE EAST WITH COOLER READINGS WEST
TONIGHT. AFTER TONIGHT...RAPID CLEARING SHOULD TAKE PLACE WITH POSS
SOME LINGERING STRATIFORM PRECIP IN ZONE 77 SUN MORNING. NO MAJOR
WEATHER PROBLEMS EXPECTED DURING THE REST OF THE FCST AS GULF WILL
BE CUT OFF TOO LONG FOR ANY MOISTURE TO RETURN. EXTENDED MODELS
SHOW UPPER FLOW PATTERN WILL REMAIN NEARLY ZONAL WITH SWLY FLOW
OVER WRN CANADA HELPING TO KEEP THE ULTRA COLD AIRMASS IN PLACE
RATHER THAN SLIDING SOUTH DOWN THE CENTRAL US PLAINS. /26

TUL BA 040/053 038/068 049 26+000
FSM BA 046/056 035/067 040 26+-00
MLC BA 044/055 036/070 045 26+000
BVO BA 038/053 038/068 048 26+000
FYV BA 042/051 030/065 038 26+-00
IDB EA 051/055 031/068 039 268200
BYV BA 042/050 029/064 037 26+-00

.TUL...R
OK...FLASH FLOOD WATCH ZONES 54>76.
AR...FLASH FLOOD WATCH ALL ZONES (1/2/10/11/19/29).

ARZ001-002-010-011-019-029-OKZ054>076-171200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
1245 PM CST SAT NOV 16 1996

A FEW SEVERE THUNDERSTORMS ARE EXPECTED ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS THIS AFTERNOON AND EARLY TONIGHT.

THE MAIN THREAT OF SEVERE WEATHER OVER EASTERN OKLAHOMA WILL BE
MAINLY BETWEEN 2PM AND 8PM...WITH THE THREAT OVER NORTHWEST ARKANSAS
MAINLY BETWEEN 6PM AND MIDNIGHT.

EARLY THIS AFTERNOON A STRONG COLD FRONT EXTENDED FROM A LOW PRESSURE
CENTER NEAR GAGE OKLAHOMA ACROSS KANSAS INTO SOUTHEAST NEBRASKA.
A VIGOROUS UPPER LEVEL DISTURBANCE THAT WAS MOVING INTO SOUTHWEST
TEXAS WILL QUICKLY MOVE NORTHEAST ACROSS OKLAHOMA LATE THIS AFTERNOON
AND THIS EVENING. AS THE STRONG UPPER LEVEL SYSTEM MOVES NORTHEAST
INTO THE PLAINS..THE COLD FRONT WILL BEGIN MOVING SOUTHEASTWARD INTO
OKLAHOMA. WIDESPREAD SHOWERS AND THUNDERSTORMS ALREADY OCCURRING FROM
SOUTHCENTRAL KANSAS INTO WESTERN AND CENTRAL OKLAHOMA WILL SPREAD
EASTWARD INTO NORTHEAST OKLAHOMA BY MID AFTERNOON. ADDITIONAL THUNDERSTORMS
ARE EXPECTED TO DEVELOP ALONG A DRYLINE IN SOUTHWEST OKLAHOMA AND WEST
TEXAS BY MID AFTERNOON AND THESE WILL ALSO RACE QUICKLY TO THE NORTHEAST
AND MAY AFFECT SOUTHEAST OKLAHOMA AND LATER...WESTERN ARKANSAS.

THE INSTABILITY ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS IS EXPECTED TO
REMAIN SOMEWHAT LIMITED THIS AFTERNOON AS CLOUDY SKIES KEEP TEMPERATURES
FROM WARMING OUT OF THE MID 60S TO LOWER 70S. HOWEVER...AS THE UPPER SYSTEM
MOVES OVERHEAD...COLD AIR ALOFT WILL PROVIDE MODERATE INSTABLILTY AND
GIVEN THE STRENGTH OF THE WIND FIELDS...A FEW SEVERE THUNDERSTORMS ARE
EXPECTED TO DEVELOP. THE UPPER LEVEL SYSTEM AND COLD FRONT ARE EXPECTED
TO MOVE EAST OF THE AREA SHORTLY AFTER MIDNIGHT ENDING THE THREAT FOR
SEVERE THUNDERSTORMS.

THE MAIN THREAT WITH ANY STORMS THAT BECOME SEVERE WILL BE STRONG
DAMAGING WINDS AS THE STORMS RACE NORTHEASTWARD...HOWEVER STRONG
WINDS IN THE MID-LEVELS OF THE ATMOSPHERE AND THE EXPECTED VERTICAL
WIND PROFILE OVER THE AREA WILL ALSO PROVIDE THE POTENTIAL FOR A
FEW TORNADOES TO DEVELOP.

IN ADDITION TO THE THREAT OF SEVERE WEATHER...THERE IS ALSO THE
POTENTIAL FOR VERY HEAVY RAIN THROUGH TONIGHT.  ALTHOUGH STORMS
WILL BE MOVING QUICKLY TO THE NORTHEAST...SOME LOCALIZED FLOODING
OF LOW LYING AREAS AND POOR DRAINAGE AREAS WILL BE POSSIBLE WHERE
STORMS REPEATEDLY MOVE ACROSS THE SAME AREAS.

EMERGENCY MANAGEMENT AGENCIES AND STORM SPOTTERS SHOULD
BE PREPARED FOR POSSIBLE ACTIVATION.

THIS IS A SPECIAL ISSUANCE OF THE EASTERN OKLAHOMA/NORTHWEST
ARKANSAS THUNDERSTORM OUTLOOK.  THESE OUTLOOKS ARE ISSUED DAILY
FROM MID MARCH TO MID JUNE AND AS NEEDED AT OTHER TIMES OF THE
YEAR.