FXUS63 KGID 231232
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
632 AM CST WED DEC 23 2009

.AVIATION...12Z KGRI TAF. A MAJOR WINTER STORM SYSTEM IS IMPACTING
THE AREA. A BAND OF PRECIPITATION IS HEADING NORTH OUT OF KANSAS
THIS MORNING. CURRENTLY THE PRECIPITATION TYPE TO THE SOUTH IS
FREEZING RAIN/SLEET. AS THE BAND MOVES NORTH...IT WILL ENCOUNTER
COLDER TEMPERATURE PROFILES. CURRENTLY...A DRY LAYER OF AIR IN
MID-LEVELS IS KEEPING PRECIPITATION TYPE TO MOSTLY FREEZING
DRIZZLE. AS PRECIPITATION MOVES NORTH...THIS WILL SATURATE...WITH
SOUNDING JUST COLD ENOUGH TO KEEP PRECIPITATION SNOW BY MY BEST
ESTIMATION. THERE IS AN OUTSIDE CHANCE OF A LITTLE SLEET THIS
MORNING...BUT LATEST SOUNDINGS INDICATE THAT THIS WILL PROBABLY
NOT OCCUR. THE SNOW THIS MORNING LOOKS LIKE IT COULD BE MODERATE
SNOW FOR AWHILE. THEN A LULL IN ACTIVITY WILL PROBABLY OCCUR
DURING THE LATE MORNING BEFORE ANOTHER WAVE OF PRECIPITATION HITS
DURING THE AFTERNOON...WITH MORE MODERATE SNOW PROBABLE. LATEST
MODELS SHOW THAT PRECIPITATION TYPE IS POISED TO CHANGE AGAIN THIS
EVENING...BACK TO FREEZING DRIZZLE AS THE AIR DRIES OUT IN MID-
LEVELS AGAIN. NORTH WIND SHOULD NOTABLY INCREASE OVERNIGHT
TONIGHT AS WIND NEAR 900 MB GETS CLOSE TO AROUND 40 KTS. MOMENTUM
TRANSFERS SUGGEST THAT AT LEAST SOME OF THIS WILL MAKE IT DOWN TO
THE SURFACE...GIVING US NEAR 33KT WIND GUSTS BY THE END OF THE
FORECAST. 

&&

.PREV DISCUSSION... /ISSUED 348 AM CST WED DEC 23 2009/ 

DISCUSSION...MAIN FORECAST CONCERNS WILL BE WINTER WEATHER 
AFFECTING THE AREA TODAY THROUGH FRIDAY. 

CURRENT RADAR INDICATES THAT THERE IS AN AREA OF PRECIPITATION JUST 
TO THE SOUTH OF THE FORECAST AREA THIS MORNING. EXPECT THAT THIS IS 
MOST LIKELY FREEZING RAIN. FREEZING DRIZZLE HAS SPREAD ACROSS MUCH 
IF NOT ALL OF THE FORECAST AREA DURING THE EVENING. FROM REPORTS IT 
SEEMS THAT SLIPPERY CONDITIONS HAVE BEEN FOUND AROUND THE AREA. 

MODELS HAVE MADE SOME FAIRLY SIGNIFICANT CHANGES IN THE LOOK OF THIS 
STORM. THE MAIN UPPER LEVEL LOW IS FURTHER SOUTH THAN PREVIOUS RUNS 
AND THE TIMING AND LOCATION HAVE CHANGED. HATE TO MAKE MAJOR CHANGES 
ON JUST ONE MODEL RUN...BUT HAVE TRENDED TOWARD THE LATEST RUN. 

FOR TODAY THE FREEZING DRIZZLE OR FREEZING RAIN IS EXPECTED TO 
SPREAD NORTH ACROSS THE FORECAST AREA THIS MORNING AS THE FIRST 
UPPER WAVE MOVES THROUGH THE AREA. FAIRLY GOOD QPF IS POSSIBLE AS 
THIS MOVES THROUGH. THE CONCERN IS MAINLY PRECIPITATION TYPE. THERE 
IS STILL A FAIRLY TIGHT TEMPERATURE GRADIENT ALOFT...PARTICULARLY 
IN THE SOUTHEAST PART OF THE FORECAST AREA. BOTH THE GFS AND ECMWF 
COOL THE TEMPERATURES ALOFT FAIRLY QUICKLY TODAY. THE NORTHWEST IS 
STILL FAIRLY LIKELY TO SEE SOME FREEZING DRIZZLE THIS MORNING UNTIL 
THE DENDRITIC LAYER MOISTENS UP...BUT THAT SHOULD BE EASILY BY MID 
DAY. THERE REMAINS A WARM LAYER ALOFT FOR THE MUCH OF THE FORECAST 
AREA THIS MORNING...BUT DURING THE AFTERNOON THAT APPEARS TO RETREAT 
TO THE SOUTHEAST AND BY THIS EVENING MIXED FREEZING RAIN...SLEET AND 
SNOW SHOULD CHANGE TO SNOW FOR THE FORECAST AREA. 

HERE IS WHERE MODELS TEND TO DIVERGE FROM PREVIOUS RUNS. WITH THE 
UPPER LOW FURTHER SOUTHEAST THE DRY SLOT MOVES ACROSS THE AREA. AM 
STILL PLANNING TO KEEP SNOW ACROSS THE AREA...BUT WILL TREND TOWARDS 
LOWER AMOUNTS OF SNOW AND LIGHT AS OPPOSED TO MODERATE SNOW. THIS 
LIGHTER PERIOD FOR SNOW SHOULD BE MAINLY FROM LATER TONIGHT THROUGH 
THURSDAY. 

THURSDAY NIGHT INTO FRIDAY THE UPPER LOW MOVES FROM EASTERN OKLAHOMA 
TO CENTRAL IOWA. THIS SHOULD BEING SOME WRAP AROUND SNOW INTO THE 
NORTH THURSDAY NIGHT AND ACROSS THE AREA FRIDAY. THIS SHOULD BE 
HEAVIER SNOW AGAIN WITH GREATER AMOUNTS EXPECTED. 

IN ADDITION TO THE PRECIPITATION AS THE SURFACE GRADIENT TIGHTENS 
WINDS ARE EXPECTED TO INCREASE. EXPECT WINDS TO INCREASE DURING THE 
NIGHT TONIGHT AND SHOULD CONTINUE THROUGH MUCH OF FRIDAY. THIS WILL 
CAUSE AREAS OF BLOWING AND DRIFTING SNOW. THE LOW FINALLY MOVES FAR 
ENOUGH TO THE NORTHEAST FRIDAY NIGHT THAT SNOW WILL GRADUALLY COME 
TO AN END. 

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR NEZ039>041-
     046>049-060>064-072>077-082>087.

     BLIZZARD WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR 
     NEZ039>041-046>049-060>064-072>077-082>087.

KS...WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR KSZ005>007-
     017>019.

     BLIZZARD WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR 
     KSZ005>007-017>019.

&&

$$

HEINLEIN