FXUS63 KGID 112124
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
324 PM CST FRI DEC 11 2009

 .SHORT TERM...TONIGHT THROUGH 12Z SUNDAY. PRIMARY FORECAST
CONCERNS LIE WITH TEMPERATURES AND POTENTIAL FOR SOME LIGHT FREEZING
PRECIPITATION.

BEEN ANOTHER QUIET SUNNY DAY ACROSS THE CWA...WITH A GENERALLY ZONAL 
UPPER LEVEL PATTERN ACROSS THE REGION.  AT THE SURFACE...CWA REMAINS 
UNDER THE INFLUENCE OF A LARGE AREA OF HIGH PRESSURE WHICH SITS 
CENTERED OVER THE SOUTHEASTERN CONUS...BRINGING SOUTH/SOUTHEASTERLY 
WINDS.  PLENTY OF SNOW COVER KEEPING TEMPERATURES FROM DOING 
MUCH...AND ARE PRETTY SIMILAR TO YESTERDAY...IN THE UPPER TEENS TO 
MID 20S. 

MEASURABLE PRECIPITATION IS NOT EXPECTED THROUGH THE SHORT TERM 
PERIOD...BUT THERE IS THE POTENTIAL FOR SOME LIGHT FREEZING 
PRECIPITATION DURING THE DAY ON SATURDAY ACROSS PORTIONS OF THE 
CWA.  MODELS IN GOOD AGREEMENT KEEPING THINGS DRY DURING THE 
OVERNIGHT HOURS...BUT AS WE GET INTO THE DAYTIME HOURS...A WEAK MID 
LEVEL SHORTWAVE TROUGH SHIFTS EAST OUT OF THE ROCKIES AND RIGHT 
ACROSS THE CWA. AHEAD OF THIS TROUGH...LIFT INCREASES...AND
MOISTURE BEING PULLED IN FROM THE SOUTH TRIES TO SATURATE THE
LOWER LEVELS OF THE ATMOSPHERE. FORECAST SOUNDINGS SHOW A FAIRLY
SHALLOW LAYER OF MOISTURE...WITH PLENTY OF DRY AIR ABOVE AND SOME
TURB MIXING AVAILABLE...POINTING TOWARDS FREEZING DRIZZLE WITH
TEMPS REMAINING COLD. KEPT MENTION CONFINED TO THE EASTERN HALF
OR SO OF THE CWA...WHERE BEST COMBO OF LIFT/MOISTURE/MIXING LIES
AS BY MIDDAY THE TROUGH AXIS IS EXPECTED TO ALREADY BE IN THE CWA.
DEBATED TAKING MENTION OUT COMPLETELY...AS PAST FEW MODELS HAVE
BEEN TRENDING PRECIPITATION FURTHER EAST...BUT NOT CONFIDENT ENOUGH
TO REMOVE FROM THE EASTERN AREAS. DRIED THINGS OUT FOR SATURDAY
EVENING/NIGHT...WITH MODELS IN GOOD AGREEMENT PUSHING THE WAVE
EAST OF THE CWA.

TEMPERATURES REMAIN TRICKY WITH ALL THE SNOW...WITH HIGHS FOR 
SATURDAY FORECAST TO RANGE FROM THE MID 20S TO LOWER 30S.  LOWS 
EXPECTED TO REMAIN IN THE SINGLE DIGITS TO MID TEENS.

.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.
&&

$$