National Weather Service Raw Text Product

635 
FXUS63 KTOP 191737
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1137 AM CST SAT JAN 19 2013

...UPDATE TO AVIATION...

.DISCUSSION...
LATEST WATER VAPOR IMAGERY SHOWING A GRADUAL DEEPENING OF A LARGE 
SCALE TROUGH EXTENDING FROM NEAR HUDSON BAY SOUTHWESTWARD INTO
THE NORTHERN PLAINS. THIS IS BEING AIDED BY THE CONTINUED
AMPLIFICATION OF UPPER LEVEL RIDGING IN THE PACIFIC...JUST OFF THE
WEST COAST WHICH IS DRIVING SHORTWAVE TROUGHS UP THROUGH THE GULF
OF ALASKA AND INTO THE CANADIAN TROUGH. THE MOST RECENT SHORTWAVE
TROUGH NOW MOVING SOUTHEAST ACROSS WY WILL PUSH A TROUGH OF LOW
PRESSURE SOUTHEAST ACROSS THE COUNTY WARNING AREA TODAY WITH A
WINDSHIFT TO THE NORTHWEST...BUT WARM AIR ALREADY OUT AHEAD OF THE
SYSTEM WILL COMBINE WITH ABUNDANT SUNSHINE AND RELATIVELY MILD
LOWS FOR MID JANUARY...TO PUSH HIGHS BACK INTO THE MIDDLE TO UPPER
50S...WITH NEAR 60 DEGREES EXPECTED SOUTH OF THE I 35 CORRIDOR.
THIS WILL LIKELY BE THE WARMEST DAY IN GENERAL ACROSS THE CWA FOR
THE WEEK. COOLER AIR WILL BEGIN TO WORK SOUTHWARD INTO THE CWA
LATER TONIGHT AND SUNDAY. AFTER LOWS TONIGHT IN THE 20S...HIGHS
SUNDAY WILL BE MORE SEASONABLE IN THE MID 30S NORTH TO LOWER 40S
SOUTH.

THE COLDEST SURGE OF CANADIAN AIR WILL ARRIVE SUNDAY NIGHT THEN 
LINGER THROUGH THE DAY MONDAY. AFTER LOWS MONDAY MORNING FROM NEAR 6 
ABOVE ZERO IN THE FAR NORTHEAST CORNER NORTH OF HIAWATHA TO AROUND 
13 IN THE SOUTHWEST AREAS OF THE CWA...WINDCHILLS WILL RANGE FROM 
NEAR 9 BELOW FAR NORTHEAST TO THE SINGLE DIGITS IN THE SOUTHWEST 1/3 
OF THE CWA. HIGHS WILL RECOVER BACK INTO PRIMARILY THE 20S MONDAY 
WITH A FEW LOW 30S SOUTHWEST COUNTIES. AS THE CENTER OF THE COLD 
HIGH PRESSURE MOVES EAST OF THE CWA LATE MONDAY NIGHT...WINDS WILL 
REMAIN LIGHT...BUT BECOME SOUTHEASTERLY. AS A RESULT....TEMPS WILL 
NOT BE QUITE AS COLD MONDAY NIGHT WITH READINGS ABOUT 3 DEGREES 
WARMER THAN THE PREVIOUS NIGHT. 

AS THE LARGE SCALE TROUGH OVER THE EASTERN CONUS GRADUALLY SHIFTS 
OFFSHORE THROUGH MID WEEK...HEIGHT RISES AND LEESIDE TROUGHING IN 
THE HIGH PLAINS SHOULD RESULT IN A GRADUAL MODERATION IN TEMPS. 
HIGHS PRIMARILY IN THE 30S ON TUESDAY WILL WARM INTO THE 40S 
WEDNESDAY...THEN THE UPPER 40S TO LOWER 50S THURSDAY BEFORE ANOTHER 
SHORTWAVE TROUGH FROM THE PACIFIC RACES SOUTHEAST ACROSS THE PLAINS 
INTO FRIDAY RESULTING IN HIGHS GENERALLY IN THE 30S. AT THIS 
POINT...MOISTURE RETURN AHEAD OF THE END OF THE WEEK SYSTEM APPEARS 
TO BE DIRECTED GENERALLY SOUTHEAST OF THE CWA...SO WILL MAINTAIN A 
DRY FCST THROUGH THE WEEK. 63

&&

.AVIATION...

VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. A SURFACE TROUGH
IS PROGRESSING EASTWARD THROUGH THE AREA TODAY. THIS TROUGH WILL
SHIFT THE WINDS TO THE NORTHWEST THIS AFTERNOON AS IT CONTINUES
EASTWARD...WINDS GRADUALLY VEER TO THE EAST NORTHEAST TOWARD THE END OF
THE PERIOD.

SANDERS

&&

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

$$