FXUS63 KSGF 222319
AFDSGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
520 PM CST TUE DEC 22 2009
...AVIATION UPDATE...
.DISCUSSION...
SHORT TERM (TONIGHT THROUGH CHRISTMAS MORNING)...
A SIGNIFICANT WINTER STORM WITH THE POTENTIAL FOR SEVERE WEATHER
AND ACCUMULATING WINTER PRECIPITATION IS THE MAIN FORECAST
CHALLENGE FOR THE SHORT TERM.
SIGNIFICANT MOISTURE ADVECTION OFF THE WESTERN GULF IS BEING
TRANSPORTED NORTH INTO THE PLAINS VIA A STRONG LOW LEVEL JET.
SURFACE DEW POINT INTO THE 50S HAVE SURGED AS FAR NORTH AS THE
RED RIVER VALLEY. THIS WILL BECOME PROBLEMATIC FOR THE REGION AS
LEE SIDE CYCLOGENESIS ONGOING IN THE TEXAS PAN HANDLE WILL BEGIN
TO SHIFT TOWARDS THE REGION. CONTINUED MOISTURE ADVECTION ACROSS
THE REGION AND SOME ELEVATED INSTABILITY COULD BRING A CHANCE OF
SOME ISOLATED TO WIDELY SCATTERED THUNDERSTORMS OVER THE AREA
OVERNIGHT TONIGHT. CURRENTLY FEEL THAT WE SHOULD SEE SOME SHOWERS
DEVELOP THIS EVENING AND CONTINUE INTO WEDNESDAY AHEAD OF THE
FIRST OF TWO LOWS THAT WILL IMPACT THE REGION.
INITIAL LOW WILL TRACK NORTH ALONG THE MISSOURI...KANSAS STATE
LINE WEDNESDAY AFTERNOON AND INTO EARLY THURSDAY MORNING. WITH
THE WARM AND MOIST AIR IN PLACE...THE LIFT ASSOCIATED WITH THE
SYSTEM AND APPROACHING COLD FRONT...ALONG WITH SOME
INSTABILITY...IT WILL BE POSSIBLE FOR STRONG TO SEVERE
THUNDERSTORMS TO DEVELOP. WITH LOW FREEZING LEVELS AND THE
SIGNIFICANT AMOUNTS OF LIFT THAT WILL BE AVAILABLE...THE STORMS
WILL HAVE THE POTENTIAL TO PRODUCE HAIL TO QUARTER SIZE AND SOME
ISOLATED WIND GUSTS TO 60 MPH. THIS WILL BE IN ADDITION TO
SYNOPTIC WINDS EXPECTED TO BE GUSTING TO 20 TO 30 KTS.
FLASH FLOODING WILL ALSO BE AN ISSUE...THOUGH MAINLY FOR
LOCATIONS EAST OF HIGHWAY 65 FROM THURSDAY MORNING AND INTO THE
AFTERNOON AS THE SECOND AND STRONGER SURFACE LOW THAT DEVELOPS
OVER SOUTHERN ARKANSAS BEGINS TO DEEPEN. THIS WILL BE IN RESPONSE
TO A COUPLED UPPER LEVEL JET WHICH WILL PRODUCE AN AREA OF UPPER
LEVEL DIVERGENCE OVER ARKANSAS AND INTO SOUTHERN MISSOURI. THIS
WILL PROVIDE AN AREA OF DEEP LIFT AND ALLOW THE LOW TO DEVELOP
NORTHWARD ACROSS EASTERN MISSOURI. RAINFALL AMOUNTS ACROSS THE
EASTERN OZARKS ARE EXPECTED TO BE IN THE ONE TO THREE INCH RANGE.
AS THE SURFACE LOW MOVES NORTH...COLD AIR WILL QUICKLY FILTER
INTO THE REGION BEHIND A SHARP COLD FRONT. AS THIS OCCURS...THE
RAINFALL IS EXPECTED TO CHANGE QUICKLY OVER TO SNOW AS STRONG
COLD AIR ADVECTION AND NORTH WESTERLY WINDS BRING A ARCTIC
AIRMASS INTO THE REGION. CURRENT RUNS OF THE GFS AND ECMWF
INDICATE AN AREA OF ACCUMULATION SNOW DEVELOPING IN THE WAKE OF
THE COLD FRONTAL PASSAGE. CURRENT THINKING IS THAT ACCUMULATING
SNOWFALL AMOUNTS FROM ONE TO THREE INCHES ALONG AND WEST OF
HIGHWAY 65 ARE POSSIBLE.
THERE REMAINS SOME SUBTLE DIFFERENCES IN THE SUITE OF MODELS
THOUGH MOST ARE IN GENERAL AGREEMENT WITH LARGE SCALE FEATURES.
FEEL THAT THE MESOSCALE FEATURES WILL NEED TO BE WATCHED VERY
CLOSELY FROM THIS EVENING THROUGH CHRISTMAS MORNING AS SMALL
CHANGES IN LOCAL FEATURES COULD PRODUCE LOCALIZED CHANGES.
OVERALL EXPECT THE NEXT 72 HOURS TO BE VERY ACTIVE ACROSS THE
PLAINS AND INTO THE MISSOURI OZARKS. FOR THOSE TRAVELING ACROSS
THE CENTRAL STATES FOR THE HOLIDAYS...STAY TUNED TO THE LATEST
INFORMATION WITH THE POTENTIAL OF SEVERE WEATHER AND A
SIGNIFICANT WINTER STORM IN THE FORECAST.
HATCH
LONG TERM (FRIDAY THROUGH TUESDAY)...
HIGH TEMPERATURES AT OR NEAR FREEZING WILL BE HERE TO STAY AT
LEAST THROUGH MONDAY AS ARCTIC AIR FLOWS INTO THE NATIONS MID
SECTION. THROUGH SUNDAY MORNING...WIND CHILLS IN THE SINGLE
DIGITS ARE EXPECTED WITH STRONG WESTERLY SURFACE WINDS IN THE
WAKE OF THE CHRISTMAS DAY STORM SYSTEM.
REGARDING PATTERN EVOLUTION...THE UPPER LOW SUPPORTING THE
PASSING SURFACE LOW IS EXPECTED BY BOTH THE ECMWF AND GFS TO
LINGER OVER THE EASTERN CONUS INTO MONDAY WITH A LONGWAVE RIDGE
BUILDING OVER THE CENTRAL CONUS. BOTH SOLUTIONS DEPICT A SECOND
PACIFIC CUT OFF LOW TO PROGRESS ACROSS THE SOUTHWEST AND ALONG
THE GULF COAST BY WEDNESDAY. THE BULK OF THE PRECIPITATION LOOKS
TO BE WELL SOUTH OF THE CWA.
KARDELL
&&
.AVIATION...
AN INTENSE STORM SYSTEM WILL APPROACH THE REGION OVER THE NEXT
24 HOURS. THIS SYSTEM WILL IMPACT FLIGHTS IN AND OUT OF THE
SOUTHWEST MISSOURI AIRPORTS. AS A MATTER OF FACT...MOISTURE ALREADY
STREAMING NORTHWARD OUT OF THE GULF OF MEXICO HAS CAUSED A DECK OF
MVFR STRATUS TO UNFOLD. THIS STRATUS WILL CONTINUE TO LOWER AS THE
NIGHT PROGRESSES...MEANWHILE...SHOWERS AND ISOLATED THUNDERSTORMS
ARE EXPECTED TO DEVELOP AFTER MIDNIGHT TONIGHT. ANY SHOWER OR
STORM THAT DIRECTLY IMPACTS AN AIRPORT COULD SEND FLIGHT CONDITIONS
DOWN TO IFR AT TIMES.
PILOTS SHOULD ALSO BE AWARE OF LOW LEVEL SHEAR DEVELOPING TONIGHT
AND CONTINUING INTO WEDNESDAY MORNING. THIS LOW LEVEL WIND SHEAR
WILL OCCUR IN RESPONSE TO A DEVELOPING LOW LEVEL JET.
CRAMER
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
