FXUS63 KTOP 270542
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1142 PM CST THU NOV 26 2009
.UPDATE...
UPDATE FOR 06Z AVIATION.
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.DISCUSSION...
SEE PREVIOUS DISCUSSION.
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.AVIATION...
SURFACE OBSERVATIONS OF LOCALLY STEADYING TEMPERATURES AND MUCH
STRONGER WINDS AT KCNK SUGGEST WINDS JUST OFF THE SURFACE ARE
INCREASING. LATEST BUFKIT DATA CONSISTENT WITH NEAR 30KT OF WSW
WIND JUST A FEW HUNDRED FEET OFF THE SURFACE OVERNIGHT...SO WILL
GO AHEAD WITH LLWS MENTION. UPPER RIDGE BUILDING INTO THE PLAINS
WILL BRING LITTLE CLOUD OR OTHER SIGNIFICANT WEATHER.
65
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.PREV DISCUSSION... /ISSUED 305 PM CST THU NOV 26 2009/
DISCUSSION...
MAIN FORECAST PROBLEM THROUGH FRIDAY IS TEMPERATURES. RIDGE OF
HIGH PRESSURE OVER EASTERN KS AT MID AFTERNOON WILL CONTINUE
MOVING SEWD. WHILE PRESSURE GRADIENT STRENGTHENS LATER
TONIGHT...EXPECT LIGHT WINDS UNTIL AFTER SUNRISE.
THUS...TEMPERATURES SHOULD FALL QUICKLY. STATISTICAL GUIDANCE
FORECAST LOWS FOR TONIGHT ARE MAINLY UPPER 20S TO LOWER 30S.
BELIEVE LOWS MAY FALL BELOW THOSE AS DEWPOINTS ARE ONLY IN THE
LOWER TO MIDDLE 20S...AND ONLY THIN CIRRUS FOR CLOUDS. WILL
UNDERCUT GUIDANCE LOWS BY A COUPLE DEGREES FOR TONIGHT. ON
FRIDAY...SSWLY LOW-LEVEL WINDS SHOULD INCREASE AND LEAD TO SOME
MIXING. CONTINUED CLEAR SKIES WILL HELP THINGS WARM UP AT LEAST
35 DEGREES FOR MOST AREAS. NAM GUIDANCE HAS 72 FOR A HIGH FOR
TOP...AND THAT APPEARS TOO WARM AS DIFFICULT TO SEE A RISE OF NEAR
45 DEGREES WITH RELATIVELY WEAK SUN THIS TIME OF YEAR. HAVE GONE
SLIGHTLY WARMER THAN GFS GUIDANCE WITH MAINLY MID 60S EXPECTED.
SHOULD BE ABLE TO GET ONE MORE NICE DAY OVER THE WEEKEND AS A
FRONT SLOWLY APPROACHES THE AREA ON SATURDAY. MID LEVEL TEMPS
AHEAD OF THE BOUNDARY ARE CONSERVATIVELY 10-12C. CURRENTLY HAVE
HIGHS IN THE UPPER 50S ACROSS THE NW WHERE THE BOUNDARY MOVES IN
DURING THE AFTERNOON...WITH LOWER 60S SE. WOULDNT BE SURPRISED IF
SE NUMBERS NEED TO BE NUDGED UP A FEW MORE DEGREES.
FRONT THEN PROGGED TO MOVE SOUTHWARD OVER SOUTHERN KS SATURDAY
NIGHT...AND SLOW ITS FORWARD PROGRESSION UNDER NEARLY PARALLEL WSW
FLOW ALOFT. FRONT INITIALLY PUSHES THROUGH DRY...AS BETTER THETAE
NUMBERS STRUGGLE TO MAKE IT BACK INTO SE KS. NEXT UPPER TROF THEN
DROPS INTO THE CTRL ROCKIES EARLY MORNING SUNDAY...AND WILL ALSO
BRING BETTER LIFT ACROSS THE STATE AS IT DOES SO. DURING THE DAY
SUNDAY THE MOISTURE OUTRUNS MOST OF THE LIFT SUCH THAT DESPITE
COLDER TEMPERATURES WOULD ONLY EXPECT A BRIEF ROUND OF RAIN SHOW
MIX AT BEST...WITH RAIN SE. DID TRIM DOWN INHERITED POPS FOR
SUNDAY NIGHT AS LATEST RUNS SUGGEST A FASTER DEPART OF THE
BOUNDARY INTO THE SOUTHERN PLAINS...LEAVING HIGHS ONLY IN THE 40S
FOR MONDAY.
TUES-THURS...WENT TOWARDS COOLER SIDE OF GUIDANCE THESE PERIODS.
UPPER LOW MOVES THROUGH THE SOUTHERN PLAINS AND RAPIDLY INTO THE
NE TUESDAY AND WEDNESDAY. THINK THE PATTERN REFLECTS A COOLER
TREND...WITH CWA BETWEEN THIS SOUTHERN SYSTEM AND THE
NORTHWESTERLY FLOW TO THE NORTH THAT SHIFTS SOUTH OVER THE AREA ON
TUESDAY. CONSIDERABLE VARIABILITY IN THE SOLUTIONS SEEN IN THE
ENSEMBLE MEMBERS AND KEPT MOST GUIDANCE TOWARDS HPC ATTM. 67
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.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
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