AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 541 AM CST WED NOV 13 2013 .AVIATION...12Z TAF ISSUANCE... VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. BROAD AREA OF SFC HIGH PRESSURE WILL SHIFT E/SE THROUGH THE DAY. IN RESPONSE...SOUTH WINDS WILL INCREASE AT AREA AIRFIELDS THROUGH THE DAY. GUSTS OF 20 TO 25 KTS CAN BE EXPECTED FOR SITES ACROSS WRN OK THIS AFTERNOON. JTK && .PREV DISCUSSION... /ISSUED 413 AM CST WED NOV 13 2013/ DISCUSSION... PRIMARY FORECAST CONCERN WILL FOCUS ON PRECIP CHANCES AND ABOVE AVERAGE TEMPS THROUGH THE WEEKEND. CURRENTLY... THE CANADIAN SFC HIGH REMAINS POSITIONED ACROSS THE VAST MAJORITY OF THE CENTRAL AND ERN CONUS... FROM THE OHIO RIVER VALLEY WWRD THROUGH THE SRN PLAINS INTO SWRN TX. TEMPS CONTINUE TO BOTTOM OUT ACROSS THE REGION UNDER CLEAR SKIES AND CALM WINDS. THROUGH 3 AM...LOWS THIS MORNING HAVE DIPPED AS FAR AS THE UPPER TEENS TO LOWER 20S. TEMPS WILL LIKELY DROP 1 OR 2 DEGREES MORE OVER THE NEXT FEW HOURS BEFORE DAWN. TODAY... TEMPS WILL REBOUND SLIGHTLY AS THE SYNOPTIC PATTERN BEGINS TO TRANSITION. THE ERN TROUGH WILL CONTINUE TO SHIFT EWRD AS THE H500 LOW BEGINS TO LIFT ACROSS THE N. ATLANTIC AND THE WRN RIDGE BREAKS DOWN WITH THE DEVELOPMENT OF AN TROUGH OVER THE ROCKIES. ANALYSIS OF WV IMAGERY THIS MORNING SHOWS A WEAK FEATURE OVER ID AND WRN MT. WITH THE DEVELOPMENT/APPROACH OF THE H500 TROUGH... WINDS WILL INCREASE AND VEER TO THE SOUTH THROUGH THE AFTERNOON ACROSS THE SRN PLAINS AS THE SFC HIGH BEGINS TO EXIT ACROSS THE SERN U.S. TEMPS WILL STILL REMAIN COOL...AND BELOW AVG...WITH HIGHS THIS AFTN IN THE LOW 50S ACROSS MUCH OF CENTRAL OK... TO THE UPPER 50S ACROSS FAR WRN OK AND WRN N TX. FOR THE REMAINDER OF THE WEEK... MID-RANGE GUIDANCE REMAINS IN RELATIVE AGREEMENT... AS THE DEEPENING WRN TROUGH THROUGH THU MORNING MERGES WITH A WEAKER SRN STREAM H500 WAVE... THIS SHORTWAVE WILL LIFT E/NE ACROSS THE SRN PLAINS THU EVENING THROUGH FRI MORNING TRAVERSING THE LARGE SCALE WAVE. THE ECMWF REMAINS THE MORE AGGRESSIVE SOLUTION FOR QPF... FOCUSING DEVELOPMENT ACROSS ERN OK AND TX FRI MORNING. KEPT POPS LOW FOR THU NIGHT/FRI MORNING... AND ONLY ACROSS FAR SOUTH CENTRAL OK... AS MOISTURE RETURN THROUGH THE LOW- LEVELS WILL BE HAMPERED BY DRIER SWRLY FLOW ALOFT ACROSS WRN OK AND WRN N TX... AS INDICATED BY NAMBUFR PROFILES. FOR THE WEEKEND... BETTER RAIN CHANCES WILL EXIST. A STRONGER SHORT WAVE H500 TROUGH DIGGING ALONG THE FRONT RANGE OF THE SIERRA NEVADAS FRIDAY WILL LIFT ACROSS THE FOUR CORNERS REGION AND ACROSS THE SRN ROCKIES THROUGH SAT MORNING. IN RESPONSE... A DECENT COLORADO LOW WILL DEVELOP AND SWING A STRONG...FOR NOVEMBER... COLD FRONT ACROSS THE SRN PLAINS THROUGH SUNDAY MORNING. GOOD THETA E ADVECTION AHEAD OF THE FRONT WILL PROVIDE SUFFICIENT MOISTURE... ESPECIALLY ACROSS SRN AND ERN OK... WHERE THE BETTER RAIN CHANCES WILL EXIST. EXPECTING PRIMARILY JUST RAIN...ESPECIALLY DURING THE LATE FRI/EARLY SAT MORNING HOURS...HOWEVER ISOLATED THUNDER IS POSSIBLE SAT AFTN...SUPPORTED BY A NARROW RIBBON OF LOW-LEVEL INSTABILITY. OVERALL... AT THE MOMENT... BETTER COMBINATION OF INGREDIENTS FOR THUNDER WILL EXIST FARTHER EAST OF THE FORECAST AREA... ACROSS ERN OK/AR/SRN MO THROUGH SAT AFTN AND OVERNIGHT. OF POSSIBLY GREATER INTEREST... TEMPERATURES THROUGH THE WEEKEND WILL WARM CONSIDERABLY... WITH INCREASED CONFIDENCE IN ABOVE AVERAGE HIGHS FOR BOTH SAT AND SUN. DOWN-SLOPE FLOW OFF THE LLANO ESTACADO INTO THE SRN PLAINS THROUGH THE WEEKEND WILL RESULT IN HIGHS SAT IN THE 70S...AND WARMER ON SUN WITH UPPER 70S TO LOW 80S ACROSS WRN N TX AND MID TO UPPER 70S ACROSS CENTRAL AND WRN OK. SUNDAY ALSO LOOKS PARTICULARLY WINDY... WITH THE SFC PRESSURE GRADIENT TIGHTENING AHEAD OF THE H500 WAVE AS IT TRAVERSES THE PANHANDLES... AS WELL AS LOW LEVEL (0-1KM AGL) LAPSE RATES OF 8 TO 10 C/KM. OVERALL.. WILL HAVE TO KEEP AN EYE ON THE SYNOPTIC SETUP AS THE WEEKEND APPROACHES. AT THE MOMENT...THE ECMWF IS A BIT MORE BULLISH WITH THE STRENGTH OF THE H500 TROUGH...BUT WRT THE OVERARCHING PATTERN...THERE IS DECENT AGREEMENT BETWEEN THE LONG RANGE GUIDANCE. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 50 30 56 40 / 0 0 0 10 HOBART OK 49 30 57 37 / 0 0 0 0 WICHITA FALLS TX 51 30 60 40 / 0 0 10 10 GAGE OK 57 31 59 32 / 0 0 0 0 PONCA CITY OK 50 31 57 37 / 0 0 0 10 DURANT OK 51 30 57 44 / 0 0 0 20 &&
Posted on: Wed, 13 Nov 2013 12:21:57 +0000
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