FXUS63 KOAX 072148
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
348 PM CST MON DEC 7 2009

.DISCUSSION...

OR

.SHORT TERM...TONIGHT THROUGH THURSDAY

SYNOPSIS...12Z ANALYSIS HAS UPPER TROF OVER NORTHERN CALIFORNIA WILL 
BE MOVING OUT INTO THE PLAINS. UPPER LOW IS FORECAST TO MOVE ACROSS 
THE SOUTHERN ROCKIES AND INTO THE CENTRAL PLAINS ON WEDNESDAY. 
GREATEST HEIGHT FALLS AT 12Z WAS AT KOAK...BUT APPEARS THE GREATEST 
500 MB HEIGHT FALLS WERE OFF THE CALIFORNIA COAST.  WATER VAPOR 
IMAGERY SHOWS AN IMPRESIVE PLUME OF MOISTURE OVER THE INTERMOUNTAIN 
REGION AND BEGINNING TO SPREAD INTO THE CENTRAL PLAINS.  

FORECAST...ALL THE INGREDIANTS OF A SIGNIFICANT WINTER STORM EVENT 
ARE COMING INTO PLACE FOR TUESDAY INTO WEDNESDAY. WARM AIR ADVECTION 
SNOW IS EXPECTED TO START TONIGHT...MAINLY AFTER 06Z. THEN THE 
SURFACE LOW WILL MOVE ACROSS FRM WICHITA KANSAS AT 08/12Z AND THEN 
HEAD TOWARDS CHICAGO BY TO 09/12Z. GFS INTIALIZATION WAS SPOT ON 
WITH UPPER AND SURFACE FEATURES AND IS THE PREFERRED MODEL OF 
CHOICE. BOTH THE GFS AND ECMWF ARE INDICATING A BROAD AREA OF 
PRECIPITATION ACROSS THE AREA. SNOW SHOULD BECOME HEAVY AFTER 18Z 
ACROSS MUCH OF THE CWA. 

WINDS SHOULD ALSO INCREASE IN THE LATE AFTERNOON TUESDAY AND 
CONTINUE THROUGHOUT MIDDAY WEDNESDAY. CONDITIONS WARRANT A BLIZZARD 
WATCH...BECAUSE WINDS WITH GUSTS UP TO 40 KT CAN BE EXPECTED EVEN 
INTO WEDNESDAY MORNING. SNOWFALL IS EXPECTED TO BE HEAVIEST NEAR THE 
KS/NE BORDER WITH ABOUT A FOOT OF TOTAL ACCUMULATION.  UP AT NORTH 
AT OMAHA WE SHOULD SEE THE 8-10 INCHES.  THE MAIN QUESTION FOR THE 
WINTER STORM WARNING IS THE FAR NW PART OF THE CWA.  BUT STILL SEE 
AROUND 6 INCHES.  

BY WEDNESDAY NIGHT...AREA SHOULD CLEAR OUT AND TEMPS WITH SNOW COVER 
WILL DROP TO THE LOW SINGLE DIGITS.

.LONG TERM...THURSDAY NIGHT THROUGH MONDAY

COLD TEMPERATURES WILL BE THE PRIMARY WEATHER STORY FOR THE END OF 
THE WEEK THROUGH THE WEEKEND.  DID NOT CHANGE THE GOING TEMPERATURE 
FORECAST TOO MUCH OTHER THAN TO LOWER THE LOWS A FEW DEGREES...CLOSE 
TO THE ENSEMBLE MOS COOLEST VALUES.  SHOULD DROP SLIGHTLY BELOW ZERO 
MOST AREAS FRIDAY MORNING WITH DEEP SNOW COVER AND ARCTIC AIRMASS.  

SOME AGREEMENT WITH THE MODEL SOLUTIONS ON A SHORTWAVE PROGGED TO 
MOVE THROUGH LATE SUNDAY OR MONDAY.  HAVE INTRODUCED A SLIGHT CHANCE 
FOR LIGHT SNOW MONDAY.  

&&

.AVIATION...
TAF SITES KOFK/KOMA/KLNK 

18Z TAFS

SFC HIGH PRESSURE WILL GIVE WAY TO DEVELOPING LOW PRES OVR 
CO/NM/NORTH TX.  MEANWHILE...SOME LEADING STORM ENERGY WILL MOVE 
INTO THE PLAINS TONIGHT...WITH THE MAIN STORM SYSTEM HEADING INTO 
THE REGION TUESDAY.  AS A RESULT...SOME FLURRIES AND MVFR CIGS AT 
KOFK CAN BE EXPECTED THIS AFTERNOON...WITH SNOW AND MVFR/IFR 
CIGS/VISIBILITIES SPREADING ACROSS ALL OF THE TAF SITES TONIGHT AND 
LIFR CIGS/VSBYS POSSIBLE TUESDAY WITH MODERATE TO HEAVY SNOW.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER STORM WARNING FROM 3 AM TUESDAY TO NOON CST WEDNESDAY FOR 
     NEZ011-012-015>018-030>034-042>045-050>053-066>068-091-093.

     BLIZZARD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING 
     FOR NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-
     088>093.

     WINTER STORM WARNING UNTIL NOON CST WEDNESDAY FOR NEZ065-078-
     088>090-092.

IA...WINTER STORM WARNING FROM 3 AM TUESDAY TO NOON CST WEDNESDAY FOR 
     IAZ043-055-056-069-079-080-090-091.

     BLIZZARD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING 
     FOR IAZ043-055-056-069-079-080-090-091.

&&

$$

SMITH/NIETFELD/ZAPOTOCNY