FXUS63 KEAX 291138
AFDEAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
538 AM CST SUN NOV 29 2009
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
MAIN FORECAST CHANGE IS TO RAISE TEMPERATURES A BIT ON TUESDAY AND
REMOVE THE SILENT SLIGHT CHANCE POPS WE HAD GOING ON WEDNESDAY.
SURFACE FRONT HAS BEEN PUSHING SOUTHEAST ACROSS THE FORECAST AREA
OVERNIGHT. STRONGEST HEIGHT RISES BEHIND THIS FRONT HAVE BEEN OVER
SOUTH CENTRAL KANSAS AND NORTHWEST OKLAHOMA...AS SURFACE RIDGE DIVES
INTO THE HIGH PLAINS. NORTHERN STREAM SHORT WAVE MOVING INTO THE
UPPER MIDWEST BY 12Z...WITH ONLY A WEAK REFLECTION OF A SURFACE LOW
HEADING FROM SOUTHEAST IOWA INTO NORTHERN ILLINOIS. THUS EXPECT
FRONT ONLY TO MAKE SLOW BUT STEADY PROGRESS SOUTHEAST AND TO STILL
BE ON SOUTHEAST FRINGES OF CWFA AT 12Z. MODELS STILL ADVERTISING A
PERIOD OF SATURATION IN THE VICINITY OF THIS FRONT AT 12Z...SO CAN
NOT RULE OUT SOME DRIZZLE OR A SLIGHT CHANCE OF LIGHT RAIN. BUT WILL
CONFINE THE MENTION OF PRECIPITATION TO THE MORNING HOURS...AS BY
18Z...THE SURFACE AND 850MB FRONT SHOULD BE EAST OF THE FORECAST
AREA...WITH DRIER MID LEVEL AIR STARTING TO MIX DOWN.
EVEN TRICKIER ARE TEMPERATURES TODAY AS THERE WILL BE COLD AIR
ADVECTING IN BEHIND THIS FRONT...SO IN SOUTHEAST AREAS THAT ARE
STILL WARM...THERE MAY BE A DROP THIS MORNING AND NOT RECOVER AS
MUCH THIS AFTERNOON AS CLOUDS MAY NOT BE CLEARING UNTIL LATER THIS
AFTERNOON. ON THE OTHER HAND...EXPECT NORTHWEST AREAS WILL SEE MORE
SUNSHINE WITH DRIER AIR ADVECTING IN BEHIND THE FRONT...SO WILL
STILL GO WITH ABOUT A 10 DEGREE DIURNAL RISE THERE DESPITE CAA.
SURFACE RIDGE AXIS WILL NOSE ACROSS THE FORECAST AREA TONIGHT...AND
ALTHOUGH SOURCE REGION FOR THIS AIRMASS IS MORE OF PACIFIC
ORIGIN...DRYING AND COOLING OF THIS AIR OVER THE ROCKIES...SHOULD
STILL SUPPORT TEMPERATURES AT OR BELOW FREEZING TONIGHT AS THIS AIR
SPILLS INTO THE PLAINS...ESPECIALLY WITH MOSTLY CLEAR SKIES AND
LIGHT WINDS SUPPORTING RADIATIONAL EFFECTS.
TEMPERATURES SHOULD START TO RECOVER ON MONDAY AS SURFACE RIDGE
DROPS SOUTH OF THE REGION AND LOW LEVEL WINDS TURN WESTERLY. MORE
SIGNIFICANT WARM UP LOOKS TO BE ON TUESDAY. NORTHERN STREAM FLOW
FLATTENS AND SOUTHERN STREAM RIDGING AHEAD OF A CUT OFF LOW ALSO
NOSES INTO MISSOURI. WILL GO TOWARD THE HIGH END OF GUIDANCE
NUMBERS. MAY BE EVEN WARMER...BUT WITH THIS SPLIT FLOW...TOO MUCH
UNCERTAINTY ON EXACT FLOW WE WILL BE SEEING TO GO TOO EXTREME AT
THIS POINT.
FOR WEDNESDAY...CONSENSUS BETWEEN LATEST OPERATIONAL ECMWF AND GFS
SEEMS TO KEEP SOUTHERN STREAM WAVE FAR ENOUGH TO THE SOUTH TO KEEP
FORECAST AREA DRY AT THIS POINT. SO WILL PULL THE SLIGHT CHANCE POPS
WE HAD GOING FOR THE DAY ON WEDNESDAY.
PC
&&
.AVIATION...
FOR THE 12Z TAFS...EARLY MORNING FRONTAL PASSAGE HAS SHIFTED WINDS TO
THE NORTH AT ALL THREE TERMINAL SITES...AND BROUGHT IN SOME IFR
CEILINGS. WINDS BEHIND THE FRONT WILL REMAIN OUT OF THE NORTH THROUGH
THE DAY AND BE A BIT GUSTY. HOWEVER...LATE IN THE DAY THE PRESSURE
GRADIENT WILL RELAX ENOUGH TO ALLOW THE WIND TO SUBSIDE. ALSO...EARLY
SUNDAY MORNING WINDS WILL BACK TO THE WEST AS A WEAK SURFACE RIDGE
BEHIND THE FRONT SETTLES SOUTH THROUGH THE REGION. OTHERWISE...IFR
CEILINGS SHOULD PERSIST ONLY THROUGH THE MID MORNING HOURS. AFTER
THAT DRIER AIR BEHIND THE FRONT WILL MOVE IN AND SHOVE THE CLOUD
COVER EAST LIFTING CEILINGS BACK INTO THE MVFR RANGE AT A MINIMUM FOR
THE REMAINDER OF THE AFTERNOON HOURS.
CUTTER
&&
.CLIMATE...
THERE WILL BE POTENTIAL FOR THE TEMPERATURE AT THE KANSAS CITY
INTERNATIONAL OFFICIAL REPORTING SITE TO REACH 28 DEGREES TONIGHT.
THAT WILL BECOME THE LATEST DATE THAT 28 DEGREES HAS OCCURRED. IF IT
DOES NOT OCCUR TONIGHT...THEN BY THURSDAY MORNING WE WILL SEE A HARD
FREEZE. HERE ARE THE TOP 5 LATEST OCCURRENCES OF 28 DEGREE LOW
TEMPERATURES IN KANSAS CITY:
RANK DATE YEAR
----- ------ ------
? ?????? 2009
1 NOV 29 1905
2 NOV 27 1944
3 NOV 26 1902
4 NOV 26 1958
5 NOV 25 1928
FOR ADDITIONAL INFORMATION...PLEASE VISIT OUR WEBSITE AT
WWW.WEATHER.GOV/KC.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
