FXUS63 KLSX 132100
AFDLSX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
300 PM CST SAT MAR 13 2010
.DISCUSSION...
/300 PM CST SAT MAR 13 2010/
LARGE STORM SYSTEM CENTERED NEAR THE INTERSECTION OF TN/AL/GA IS
SLOWLY PROGRESSING EWD TOWARDS THE MID ATLANTIC CONUS...AND AS IT
DOES SO...WILL CONTINUE TO SWING AROUND A PARADE OF VORT MAXES ON
ITS VAST WRN FLANK. THE RAIN ASSOCIATED WITH ONE OF THESE IS ALREADY
APPROACHING THE FA...MOVING THRU CNTRL IL ATTM...AND WILL PRIMARILY
IMPACT THE FA THIS EVENING. BY MIDNIGHT...MOST OF THE POTENTIAL FOR
MEASURING RAINFALL WILL BE S OF THE STL METRO AREA LEAVING BEHIND
MAINLY DRIZZLE. PREFER THE HIGHER MAVMOS POPS WHICH HAVE HANDLED
THIS GENERAL SCENARIO THE BEST OVER THE PAST COUPLE OF DAYS. SIMILAR
TEMP PROFILE EXPECTED AS WE HAVE HAD THE PAST 24HRS...AND SO A
PERSISTENCE MIN TEMP FCST IS ALSO CALLED FOR AS CLOUDY SKIES CONT.
ANOTHER VORT MAX WILL DRIVE THE RAIN CHCS ON SUNDAY...BUT THIS WILL
BE WEAKER THAN ITS PREDECESSORS...AND SO THE ABILITY TO MEASURE WILL
BE IMPEDED DESPITE MOST LOCNS SEEING RAINDROPS ONCE AGAIN...BUT THEY
WILL BE LIGHT. TEMPS WILL STRUGGLE TO RISE OUT OF THE 40S AGAIN AND
SO PREFER THE COLDEST METMOS...AND EVEN A BIT COLDER. A FEW
SPRINKLES MAY LINGER INTO SUNDAY EVENING.
THE SUN SHOULD MAKE AN APPEARANCE AGAIN BY MONDAY WITH PARTLY SUNNY
SKIES EXPECTED...AND TEMPS WILL REBOUND INTO THE 50S. SIMILAR CONDS
EXPECTED ON TUESDAY BUT WITH THICKER CLOUDS RETURNING AHEAD OF NEXT
SYSTEM.
FOR THE EXTENDED PERIOD (TUESDAY NIGHT - SATURDAY)...MODELS IN
DECENT AGREEMENT WITH OVERALL PATTERN. A PAIR OF STRONG SHORTWAVES
WILL ENSURE THAT A MEAN TROF EXISTS OVER THE CNTRL CONUS FOR MUCH OF
THIS TIME PERIOD...ONLY TO BE BRIEFLY INTERRUPTED ON THURSDAY. MORE
SPECIFICALLY...THE FIRST STRONG SHORTWAVE WILL DROP S-SEWD THRU THE
FA ON TUESDAY NIGHT AND WEDNESDAY...WITH THE SECOND IMPACTING THE
AREA ON SATURDAY...PERHAPS LATE FRIDAY. PREFER THE OVERALL MORE
CONSISTENT TIMING OF THE ECMWF WHICH IS A BIT SLOWER THAN THE GFS ON
THE SECOND SYSTEM. INTRODUCED POPS WITH THE FIRST SHORTWAVE TUESDAY
NIGHT AND WEDNESDAY ON ACCOUNT OF ITS STRENGTH AND CONSISTENCY SHOWN
BY THE MODELS...AND WITH THE SECOND BASED ON VERY GOOD INTER-MODEL
CONSISTENCY. KEEPING IN MIND THAT CLIMO POPS THIS TIME OF YEAR ARE
30PCT...THIS IS NOT JUMPING THE GUN IN THE LEAST. ABOVE NORMAL TEMPS
EXPECTED IN-BTWN SYSTEMS ON THURSDAY AND FRIDAY AS SLY FLOW
DEVELOPS.
TES
&&
.AVIATION...
/1131 AM CST SAT MAR 13 2010/
AREAS OF LIGHT RA AND DZ WILL CONTINUE INTO THIS AFTERNOON. MAIN
AREA OF RA WILL HOLD OFF UNTIL THIS EVENING WHEN RA OVER IL/IA
MOVES INTO THE REGION. BELIEVE MUCH OF THE RA WILL BE ENDING EARLY
MORNING...AROUND 09Z...AND BECOMING MORE OF A DZ SITUATION AFTER
THAT. HOWEVER...EXPECT VISBYS TO REMAIN IN THE MVFR RANGE INTO THE
LATE MORNING. VISBYS AND CIGS SHUD IMPROVE LATE SUN MORNING. WINDS
WILL REMAIN NWLY TO NLY THROUGH THE END OF THE TAF PERIOD.
SPECIFICS FOR KSTL...OTHER THAN THAT MENTIONED ABOVE...WINDS WILL
START OUT AS WLY THIS AFTERNOON BEFORE BECOMING MORE NWLY THIS
EVENING. CIGS MAY IMPROVE TO LOW END MVFR RANGE THIS AFTERNOON
BRIEFLY BEFORE BECOMING IFR AGAIN THIS EVENING.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
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