000 
FXUS63 KTOP 222153
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
352 PM CST SAT DEC 22 2007

.DISCUSSION...

TONIGHT AND SUNDAY...LATEST WATER VAPOR SHOWING SOUTHERN STREAM
SHORTWAVE MOVING NORTHEAST ACROSS OK WITH NORTHERN STREAM WAVE 
MOVING EAST ACROSS THE NORTHERN PLAINS. STRONG FRONTOGENETIC FORCING 
IN DEFORMATION ZONE EXTENDING FROM BROWN COUNTY SOUTHWEST INTO 
MORRIS COUNTY WILL SLOWLY PIVOT EASTWARD INTO THE EVENING HOURS AS 
CSI BANDING FEEDS INTO THIS AREA FROM THE SOUTH. THIS SHOULD SUSTAIN 
THE HEAVY SNOW BAND ACROSS THE SOUTHEAST 1/2 OF THE CWA INTO THE 
EARLY EVENING...BEFORE THE NORTHERN STREAM WAVE HELPS TO RAPIDLY 
LIFT THE SOUTHERN WAVE OUT. STRONG NORTH WINDS WITH GUSTS TO 35 TO 
40 MPH AT TIME THIS AFTERNOON WILL DIMINISH INTO THE EVENING...BUT 
CONTINUE WITH CONSIDERABLE BLOWING SNOW OVER THE NORTHEAST AND EAST 
CENTRAL WHERE DEEPER FRESH SNOW HAS/WILL FALL INTO THE EVENING. 
SLEET AND SOME FREEZING RAIN EARLIER THIS AFTERNOON OVER THE FAR 
EAST HAS LIMITED SNOW TOTALS THERE WITH HEAVIER AMOUNTS TO THE WEST. 
APPEARS THE LARGEST AMOUNTS WILL OCCUR FROM SOUTHEAST 
MORRIS/NORTHERN LYON NORTHEAST INTO SHAWNEE/JEFFERSON/JACKSON 
COUNTIES WITH 6 TO 8 INCHES EXPECTED BY THIS EVENING. HAVE CANCELLED 
SNOW/BLOWING SNOW ADVISORY EARLY IN THE NORTHCENTRAL WHERE SNOW HAS 
ENDED AND AMOUNTS LIGHT. WILL CONTINUE ADVISORY UNTIL 6 PM ABILENE 
TO HIAWATHA WITH SNOWFALL AND WINDS EXPECTED TO DECREASE BY THEN. 
WILL KEEP WINTER STORM WARNING REMAINDER OF THE CWA TO THE SOUTH AND 
EAST UNTIL 9 PM WITH ADDITIONAL ONE TO FOUR INCHES. EXPECT WINDS TO 
DECREASE ENOUGH BY MID EVENING TO IMPROVE VISIBILITIES 
SIGNIFICANTLY. OTHERWISE GRADUAL CLEARING WEST TO EAST OVERNIGHT AS 
TROUGH PULLS RAPIDLY EASTWARD. WITH THE CLEARING...SNOW COVER AND 
DECREASING WINDS...WENT WELL BELOW GUIDANCE ON LOWS IN THE LOWER 
TEENS. DESPITE SUNSHINE ON SUNDAY...COLD START TO THE DAY ALONG WITH 
SNOW COVER...WENT 5 TO 10 DEGREES BELOW GUIDANCE WITH HIGHS IN THE 
UPPER 20S TO LOWER 30S.

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SUNDAY NIGHT THROUGH TUESDAY NIGHT...A 5H TROUGH WILL DIG SOUTHEAST 
ACROSS THE WESTERN CONUS INTO THE SOUTHERN PLAINS. THE BEST LIFT AND 
MOISTURE AHEAD OF THIS 5H TROUGH WILL REMAIN WELL SOUTH OF THE CWA 
MONDAY AND MONDAY NIGHT. IN AREAS OF DEEPER SNOW COVER HIGH TEMPS 
MAY ONLY REACH THE MID TO UPPER 30S MONDAY AND TUESDAY AFTERNOONS. 
LOWER 40S MAY BE POSSIBLE IN AREAS WITHOUT MUCH SNOW PACK. OVERNIGHT 
LOWS WILL BE MAINLY IN THE MID TO UPPER TEENS.

WEDNESDAY AND WEDNESDAY NIGHT. ANOTHER 5H TROUGH WILL DIG SOUTHEAST 
ACROSS THE WESTERN CONUS AND INTO THE CENTRAL AND SOUTHERN PLAINS. 
THIS 5H TROUGH MAY TRACK FAR ENOUGH NORTH TO PROVIDE THE CWA WITH 
ACCUMULATING SNOW. ATTM BOTH THE ECMWF AND GFS SHOW THE HEAVIER 
PRECIP REMAINING ACROSS SOUTHERN KS. A SURFACE COLD FRONT WILL PUSH 
SOUTHWARD ACROSS THE CWA WEDNESDAY MORNING...THUS HIGHS FOR THE 
DAY...LOWER TO MID 30S...MAY OCCUR DURING THE MORNING HOURS WITH 
TEMPERATURES SLOWLY FALLING INTO THE 20S DURING THE AFTERNOON.

THURSDAY THROUGH FRIDAY...ANOTHER QUICK MOVING 5H TROUGH WILL DIG 
SOUTHEAST INTO NM AND CO AND DIG NORTHEAST ACROSS THE SOUTHERN AND 
CENTRAL PLAINS. THE GFS TRACKS THIS SYSTEM NORTH OF THE CWA AND MAY 
PROVIDE STRONG WAA FOR A FREEZING RAIN TO RAIN EVENT ACROSS THE CWA. 
THE ECMWF LIFTS THE UPPER TROUGH FARTHER SOUTH AND PROVIDES A MOSTLY 
SNOW EVENT ACROSS MOST OF THE CWA. THERE IS STILL A LOT OF 
UNCERTAINTIES WITH THE TRACK AND INTENSITY OF THIS 5H TROUGH. HIGHS 
WILL BE IN THE 30S WITH LOWS IN THE 20S.

FRIDAY NIGHT THROUGH SATURDAY...THE TROUGH WILL LIFT NORTHEAST OF 
THE AREA AND SKIES SHOULD CLEAR ON SATURDAY. HIGHS WILL BE IN THE 
MID 30S ON SATURDAY.  THE ECMWF SHOW A VERY INTENSE 5H LOW MOVING 
INTO NM EARLY NEXT WEEK. THIS 5H TROUGH COULD PROVIDE THE AREA WITH 
ANOTHER SNOW CHANCE INTO EARLY NEXT WEEK.

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&&

.AVIATION...

IFR/LIFR CIGS AND VISBYS ASSOCIATED WITH SN/BLSN WILL COME TO AN END 
AT MHK BY 00Z...AND 03Z AT TOP/FOE. GRADIENT WILL BEGIN TO 
SLACKEN...AND WIND GUSTS WILL GRADUALLY RESIDE AFTER 00Z. RESIDUAL 
MOISTURE WILL KEEP MVFR VIS AT EACH OF THE THREE SITES THROUGH 
04/05Z...AND CLEARING TO VFR THEREAFTER. 

KONOP

&&

.TOP WATCHES/WARNINGS/ADVISORIES...

SNOW AND BLOWING SNOW ADVISORY IN EFFECT UNTIL 600 PM CST FOR 
DICKINSON...GEARY...RILEY...POTTAWATOMIE...MARSHALL...NEMAHA AND 
BROWN COUNTIES.

WINTER STORM WARNING IN EFFECT UNTIL 900 PM CST FOR 
MORRIS...EMPORIA...COFFEY...ANDERSON...WABAUNSEE....OSAGE...
FRANKLIN...SHAWNEE...DOUGLAS....JACKSON AND JEFFERSON COUNTIES.

&&

$$

63/66/KONOP