Flash Flood Warning 10, NWS Tulsa, OK

FPUS3 KTUL 270854
AFDTUL

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
352 AM CDT MON APR 27 1998

AS USUAL...JUST WHEN WE NEED THOSE MODELS THE MOST...THE COMPUTER IN
WASHINGTON BITES THE DUST.  ETA WAS NOT CONSIDERED THIS PACKAGE AS
MODEL DATA IS LIMITED THIS MORNING.

MID-UPR DRYSLOT ADVANCING NEWD ACRS FCST AREA AS UPR LOW GETS CLOSER.
ON 00Z CHARTS...UPR LOW WAS OVER FAR WRN TX...HOWEVER LATEST
SATELLITE LOOPS INDICATE THAT IT MAY NOW BE OVER SWRN OK.  EXPECT LOW
TO MOVE A BIT FARTHER TO THE E TODAY...MAINTAINING DRYSLOT ACRS MUCH
OF FCST AREA THRU 00Z THIS AFTN.  NGM/AVN SUPPORT THE NOTION OF
KEEPING THE DRYSLOT OVER FCST AREA TODAY WITH DECENT ISENTROPIC
DECENT ON THE 300K SURFACE THRU 00Z.  WL BASE POPS ON RADAR POSITION
OF RAIN BAND THIS MORNING ACRS NRN AREAS...WL ADVERTISE POPS REST OF
FCST AREA BASED ON POTNL OF TSRA THAT MAY GENERATE SHOULD CLOUDS
BREAK TODAY (AND THEY MIGHT BASED ON LATEST LOW CLOUD CHANNEL LOOPS
FROM THE BIG EYE IN THE SKY).  ALSO...GIVEN MIDLVL DRYSLOT...WE MIGHT
HAVE TO WATCH OUT FOR POTNL OF DRY MICROBURSTS DOWN SOUTH THIS AFTN
SHUD TSRA DVLP.

HAVE DECIDED NOT TO ISSUE FLASH FLOOD WATCH ACRS NRN FCST AREA SEEING
THAT THE MAIN FOCUS FOR RAIN WILL SHIFT N OF FCST AREA THIS MORNING.
HOWEVER...HEAVY RAIN THREAT WILL NOT END TODAY.  NGM/AVN BOTH IN
AGREEMENT THAT LOW WILL RETROGRADE BACK TO WRN OK TONIGHT...WITH
ISENTROPIC LIFT INCREASING ACRS ERN AND NRN ZONES AFT MIDNIGHT.  WL
GO CAT POPS TONIGHT WITH HEAVY RAIN POTNL MENTIONED (GIVEN AMT OF
LIFT ADVERTISED).  LATER SHIFTS WL HAVE TO LOOK INTO POTNL OF FLASH
FLOODING TONIGHT (SEEING THAT GROUNDS NOW SATURATED).  THEY WILL ALSO
HAVE THE BENEFIT OF ADDITIONAL MODEL DATA (SPECIFICALLY AN ETA RUN).

WL CONT POPS ON INTO TUE WITH UPR LOW (AND COOL TEMPS ALOFT) IN
NEIGHBORHOOD.  NOT MUCH EXTENDED MODEL GUIDANCE TO LOOK AT THIS
MORNING...SO WL FOREGO SGFNT CHANGES TO MEDIUM RANGE PDS ATTM.

FCSTID = 14

PRELIM NUMBERS (MAY CHANGE ON OFFICIAL RELEASE)...
TUL   67  53  67  49 /  50  80  60  40
FSM   72  58  70  51 /  50  90  70  50
MLC   71  54  69  50 /  30  60  50  40
BVO   62  50  63  47 /  70  90  70  40
FYV   70  55  66  50 /  60  90  70  50
IDB   74  56  72  52 /  40  60  50  30
BYV   70  55  66  50 /  60  90  70  50
MIO   66  52  65  49 /  70  90  70  50
MKO   67  53  67  49 /  40  80  60  40
F10   67  53  67  49 /  40  80  60  40
HHW   74  56  72  52 /  30  60  50  30

.TUL...
OK...NONE.
AR...NONE.

ARZ001-002-010-011-019-020-029-OKZ049-053>076-281200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
610 AM CDT MON APR 27 1998

HEAVY RAINS MAY CAUSE FLOODING PROBLEMS OVER PARTS OF EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS TODAY AND TONIGHT.

AN AREA OF HEAVY RAIN ASSOCIATED WITH AN UPPER LEVEL LOW PRESSURE SYSTEM
HAD STALLED OVER NORTHEAST OKLAHOMA EARLY THIS MORNING. THIS RAIN IS
EXPECTED TO SLOWLY DIMINISH DURING THE MORNING...BUT THERE IS A THREAT
OF ADDITIONAL RAINFALL OVERNIGHT AS THE UPPER LEVEL SYSTEM REMAINS IN
THE AREA.

ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EARLY THIS
EVENING OVER NORTHWEST ARKANSAS AND PARTS OF FAR EASTERN OKLAHOMA.

THE THREAT FOR SEVERE STORMS WILL BE EAST OF A LINE FROM JAY OKLAHOMA TO
HUGO OKLAHOMA.

A STRONG UPPER LEVEL LOW PRESSURE SYSTEM WILL SLOWLY DRIFT INTO WESTERN
OKLAHOMA TODAY WITH A SURFACE LOW EXPECTED TO REMAIN NEARLY STATIONARY
ALONG THE OKLAHOMA...ARKANSAS BORDER. A TROUGH OF LOW PRESSURE WILL
EXTEND SOUTH OF THE LOW INTO EASTERN TEXAS. COLD AIR ALOFT COMBINED WITH
LINGERING LOW LEVEL MOISTURE WILL RESULT IN AN UNSTABLE AIRMASS ALONG
AND EAST OF THE SURFACE LOW PRESSURE TROUGH.

CLOUDINESS OVER THE AREA WILL LIMIT INSTABILITY SOMEWHAT...BUT SOME
BREAKS IN THE CLOUDS ARE EXPECTED BY AFTERNOON AND SHOULD ALLOW
TEMPERATURES TO WARM TO NEAR 70. DISTURBANCES ROTATING AROUND THE UPPER
LOW WILL CAUSE SUFFICIENT LIFT ALONG THE SURFACE TROUGH TO ALLOW
SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON. LIMITED DEEP LOW
LEVEL MOISTURE AND ONLY WEAK SURFACE CONVERGENCE WILL BE THE LIMITING
FACTORS TO SEVERE THUNDERSTORM DEVELOPMENT.

THUNDERSTORMS THAT DEVELOP WOULD LIKELY REMAIN STRONG INTO THE EVENING
HOURS BEFORE WEAKENING.

EMERGENCY MANAGERS AND STORM SPOTTER GROUPS IN FAR EASTERN OKLAHOMA AND
NORTHWEST ARKANSAS SHOULD BE PREPARED FOR POSSIBLE ACTIVATION THIS
AFTERNOON AND THIS EVENING.

ARZ001-002-010-011-019-020-029-OKZ049-053>076-281200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
610 AM CDT MON APR 27 1998

HEAVY RAINS MAY CAUSE FLOODING PROBLEMS OVER PARTS OF EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS TODAY AND TONIGHT.

AN AREA OF HEAVY RAIN ASSOCIATED WITH AN UPPER LEVEL LOW PRESSURE SYSTEM
HAD STALLED OVER NORTHEAST OKLAHOMA EARLY THIS MORNING. THIS RAIN IS
EXPECTED TO SLOWLY DIMINISH DURING THE MORNING...BUT THERE IS A THREAT
OF ADDITIONAL RAINFALL OVERNIGHT AS THE UPPER LEVEL SYSTEM REMAINS IN
THE AREA.

ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EARLY THIS
EVENING OVER NORTHWEST ARKANSAS AND PARTS OF FAR EASTERN OKLAHOMA.

THE THREAT FOR SEVERE STORMS WILL BE EAST OF A LINE FROM JAY OKLAHOMA TO
HUGO OKLAHOMA.

A STRONG UPPER LEVEL LOW PRESSURE SYSTEM WILL SLOWLY DRIFT INTO WESTERN
OKLAHOMA TODAY WITH A SURFACE LOW EXPECTED TO REMAIN NEARLY STATIONARY
ALONG THE OKLAHOMA...ARKANSAS BORDER. A TROUGH OF LOW PRESSURE WILL
EXTEND SOUTH OF THE LOW INTO EASTERN TEXAS. COLD AIR ALOFT COMBINED WITH
LINGERING LOW LEVEL MOISTURE WILL RESULT IN AN UNSTABLE AIRMASS ALONG
AND EAST OF THE SURFACE LOW PRESSURE TROUGH.

CLOUDINESS OVER THE AREA WILL LIMIT INSTABILITY SOMEWHAT...BUT SOME
BREAKS IN THE CLOUDS ARE EXPECTED BY AFTERNOON AND SHOULD ALLOW
TEMPERATURES TO WARM TO NEAR 70. DISTURBANCES ROTATING AROUND THE UPPER
LOW WILL CAUSE SUFFICIENT LIFT ALONG THE SURFACE TROUGH TO ALLOW
SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON. LIMITED DEEP LOW
LEVEL MOISTURE AND ONLY WEAK SURFACE CONVERGENCE WILL BE THE LIMITING
FACTORS TO SEVERE THUNDERSTORM DEVELOPMENT.

THUNDERSTORMS THAT DEVELOP WOULD LIKELY REMAIN STRONG INTO THE EVENING
HOURS BEFORE WEAKENING.

EMERGENCY MANAGERS AND STORM SPOTTER GROUPS IN FAR EASTERN OKLAHOMA AND
NORTHWEST ARKANSAS SHOULD BE PREPARED FOR POSSIBLE ACTIVATION THIS
AFTERNOON AND THIS EVENING.