282
FXUS63 KTOP 071717
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1117 AM CST SAT NOV 7 2009
UPDATE
UPDATED FOR 18 UTC AVIATION FORECAST.
DISCUSSION
SEE PREVIOUS FORECAST DISCUSSION BELOW.
AVIATION
CLEAR SKIES AND LIGHT WINDS WILL BE PRESENT AT ALL THREE TAF SITES
FOR MUCH OF THE DAY TODAY. DURING THE VERY EARLY MORNING HOURS LOW
LEVEL MOISTURE WILL BE ON THE INCREASE. AN AIRMASS THAT PRODUCED
VIS AND CIG RESTRICTIONS OVER NORTHEAST TEXAS THIS MORNING WILL BE
MOVING IN. ANTICIPATE SOME COMBO OF LOWER VIS AND PERHAPS SOME
STRATUS AS WELL BY MORNING. FOG COULD SET IN... PARTICULARLY AT
FOE IF THE WINDS CAN DROP OFF A BIT BUT IT CURRENTLY LOOKS LIKE
LIGHT SOUTH WINDS WILL PROMOTE MIXING AND VIS MAY STAY A BIT
BETTER THAN IT OTHERWISE WOULD. EXPECT THIS TO BURN OFF BY MID TO
LATE MORNING WITH STRONGER SOUTH WINDS TAKING OVER.
BARJENBRUCH
PREV DISCUSSION
/ISSUED 541 AM CST SAT NOV 7 2009/
00Z UPPER AIR DATA AND RECENT WATER VAPOR IMAGERY SHOWING SEVERAL
UPSTREAM FEATURES OF NOTE. LARGE UPPER LOW WAS OFF THE NORTHERN
BRITISH COLUMBIA COAST...WITH BROAD AND SOMEWHAT FAST UPPER JET
FROM 35N TO 45N OVER THE PACIFIC. APPEARS ONE WAVE IN THIS FLOW
WAS APPROACHING THE WASHINGTON COAST AT 08Z. FARTHER EAST...AN
UPPER SYSTEM CONTINUES TO WORK ITS WAY EAST INTO THE BAJA
REGION...WHILE A SHORTWAVE TROF WAS AMPLIFYING AS IT MOVED ALONG
THE SASKATCHEWAN/NORTH DAKOTA BORDER AREA. A MODIFIED PACIFIC
FRONT WITH NEARLY VERTICAL CONTINUITY UP TO 850MB WITH THE LATTER
WAVE WAS LOCATED FROM WESTERN MINNESOTA SOUTHWEST TO NORTHERN
NEBRASKA AT 0Z...WITH RECENT PROFILER...RADAR VWP...AND SURFACE
OBSERVATIONS PUTTING IT FROM NORTH CENTRAL IOWA TO SOUTHEAST
NEBRASKA TO SOUTHWEST KANSAS AT 08Z.
ALTERATIONS FROM THE PREVIOUS FORECAST WERE MINIMAL. NEARLY ZONAL
FLOW OVER THE CENTRAL PLAINS AND THE WAVE TO THE NORTH CONTINUING TO
PUSH EAST WILL STALL THE WEAK BOUNDARY NEAR INTERSTATE 70
TODAY...PROVIDING MUCH WEAKER WINDS THAN FRIDAY BUT LITTLE CHANGE IN
TEMPERATURES...AGAIN SOME 15-20 DEGREES ABOVE NORMAL. RECORD HIGHS
ARE IN THE UPPER 70S AND LOWER 80S AND SHOULD BE SAFE. SOUTHWEST
WINDS INCREASE AGAIN AROUND 925MB TONIGHT AS THE BOUNDARY RETREATS
NORTH...AND MODELS AGAIN SHOWING POSSIBLE LOW STRATUS MOVING IN LATE
IN THE NIGHT. WITH SOME STRATUS DEVELOPING IN SOUTH CENTRAL AND
EASTERN TEXAS THIS MORNING...WILL INCREASE CLOUDS SOMEWHAT...BUT NOT
SOLD ON WIDESPREAD CLOUDS AT THIS TIME. ANY CLOUD SHOULD BE RATHER
SHALLOW AND MIX OUT QUICKLY SUNDAY MORNING...WITH SLIGHTLY DEEPER
MIXING AND GOOD SOUTHWEST FLOW NOT FAR OFF THE SURFACE PROVIDING
ANOTHER SIMILARLY WARM DAY EVEN WITH SOME HIGH CLOUD.
DESPITE THE MUDDLED AFOREMENTIONED FLOW OFF THE WEST COAST...THE
MODELS REMAIN SIMILAR IN THE PAC NW WAVE DEEPENING OVER THE PLAINS
SUNDAY NIGHT AND MONDAY. THOUGH THE BAJA WAVE WILL BE MOVING ACROSS
THE SOUTHERN PLAINS...COOLING TEMPERATURES ALOFT WITH DECENT MID
LAYER FRONTOGENESIS AND SOME COUPLING OF EXITING UPPER JET TO THE
NORTHEAST AND WESTERN JET MOVING IN SHOULD ALLOW FOR SOME
PRECIPITATION TO RESULT MAINLY DURING THE DAY MONDAY...BUT POSSIBLY
AS EARLY AS SUNDAY NIGHT AND STRETCHING INTO THE OVERNIGHT HOURS
MONDAY NIGHT. ELEVATED INSTABILITY REMAINS MEAGER...AND THUNDER
CHANCES CONTINUE TO BE LOW. TEMPERATURES MONDAY SHOULD BE MUCH
CLOSER TO MID NOVEMBER NORMALS.
65
TOP WATCHES/WARNINGS/ADVISORIES
NONE.
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