187
FXUS63 KEAX 250858
AFDEAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
258 AM CST WED NOV 25 2009
DISCUSSION
MAIN CONCERN FOR THIS FORECAST DEALS PRIMARILY WITH TEMPERATURES...
WITH A CLIPPER SYSTEM REINFORCING COOLER AIR IN THE REGION TODAY AND
THURSDAY. THEN UPPER RIDGING WILL ALLOW FOR A NICE WARM UP HEADING
INTO THE WEEKEND.
SYNOPSIS:
WATER VAPOR IMAGERY SHOWED A FAST MOVING CLIPPER SYSTEM DIVING
THROUGH THE NORTHERN PLAINS. MODELS SEEM TO BE TRACKING THIS SYSTEM
WELL WITH ALL SHOWING A STRONG PV ANOMALY ON THE 1.5 PVU SURFACE IN
DECENT CORRELATION TO THE WV IMAGERY. 00Z UA CHARTS SHOW AN
APPROXIMATELY 100 TO 110 KT UPPER JET IS ASSOCIATED WITH THIS
ANOMALY. IN THE MID LEVELS...VERY COLD AIR IS ASSOCIATED WITH THIS
SYSTEM WITH -13C AND -32C AT 700MB AND 500MB RESPECTIVELY AT GGW.
THIS INDICATES THAT AS THE SYSTEM MOVES OVER US STEEP MID LEVEL
LAPSE RATES CAN BE EXPECTED. AT THE SURFACE...A WOUND UP LOW
PRESSURE AREA CAN BE SEEN IN THE UPPER MISSISSIPPI VALLEY IN
ASSOCIATION WITH THE WAVE THAT MOVED THROUGH TUESDAY. ANOTHER LOW
PRESSURE AREA WAS FORMING AHEAD OF THE CLIPPER SYSTEM IN EASTERN
SD/SOUTHWEST MN WITH 4MB 6 HOUR PRESSURE FALLS NOTED.
TODAY THROUGH TONIGHT:
THE UPPER LEVEL PV ANOMALY WILL BEGIN TO IMPACT THE AREA LATER THIS
MORNING. AS THIS FORCING MECHANISM APPROACHES THE REGION THERE MAY
BE ENOUGH UPWARD MOTION TO WRING OUT A FEW SNOW FLURRIES THROUGH MID
MORNING IN NORTHERN/NORTHWEST MISSOURI. AS THE LOW LEVELS WARM UP
THIS WOULD LIKELY TREND TO SPRINKLES. SO CONTINUED MENTION OF THIS
AHEAD OF THE ANOMALY ACROSS WESTERN AND CENTRAL MISSOURI. AS THE
ANOMALY WRAPS UP JUST EAST OF THE AREA IT MAY TRIGGER A FEW SHOWERS
ACROSS NORTHERN/NORTHEAST MISSOURI. FORECAST SOUNDINGS SHOW A FAIR
AMOUNT OF INSTABILITY FOR THIS TIME OF YEAR THROUGHOUT THE REGION
DUE TO THE STEEP MID LEVEL LAPSE RATES. THE BEST MOISTURE HOWEVER
SHOULD STAY GENERALLY NORTH OF MISSOURI RIVER. SO KEPT AFTERNOON
SHOWER MENTION TO NORTHERN/NORTHEASTERN SECTIONS OF THE FORECAST
AREA. AS COLD AIR FILTERS INTO THE AREA A TRANSITION TO SNOW SHOULD
OCCUR DURING THE OVERNIGHT HOURS. AGAIN THIS SHOULD BE CONFINED TO
NORTHERN/NORTHEASTERN SECTIONS OF THE FORECAST AREA. OVERALL...
MOISTURE SEEMS FAIRLY LIMITED SO ONLY TRACE AMOUNTS OF PRECIPITATION
ARE EXPECTED.
THANKSGIVING DAY:
A CHILLY BUT FAIR WEATHER DAY IS EXPECTED FOR THANKSGIVING. AS THE
UPPER SYSTEM PULLS AWAY SKIES WILL CLEAR FROM WEST TO EAST ACROSS
THE REGION AND SOMEWHAT BRISK NORTHWEST WINDS WILL PREVAIL. WITH
MIXING TO ABOUT 900MB HIGHS SHOULD TOP OUT IN THE LOWER TO MID 40S
WITH THE WARMER TEMPERATURES ACROSS WESTERN MISSOURI AND EASTERN
KANSAS.
FRIDAY THROUGH SATURDAY:
UPPER LEVEL RIDGING AND WARMING TEMPERATURES ALOFT WILL ALLOW FOR A
NICE WARM UP TO START THE WEEKEND. HIGHS SHOULD BE ABLE TO REBOUND
INTO THE MID TO UPPER 50S FOR FRIDAY WITH SIMILAR READINGS FOR
SATURDAY. THE UPPER RIDGING SHOULD KEEP THINGS DRY AS WELL. A DECENT
LOW LEVEL JET DEVELOPS SATURDAY MORNING BUT FORECAST SOUNDINGS ARE
SO DRY I DO NOT EXPECT ANYTHING FROM THIS FEATURE SO THE FORECAST
REMAINS DRY THROUGH SATURDAY. MODELS WANT TO BRING A FRONT THROUGH
THE AREA LATE SATURDAY NIGHT OR EARLY SUNDAY MORNING. WHILE FORECAST
SOUNDINGS FOR THIS TIME FRAME ARE VERY DRY THERE MAY BE ENOUGH
FORCING TO TRIGGER SOMETHING. GOING FORECAST HAD SLIGHT CHANCE
MENTION FOR THIS TIME FRAME AND SEE NO REASON TO ADJUST THAT AT THIS
POINT IN TIME.
CDB
AVIATION
FOR THE 06Z TAFS...THE CLOUDS HAVE JUST ABOUT CLEARED THE TERMINALS
AS THE UPPER LEVEL LOW PULLS RAPIDLY NE. ANOTHER STG SHORTWAVE TROUGH
WILL DIVE INTO THE MISSOURI AND IOWA ON WEDNESDAY. THIS SYSTEM WILL
BE MOISTURE STARVED...BUT GIVEN THE COLD POOL ALOFT...CANNOT RULE OUT
A VFR SHOWER. OTHERWISE...INTERMITTENT VFR SC/AC DECK IS EXPECTED
WITH GUSTY NW WINDS...ESPECIALLY DURING THE AFTN HOURS.
DB
EAX WATCHES/WARNINGS/ADVISORIES
MO...NONE.
KS...NONE.
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