FXUS63 KTOP 251739
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1139 AM CST FRI DEC 25 2009

.UPDATE...

UPDATED FOR THE 18 UTC AVIATION.

&&

.DISCUSSION...

SEE THE PREVIOUS DISCUSSIONS BELOW.

&&

.AVIATION...

A BROAD UPPER LOW OVER KS THIS AFTERNOON WILL MOVE NORTHEAST INTO
THE MIDWEST TONIGHT. MVFR CEILINGS...OCCASIONAL LIGHT SNOW AND
BLOWING SNOW WILL BE POSSIBLE AT THE TAF SITES THROUGH 00Z...MAY
SEE SOME FLURRIES THROUGH THE NIGHT. I KEPT VISBYS BETWEEN 1.5 AND
2 MILES DUE TO BLOWING SNOW AT THE TAF SITES THIS AFTERNOON. WEST TO
NORTHWEST WINDS OF 20 TO 30 KTS WITH GUSTS OF 30 TO 40 KTS WILL
DIMINISH TO 12 TO 15 KTS AFTER 00Z WITH MUCH LOWER WIND GUSTS AT
ALL TAF SITES THROUGH THE NIGHT. THERE MAY BE A FEW SNOW FLURRIES
TONIGHT ACROSS THE TAF SITES.

GARGAN

&&

.PREV DISCUSSION... /ISSUED 727 AM CST FRI DEC 25 2009/ 

UPDATE...
UPDATED THE FORECAST TO DOWNGRADE THE BLIZZARD WARNING TO AN 
ADVISORY.

DISCUSSION...
THE MAIN DEFORMATION AND BANDS OF MODERATE SNOW CONTINUE TO LIFT 
NORTH. AREA OBSERVATIONS SHOW VISIBILITIES SLOWLY IMPROVING. WITH 
MODELS SHOWING THE BETTER SNOWFALL RATES REMAINING NORTH THROUGH THE 
DAY...EXPECT CONDITIONS TO KEEP A TREND OF GRADUAL IMPROVEMENT. 
ADDITIONAL SNOW ACCUMULATIONS WILL ONLY BE AROUND 1 INCH NEAR I-70 
TO POSSIBLY AS MUCH AS 3 INCHES OVER FAR NORTHEAST KS. THE WINDS 
WILL BE THE BIG PROBLEM THOUGH AS WEST WINDS STAY UP BETWEEN 20 AND 
30 MPH. THIS WILL LIKELY KEEP SNOW DRIFTING...HENCE THE ADVISORY. 

WOLTERS

PREV DISCUSSION.../308 AM CST FRI DEC 25 2009/
ONGOING SIGNIFICANT WINTER STORM CONTINUES TO BE MAIN FOCUS WITHIN 
FORECAST PACKAGE. AS OF EARLY THIS MORNING...THE UPPER LOW WAS 
CENTERED ACROSS SOUTHERN MISSOURI WITH THE SFC LOW OVER EAST CENTRAL 
MISSOURI. LATE EVENING DEFORMATION BAND REMAINS OVER EASTERN KANSAS 
WITH A NEW MORE PRONOUNCED BAND ACROSS WESTERN MISSOURI. SNOWFALL 
RATES THIS MORNING HAVE AVERAGED ONE HALF INCH OR LESS PER HOUR. 
INITIAL BAND CONTINUES TO SHOW SIGNS OF WEAKENING AS RADAR 
REFLECTIVITY RETURNS HAVE TRENDED DOWNWARD AND IR IMAGERY SHOWS 
CLOUD TOPS WARMING. EXPECT HEAVIEST ACTIVITY TO BE LOCATED ACROSS 
FAR EASTERN AND FAR NORTHEAST PORTIONS OF THE CWA BY SUNRISE. THE 
OTHER IMPACT CONTINUES TO BE THE STRONG NORTH-NORTHWEST WINDS OF 20 
TO 30 MPH WITH GUSTS IN EXCESS OF 40 MPH. THIS HAS LED TO WIDESPREAD 
REDUCED VISIBILITIES WITH AREAS OF BLIZZARD CONDITIONS AND 
SIGNIFICANT DRIFTING AND BLOWING OF SNOW...WITH MANY DRIFTS IN 
EXCESS OF A FOOT.

AS THE UPPER LOW MOVES INTO SOUTHERN IOWA TODAY...A SECONDARY VORT 
MAX WILL DIVE INTO THE REGION AND PHASE WITH THE INITIAL 
DISTURBANCE. AS THE SFC LOW OCCLUDES...IT WILL BEGIN MOVING BACK 
WESTWARD AND THEN SOUTHWESTWARD INTO SOUTHWEST IOWA BY SUNSET. THE 
CONTINUING CLOSE PROXIMITY OF THIS SYSTEM WILL ALLOW FOR ADDITIONAL 
LIGHT SNOWFALL OVER THE MAJORITY OF THE CWA. THE HIGHEST PROBABILITY 
OF ACCUMULATING SNOWFALL...WHERE OCCASIONALLY MODERATE SNOWS WILL BE 
POSSIBLE...WILL BE ACROSS FAR NORTHEAST KANSAS CLOSEST TO THE NEAR 
VERTICALLY STACKED SYSTEM. ADDITIONAL SNOWFALL ACCUMULATIONS NOW 
THROUGH SATURDAY WILL RANGE FROM ONE INCH OR LESS SOUTH OF
INTERSTATE 70...ONE TO TWO INCHES ALONG INTERSTATE 70 TO HIGHWAY
36...AND TWO TO THREE INCHES NORTH OF HIGHWAY 36. IN ADDITION TO
THE SNOW...GUSTY NORTHERLY WINDS WILL CONTINUE THROUGH SATURDAY.
THIS WILL LIKELY LEAD TO ADDITIONAL BLOWING AND DRIFTING OF NEW
AND ALREADY FALLEN SNOW. WILL CONTINUE WINTER WEATHER HEADLINES AS
IS THIS MORNING FOR THE AFOREMENTIONED HAZARDOUS CONDITIONS.

THE UPPER SYSTEM WILL FINALLY MAKE PROGRESS AWAY FROM THE CWA BY 
SATURDAY NIGHT. LIKEWISE...LIGHT SNOW CHANCES WILL END FROM WEST TO 
EAST BEGINNING SATURDAY AFTERNOON INTO SATURDAY NIGHT. BY SUNRISE 
SUNDAY...EXPECT ALL PRECIPITATION TO BE EAST OF THE REGION.

AS FOR TEMPERATURES...CLOUD COVER...CAA...AND SNOW COVER WILL KEEP 
HIGHS TODAY IN THE MIDDLE TEENS TO LOWER 20S. ADDITIONALLY...WIND 
CHILL VALUES THIS MORNING AND AGAIN TONIGHT WILL FALL INTO THE ZERO 
TO MINUS 10 RANGE. MINIMUM TEMPERATURES THE NEXT COUPLE DAYS WILL 
REMAIN IN THE LOWER TO MIDDLE TEENS AS LOW LEVEL CLOUD COVER AND 
WIND SPEEDS HELP MITIGATE COLD POTENTIAL WITH FRESH SNOW COVER. NO 
CHANGES MADE TO FORECAST BEYOND MONDAY.

BLAIR

&&

.TOP WATCHES/WARNINGS/ADVISORIES...WINTER WEATHER ADVISORY UNTIL 6 PM FRIDAY FOR KSZ008-KSZ009-
KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026-
KSZ034-KSZ035-KSZ036-KSZ038-KSZ039-KSZ040-KSZ055-KSZ056.

&&

$$