FXUS63 KGID 150435
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1035 PM CST MON DEC 14 2009

.AVIATION...06Z KGR TAF. SURFACE HIGH PRESSURE IS IN CONTROL. SOME
MID-LEVEL CLOUDS MAY PASS OVERHEAD FROM TIME TO TIME
OVERNIGHT...AND THEN SOME CIRRUS...ESPECIALLY TOWARD TUESDAY
EVENING...BUT NO HUGE CONCERN. LIGHT WIND WILL EVENTUALLY BACK
FROM WEST TO A MORE SOUTH SOUTHWEST COMPONENT WITH TIME.

&&

.PREV DISCUSSION... /ISSUED 510 PM CST MON DEC 14 2009/ 

AVIATION...00Z KGRI TAF. ANY LEFT OVER CUMULUS SHOULD
DISSIPATE/MOVE OUT OF THE AREA WITH SURFACE HIGH PRESSURE MOVING
IN AND WIDESPREAD SUBSIDENCE EXPECTED FOR THIS FORECAST. VFR
CONDITIONS SHOULD EASILY PREVAIL. 

PREV DISCUSSION... /ISSUED 413 PM CST MON DEC 14 2009/ 

SHORT TERM...TONIGHT THROUGH 12Z WEDNESDAY. THE MAIN ISSUE DURING
THIS PERIOD WILL BE WIND CHILLS TONIGHT...WHICH COULD EASILY FLIRT
WITH ADVISORY CRITERIA IN SOME SPOTS.

MID AFTERNOON OBJECTIVE SURFACE ANALYSIS INDICATES AN EXPANSIVE
HIGH PRESSURE RIDGE EXTENDING SOUTHWARD ACROSS THE CENTRAL PLAINS
OUT OF SOUTHWEST CANADA...WITH PRESSURE VALUES UP TO 1028 MB OVER
CENTRAL NEBRASKA. ALOFT...A NEARLY ZONAL FLOW WAS IN PLACE OVER
THE REGION...IN THE WAKE OF THE FAST MOVING DISTURBANCE THAT
DROPPED A LIGHT DUSTING OF SNOW OVERNIGHT. ALTHOUGH A STUBBORN
STRATUS DECK LINGERED THROUGH MUCH OF THE DAY...ALONG WITH
SCATTERED FLURRIES...THESE LOW CLOUDS WERE RAPIDLY BREAKING UP
ACROSS MUCH OF THE CWA THIS AFTERNOON. 

FOR TONIGHT...THE SURFACE HIGH WILL CONTINUE EDGING
SOUTHWARD...WITH THE RIDGE AXIS BECOMING PRETTY WELL CENTERED
ACROSS MAINLY WESTERN PORTIONS OF THE CWA BY SUNRISE. GIVEN THE
CLEARING SKIES...DIMINISHING BREEZES...SNOW COVER...AND FACT THAT 
THE SURFACE HIGH WILL BE STRENGTHENING TO AROUND 1040 MB
OVERNIGHT...THIS LOOKS LIKE A PRETTY CLASSIC SET UP FOR A RAPID
TEMPERATURE DROP. FORECAST LOWS TONIGHT UNDERCUT MOST GUIDANCE BY
AT LEAST A COUPLE DEGREES...WITH SOME AREAS ALONG AND NORTH OF
INTERSTATE 80 LIKELY SLIPPING INTO THE -10 TO -12 RANGE.
FORTUNATELY...BREEZES WILL BE STEADILY SUBSIDING TO UNDER 10 MPH
AS THE RIDGE BUILDS IN. HOWEVER...WIND CHILL VALUES SHOULD STILL
APPROACH...IF NOT SLIP SLIGHTLY UNDER 20 BELOW ZERO ACROSS PARTS
OF THE CENTRAL AND NORTHERN CWA. GIVEN THESE LOW-END VALUES FOR AN
ADVISORY...HAVE DECIDED TO HANDLE WITH AN HWO MENTION FOR NOW
INSTEAD OF A HEADLINE.

ONE OTHER SMALL CONCERN FOR TONIGHT WILL BE THE POSSIBILITY OF
PATCHY FREEZING FOG...MAINLY ACROSS FAR SOUTHWEST PORTIONS OF THE
CWA. THIS AREA IS JUST BEHIND THE RIDGE AXIS WITH LIGHT SOUTHERLY
FLOW DEVELOPING...BUT FEEL THE BETTER FOG POTENTIAL SHOULD REMAIN
JUST WEST OF THE AREA. 

TOMORROW...THE SURFACE HIGH CENTER WILL GRADUALLY MIGRATE EAST
FROM SOUTH CENTRAL AND SOUTHEAST NEBRASKA INTO IOWA AND MISSOURI.
THIS WILL RESULT IN LIGHT AND VARIABLE BREEZES FOR MUCH OF THE
DAY...BECOMING LIGHT AND SOUTHERLY MAINLY ACROSS WESTERN AREAS IN
THE RETURN FLOW. GIVEN THE VERY COLD START TO THE DAY...ALONG WITH
VERY LITTLE MIXING THANKS TO THE RIDGE AXIS...FEEL THAT
TEMPERATURES WILL REALLY STRUGGLE TO REBOUND TOMORROW. AS A
RESULT...TUESDAY HIGHS SHOULD ONLY MANAGE BETWEEN 12-17 DEGREES
ACROSS MOST OF THE CWA...WITH FAR SOUTHERN AND WESTERN AREAS
STANDING THE BEST CHANCE OF MAKING A RUN AT 20.

TOMORROW NIGHT...WEAK RIDGING WILL REMAIN IN PLACE ALOFT OVER THE
REGION...AS SOUTH/SOUTHWEST SURFACE BREEZES OF 5 TO 15 MPH BECOME
ESTABLISHED THROUGH THE NIGHT. THIS COULD EASILY RESULT IN
STEADYING...OR EVEN SLOWLY RISING TEMPERATURES OVERNIGHT...BUT
WILL DEFER TO LATER SHIFTS TO INSERT THIS TREND. NONETHELESS...AS 
LONG AS SKIES REMAIN MOSTLY CLEAR...LOWS SHOULD HAVE NO PROBLEM
FALLING TO BETWEEN 3-8 DEGREES ABOVE ZERO ACROSS MOST OF THE CWA.

LONG TERM...12Z WEDNESDAY THROUGH MONDAY. AT THE ONSET OF THE
EXTENDED PERIODS MODELS ARE IN DECENT AGREEMENT THAT THE PATTERN
ALOFT WILL BE FAIRLY ZONAL ACROSS THE PLAINS STATES. THE AIRMASS
WILL CONTINUE TO MODERATE AS THE ARCTIC AIR DEPARTS AND A MILDER
ONE ARRIVES. MIXING IS NOT THAT DEEP BUT AS THE ARCTIC AIR IS
DISPLACED...TEMPERATURES WILL WARM BUT TO WHAT DEGREE IS STILL
UNCERTAIN. SO FAR WHEN THE ARCTIC AIR HAS BEEN DISPLACED WE'VE
MANAGED TO RISE TO THE UPPER 20S FOR HIGHS. HAVE GENERALLY WENT
WITH THIS TREND FOR WEDNESDAY AND THURSDAY HIGHS WITH SOME 30S
ACROSS PORTIONS OF OUR SOUTH AND WEST.

MODELS DIVERGE IN THE PATTERN ON FRIDAY AND OVER THE WEEKEND.  THE 
ECMWF SUGGESTS A DEEPER MORE WESTERN TROUGH WILL CROSS THE PLAINS 
WHEREAS THE GFS SUGGESTS IT WILL BE MORE OF A CLIPPER SYSTEM.  
REGARDLESS...SOME LIGHT SNOW WILL BE POSSIBLE AS EARLY AS THURSDAY 
NIGHT ON INTO FRIDAY/FRIDAY NIGHT.  THE REMAINDER OF THE WEEKEND 
INTO NEXT WEEK STILL LOOKS MAINLY DRY FOR NOW OTHER THAN THE GFS IS 
BEGINNING TO SUGGEST SOME UPSLOPE SNOW OR FLURRIES MAY OCCUR.  BY 
DAY 7 THE GFS SETS UP A BLOCKING PATTERN WHEREAS THE NAM FEATURES A 
WESTERN CONUS RIDGE/EASTERN CONUS TROUGH WITH NORTHWEST FLOW ACROSS 
OUR AREA.  GIVEN MODEL DIFFERENCES...DID NOT DEVIATE MUCH FROM HPC 
OTHER THAN TO LOWER TEMPS DUE TO SNOW ON THE GROUND AND POTENTIAL 
FOR A COOLER PATTERN MORE SIMILAR TO GFS ENSEMBLE MEAN/GEM/ECMWF.

&&

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

$$

AVIATION...HEINLEIN