334 
FXUS63 KTOP 062125
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
325 PM CST WED FEB 6 2013

.DISCUSSION...

TONIGHT THROUGH THURSDAY...

SURFACE HIGH PRESSURE SITUATED ACROSS THE EASTERN CWA THIS
AFTERNOON WILL PUSH EAST AS AN AREA OF LOW PRESSURE CURRENTLY OVER
EASTERN COLORADO SHIFTS EASTWARD INTO KANSAS. LOW CLOUDS WILL
BEGIN TO BUILD INTO THE REGION TONIGHT AHEAD OF THE ADVANCING COLD
FRONT. THIS FRONT WILL MOVE EAST INTO CENTRAL KANSAS BY AROUND 06Z
AND PROGRESS EAST OF THE CWA BY AROUND 15Z AS AN UPPER LEVEL
SHORTWAVE TROUGH SKIMS ACROSS THE NORTHERN AND CENTRAL PLAINS.
MODELS SHOW PRECIPITATION DEVELOPING ALONG AND BEHIND THIS FRONT
AS IT TRACKS EASTWARD ACROSS THE CWA OVERNIGHT INTO THURSDAY
MORNING. WITH A SOUTHERLY FLOW STILL IN PLACE AHEAD OF THE FRONTAL
PASSAGE...TEMPERATURES OVERNIGHT WILL ONLY DROP INTO THE 40S AND
POSSIBLY UPPER 30S ACROSS FAR NORTH CENTRAL KANSAS. AS A
RESULT...PRECIPITATION WILL STAY IN THE FORM OF RAIN
SHOWERS...WITH THE POTENTIAL FOR A FEW ISOLATED THUNDERSTORMS AS
WEAK INSTABILITY LOOKS TO BE PRESENT WITH MUCAPE GENERALLY RANGING
FROM 100-300 J/KG. WITH LIMITED FORCING AVAILABLE WITH THIS
SYSTEM...QPF VALUES WILL GENERALLY BE LIGHT...RANGING FROM ONLY A
FEW HUNDREDTHS OF AN INCH ACROSS NORTH CENTRAL KANSAS UPWARDS OF
AROUND THREE-QUARTERS OF AN INCH OVER EAST CENTRAL KANSAS. MODELS
SHOW THE BEST TIMEFRAME FOR PRECIPITATION BEING ROUGHLY BETWEEN
09Z AND 15Z...EXITING OUT OF EAST CENTRAL KANSAS AROUND 18Z. AS
WINDS VEER TO THE NORTH BEHIND THE FRONT THURSDAY MORNING AND
BECOME BREEZY AT TIMES DURING THE AFTERNOON...COOLER TEMPERATURES
ARE EXPECTED FOR THURSDAY. HOWEVER THE AIRMASS THAT WILL FILTER
INTO THE REGION WITH THIS NORTHWEST FLOW WILL NOT BE VERY
COLD...AND EXPECT TEMPERATURES TO ONLY DROP INTO THE LOW/MID 50S
WHICH IS STILL ROUGHLY 10F DEGREES ABOVE THE SEASONAL NORMALS.

ACH  

THURSDAY NIGHT THROUGH WEDNESDAY...

THURSDAY NIGHT THROUGH FRIDAY NIGHT...A SURFACE RIDGE OF HIGH 
PRESSURE WILL BUILD SOUTHWARD ACROSS EASTERN KS. HIGHS WILL REACH 
THE MID 40S TO LOWER 50S. OVERNIGHT LOWS WILL BE IN THE 20S TO LOWER 
30S.

SATURDAY THROUGH SUNDAY...

AN UPPER LEVEL TROUGH WILL MOVE ONSHORE ACROSS THE PACIFIC NORTHWEST 
AND DIG INTO THE FOUR CORNERS REGION BY 18Z SATURDAY. A LEE SFC 
TROUGH WILL DEEPEN ACROSS THE CENTRAL AND SOUTHERN HIGH PLAINS AHEAD 
OF THE H5 TROUGH. SOUTHERLY LOW-LEVEL WINDS WILL ADVECT GULF 
MOISTURE NORTHWARD INTO THE PLAINS. WAA/ISENTROPIC LIFT WILL 
INCREASE THROUGH THE DAY SATURDAY AND RAIN CHANCES WILL INCREASE 
FROM SOUTHWEST TO NORTHEAST ACROSS THE CWA. THE H5 TROUGH ACROSS THE 
FOUR CORNERS WILL LIFT NORTHEAST INTO NORTHEAST NE AND EXTEND 
SOUTHWARD ACROSS THE SOUTHERN PLAINS SATURDAY NIGHT AND SUNNY 
MORNING. AS THE H5 TROUGH LIFTS NORTHEAST THE ASCENT AHEAD OF THE H5 
TROUGH WILL INCREASE AND NUMEROUS SHOWERS AND PERHAPS SOME ISOLATED 
THUNDERSTORMS WILL DEVELOP THROUGH THE EVENING HOURS ACROSS CENTRAL 
AND NORTH CENTRAL KS...THEN SHIFT NORTHEAST ACROSS THE CWA DURING 
THE NIGHT AND INTO THE MORNING HOURS OF SUNDAY. THE 700MB DRY SLOT 
WILL SHIFT NORTHEAST ACROSS THE CWA SUNDAY AFTERNOON...AND SKIES 
SHOULD CLEAR FOR SOME AFTERNOON INSOLATION. HIGHS ACROSS EAST 
CENTRAL KS WILL REACH THE MID 50S...WITH UPPER 40S ACROSS NORTH 
CENTRAL KS.

SUNDAY NIGHT...THE UPPER LEVEL TROUGH WILL LIFT NORTHEAST INTO 
SOUTHERN MN. ATTM...MOST OF THE WRAP AROUND MOISTURE WILL STAY TO 
THE NORTH OF THE CWA...THE NORTHERN COUNTIES ALONG THE NE BORDER MAY 
SEE A SLIGHT CHANCE FOR LIGHT SNOW OR FLURRIES DURING THE EVENING 
HOURS. OVERNIGHT LOWS WILL REACH THE MID TO UPPER 20S.

MONDAY THROUGH WEDNESDAY...ANOTHER UPPER LEVEL TROUGH WILL DIG 
SOUTHWARD ACROSS THE WEST CENTRAL CONUS INTO THE SOUTHERN NM BY 
EARLY TUESDAY MORNING. THE H5 TROUGH WILL MOVE EAST ACROSS NORTH TX 
AND OK AND THE STRONGER ASCENT WILL REMAIN WELL SOUTH OF THE CWA. 
THEREFORE...THE PRECIP CHANCES SHOULD STAY SOUTH ACROSS EXTREME 
SOUTHERN KS AND OK TUESDAY INTO WEDNESDAY. HIGHS WILL BE NEAR 
SEASONAL NORMS...WITH MID TO UPPER 40S. THE CLOUD COVER WILL 
INCREASE TUESDAY INTO WEDNESDAY. OVERNIGHT LOWS WILL BE IN THE 20S.
 
GARGAN



&&

.AVIATION...

FOR 18Z TAFS...INCREASING CLOUD COVER EXPECTED THROUGH THE AFTERNOON 
AND EVENING HOURS AS THE NEXT SYSTEM APPROACHES THE REGION...WITH 
CIGS DROPPING TO MVFR CONDITIONS BY LATE AFTERNOON/EARLY EVENING. CIGS/VIS 
MAY REACH BORDERLINE IFR/MVFR OVERNIGHT AS LIGHT RAIN...AND POSSIBLY 
A FEW ISOLATED THUNDERSTORMS...MOVES OVER THE TAF SITES. THESE 
SHOWERS WILL EXIT FROM WEST TO EAST THURSDAY MORNING WITH DRY 
CONDITIONS BY MID/LATE MORNING. WITH A FRONTAL PASSAGE MOVING 
THROUGH THE REGION OVERNIGHT...SOUTHERLY WINDS THIS AFTERNOON WILL 
VEER TO THE NORTHWEST BY THURSDAY MORNING. 

ACH 


&&

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

$$