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000
FXUS63 KILX 152003
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
303 PM CDT WED MAY 15 2013

.DISCUSSION...
ISSUED 259 PM CDT WED MAY 15 2013

FORECAST CONCERN TODAY IS THE POPS ASSOCATED WITH THE STALLING
FRONT OVER THE REGION INTO THE WEEKEND...AND THEN THE APPROACH OF
THE MAIN UPPER WAVE AND FRONT THE FIRST PART OF NEXT WEEK.

.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT.
MORNING UPPER AIR DATA AND SPC INSTABILITY ANALYSIS SHOWS THE
EAST-WEST FRONTAL ZONE HAD MADE INTO THE NORTH CENTRAL PART OF IL
TODAY...WITH ENOUGH CONVERGENCE ON THE BOUNDARY TO CONTINUE THE
TREND THAT BEGAN OVERNIGHT...OF ELEVATED CONVECTION FORMING AND
MOVING EAST ALONG THE FRONTAL ZONE. THIS TREND HAS BEEN THE CASE
ALL DAY...AS THE UPPER AIR SHOWED A TONGUE OF LOW LEVEL MOISTURE
SURGING NORTH FROM TX OVER MO INTO THE BOUNDARY ZONE. SPC MESODATA
CONTINUED TO SHOW AIR SOUTH OF THE BOUNDARY CAPPED AND THE PCPN
REMAINING ELEVATED. EXPECT THIS TREND TO REMAIN OVERNIGHT...WITH
THE FRONT SAGGING A LITTLE SOUTH.

WITH THE FRONT PROGGED TO BE IN THE REGION BY ALL THE MODELS ON
THURSDAY...WILL KEEP POPS IN THE LIKELY CAT THROUGH CENTRAL REGION.
ADDITIONAL SUPPORT FOR DEVELOPMENT WITH UPPER LEVEL REMAINS OF THE
WEAKENING UPPER WAVE THAT IS OVER TX TODAY. THAT SYSTEM WILL BE
DRIFTING TO THE EAST NORTHEAST OVER OK TO AR. THIS SYSTEM IS
FORECAST TO WASH OUT THURSDAY NIGHT AND THEN THE UPPER RIDGE
BEGINS TO START TO BUILD OVER AREA. LOWERING POPS THEN FRIDAY AND
INTO FRIDAY NIGHT.

.LONG TERM...SATURDAY THROUGH WEDNESDAY.
THE APPROACH OF THE DEEPENDING UPPER LOW/WAVE ON SUNDAY GRADUALLY
INCREASES POPS OVER WEST SUNDAY. GFS AND NEW EUR ARE DIFFERENT IN
THE DETAILS ON THE APPROACHING FRONT AND THE UPPER LOW/TROUGH
CONFIGURATION. TODAYS RUN DOES NOT DISPLAY A CLEAR SYSTEM MOVING
THROUGH...BUT A MORE GRADUAL MOVEMENT OF THE UPPER SYSTEM...WHICH
RESULTS IN A LONGER PERIOD OF POPS...FOR SUNDAY INTO THE DAY
WEDNESDAY. WILL STILL HAVE TO WATCH MONDAY FOR SIGNIFICANT
CONVECTION...AS SOUNDING AND HODOGRAPH ON THAT DAY STILL SHOW
POTENTIAL FOR STRONG STORMS.

GOETSCH
&&

.AVIATION...
ISSUED 1219 PM CDT WED MAY 15 2013

SHOWERS AND ISOLATED THUNDERSTORMS INCREASING ALONG A FRONTAL
BOUNDARY...WHICH EXTENDS FROM KMQB TO JUST SOUTH OF KIKK AT 17Z.
COVERAGE IS SCATTERED...AND WILL ADDRESS IT WITH VCTS INITIALLY AT
KPIA/KBMI...THEN FURTHER SOUTH MID TO LATE AFTERNOON AS THE
BOUNDARY SLOWLY SINKS. MOST 12Z MODEL GUIDANCE IN AGREEMENT WITH
STALLING THIS BOUNDARY OVER CENTRAL ILLINOIS THIS EVENING...WITH A
NORTHWARD PUSH BEGINNING ON THURSDAY MORNING. SHOWERS/STORMS WILL
REMAIN SCATTERED WITH THIS BOUNDARY AROUND...WITH THE 06-12Z TIME
FRAME MOST LIKELY TO SEE THE BETTER CHANCES OF DRY WEATHER. ENOUGH
CONFIDENCE EXISTS FOR A TEMPO MENTION OF TSRA FROM ABOUT 03-07Z
FROM KSPI EAST TO KCMI.

GEELHART
&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$