FXUS63 KGID 120108 AAA
AFDGID

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HASTINGS NE
708 PM CST FRI DEC 11 2009

.AVIATION...00Z KGRI TAF. HIGH PRESSURE WILL BE IN CONTROL TO KICK
OFF THE FORECAST WITH ONLY SOME HIGH-LEVEL CLOUDINESS EXPECTED.
EARLY TOMORROW...HOWEVER...MOISTURE ADVECTION COULD HELP TO REDUCE
VISIBILITY SOMEWHAT AND BY SATURDAY AFTERNOON...WE STAND A CHANCE
OF MVFR CEILINGS/VISIBILITY. THE TERMINAL WOULD BE ON THE EXTREME
WESTERN EDGE OF THESE POTENTIAL MVFR CONDITIONS. PROGGED SOUNDINGS
INDICATE SHALLOW MOISTURE WITH AN INVERTED WIND PROFILE IN LOW-
LEVELS...WITH AN ELEVATED DRY LAYER. THERE MAY BE ENOUGH BOUNDARY
LAYER MOISTURE AND LOW-LEVEL TURBULENCE TO CAUSE FREEZING DRIZZLE
TO OCCUR BY SATURDAY AFTERNOON TO THE EAST OF THE TERMINAL...BUT
FOR NOW LOOKS LIKE IT WOULD REMAIN JUST TO THE EAST. 

&&

.PREV DISCUSSION... /ISSUED 324 PM CST FRI DEC 11 2009/ 

LONG TERM...12Z SUNDAY THROUGH FRIDAY.  A SERIES OF UPPER WAVES 
WILL MOVE ACROSS THE REGION IN THE FIRST PART OF THE LONG TERM
PERIOD. THIS WILL ALSO BRING ACROSS SURGES OF COLDER AIR...WITH
PARTS OF THE NORTHERN FORECAST AREA ALREADY GETTING A COLDER SHOT
OF AIR ON SUNDAY. ANOTHER WAVE ALLOWS EVEN COLDER AIR TO DROP
SOUTH ON MONDAY...AND THINK THAT MANY LOCATIONS MAY STRUGGLE TO
CLIMB OUT OF THE TEENS. ANOTHER POTENTIAL CONCERN FOR SUNDAY NIGHT
INTO MONDAY IS STRATUS/FOG AND POTENTIALLY FREEZING DRIZZLE. THE
12Z NAM IS SHOWING A DEEPER LAYER OF LOW LEVEL SATURATION THAN THE
12Z GFS...BUT THE GFS DOES ALSO CATCH ONTO THE IDEA OF POTENTIAL
STRATUS FOR SUNDAY NIGHT INTO EARLY MONDAY. IF THE NAM IS
CORRECT...THERE COULD ALSO BE SOME FOG OR PATCHY FREEZING
DRIZZLE...BUT WITH ENOUGH UNCERTAINTY IN THAT SCENARIO DID NOT PUT
IT INTO THE GRIDS YET.

THE COLD AIR REMAINS IN PLACE ON TUESDAY...HOWEVER A RIDGE ACROSS 
THE WESTERN UNITED STATES THEN BEGINS TO BUILD EAST TOWARDS THE 
MIDDLE OF NEXT WEEK.  THIS ALLOWS HEIGHTS TO RISE ACROSS THE CENTRAL 
PLAINS AND ALSO BRINGS IN WARMER AIR.  IT TOUGH TO SAY HOW MUCH ANY 
REMAINING SNOW ON THE GROUND MAY IMPACT TEMPERATURES AT THAT 
POINT..BUT IT DOES APPEAR THAT HIGHS HAVE A GOOD CHANCE OF REACHING 
THE MID 30S TO LOWER 40S LATE NEXT WEEK.

AVIATION...18Z KGRI TAF. CLEAR...VFR FLIGHT CONDITIONS
ANTICIPATED THROUGH AT LEAST THE FIRST 12-18 HOURS OF THE
PERIOD...AS EXPANSIVE SURFACE HIGH PRESSURE CENTERED OVER THE
EASTERN UNITED STATES REMAINS THE DOMINANT INFLUENCE. AS LOW LEVEL
MOISTURE INCREASES OVERNIGHT AND INTO SATURDAY MORNING...THERE IS
SOME CONCERN FOR FOG OR IFR/MVFR STRATUS DEVELOPMENT. HOWEVER...THIS
MOISTURE IS VERY SHALLOW AND THE FOG/STRATUS POSSIBILITY APPEARS
TO BE A SOMEWHAT GREATER THREAT OVER EASTERN NEBRASKA VERSUS SOUTH
CENTRAL AREAS. FOR THESE REASONS...ALONG WITH NUMERICAL GUIDANCE 
THAT IS NOT IN GREAT AGREEMENT AT THIS TIME...DECIDED TO KEEP THE
FORECAST VFR FOR NOW BUT HINT AT THE POSSIBILITY OF WORSE
CONDITIONS BY INCLUDING A SCATTERED LOW CLOUD MENTION. LATER
FORECASTS MAY ULTIMATELY HAVE TO INSERT AN MVFR/IFR MENTION BUT
CONFIDENCE IS TOO LOW FOR NOW. WINDS WILL REMAIN LIGHT AND
SOUTHERLY THROUGH THE PERIOD...AT 10 KTS OR LESS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

AVIATION...HEINLEIN