000
FXUS63 KEAX 071103
AFDEAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
603 AM CDT SUN SEP 7 2008
...UPDATE AVIATION DISCUSSION...
.DISCUSSION...
/402 AM CDT SUN SEP 7 2008/
A CHALLENGING FORECAST IN TERMS OF PRECIPITATION CHANCES THROUGH THE
EARLY PART OF THE WEEK. TEMPERATURES WILL ALSO BE TRICKY DUE TO THE
ANTICIPATED CLOUD COVER AND POSSIBLE PRECIPITATION FOR THE NEXT
COUPLE DAYS.
AN UPPER SHORTWAVE TROUGH IS NOW MAKING AN EXIT TOWARD NORTHEAST
MISSOURI...TAKING THE ASSOCIATED SHOWER ACTIVITY EASTWARD WITH
IT. THIS HAS LEFT THE FORECAST AREA WITHOUT PRECIPITATION EARLY THIS
MORNING...BETWEEN THE EXITING SHOWERS TO THE EAST AND AN AREA OF
SHOWERS AND THUNDERSTORMS THAT HAS DEVELOPED OVER SOUTH CENTRAL INTO
SOUTHEAST KANSAS AND NORTHEAST OKLAHOMA. THIS AREA OF PRECIPITATION
IS VERY SIMILAR TO WHAT OCCURRED YESTERDAY MORNING...RESULTING FROM
ISENTROPIC LIFT NEAR THE 310K SURFACE. THIS AREA OF ISENTROPIC LIFT
IS FORECAST TO WEAKEN AS IT SPREADS NORTHEAST TOWARD CENTRAL
PORTIONS OF MISSOURI. THEREFORE...HAVE GONE WITH LOW END
PRECIPITATION CHANCES FOR THE SOUTHERN FORECAST SECTIONS DURING THE
DAYTIME TODAY.
TEMPERATURES TODAY WILL AGAIN POSE A CHALLENGE. RATHER EXTENSIVE
AREA OF STRATUS HAS DEVELOPED OVER MOST OF THE FORECAST AREA EARLY
THIS MORNING. THOUGH CEILINGS ARE EXPECTED TO IMPROVE INTO THE
AFTERNOON...SKIES ARE EXPECTED TO REMAIN MOSTLY CLOUDY THROUGHOUT.
HAVE TRIMMED TEMPERATURES BACK TO THE LOWER TO MIDDLE 70S FOR
TODAY...ONLY SLIGHTLY WARMER THAN YESTERDAY.
THE EVENING MODEL RUNS OF THE GFS AND SREF SHOWED TO BE QUITE
SIMILAR THROUGH TUESDAY...WITH THE NAM ONLY SLIGHTLY DIFFERENT
THROUGH MONDAY. THAT SAID...NOT TOO MUCH TO ARGUE WITH THE RATHER
CONSISTENT MODEL SOLUTIONS...REMAINING GENERALLY ON TRACK WITH THE
GOING FORECAST. MAIN ITEMS TO RESOLVE WILL BE THE MOVEMENT OF THE
MID LEVEL BAROCLINIC ZONE AND SURFACE FRONT TONIGHT THROUGH
MONDAY. THE MODELS HAVE BEEN CONSISTENT IN SHIFTING THE BAROCLINIC
ZONE NORTH TODAY AND TONIGHT...WITH IT FORECAST TO REACH NORTHERN
MISSOURI DURING THE EARLY MORNING HOURS MONDAY. THE GFS TAKES THE
BAROCLINIC ZONE A BIT FURTHER NORTH THAN THE NAM. DESPITE THE MINOR
PLACEMENT DIFFERENCE...THE MODELS AGREE ON BRINGING A SHORTWAVE
ACROSS SOUTHEASTERN NEBRASKA TOWARD NORTHWEST MISSOURI 06-12Z
MONDAY. THIS SHOULD AID IN THE DEVELOPMENT OF SHOWERS AND POSSIBLY
SOME THUNDERSTORMS...ESPECIALLY OVER THE NORTHERN HALF OR SO OF THE
FORECAST AREA OVERNIGHT TONIGHT.
THE MODELS THEN AGREE ON ADDITIONAL SHORTWAVE ENERGY TO DRIVE THE
FRONT SOUTH ON MONDAY. INCREASED CHANCES FOR SHOWERS AND SOME
THUNDERSTORMS WILL COME IN THE POST FRONTAL AIRMASS MONDAY INTO
MONDAY NIGHT. A PERIOD OF GUSTY NORTH WINDS SHOULD FOLLOW THE
FRONT MONDAY AFTERNOON AND EVENING. THERE SHOULD BE A MODEST RANGE
IN TEMPERATURES ACROSS THE FORECAST AREA FOR MONDAY...DEPENDENT ON
THE SPEED OF THE FRONT.
ANY LINGERING PRECIPITATION ACROSS THE EASTERN AND SOUTHEASTERN
FORECAST SECTIONS SHOULD MOVE OUT TUESDAY MORNING. COOLER AND DRIER
AIR WILL SPREAD ACROSS THE REGION AS A SURFACE HIGH MOVES ACROSS.
DID CUT BACK PRECIPITATION CHANCES MAINLY ACROSS THE SOUTHERN
FORECAST SECTIONS FOR WEDNESDAY. KEPT LOW END PRECIPITATION CHANCES
ACROSS NORTHERN MISSOURI WITH A WARM ADVECTION REGIME AND CLOSER TO
A POSSIBLE SHORTWAVE PASSING BY. OTHERWISE FEW CHANGES MADE PAST
WEDNESDAY.
STOFLET
&&
.AVIATION...
FOR THE 12Z TAFS...CIGS AND VSBYS SHOULD IMPROVE BY MID
MORNING...LIKELY GOING INTO THE VFR CATEGORY BY NOONTIME AS BULK OF
LOW LEVEL MOISTURE MOVES EAST WITH EXITING SHORT WAVE. AREA THEN
UNDERGOES A BRIEF PERIOD OF ZONAL FLOW DURING THE AFTERNOON AND
EVENING HOURS...BEFORE NEXT SHORT WAVE STARTS TO DIG INTO THE
NORTHERN PLAINS LATE TONIGHT. IN RESPONSE TO THIS SHORT WAVE...A
FRONT WILL BE TAKING SHAPE OVER NORTHERN MISSOURI...WHICH MAY
PROVIDE THE FOCUS FOR MORE LOW CLOUDS AND FOG OVERNIGHT. NOT OUT OF
THE QUESTION RAIN MAY MAKE IT INTO THE SITES BY 12Z...BUT LLJ SHOULD
SUPPORT HIGHER THREAT OF RAIN WEST OF THE REGION...SO WILL KEEP TAFS
DRY FOR NOW.
PC
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
$$
