Severe Thunderstorm Warning 677, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
1115 AM CST MON DEC  6 2004

STRONG FORCING ASSOCIATED WITH THE UPPER LEVEL STORM SYSTEM MOVING
EAST FROM NEW MEXICO IS RESULTING IN AN INCREASE OF SHOWERS AND
T-STORMS OVER WESTERN TEXAS AT LATE MORNING. INCREASING WARM
ADVECTION AND MOISTURE ADVECTION OVER NORTH TEXAS HAS ALSO AIDED IN
DEVELOPMENT OF SHOWERS AND T-STORMS OVER NORTH TEXAS. ALL OF THIS
ACTIVITY WILL CONTINUE TO SPREAD NORTH AND EAST INTO THE FA THROUGH
THE AFTERNOON. ALTHOUGH WIDESPREAD CLOUD COVER AND COOL AIR AT THE
SURFACE WILL LIMIT SUFACE BASED INSTABILITIES... COLD TEMPS ALOFT
MOVING IN WITH THE UPPER SYSTEM WILL LIKELY RESULT IN SUFFICIENTLY
STEEP LAPSE RATES TO SUPPORT DECENT MID LEVEL INSTABILITIES. COULD
SEE SOME HAIL OVER ABOUT THE SOUTHEAST HALF OF THE AREA... WITH
POSSIBLY SOME STRONG WINDS MAKING IT TO THE GROUND IN SOUTHEAST
OKLAHOMA. FOG HAS BEEN GRADUALLY LIFTING OVER THE SOUTHEAST AND FAR
NORTH THORUGH THE LATE MORNING HOURS. COOLED TEMPS A BIT IN FAR
NORTHWEST OKLAHOMA WHERE STATIONARY FRONT HAS BEEN HANGING OUT AND
SLOWING THE WARM UP.

&&

32

347 AM CST MON DEC  6 2004

.DISCUSSION...
MODEL CONSISTENCY HAS LED TO RELATIVELY FEW CHANGES IN THIS FORECAST
PACKAGE.

THE MAIN EVENT WILL BE THE UPPER WAVE THAT WILL AFFECT THE REGION
TODAY AND THIS EVENING.  WIDESPREAD RAIN... WITH FAIRLY HIGH
RAINFALL AMOUNTS... IS LIKELY ACROSS ALL BUT THE NORTHWEST EDGE OF
OUR FORECAST AREA.  SCATTERED THUNDERSTORMS WILL PROBABLY FIRE
ACROSS MUCH OF THE AREA AS WELL... AND A FEW MAY BE SEVERE OVER OUR
SOUTHEASTERN COUNTIES.

AS THE WAVE HEADS OFF TO THE NORTHEAST TONIGHT... GENERAL CLEARING
CONDITIONS ARE EXPECTED... FOLLOWED BY A RELATIVELY TRANQUIL AND
WARM PERIOD.  POPS ON WEDNESDAY AND VICINITY WERE LOWERED OR REMOVED
AS THE NEXT SYSTEM WILL BE HARD-PRESSED TO FIND SUFFICIENT MOISTURE
TO GENERATE SIGNIFICANT PRECIPITATION.

THE GFSLR BRINGS IN A NOTEWORTHY COLD FRONT LATE NEXT WEEKEND...
WHICH CURRENTLY APPEARS TO HAVE THE EFFECT OF LOWERING TEMPERATURES
BACK DOWN TO SEASONAL NORMS.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  60  39  56  36 /  80  20   0   0
HOBART OK         60  38  56  36 /  70  10   0   0
WICHITA FALLS TX  63  41  59  37 /  80  10   0   0
GAGE OK           54  30  55  32 /  40  10   0   0
PONCA CITY OK     57  34  54  33 /  60  40   0   0
DURANT OK         65  47  61  38 /  80  10   0   0

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.

&&

23 = CMS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1155 AM CST MON DEC 6 2004

OKZ004>048-050>052-TXZ083>090-071300-

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

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

THUNDERSTORM OUTLOOK...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING ACROSS PORTIONS OF OKLAHOMA AND WESTERN NORTH TEXAS.

LOCATION...
THE SLIGHT RISK COVERS MUCH OF SOUTHERN OKLAHOMA AND WESTERN NORTH
TEXAS...MAINLY SOUTH AND EAST OF A LINE EXTENDING FROM NEAR
CHANDLER... TO OKLAHOMA CITY... TO HOLLIS.

TIMING...
THE MOST LIKELY TIME FOR SEVERE THUNDERSTORMS WILL BE DURING THE
AFTERNOON AND EVENING HOURS.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE
RISK AREA SHOULD PLAN FOR SEVERE WEATHER OPERATIONS THIS AFTERNOON
AND EVENING.

DISCUSSION...
A STRONG UPPER LEVEL STORM SYSTEM OVER SOUTHERN NEW MEXICO AT MIDDAY
WILL MOVE QUICKLY EASTWARD THIS AFTERNOON AND TONIGHT. AS THE STORM
SYSTEM APPROACHES... THUNDERSTORMS WILL INCREASE ACROSS THE SOUTHERN
PLAINS. THUNDERSTORMS... WHICH WERE BEGINNING TO MOVE INTO WESTERN
NORTH TEXAS AND SOUTHWEST OKLAHOMA... WILL CONTINUE TO MOVE EAST
THROUGH THE RED RIVER VALLEY. LARGE AREA OF RAIN AND EMBEDDED
THUNDERSTORMS WILL ALSO CONTINUE TO SPREAD FROM NORTHERN TEXAS
THROUGH SOUTHERN OKLAHOMA DURING THE AFTERNOON.

EXTENSIVE CLOUD COVER AND RELATIVELY COOL AIR WILL TEND TO LIMIT THE
AMOUNT OF INSTABILITY THAT WILL BE AVAILABLE FOR THE THUNDERSTORMS.
HOWEVER... EVEN THROUGH THE INSTABILITY MAY REMAIN LIMITED... STRONG
DEEP LAYER WIND SHEAR WILL PROVIDE CONDITIONS FAVORABLE FOR A FEW
STORMS TO REACH SEVERE LEVELS OVER THE SLIGHT RISK AREA THIS
AFTERNOON THROUGH EARLY EVENING. ALTHOUGH THE PRIMARY SEVERE WEATHER
CONCERN WILL BE LARGE HAIL... THE COOL... STABLE AIR AT LOW LEVELS
OVER SOUTH CENTRAL AND SOUTHEAST OKLAHOMA MAY BECOME SHALLOW ENOUGH
TO ALLOW SOME STRONG WINDS TO ALSO REACH GROUND LEVEL IN THOSE AREAS.

THE RISK OF SEVERE WEATHER WILL SUBSIDE OVER SOUTHEAST OKLAHOMA BY
MID TO LATE EVENING AS THE UPPER AIR STORM SYSTEM QUICKLY EXITS THE
AREA.

PROBABILITY TABLE...
VALID THROUGH 700 AM CST TUESDAY DEC 7.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...80 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...30 PERCENT.

OTHER HAZARDOUS WEATHER...
NONE

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

THUNDERSTORM OUTLOOK...
NO THUNDERSTORMS ARE FORECAST.

OTHER HAZARDOUS WEATHER...
NONE.

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

CJS