FXUS63 KGID 152221
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
421 PM CST TUE DEC 15 2009

.AVIATION...00Z KGRI TAF. VFR CONDITIONS FOR THIS FORECAST. HIGH
PRESSURE STILL GENERALLY IN CONTROL. SOUTH WIND WILL BECOME MORE
SOUTHWEST OVERNIGHT TONIGHT AS A WARM FRONT/TROUGH MOVES THROUGH.
WIND WILL TURN NORTH BY WEDNESDAY AFTERNOON AFTER A COLD FRONT
MOVES THROUGH. WIND SHOULD REMAIN RELATIVELY LIGHT THROUGHOUT THIS
FORECAST. HIGH CEILINGS WILL ENTER OVERNIGHT AND EVENTUALLY
THICKEN AND LOWER TO MID-LEVEL BY WEDNESDAY AFTERNOON. 

&&

.PREV DISCUSSION... /ISSUED 225 PM CST TUE DEC 15 2009/ 

SHORT TERM...THE MAIN SHORT TERM ISSUE WILL PROBABLY BE LOOKED
UPON AS GOOD NEWS...MODERATING TEMPERATURES. 

STRONG 1036MB HIGH PRESSURE HAS MOVED EAST INTO NORTHWEST MISSOURI
THIS MID AFTERNOON...AND WEAK SOUTHERLY FLOW AS SET UPON THE BACK
SIDE ACROSS WESTERN NEBRASKA/KANSAS. WARMER AIR IS SETTING UP TO
THE WEST ALREADY WITH SOME AID OF WESTERLY/ORORGRAPHIC IMPACTS.
STILL COLD OVER THE CWFA...WITH TEMPERATURES ABOUT AS EXPECTED
THIS AFTERNOON AND RANGING FROM 10 TO 20 DEGREES.

TONIGHT WILL BE COLD...BUT FORTUNATELY NOT AS COLD AS RECENT
NIGHTS. QUICK DROP OFF IS MOST LIKELY IN THE EASTERN ZONES EARLY
THIS EVENING...BUT TEMPERATURES WILL STEADY OFF MAY RISE
OVERNIGHT WITH SOUTHERLY FLOW. 

HAVE UNDERCUT NUMERICAL GUIDANCE AGAIN WEDNESDAY...IN HOPES I WILL
BE WRONG AND IT WARMS MORE THAN EXPECTED OVER LARGE SNOW FIELD. 
RIGHT NOW...WILL EXPECT UPPER 20S FOR MOST OF THE AREA WITH SOME
30S ON THE WESTERN/SOUTHERN FRINGES. ALWAYS HARD TO GAGE JUST 
HOW MUCH THINGS WILL WARM...BUT THAT IS A GOOD STARTING POINT FOR
NOW. SOME PASSING CIRRUS LEVEL CLOUDS WILL MAKE IT A PARTLY/MOSTLY
SUNNY DAY. WINDS WILL TURN LIGHT BY AFTERNOON...AS A WEAK SURFACE
TROUGH MOVES INTO THE AREA...AND SORT OF FADES AWAY WITH TIME. 

LONG TERM...THURSDAY THROUGH TUESDAY. A MILD ZONAL FLOW PATTERN
WILL START OFF THE EXTENDED ON THURSDAY...HOWEVER THE AIRMASS WILL
COOL DURING THE AFTERNOON FOLLOWING A WEAK WAVE/COOL FRONT.
THURSDAY WILL ROUND OFF ONE OF THE WARMER DAYS OF THE WEEK WITH
HIGHS IN THE UPPER 20S TO THE LOW/MID 30S.

THE PATTERN AMPLIFIES THURSDAY NIGHT/FRIDAY AS A TROUGH REACHES THE 
PACIFIC NORTHWEST...THE RIDGE AMPLIFIES OVER THE INTERIOR ROCKY 
MOUNTAIN REGION AND NORTHWEST FLOW SETS UP ACROSS THE CENTRAL 
PLAINS. MODELS ARE FAIRLY SIMILAR WITH A STRONGER MID LEVEL WAVE 
PROGGED TO CROSS THE PLAINS THURSDAY NIGHT/FRIDAY.  THE BEST FORCING 
IS FORECAST FROM AFTER DARK THURSDAY NIGHT UNTIL AROUND MIDDAY 
FRIDAY WHEN DECENT MID LEVEL FRONTOGENESIS AND LIFT IS PROGGED.  
CHANCES FOR LIGHT SNOW LOOK MORE PROBABLE AND HAVE RAISED POPS INTO 
THE CHC CATEGORY.  THE GFS IS FAIRLY ROBUST ON SNOW ACCUMULATION 
POTENTIAL OF AN INCH OR TWO BUT OVERALL THOUGHT ATTM IS THAT AMOUNTS 
OF A DUSTING UP TO A HALF INCH OR SO LOOK MORE REASONABLE ATTM.  
POPS MAY NEED TO BE RAISED FURTHER WITH TIME IF LIGHT ACCUMULATIONS 
ARE STILL ON TRACK.  THE GFS BRINGS IN SOME REINFORCING COLD AIR 
FRIDAY NIGHT AND HAVE MAINTAINED A FLURRY MENTION INTO THE FIRST 
PART OF THE NIGHT.  

COOL AIR WHICH ARRIVES FRIDAY NIGHT/EARLY SATURDAY MODERATES DURING 
THE AFTERNOON EVENING AS HEIGHTS BEHIND THE DEPARTING SYSTEM AND 
AHEAD OF THE NEXT...SET TO ARRIVE ON SUNDAY.  MODELS DIVERGE IN 
HANDLING THE SUNDAY CLIPPER WITH THE GFS DEEPER AND FARTHER WEST 
WITH THE H7 LOW THAN THE GEM/ECMWF.  THE GFS CLOSES OFF THE LOW IN 
SW SD WHEREAS THE EC KEEPS AN OPEN WAVE IN EASTERN SOUTH DAKOTA 12Z 
SUNDAY.  BY 00Z THE EC CLOSES THE H7 LOW IN IOWA WHEREAS THE GFS 
PLACES AN OPEN TROUGH ACROSS EASTERN NEB/KS...WHILE THE GEM NEVER 
CLOSES THE H7 LOW.  GIVEN THE DIFFERENCES AMONG THE 
MODELS...CONFIDENCE IS NOT HIGH IN THIS PERIOD...HOWEVER DO BELIEVE 
LOW POPS ARE WARRANTED WITH THE PASSING CLIPPER.  IF THE STRONGER 
GFS SOLUTION VERIFIES...ACCUMULATING SNOW WILL BE A CONCERN...BUT 
FOR NOW THE STRONGER GFS IS AN OUTLIER. 

MODELS CONTINUE TO DIVERGE NEXT WEEK IN PLACEMENT OF THE POLAR 
VORTEX/VORTICES AND THE WESTERN RIDGE...AND THEIR PROGRESSION.  
ANOTHER SOUTHWARD PUSH OF ARCTIC AIR LOOKS ON TRACK BUT TRYING TO 
PINPOINT ANY MID WEEK STORM WITH MODEL DIFFERENCES IS TOO UNCERTAIN 
ATTM AND DIDN'T DEVIATE MUCH FROM HPC OTHER THAN TO LOWER TEMPS.

CLIMATE...1ST HALF OF DECEMEBER IS SHAPING UP TO BE ONE OF THE TOP
5 COLDEST STARTS TO THE MONTH EVER. THROUGH 14TH...HASTINGS WAS IN
3RD PLACE...GRAND ISLAND IN 3RD...AND KEARNEY IN 5TH. IT LOOK LIKE
WE WILL HOLD IN THIS AREA FOR A NEAR FUTURE. 1983 IS THE STANDARD
BEARER FOR COLDEST DECEMBERS...AND THAT IS REALLY NOT IN REACH. WE
ARE ACTUALLY RUNNING COLDER SO FAR THIS DECENBER FOR THE FIRST 14
DAYS THAN WE DID IN 1983...BUT IN 1983 WE STARTED A BRUTUALLY COLD
STRETCH OF 6-7 DAYS STRAIGHT (AROUND THE 18TH) OF BELOW ZERO
TEMPERATURES TO SALT THAT MONTH AWAY AS THE COLDEST.

&&

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

$$

AVIATION...HEINLEIN