268
FXUS63 KGID 072029
AFDGID
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
229 PM CST SAT NOV 7 2009
SHORT TERM
TONIGHT THROUGH SUNRISE TUESDAY. MAIN FOCUS IN THE
SHORT TERM WILL BE SMALL PRECIPITATION CHANCES LATE SUNDAY NIGHT
INTO MONDAY.
UPPER AIR ANALYSIS...WIND PROFILER DATA AND WATER VAPOR IMAGERY
CURRENTLY SHOWING ZONAL FLOW OVER THE NORTHERN HALF OF THE COUNTRY
WITH EMBEDDED WEAK SHORTWAVES. MAIN JET AXIS LOOKS TO BE ACROSS THE
NORTHERN PLAINS WITH 100+ KT 300 MB JET OVER NDAK. PROFILER CONFIRM
WITH 80KT FROM NW NEB TO SOUTHERN MN...WHILE FURTHER SOUTH WINDS
DROP OFF TO 30 KT OVER KS. AT THE SURFACE...MSAS DATA AND CURRENT
OBS SHOW HIGH PRESSURE HAS PUSHED INTO NORTHERN NEB WITH FRONT NOW
STRETCHING FROM OKLAHOMA PANHANDLE TO NORTHEAST KANSAS. DRIER AIR AT
SURFACE...DEWPOINT WAS 28 AT KGRI AT 18Z...HAS ALLOWED TEMPS TO
CLIMB INTO THE MID 60S DESPITE THE NORTHEAST FLOW. DRY AIR MASS
EXTENDS UPWARD WITH PRECIPITABLE WATER ONLY RUNNING AROUND A HALF AN
INCH AT PRESENT. WINDS WERE A LITTLE STRONGER THAN ANTICIPATED THIS
MORNING BUT HAVE DECREASED A BIT IN PAST COUPLE OF HOURS AS PRESSURE
GRADIENT RELAXES.
FIRST QUESTION IS WILL WE GET ANY LOW CLOUDS AND FOG OVERNIGHT.
BOTH NAM AND GFS TIME HEIGHT SECTIONS AND FORECAST SOUNDINGS
CONTINUE TO DEPICT A SHALLOW AREA OF LOW LEVEL MOISTURE WHICH POOLS
NORTH OF THE STALLED FRONTAL BOUNDARY OVERNIGHT. DEPTH IS LIMITED
BUT WITH LIGHT EAST FLOW COULD GET A BIT OF PATCHY TOWARDS
SUNRISE...ALTHOUGH NOT CONVINCED ENOUGH TO INSERT FOG WORDING INTO
FORECAST. LOOKS LIKE BOUNDARY TO THE SOUTH WILL LIFT NORTH INTO
SUNDAY AS A WARM FRONT. EXPECT SUNDAY TO BE DRY AS MOISTURE
CONTINUES TO BE LIMITED AND MID AND UPPER LEVEL FORCING LOOKS TO BE
BETTER WELL NORTH OF THE CWA.
A LITTLE BETTER CHANCE FOR RAIN LOOKS TO COME LATE SUNDAY INTO
MONDAY EVENING. BOTH THE GFS AND THE NAM HAVE DECENT MID LEVEL
SHORTWAVE CROSSING THE CWA. TIME HEIGHT FORECAST PLOTS SHOULD GOOD
OMEGA VALUES IN THE MID LEVELS AROUND NOON MONDAY ON THE NAM
ALTHOUGH THE GFS IS NOT QUITE SO ROBUST. NAM ALSO LACKING IN LOW
LEVEL MOISTURE SO MAY HAVE TROUBLE SATURATING DOWN ESPECIALLY IN THE
NORTHWEST PART OF THE CWA. GFS A LITTLE MORE GENEROUS WITH THE
MOISTURE BUT AS NOTED ABOVE...NOT AS GOOD WITH THE FORCING. AT THIS
POINT PLAN TO LEAVE ONGOING FORECAST PRETTY MUCH AS IS WITH BETTER
CHANCES IN THE SOUTHEAST ON MONDAY. THIS SYSTEM SHOULD MOVE THROUGH
QUICKLY AND EXPECT MAINLY DRY WEATHER OVERNIGHT MONDAY.
LONG TERM
12Z TUESDAY THROUGH SATURDAY. THE PRIMARY ISSUE IN THE
EXTENDED PERIOD WILL BE THE CHANCE OF RAIN TOWARDS THE END OF THE
WEEK. A QUIET START IS EXPECTED IN THE EXTENDED PERIOD WITH AN
UPPER RIDGE IN PLACE ON TUESDAY. THE UPPER FLOW THEN BECOME MORE
WEST/SOUTHWEST FOR WEDNESDAY AND THURSDAY AS A LARGE TROUGH MOVES
EAST ACROSS THE WESTERN UNITED STATES. THE RUN TO RUN CONSISTENCY
FROM THE GFS AND ECMWF HAS NOT BEEN VERY GOOD IN REGARDS TO THE
PROGRESSION OF THE WESTERN UNITED STATES TROUGH. THAT BEING
SAID...THE 12Z ECMWF AND GFS DO STILL SHOW THE PASSING OF A COLD
FRONT TOWARDS FRIDAY...AHEAD OF THE MAIN TROUGH WHICH IS EXPECTED
TO MOVE THROUGH ON SATURDAY. WILL KEEP IT DRY WEDNESDAY AND
THURSDAY...BUT KEEP A CHANCE OF SHOWERS FOR FRIDAY AS THE BOUNDARY
PASSES ACROSS THE REGION. HAVE ALSO PUT IN A CHANCE OF
RAIN/SHOWERS FOR SATURDAY WITH THE MAIN UPPER SYSTEM MOVING
THROUGH.
AVIATION
18Z KGRI TAF. VFR CONDITIONS EXPECTED THIS AFTERNOON
AND EVENING. WINDS SHOULD VEER FROM NORTHEAST TO EAST NORTHEAST THIS
AFTERNOON AS HIGH PRESSURE SLIDES ACROSS NORTHERN NEBRASKA. A FEW
HIGH CLOUDS MAY DRIFT IN FROM THE SOUTHWEST THIS EVENING. WILL
CONTINUE WITH THOUGHT PROCESS FROM PREVIOUS AVIATION ISSUANCE OF
SHALLOW LOW LEVEL MOISTURE POOLING NORTH OF THE SURFACE FRONT
OVERNIGHT WITH A FEW LOW CLOUDS AND PATCHY FOG POSSIBLE.
GID WATCHES/WARNINGS/ADVISORIES
NE...NONE.
KS...NONE.
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