Flash Flood Warning 17, NWS Norman, OK

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
1040 AM CDT SUN AUG 14 2005

.UPDATE...
WILL TWEAK POPS A LITTLE MORE SOUTHWARD AND UP THEM INTO CATAGORICAL
RANGE AS ANOTHER BATCH OF MODERATE TO HEAVY RAIN MAKES ITS WAY ENE
OUT OF NORTH TX INTO SRN OK. EMBEDDED MCV SHOULD HELP TO MAINTAIN
THIS PRECIP SHIELD NORTH WELL INTO THE AFTN HOURS. SFC FRONT
BISECTING THE AREA HAS MADE LITTLE TO NO PROGRESS TODAY WITH MOST
AREAS TO THE NORTH OF FRONT REMAINING IN THE 60S. SOUTH OF FRONT
WIDESPREAD RAIN SHOULD KEEP TEMPS IN CHECK TODAY. WILL THEREFORE
LOWER TEMPS AREAWIDE. WILL NOT MAKE ANY CHANGES TO FFA AT THIS
POINT.

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523 AM CDT SUN AUG 14 2005

.UPDATE...
NOTE TO USERS OF KTLX RADAR DATA. AT 10Z... WE CHANGED THE Z/R
RELATIONSHIP TO TROPICAL SETTINGS AS THE OVERNIGHT KTLX RAINFALL
ESTIMATES HAD SIGNIFICANTLY UNDERESTIMATED PRECIPITATION IN
COMPARISON TO MESONET AND METAR OBSERVATIONS. IN SOME CASES...
REPORTED RAINFALL WAS NEARLY TWICE AS MUCH AS KTLX ESTIMATES. THIS
CHANGE IN Z/R WILL GIVE INCONSISTENT RESULTS FOR PRECIPIATION
ESTIMATES THAT INCLUDE ACCUMULATIONS BEFORE 10Z. THIS WILL
ESPECIALLY AFFECT ESTIMATES IN COTTON/CLAY/WICHITA COUNTIES WHERE
HEAVY RAINFALL OCCURRED THIS MORNING AND HEAVY RAIN IS STILL
FALLING. BUT HOPEFULLY RADAR ESTIMATES WILL IMPROVE NOW.

&&

.PREV DISCUSSION... (ISSUED 346 AM CDT SUN AUG 14 2005)

..CORRECTED START TIME OF FLASH FLOOD WATCH...

DISCUSSION...
WE WILL BE ISSUING A FLASH FLOOD WATCH FOR TODAY FOR MUCH OF
SOUTHWEST OKLAHOMA INTO PORTIONS OF SOUTH CENTRAL OKLAHOMA AND FOR
ALL OF OUR NORTH TEXAS COUNTIES. THE SLOW MOVING FRONT... WHICH IS
BEING SOMEWHAT MASKED BY SEVERAL OUTFLOW BOUNDARIES... WILL CONTINUE
TO PROVIDE SUPPORT FOR SHOWERS AND TSTMS OVER THE AREA TODAY. WITH
PRECIPITABLE WATER AMOUNTS APPROACHING 2 INCHES...LOCALLY HEAVY
RAINFALL WILL BE POSSIBLE. THE BEST CHANCE FOR HEAVY RAINS ARE
EXPECTED TO BE ACROSS PORTIONS OF SOUTHERN OKLAHOMA INTO NORTH
TEXAS. FOR NOW... THE NORTHERN PART OF THE FLASH FLOOD WATCH ALSO
EXTENDS NORTH INTO BECKHAM AND WASHITA COUNTIES. ALTHOUGH THESE
AREAS WILL LIKELY NOT SEE THE HEAVIEST RAINS... WE HAVE INCLUDED
THEM BECAUSE OF EXCESSIVE ANTECEDENT RAINFALL... AND THUS A REDUCED
FLASH FLOOD THRESHOLD. KTLX RADAR APPEARS TO BE UNDERESTIMATING
RAINFALL AMOUNTS BY ABOUT A THIRD. WEAK WAVES MOVING THROUGH THE
SOUTHERN PLAINS TODAY WILL ALSO PROVIDE SOME FORCING... AS WILL THE
JUXTAPOSITION OF THE RIGHT REAR QUADRANT OF THE UPPER LEVEL JET
ACROSS THE AREA. RAIN CHANCES WILL REMAIN FAIRLY HIGH TONIGHT AND
MONDAY... BEFORE TAPERING OFF ON TUESDAY. WE CURRENTLY HAVE THURSDAY
DRY... BEFORE INCREASING AGAIN BY LATE IN THE WEEK AS ANOTHER FRONT
APPROACHES THE AREA. HOWEVER... THE LATEST RUN OF GFS80 IS SLOWING
DOWN PROGRESS OF THIS COLD FRONT COMPARED TO THE OTHER MODELS. AT
THIS POINT... WE WILL NOT MAKE ANY DRASTIC CHANGES IN TIMING OR POPS
UNTIL WE GET A LITTLE MORE CONSISTENCY IN THE TIMING OF THIS NEXT
SYSTEM.

THE CLOUDS AND PCPN WILL RESULT IN COOLER TEMPS TODAY... ALTHOUGH
LOCATIONS THAT SEE SOME SUN... MAINLY IN THE SOUTHEAST... COULD
JUMP UP SEVERAL DEGREES DURING THE AFTERNOON. TEMPS WILL WARM UP
AGAIN IN MOST AREAS BY MID WEEK.

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH UNTIL 6 PM SUNDAY FOR OKZ021-OKZ022-OKZ023-
     OKZ027-OKZ028-OKZ033-OKZ034-OKZ035-OKZ036-OKZ037-OKZ038-
     OKZ039-OKZ040-OKZ041-OKZ044-OKZ045-OKZ046-OKZ050.

TX...FLASH FLOOD WATCH UNTIL 6 PM SUNDAY FOR TXZ083-TXZ084-TXZ085-
     TXZ086-TXZ087-TXZ088-TXZ089-TXZ090.

&&

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HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1125 AM CDT SUN AUG 14 2005

OKZ004>048-050>052-TXZ083>090-151200-

THIS HAZARDOUS WEATHER OUTLOOK COVERS NORTHERN...WESTERN...
CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

THUNDERSTORM OUTLOOK...
THUNDERSTORMS ARE POSSIBLE... HOWEVER NO SEVERE THUNDERSTORMS ARE
EXPECTED THROUGH TONIGHT.

DISCUSSION...
ONGOING SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS MUCH OF CENTRAL
AND SOUTHERN OKLAHOMA... INTO WESTERN NORTH TEXAS... WILL CONTINUE
THROUGH THE DAY. A SERIES OF WEAK UPPER LEVEL STORM SYSTEMS MOVING
THROUGH THE AREA WILL PROVIDE SUPPORT FOR SHOWER AND THUNDERSTORM
DEVELOPMENT THROUGH TONIGHT...ESPECIALLY ACROSS THESE SAME AREAS.
THE AIRMASS REMAINS VERY MOIST... AND A WEAK COLD FRONT WILL
CONTINUE TO SAG VERY SLOWLY SOUTHEAST ACROSS CENTRAL AND SOUTHWEST
OKLAHOMA. DEEP-LAYER MOISTURE AND WEAK INSTABILITY...ALONG WITH
RELATIVELY LIGHT WINDS ALOFT...WILL MINIMIZE THE POTENTIAL FOR
SEVERE THUNDERSTORMS THROUGH TONIGHT.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT MONDAY AUG 15.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...10 PERCENT.

OTHER HAZARDOUS WEATHER...
A FLASH FLOOD WATCH REMAINS IN EFFECT TODAY FOR WESTERN NORTH TEXAS
AND MOST OF SOUTHWESTERN AND SOUTH CENTRAL OKLAHOMA. THE WATCH MAY
BE EXTENDED INTO TONIGHT... AND ALSO MAY BE EXPANDED INTO A LARGER
PART OF CENTRAL AND SOUTHEASTERN OKLAHOMA LATER THIS AFTERNOON.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY...

THUNDERSTORM OUTLOOK...
SCATTERED THUNDERSTORMS ARE EXPECTED MONDAY AND MONDAY NIGHT... WITH
AT LEAST SLIGHT CHANCES OF THUNDERSTORMS CONTINUING IN THE FORECAST
THROUGH WEDNESDAY... AND AGAIN ACROSS MAINLY NORTHERN OKLAHOMA
AROUND FRIDAY.

OTHER HAZARDOUS WEATHER...
THE POSSIBILITY OF LOCALLY HEAVY RAINFALL AND FLASH FLOODING MAY
CONTINUE INTO MONDAY.

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

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