FXUS63 KGID 010525
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1125 PM CST MON NOV 30 2009
.AVIATION...06Z TAF. VFR CONDITIONS ARE FORECAST...BUT THERE
ARE CHANGES LATE IN THE FORECAST AS A COLD FRONT PLOWS THROUGH
THE AREA. THE FRONT WILL BRING STRONG NORTHWEST WINDS OF
18 TO 25 KTS WITH STRONG PRESSURE RISES AND TIGHTENING GRADIENT.
THOSE WINDS WILL HOLD ON THROUGH THE EVENING. DOESN/T APPEAR TO
BE ANY LOW CLOUDS OR VISIBILITY RESTRICTIONS WITH THE FRONTAL
PASSAGE...AT LEAST THROUGH THIS FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 515 PM CST MON NOV 30 2009/
AVIATION...00Z TAF. VFR CONDITIONS ARE FORECAST FOR KGRI
THROUGH THE PERIOD. ONE THING TO MENTION WILL BE A SHARP
COLD FRONT MOVING THROUGH AROUND 18Z TUESDAY...WHICH WILL
SWITCH WINDS TO THE NORTHWEST AND INCREASE SPEEDS ABOVE
15KTS WITH GUSTS OVER 20KTS. ONLY MID/HIGH CLOUDS ARE
EXPECTED WITH THE FRONTAL PASSAGE.
PREV DISCUSSION... /ISSUED 232 PM CST MON NOV 30 2009/
SHORT TERM...THROUGH 12Z WEDNESDAY. CHARACTERISTIC OF THE MONTH AS
A WHOLE...THE FINAL DAY OF NOVEMBER HAS BEEN A MILD ONE ACROSS
THE REGION. COMBINATION OF WEST/SOUTHWEST DOWN-SLOPE WINDS BETWEEN
SOUTHERN PLAINS SURFACE HIGH AND DEEPENING LEE TROUGH OVER THE
CENTRAL HIGH PLAINS...STEADY WAA THROUGH THE DAY...AND FULL
SUNSHINE HAS ALLOWED TEMPERATURES TO CLIMB WELL INTO THE 50S THIS
AFTERNOON. TAKING A LOOK AT THE BIGGER PICTURE...AFTERNOON WATER
VAPOR IMAGERY SHOWED THE REGION UNDER A NORTHWEST FLOW ALOFT. A
SOUTHERN STREAM CLOSED LOW WAS LOCATED SOUTH OF AZ OVER MEXICO...
WHILE A NORTHERN STREAM TROUGH EXTENDED SOUTH FROM THE HUDSON BAY LOW
THROUGH THE TN VALLEY.
QUIET CONDITIONS WILL PERSIST ACROSS THE AREA OVERNIGHT. WINDS WILL
REMAIN OUT OF THE SOUTHWEST THROUGH THE NIGHT...AND COMBINE WITH
THE MILD AIRMASS IN PLACE TO KEEP LOWS ABOVE AVERAGE DESPITE
CLEAR SKIES. THE SOUTHERN PLAINS LOW WILL SLOWLY ADVANCE EAST
TONIGHT AND TOMORROW...REACHING SOUTHWEST TX BY 00Z WEDNESDAY.
MEANWHILE...A SHORTWAVE CURRENTLY OVER BRITISH COLUMBIA/ALBERTA
WILL CONTINUE TO DIG SOUTHEAST THROUGH THE NORTHERN ROCKIES AND
NORTHERN PLAINS. THIS WAVE WILL SEND A COLD FRONT SOUTH THROUGH
THE CWA TOMORROW...BRINGING AN END TO THE RECENT STRETCH OF MILD
WEATHER. HOWEVER...WE SHOULD BE ABLE TO SQUEEZE OUT ONE MORE
DECENT DAY TOMORROW BEFORE THE COLD SETS IN BY WEDNESDAY. MODELS
HAVE COME INTO PRETTY GOOD AGREEMENT ON THE FRONTAL
TIMING...BRINGING THE FRONT INTO THE NORTHWEST CWA BETWEEN 12 AND
15Z...WITH THE FRONT BISECTING THE CWA FROM NORTHEAST TO SOUTHWEST
BY 18Z...AND PUSHING SOUTH OF THE CWA BY 00Z. H85 TEMPS START OFF
WARM IN THE MORNING AT AROUND +10C...BUT FALL TO -2C NORTH TO
+3-5C SOUTH BY 00Z WEDNESDAY THANKS TO SOLID CAA ON NORTH WINDS.
GIVEN THE MILD START AND ENHANCED MIXING WITH THE FRONT COMING
THROUGH...WILL AIM HIGHS FROM NEAR 50F NORTHWEST TO THE UPPER 50S
SOUTHEAST. A DRY AIRMASS WILL PRECLUDE ANY PRECIP FROM OCCURRING
WITH THE FRONTAL PASSAGE. MAINLY MID AND HIGH CLOUDS WILL INCREASE
LATER TUESDAY INTO TUESDAY NIGHT AS NORTHERN STREAM WAVE AND
SOUTHERN STREAM LOW IMPINGE ON THE AREA TO SOME DEGREE.
HOWEVER...THE UPPER FORCING REMAINS FAR ENOUGH REMOVED /COMBINED
WITH THE LACK OF MOISTURE TO WORK WITH/ TO HOLD ANY PRECIP CHANCES
AT BAY.
LONG TERM...THE PRIMARY ISSUE IN THE LONG TERM WILL BE
TEMPERATURES. THE START OF THE EXTENDED PERIOD WILL START WITH A
LARGE UPPER TROUGH ACROSS THE CENTRAL AND NORTHERN PLAINS. THIS
WILL REMAIN IN PLACE THROUGH THE END OF THE WEEK...ALLOWING MUCH
COLDER AIR TO DROP INTO THE REGION. PRECIPITATION CHANCES INTO THE
WEEKEND LOOK MINIMAL...HOWEVER THERE COULD BE A FEW FLURRIES
WEDNESDAY NIGHT INTO THURSDAY NIGHT AS DENDRITIC MOISTURE
INCREASES. THE PERIOD OF BETTER/DEEPER MOISTURE APPEARS TO BE ON
THURSDAY...SO WILL PUT IN A FEW FLURRIES FOR THAT TIME.
UPPER HEIGHTS RISE A BIT FOR SATURDAY WHICH MAY IN TURN ALLOW
TEMPERATURES TO WARM A FEW DEGREES ON SATURDAY...HOWEVER ANOTHER
WAVE BRINGS A REINFORCING SHOT OF COLD AIR AGAIN BY SUNDAY. THE
COLD AIR THEN REMAINS IN PLACE EARLY NEXT WEEK. QUESTIONS ARISE
LATE IN THE PERIOD WITH SOME MODEL SOLUTIONS SHOWING THE
POSSIBILITY OF A PRECIPITATION EVENT TOWARDS MONDAY. THUS FAR
THERE HAS NOT BEEN VERY GOOD AGREEMENT/CONTINUITY IN THE MODEL
SOLUTIONS FOR THAT PERIOD SO HAVE LEFT IT DRY...BUT ITS SOMETHING
TO WATCH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$