Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 290825 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 325 AM CDT FRI AUG 29 2014 .SHORT TERM...
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(TODAY THROUGH SUNDAY) ISSUED AT 325 AM CDT FRI AUG 29 2014 THE PRIMARY FORECAST CHALLENGES WILL BE IN REGARDS TO PCPN CHANCES TODAY INTO TONIGHT AND THEN TIMING THE NEXT ROUND OF CONVECTION SUNDAY INTO SUNDAY NIGHT. SOME SEVERE STORMS WILL BE POSSIBLE MAINLY FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING. MAIN FEATURES FROM THE UPPER AIR CHARTS LAST EVENING INCLUDED THE FOLLOWING. AT 300 MB A JET SEGMENT OF AROUND 70 KNOTS WAS PUNCHING NORTHEAST FROM SOUTHWEST KS. THIS WAS AHEAD OF A 500 MB TROUGH THAT STRETCHED FROM THE DAKOTAS DOWN INTO WEST TEXAS. 12 HOUR HEIGHT FALLS OF UP TO AROUND 40 METERS WERE NOTED AT AMARILLO AND DODGE CITY. DECENT MOISTURE WAS STILL IN PLACE AT 700 MB AND 850 MB AHEAD OF THE MID LEVEL TROUGH. THE KOAX SOUNDING WAS STILL FAIRLY MOIST WITH 1.70 PRECIPITABLE WATER. SURFACE ANALYSIS AT 08Z SHOWED LOW PRESSURE CENTERED OVER SOUTHEAST SOUTH DAKOTA AND A COLD FRONT EXTENDING SOUTHWARD FROM THE LOW INTO WEST TEXAS. DEWPOINTS WERE IN THE 60S TO LOWER 70S. WATER VAPOR LOOP EARLY THIS MORNING SHOWED THAT THE TROUGH TO OUR WEST HAD MADE SOME EASTWARD PROGRESS SINCE LAST EVENING. IT SHOULD CONTINUE TO HAVE AN IMPACT ON US UNTIL A LITTLE AFTER MIDNIGHT TONIGHT. KEPT FAIRLY HIGH POPS GOING TODAY...SINCE WE SHOULD SEE REDEVELOPMENT THIS AFTERNOON WITH DAYTIME HEATING. FORECAST SOUNDINGS FROM THE 00Z NAM INDICATED ELEVATED INSTABILITY OF OVER 2000 J/KG BY AROUND NOON. RECENT RUNS OF THE RAP MODEL SHOW AN INCREASE IN PCPN COVERAGE AFTER 1 PM. HIGHS WILL BE MAINLY IN THE UPPER 70S AND LOWER 80S. LOWS TONIGHT SHOULD DROP TO THE LOWER AND MID 60S AS DRIER AIR WORKS ITS WAY IN FROM THE NORTHWEST BEHIND THE COLD FRONT. SOME PATCHY FOG COULD DEVELOP LATE TONIGHT...BUT OVERALL THE ATMOSPHERE WILL BE DRYING OUT. SATURDAY LOOKS LIKE A DECENT DAY WITH A FAIR AMOUNT OF SUNSHINE AND HIGHS IN THE 80S. CLOUDS WILL START TO INCREASE SATURDAY NIGHT... ESPECIALLY IN OUR FAR WESTERN ZONES. KEPT A SMALL CHANCE OF LATE NIGHT TSTMS IN NORTHEAST NEBRASKA. MODELS HAVE SOME TIMING DIFFERENCES FOR SUNDAY INTO SUNDAY NIGHT. KEPT SOME LOW POPS LATE SATURDAY NIGHT WEST OF A LINE FROM WAYNE TO COLUMBUS. 00Z RUNS OF THE NAM AND CANADIAN MODEL WERE A BIT SLOWER WITH DEVELOPMENT OF STORMS SUNDAY AFTERNOON. FOR NOW...BLENDED IN SOME OF THE GFS AND ECMWF WHICH SHOW SOME RAINFALL AMOUNTS OVER A QUARTER OF AN INCH SUNDAY AFTERNOON. IF THE NAM IS MORE CORRECT... THE SEVERE WEATHER POTENTIAL IS PROBABLY HIGHER SUNDAY EVENING THAN IF THE GFS AND ECMWF VERIFY BETTER. LOOK FOR HIGHS MAINLY IN THE 80S AND MAYBE NEAR 90 FOR PARTS OF SOUTHEAST NEBRASKA. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 325 AM CDT FRI AUG 29 2014 TRENDED POPS DOWNWARD SUNDAY NIGHT FROM NORTHWEST TO SOUTHEAST AS THE SYSTEM MOVES THROUGH...BUT LINGERED A SLIGHT CHANCE OF TSTMS INTO MONDAY MORNING. A 500 MB LONGWAVE TROUGH AXIS WILL BE LOCATED OVER THE EASTERN ROCKIES AND WESTERN HIGH PLAINS AT THE BEGINNING OF THIS PERIOD. BY TUESDAY...THAT SHIFTS EAST OF OUR AREA AND THEN THE FLOW IS FAIRLY ZONAL ACROSS MID AMERICA INTO WEDNESDAY. LATER IN THE WEEK ANOTHER TROUGH WILL DIG INTO THE PACIFIC NORTHWEST...WITH OUR AREA UNDER THE INFLUENCE OF SOUTHWEST MID LEVEL FLOW. ALTHOUGH THUNDERSTORM CHANCES WILL NOT BE COMPLETELY ABSENT...NEXT WEEK SHOULD BE A LOT DRIER THAN THIS WEEK HAS BEEN. HIGHS WILL MODERATE FROM MAINLY 80S TO AROUND 90 AND LOWS WILL INCREASE FROM 60S TO AROUND 70 OR THE LOWER 70S.
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&& .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1137 PM CDT THU AUG 28 2014 CONVECTION AROUND OR DEVELOPING IN THE AREA WILL AFFECT KOFK THROUGH ABOUT 08Z...KLNK THROUGH ABOUT 10Z...AND KOMA 08-12Z. OTHERWISE...VFR CONDITIONS EARLY IN THE PERIOD...BUT COULD SEE TEMPORARY MVFR CONDITIONS AT ALL THREE TAF SITES 10-15Z...WITH TEMPORARY IFR CONDITIONS POSSIBLE AT KOFK. COULD ALSO SEE AN ADDITIONAL 30 PERCENT CHANCE OF OF SHOWERS/THUNDERSTORMS AT KLNK/KOMA 16-22Z. WEAK WIND SHIFT FROM SOUTHEAST TO NORTHWEST THROUGH THE PERIOD AS WELL. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...DEWALD

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