HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE NORMAN OK 601 AM CST FRI FEB 23 2007 OKZ004>048-050>052-TXZ083>090-231800- HARPER-WOODS-ALFALFA-GRANT-KAY-ELLIS-WOODWARD-MAJOR-GARFIELD-NOBLE- ROGER MILLS-DEWEY-CUSTER-BLAINE-KINGFISHER-LOGAN-PAYNE-BECKHAM- WASHITA-CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-CLEVELAND- POTTAWATOMIE-SEMINOLE-HUGHES-HARMON-GREER-KIOWA-JACKSON-TILLMAN- COMANCHE-STEPHENS-GARVIN-MURRAY-PONTOTOC-COAL-COTTON-JEFFERSON- CARTER-JOHNSTON-ATOKA-LOVE-MARSHALL-BRYAN-HARDEMAN-FOARD-WILBARGER- WICHITA-KNOX-BAYLOR-ARCHER-CLAY- 601 AM CST FRI FEB 23 2007 THIS HAZARDOUS WEATHER OUTLOOK COVERS NORTHERN...WESTERN... CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS. .DAY ONE...TODAY AND TONIGHT... THUNDERSTORM OUTLOOK... THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS LATE TODAY THROUGH TONIGHT ACROSS ALL OF WESTERN NORTH TEXAS AND WESTERN OKLAHOMA...AND MUCH OF CENTRAL OKLAHOMA. LOCATION... IN OKLAHOMA...THE MODERATE RISK AREA INCLUDES ALL OF THE REGION WEST OF A LINE FROM PONCA CITY TO STILLWATER...TO ADA...AND MARIETTA. TIMING... THE MOST LIKELY TIME FOR SEVERE THUNDERSTORMS WILL BE FROM 4 PM THROUGH 6 AM. RECOMMENDED ACTIONS... STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE RISK AREA SHOULD PLAN FOR SEVERE WEATHER OPERATIONS FROM 4 PM UNTIL 6 AM. DISCUSSION... A CLASSIC SEVERE WEATHER PATTERN WILL DEVELOP LATE TODAY...BUT THE DETAILS OF HOW THUNDERSTORMS WILL EVOLVE REMAINS SOMEWHAT UNCERTAIN. INITIALLY...A FEW ELEVATED MORNING AND EARLY AFTERNOON THUNDERSTORMS ARE POSSIBLE ALONG THE LEADING EDGE OF DEEPER MOISTURE. THESE EARLY STORMS WILL BE ISOLATED AND WEAK. BY AFTERNOON...THE MAIN FOCUS FOR THUNDERSTORM DEVELOPMENT WILL BE A DRYLINE SETTING UP NEAR THE WESTERN BORDER OF OKLAHOMA AND TO THE WEST OF QUANAH AND BENJAMIN IN TEXAS. INSTABILITY WILL INCREASE AND BECOME BASED CLOSER TO THE SURFACE...ESPECIALLY NEAR THE DRYLINE. IT IS LIKELY THAT AT LEAST A FEW STORMS WILL FORM BEFORE DARK...MAINLY IN NORTHWEST OKLAHOMA...FAVORED BY STRONGER LIFT...AND WESTERN NORTH TEXAS...FAVORED BY DEEPER MOISTURE. STORMS WILL MOVE NORTHEAST VERY QUICKLY. AFTER DARK...STORMS ARE EXPECTED TO EXPAND INTO WESTERN AND CENTRAL OKLAHOMA...AND INCREASE IN NUMBER. THE ABSENCE OF A STRONG CAP AND THE BROAD NATURE OF THE UPPER LEVEL LIFT SUGGESTS STORMS MAY REMAIN SCATTERED WELL INTO THE NIGHT. A SINGLE SQUALL LINE MAY NOT FORM DURING THIS EVENT...BUT STORM MERGERS WILL INCREASE AS THE NIGHT PROGRESSES. EACH STORM WILL BE LIKELY TO PRODUCE DAMAGING STRAIGHT LINE WINDS AND LARGE HAIL. THERE IS ALSO A THREAT FOR TORNADOES...ESPECIALLY AS STORMS ARE EXPECTED TO REMAIN DISCRETE. WITH INTENSE LOW LEVEL WIND SHEAR IN PLACE...PEOPLE SHOULD BE GUARDED AGAINST THE POSSIBILITY THAT IF TORNADOES OCCUR...SOME MAY BE STRONG. THE THREAT MAY BE MINIMIZED...HOWEVER...BY THE TIME OF DAY...MARGINAL INSTABILITY...AND MARGINAL LOW LEVEL MOISTURE. AS THESE PARAMETERS BECOME MORE OR LESS FAVORABLE FOR TORNADO DEVELOPMENT LATER TODAY...FORECASTS MAY BE ADJUSTED. THE DRYLINE WILL MOVE TO NEAR INTERSTATE 35 BY SUNRISE SATURDAY MORNING...ENDING THE SEVERE WEATHER THREAT OVER THE WESTERN HALF OF OKLAHOMA. PROBABILITY TABLE... VALID THROUGH 700 AM CST SATURDAY FEB 24. PROBABILITY OF THUNDERSTORMS OCCURRING IN THE NWS NORMAN COUNTY WARNING AREA...80 PERCENT. PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...60 PERCENT. OTHER HAZARDOUS WEATHER... SOUTH WINDS WILL AVERAGE 20 TO 25 MPH WITH GUSTS AROUND 35 MPH FOR MUCH OF TODAY. THIS MAY HAMPER OUTDOOR ACTIVITIES AND MAKE DRIVING DIFFICULT ON EAST TO WEST ROADS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY... THUNDERSTORM OUTLOOK... THUNDERSTORMS WILL LIKELY BE ONGOING EARLY SATURDAY MORNING NEAR AND EAST OF INTERSTATE 35 IN OKLAHOMA. DESPITE THE EARLY HOURS...A FEW STORMS MAY STILL BE SEVERE BEFORE MOVING QUICKLY INTO EASTERN OKLAHOMA AND SURROUNDING STATES. OTHER HAZARDOUS WEATHER... INTENSE LOW PRESSURE WILL CREATE STRONG WINDS THROUGHOUT THE REGION SATURDAY. THESE WINDS MAY BE STRONG ENOUGH TO DISPLACE OR DAMAGE LIGHT-WEIGHT OBJECTS...AND RESULT IN AREAS OF BLOWING DUST...AS WELL AS INCREASED WILDFIRE RISK. PLEASE REFER TO THE HIGH WIND WATCH AND THE FIRE WEATHER WATCH FOR MORE DETAILS. THE NEXT SCHEDULED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AT NOON TODAY. $$ BURKE/CJS