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000 FXUS64 KOUN 230442 AFDOUN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 1042 PM CST SUN NOV 22 2009 .AVIATION... ISOLATED AREAS OF FOG WERE BEGINNING TO DEVELOP SUN EVENING WITH LIFR CONDITIONS IN SW OK AT KLAW AND MVFR IN CENTRAL OK AT KOKC AND KOUN. EXPECT THE FOG AND LOCAL IFR CEILINGS TO GRADUALLY INCREASE OVERNIGHT. HOWEVER... DRIER CONDITIONS IN NW OK... BEHIND A WEAK SURFACE TROUGH THAT MOVED THROUGH THAT AREA ON SUNDAY... WILL LIKELY LIMIT THE FOG POTENTIAL IN THAT AREA. ANY LOW CLOUDS AND FOG THAT DO FORM OVERNIGHT SHOULD LIFT BY MID TO LATE MONDAY MORNING. MEANWHILE... A COLD FRONT MOVING INTO NW OK LATE MONDAY AFTERNOON... AND THROUGH REMAINING TERMINALS BY 06Z... WILL USHER IN BRISK NW WINDS. && .PREV DISCUSSION... /ISSUED 950 PM CST SUN NOV 22 2009/ UPDATE... A FEW AREAS OF FOG HAVE DEVELOPED SOUTHWEST /KLAW AND KAXS CURRENTLY/ WITH VSBYS 1 TO 2SM ALTHOUGH HAS NOT BEEN PERSISTENT YET. BUT WITH LIGHT WINDS AND LOW LEVEL RH CLIMBING THROUGH THE NIGHT WILL MAINTAIN THE MENTION OF FOG IN THE PACKAGE THIS EVENING. MAIN MODIFICATION TO THE FORECAST IS EVENING CLOUD COVER WHERE SKIES HAVE CLEARED ACROSS ALMOST ALL OF THE AREA... ALTHOUGH DO EXPECT CLOUDS TO INCREASE OVERNIGHT. PREV DISCUSSION... /ISSUED 512 PM CST SUN NOV 22 2009/ AVIATION... A WEAK SURFACE TROUGH THAT MOVED THROUGH NORTHWEST OKLAHOMA ON SUNDAY WILL GRADUALLY WASH OUT OVERNIGHT. MEANWHILE... THE LINGERING PRESENCE OF LOW LEVEL MOISTURE EAST OF THE TROUGH COULD RESULT IN AREAS OF STRATUS DEVELOPING AROUND 1 KFT AGL" onClick="return popup(this, 'notes')">AGL... WITH AREAS OF FOG AOB 3 MI... LATE TONIGHT ACROSS CENTRAL AND SW OK INTO N-TX. THE CLOUDS AND FOG WILL LIFT BY MID TO LATE MONDAY MORNING. A COLD FRONT WILL BEGIN TO AFFECT THE NW OK TERMINALS BY LATE IN THE FORECAST PERIOD. PREV DISCUSSION... /ISSUED 250 PM CST SUN NOV 22 2009/ DISCUSSION... CONVERGENCE ZONES AHEAD OF WEAKENING FRONT ALLOWING THE PERSISTENT STRATUS THIS AFTERNOON...FROM AROUND SPS/LAW/DUC NORTHWARD TO JUST WEST OF OKC. STRATOCU BEHIND FRONT CONFINED TO FAR NORTHWEST OKLAHOMA NEAR AND NORTH OF WWR. STILL THINK THIS CLOUD COVER WILL ERODE LATE THIS AFTERNOON...BUT THIS SAME ZONE WILL BE UP FOR MORE STRATUS AND/OR DENSE FOG TONIGHT AND EARLY MONDAY MORNING. RELATIVE MOIST AXIS DOESN`T MOVE MUCH AND LOWER LEVEL FLOW BECOMES WEAK TONIGHT...SO ALMOST A REPEAT OF THIS MORNING POSSIBLE. WE WILL MENTION DENSE FOG WILL WE THINK CHANCES ARE HIGHEST...AND EVENING SHIFT CAN MONITOR FOR POSSIBLE DENSE FOG ADVISORY. MORE SUBSTANTIAL FRONT PROGD TO PASS THROUGH REGION TOMORROW AFTERNOON AND EVENING...WHICH WILL HELP ERODE THE PERSISTENT MOIST AXIS THAT HAS BEEN NEARLY STATIONARY THE PAST FEW DAYS. SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT ACROSS MAINLY FAR NORTH-CENTRAL DOWN INTO SOUTHEAST PARTS OF FORECAST AREA TOMORROW EVENING/NIGHT. SOME WRAP AROUND CLOUDS POSSIBLE OVER NORTH-CENTRAL OKLAHOMA ON TUESDAY...BUT REGION WIDE...IT IS EXPECTED TO BE A COOLER AND BREEZY DAY. REINFORCING SHOT OF COOLER AIR STILL LOOKS LIKELY ON THURSDAY...WITH FAVORABLE MID-UPPER LEVEL FLOW. STILL THINK AIR WILL BE COOLER THAN PROGD...BUT WILL NOT GET TOO DRASTIC. MEX NUMBERS LOOK REASONABLE...BUT IF WE GET SOME STRATOCU...IT WOULD BE A RAW DAY ON THURSDAY. THIS REINFORCING SHOT SHOULD BE DRY. MEDIUM RANGE MODELS DIVERGE SIGNIFICANTLY THIS COMING WEEKEND. THE GFS STAYS MORE PROGRESSIVE...WHILE THE ECMWF CUTS OFF AND INTENSIFIES SOUTHWEST U.S. SYSTEM. IF ECMWF VERIFIES...WE COULD BE LOOKING AT HIGH PROBABILITIES FOR RAIN SUNDAY INTO EARLY PART OF NEXT WEEK. AIRMASS INTRODUCED AHEAD OF SYSTEM DOESN`T LOOK ALL THAT COLD...BUT GIVEN TIME OF YEAR AND POSSIBLE DRY SURFACE AIR...A MIX WOULD BE ON THE TABLE. HOWEVER...STRONG SUPPORT OF GFS ENSEMBLES IN ITS MORE PROGRESSIVE PATTERN WILL ALLOW US TO STICK TO CURRENT FORECAST TREND. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 43 63 42 58 / 0 10 10 10 HOBART OK 40 65 36 60 / 0 0 10 0 WICHITA FALLS TX 41 75 40 64 / 0 0 10 0 GAGE OK 31 60 30 58 / 0 0 0 0 PONCA CITY OK 43 61 38 55 / 0 10 30 10 DURANT OK 46 67 45 63 / 0 0 30 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 26/11/32