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000
FXUS63 KILX 252015
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
315 PM CDT SAT MAY 25 2013

.DISCUSSION...
ISSUED 253 PM CDT SAT MAY 25 2013
HIGH PRESSURE RIDGE JUST TO THE EAST NOT QUITE STRONG ENOUGH TO
DAMPEN LEFTOVER MCS ACTIVITY MOVING INTO CENTRAL ILLINOIS THIS
AFTERNOON. WIDESPREAD SHOWERS AND ISOLATED THUNDER THROUGHOUT THE
EARLY AFTERNOON HOURS SLOWLY LOSING ITS STRENGTH AND THUNDER.
CLEARING SLOWLY MOVING TO THE EAST...THOUGH PLENTY OF -RA AND
SPRINKLES LIKELY. 4KM WRF DOING A FAIR JOB...IF NOT A FEW HOURS
BEHIND SCHEDULE. EXTRAPOLATING THE ERROR WOULD GIVE A BRIEF BREAK
WITH MORE SCATTERED ACTIVITY BEFORE THE NEXT ROUND. TODAYS WEATHER
EXPECTED TO CONTINUE THROUGH MONDAY BEFORE SLOWING ON TUESDAY.
MODELS IN PRETTY DECENT AGREEMENT THROUGH MID WEEK BEFORE
DIVERGING ON THE HANDLING OF THE UPPER WAVE PATTERN WITH THE TROF
OVER THE ERN HALF OF THE CONUS...AND ITS MOVEMENT AND TILT AS IT
PUSHES THE UPPER RIDGE OUT OF THE MIDWEST. TIMING ET AL IN
COMPLETE DISAGREEMENT BEYOND FH120.

SHORT TERM...TONIGHT THROUGH MONDAY...
PERIODIC SHOWERS AND THUNDERSTORMS LIKELY THROUGH MONDAY. WARM AIR
BUILDING UNDER THE RIDGE OVER THE PLAINS...AND A FRONT
DELINEATING THE BOUNDARY BETWEEN THE WARMER AIR TO THE SW AND THE
COOLER AIR OVER THE REGION ALMOST QUASI STATIONARY ALONG THE MISS
RIVER VALLEY FOR THE REMAINDER OF THE HOLIDAY WEEKEND. A SERIES
OF SHORT WAVES TOPPING THE RIDGE AND DIVING INTO ILX WILL KEEP THE
POPS IN PLACE THROUGH THE HOLIDAY WEEKEND. TEMPS CONTINUE TO
REMAIN MILD...EVEN THOUGH WARMING A COUPLE DEGREES EACH DAY...UNTIL THE
WARM FRONT FINALLY PASSES THROUGH THE AREA MON NIGHT/TUESDAY.

LONG TERM...TUESDAY THROUGH FRIDAY...
WARM FRONT LIFTING THROUGH THE REGION MON NIGHT AS THE ERN EDGE OF
THE RIDGE BREAKS DOWN AND PLENTY OF WARM AIR MOVES IN AT
MIDLEVELS. PRECIP SLOWLY REDUCING IN COVERAGE AND MUCH WARMER INTO
THE WORK WEEK. WESTERN TROF DIGS IN...AMPLIFYING THE WAVE PATTERN
OVER THE CONUS AND LEAVING THE UPPER MIDWEST IN SWRLY FLOW...AND
MUCH OF IL IN WEAK FLOW...IF ANY...UNDER THE BUILDING RIDGE. VERY
WARM MIDLEVELS AND THE GUIDANCE STILL BEING PULLED DOWN A BIT BY
CLIMATOLOGY INFLUENCE. HAVE BOOSTED TEMPS TO COMPENSATE...STILL MAY NOT BE
ENOUGH. RETURNING POPS ON THURS NIGHT/FRI GETTING DELAYED A BIT
MORE IN THIS RUN....AND STILL VERY MUCH IN DEBATE AS THE GFS AND
ECMWF DIVERGE QUITE A BIT WITH THE PROGRESSION OF THE WAVE PATTERN
AT DAY 7/8.

HJS
&&

.AVIATION...
ISSUED 1243 PM CDT SAT MAY 25 2013

LARGE RAIN SHIELD HAS OVERSPREAD THE CENTRAL ILLINOIS TAF SITES AT
MIDDAY. THUNDER HAS BEEN ON THE WANE...AND HAVE REMOVED THUNDER AT
ALL SITES BY ABOUT 21-22Z. HAVE SEEN SOME MVFR VISIBILITIES AT
TIMES IN THE HEAVIER SHOWERS...BUT CEILINGS WILL REMAIN FAIRLY
HIGH. MAIN QUESTION LATER ON IS WITH REDEVELOPMENT OF NOCTURNAL
CONVECTION TO THE NORTHWEST. MOST MODELS FAVOR IT DEVELOPING IN
IOWA SIMILAR TO LAST NIGHT THEN MOVING SOUTHEAST...ALTHOUGH THE
LATEST RAP MODEL IS INDICATING NORTHEAST MISSOURI AND WESTERN
ILLINOIS FOR INITIATION. HAVE MADE LITTLE CHANGE TO EARLIER TAFS
IN REGARDS TO THIS...ASIDE FROM MINOR TIMING ADJUSTMENTS...FAVORING
RAIN AND VCTS MENTIONS WHILE THE POTENTIAL CONTINUES TO BE
EVALUATED OVER THE NEXT FEW HOURS. HAVE TRIED TO INDICATE A FEW
HOURS OF DRIER CONDITIONS LATE IN THE PERIOD...BUT CONFIDENCE IS
LOW AT THIS TIME DUE TO THE EARLIER QUESTION OF OVERNIGHT CONVECTION.

GEELHART
&&

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

$$