Area Forecast Discussion Issued by NWS Topeka, KS
000
FXUS63 KTOP 241120
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
620 AM CDT FRI MAY 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT FRI MAY 24 2013
00Z 500MB RAOBS INDICATE RISING HEIGHTS OVER THE CENTRAL CONUS WITH
UPPER TROFS FLANKING A DEVELOPING RIDGE. THE RIDGE AT 700MB WAS OVER
EASTERN KANSAS...WHILE AT 850MB DEWPOINTS RANGED FROM AROUND 3C AT
KTOP AND KOUN TO AROUND 12 AT KDDC...KAMA...AND KFWD. WESTERN KANSAS
RADARS AND OBSERVATIONS INDICATING SOME ISOLATED MID LEVEL
CONVECTION WITH A WEAKENING CONVECTIVE CLUSTER OVER EASTERN COLORADO.
ISENTROPIC LIFT INCREASES AND LOWERS TO AROUND 850MB TODAY AS THE
700MB RIDGE SHIFTS TO THE MISSOURI BORDER. LOW/MID LEVELS SLOWLY
SATURATE...AND THERE MAY BE ENOUGH LIFT FOR ISOLATED TO SCATTERED
ELEVATED STORMS BY SUNRISE AND CONTINUING THROUGH MUCH OF THE DAY.
CHANCES SHOULD BE LIMITED TO THE WESTERN PORTIONS OF THE COUNTY
WARNING AREA WITH THE MID LEVEL RIDGE STILL IN PLACE. SOME WEAKENING
IN THE WAA OCCURS IN THE AFTERNOON AND COULD LEAD TO A DOWNWARD
TREND...BUT A STRONGER LOW LEVEL JET IN AN INCREASINGLY MOIST
TROPOSPHERE SUGGESTS SOME CHANCE FOR CONVECTION INCREASING AND
SPREADING ACROSS KANSAS TONIGHT. THERE IS NOT MUCH OF A FOCUSING
MECHANISM TO POINT TO ANY PARTICULAR LOCATIONS IN THE REGION FOR
BETTER PRECIP CHANCES...BUT KEPT LARGEST CHANCES IN THE NORTH AND
WEST WHERE SLIGHTLY BETTER MOISTURE ADVECTION AND PRECIPITABLE WATER
SHOULD RESIDE. SOUTHEAST WINDS WILL INCREASE MORE THAN RECENT DAYS
BY LATE THIS MORNING AS LEE LOW PRESSURE DEEPENS...WITH THE BETTER
MIXING AND MODEST LOW LEVEL WAA RESULTING IN SLIGHTLY WARMER HIGHS.
LOWS TONIGHT WILL BE SEVERAL DEGREES WARMER IN THE MORE MOIST AND
INSULATED AIRMASS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 347 AM CDT FRI MAY 24 2013
THE WEEKEND PATTERN WILL BE CHARACTERIZED BY TROUGHS IN THE WEST AND
EAST WITH A RIDGE OVER THE CENTRAL PLAINS THIS PATTERN REMAINS INTO
MONDAY BEFORE THE RIDGE MOVES OFF TO THE EAST BY WEDNESDAY. SEVERAL
PIECES OF ENERGY WILL MOVE OUT OF THE WESTERN TROUGH FROM SATURDAY
THROUGH NEXT WEDNESDAY....HOWEVER THE UPPER TROUGH WILL MOVE OUT
INTO THE EASTERN ROCKIES BY FRIDAY. THIS WILL PROVIDE NUMEROUS
CHANCES FOR THUNDERSTORMS THROUGH THE PERIOD. THE TIMING OF THE
WAVES EMANATING OUT OF THE WESTERN TROUGH IS HARD TO CALL AT THIS
TIME. ALSO ANY MESOSCALE BOUNDARIES LEFT OVER FROM DECAYING
OVERNIGHT CONVECTION WILL PROVIDE A FOCUS FOR LATER DEVELOPMENT.
MOISTURE WILL MOVE BACK INTO CENTRAL AND EASTERN KANSAS AS THE LOW
LEVEL JET BECOMES SOUTH TO SOUTHWEST OVER CENTRAL AND EASTERN
KANSAS. A THETA-E RIDGE WILL STRETCH ACROSS NORTH CENTRAL AND
NORTHEAST KANSAS THROUGH MUCH OF THE NEXT WEEK. CONVECTION IS
EXPECTED TO DEVELOP IN THE WESTERN HIGH PLAINS AND INTO CENTRAL AND
EASTERN NEBRASKA SATURDAY NIGHT WITH ISENTROPIC LIFT OVER A FRONTAL
BOUNDARY NEAR THE NEBRASKA BORDER. HIGHEST CHANCES WILL REMAIN
FOCUSED NORTH. AGAIN ANY OLD OUTFLOW BOUNDARY ACROSS THE CWA COULD
BE A FOCUS FOR AFTERNOON CONVECTION AS MCS/S MOVE ACROSS NEBRASKA
AND NORTHERN KANSAS ON SUNDAY. INSTABILITY COULD BE AS HIGH AS 3000
J/KG TO 4800 J/KG MUCAPE ACROSS THE CWA. DEEP LAYER SHEAR AROUND 30
KTS SUNDAY AFTERNOON. MOISTURE TRANSPORT VECTORS INCREASE ACROSS
CENTRAL KANSAS INTO SOUTHEAST NEBRASKA THROUGH THE DAY. PRECIPITABLE
WATER VALUES INCREASE TO AROUND 1.5 INCHES. LOCALLY HEAVY RAINFALL
IS POSSIBLE WITH ANY CONVECTION SUNDAY AND SUNDAY NIGHT.
CONTINUED CHANCES FOR NOCTURNAL CONVECTION WILL CONTINUE THROUGH THE
BULK OF THE WEEK WITH MORE WIDELY SCATTERED ACTIVITY IN THE
AFTERNOON AND EVENING HOURS. IF THUNDERSTORMS CONTINUE TO MOVE OVER
THE SAME AREAS DURING THE WEEK COULD SEE SOME FLOOD/FLASH FLOODING.
HIGHS WILL BE IN THE 80S THROUGH THE MONDAY THROUGH THURSDAY PERIOD
WITH LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 620 AM CDT FRI MAY 24 2013
VFR CONDITIONS ANTICIPATED. RESIDUAL LOW LEVEL MOISTURE AND
INCREASING MIXING COULD LEAVE TO SCATTERED MVFR CLOUDS MAINLY
THROUGH 18Z. THERE ARE SMALL CHANCES FOR HIGH-BASED CONVECTION
THROUGH MUCH OF THIS FORECAST BUT DETAILS IN COVERAGE AND WHEN ANY
WOULD IMPACT THE TERMINALS ARE TOO UNCERTAIN INCLUSION.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...53
AVIATION...65