FXUS63 KTOP 261740
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1135 AM CST SAT DEC 26 2009

.AVIATION...FOR 18Z TAFS

ONE MORE WAVE AND ASSOCIATED AREA OF LIGHT SNOW WILL MOVE ACROSS THE 
AREA THIS AFTERNOON BEFORE WE SHOULD SEE PRECIP CHCS WANE AFTER 00Z. 
MVFR CIGS WILL ALSO PERSIST INTO TONIGHT. NOT CONFIDENT ABOUT HOW 
LONG MVFR CIGS WILL PERSIST AND THERE IS A SCENARIO THAT KEEPS CIGS 
IN THE MVFR CATEGORY THROUGH 12Z SUN WHILE MOS SUGGESTS CIGS COULD 
IMPROVE TO VFR AFTER 00Z. WIND GUSTS SHOULD ALSO SUBSIDE LATER 
TONIGHT.

&&

.PREV DISCUSSION.../334 AM CST SAT DEC 26 2009/
MAIN THEME IN SHORT TERM IS GRADUALLY IMPROVING CONDITIONS OVER THE 
NEXT 24 HOURS ACROSS THE CWA. AS OF EARLY THIS MORNING...CENTER OF 
LARGE UPPER LOW WAS LOCATED OVER NORTHERN ILLINOIS. EMBEDDED VORT 
MAXES ALONG THE BROAD CIRCULATION WAS AIDING IN ENHANCING VERTICAL 
ASCENT OVER PORTIONS OF NEBRASKA AND KANSAS...WITH SCATTERED AREAS 
OF LIGHT TO OCCASIONALLY MODERATE SNOW. 24 HOUR WATER VAPOR IMAGERY 
LOOP SHOWS A DECREASING ORGANIZATIONAL PRESENTATION OF WARM CONVEYOR 
BELT ALOFT AS AXIS OF DEEPER MOISTURE CONTINUES TO SHIFT WELL TO THE 
EAST OF THE UPPER LOW OVER THE EASTERN SHORES OF THE ATLANTIC. THE 
UPPER LOW WILL WOBBLE AROUND THE WESTERN GREAT LAKES STATES TODAY AS 
THE SURFACE LOW CURRENTLY LOCATED NEAR THE MO/IA BORDER SLOWLY MOVES 
NORTHEASTWARD. THE SFC LOW WILL BEGIN TO FILL TODAY WITH A GRADUALLY 
DECREASING PRESSURE GRADIENT OVER THE AREA. WINDS WILL BE A LITTLE 
WEAKER TODAY...WITH NORTHWEST WINDS AVERAGING AROUND 20 TO 25 MPH 
WITH GUSTS UP TO 30 MPH. LIGHT TO OCCASIONALLY BRIEF PERIODS OF 
MODERATE SNOW WILL CONTINUE TODAY. NEW SNOWFALL ACCUMULATION THROUGH 
TONIGHT WILL RANGE FROM ONE HALF OF AN INCH OR LESS SOUTH OF 
INTERSTATE 70...WITH ONE HALF OF AN INCH TO ONE INCH NORTH OF 
INTERSTATE 70. WOULD STILL EXPECT TO SEE SOME DRIFTING OF SNOW IN 
LOCALIZED AREAS ALTHOUGH NOT NEARLY AS WIDESPREAD AND THE MAGNITUDE 
THAT WAS PREVIOUSLY EXPERIENCED OVER THE PAST 36 HOURS. WITH WINDS 
ON A GRADUAL DECREASING TREND AND NEW SNOWFALL ACCUMULATIONS OF ONE 
INCH OR LESS...EXPECT GREATEST IMPACT OF BLOWING/DRIFTING SNOW TO 
HAVE PASSED. THEREFORE...WILL EXPIRE WINTER WX ADVISORY THIS MORNING 
AND CONTINUE TO MENTION AREAS OF BLOWING SNOW IN FORECAST.

TONIGHT/SUNDAY/BEYOND...INFLUENCE OF UPPER LOW WILL CONTINUE TO 
LESSEN. CONTINUED CHANCES OF LIGHT SNOW OR FLURRIES ACROSS THE AREA 
TONIGHT WITH MEASURABLE PRECIPITATION CHANCES OVER BY SUNRISE 
SUNDAY. LOW CLOUDS WILL FINALLY DEPART THE REGION SUNDAY NIGHT. 
UPPER LEVEL RIDGING WILL TAKE SHAPE ACROSS THE CENTRAL PLAINS MONDAY 
INTO TUESDAY IN ADVANCE OF THE NEXT UPPER LEVEL SYSTEM...SPELLING 
DRY/TRANQUIL WEATHER.

NO BIG CHANGE MADE TO TEMPERATURES. WITH WIND...SNOW COVER...AND 
OVERCAST CONDITIONS TODAY INTO SUNDAY...SMALL DIURNAL CURVE IN 
TEMPERATURES EXPECTED WITH LOWS IN THE TEENS AND HIGHS IN THE 20S. 
AS HIGH PRESSURE MOVES INTO THE REGION AND CLOUDS CLEAR...COLDER 
MINIMUM READINGS CAN BE ANTICIPATED SUNDAY NIGHT AND MONDAY NIGHT. 
LOWS SHOULD FALL INTO THE SINGLE DIGITS TO LOWER TEENS. 

NEXT CHANCE FOR SNOW STILL ON TRACK FOR TUESDAY NIGHT INTO 
WEDNESDAY...ALTHOUGH BEST DYNAMICS/MOISTURE WELL TO THE SOUTH OF THE 
REGION. NO CHANGES MADE BEYOND TUESDAY.

BLAIR

&&

.TOP WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$