000
FXUS63 KILX 152005
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
305 PM CDT SAT JUN 15 2013

.DISCUSSION...
ISSUED 305 PM CDT SAT JUN 15 2013

MAIN CONCERN THIS FORECAST PACKAGE REMAINS WITH PCPN CHANCES IN
THE SHORT TERM TONIGHT THROUGH MONDAY NIGHT. OVERALL...MODELS IN
GOOD AGREEMENT WITH UPPER LEVEL PATTERN THROUGH MONDAY...BUT THEN
DIFFER WITH SPEED OF A WEAK TROUGH DROPPING DOWN IN NORTHWEST FLOW
MONDAY NIGHT AND TUE. NAM IS QUICKEST OF ALL OF THEM AND SEEM ODD
MAN OUT. SO WILL BE FOLLOWING GFS/ECMWF...THOUGH IT MAY NOT MAKE
MUCH DIFFERENCE IN THE END. ONCE THIS GOES THROUGH THEN RIDGE
BEGINS TO BUILD IN THE PLAINS FOR REMAINDER OF THE WEEK AND INTO
THE WEEKEND. LOTS OF UNCERTAINTY AS TO STRENGTH OF THIS
RIDGE...THOUGH TIMING IS SIMILAR. A BLEND OF THE GFS/ECMWF IN THE
SHORT TERM LOOKS GOOD...THOUGH WILL ADD NAM BACK IN LATER. A BLEND
OF THE MODELS LOOKS GOOD IN THE EXTENDED AS WELL.

SHORT TERM...TONIGHT THROUGH TUESDAY

SFC FEATURES/PATTERN IS A MESS THIS AFTERNOON WITH ONE MCV MOVING
INTO NORTHWESTERN IND AND ANOTHER MOVING OUT OF NORTHERN IOWA.
OUTFLOW AND SFC BOUNDARIES ARE LOCATED ALL OVER THE AREA THIS
AFTERNOON AS WELL. COMBINED WITH DEWPOINTS IN THE UPPER 60S TO
LOW 70S IN WEST CENTRAL IL AND AREAS BACK TO THE WEST...CONVECTION
HAS BEEN ONGOING FOR SOME TIME TODAY. THIS HAS MADE THINGS MESSY
AND SHORT TERM/MESO SCALE MODELS HAVE NOT BEEN ABLE TO LATCH ONTO
ANYTHING...AND THEREFORE APPEAR TO BE USELESS AT THE
MOMENT...EXCEPT FOR MAYBE THE 4KM WRF MODEL FOR SPC. THE 12Z RUN
SEEMS CLOSE BUT SLOW OR TO WESTWARD WITH WHERE THE PCPN IS
CURRENTLY LOCATED AT. HOWEVER...IT TRIES TO DEVELOP A LINE OF
STRONG THUNDERSTORMS IN NORTHWEST ILLINOIS AND BACK INTO CENTRAL
MO. NOT QUITE SURE WITH THIS THOUGH IT IS IN THE BEST MOISTURE
AXIS. SO THAT SEEMS FEASIBLE ENOUGH THAT WILL HAVE LIKELY POPS
ACROSS MOST OF THE AREA THIS EVENING AND INTO OVERNIGHT. LOWEST
POPS WILL BE IN SOUTHEAST ILLINOIS. LOTS OF UNCERTAINTY BEYOND
TONIGHT GIVEN THE MANY MESOSCALE BOUNDARIES THAT WILL BE OVER THE
AREA TOMORROW. WILL KEEP CHC POPS OVER THE SOUTHERN HALF OF THE
AREA TOMORROW WITH SLIGHT CHC IN THE NORTH. THE ASSOCIATED
BOUNDARY/COLD FRONT WILL STOP FAR ENOUGH SOUTH OF THE AREA THAT
PCPN CHANCES WILL ON BE SLIGHT CHC IN THE SOUTHWEST...WITH
REMAINDER OF THE AREA DRY. THEN ANOTHER WAVE MOVES ALONG THE FRONT
FROM THE SOUTHWEST AND BRINGS MORE SHOWERS AND THUNDERSTORMS TO
THE AREA FOR MONDAY AND MONDAY NIGHT. HIGHEST POPS WILL BE IN THE
SOUTH FOR MONDAY AND THEN AS THE 500 TROUGH MOVES EAST THE CHANCES
OF PCPN WILL SHIFT TO THE EAST FOR MONDAY NIGHT. THEN DRY WEATHER
IS EXPECTED ACROSS THE AREA BEGINNING TUESDAY AS HIGH PRSS BUILDS
INTO THE REGION.

TEMPS WILL WARM SLIGHTLY FOR TOMORROW AND MONDAY AND HIGHS SHOULD
BE IN THE LOWER 80S BOTH DAYS. THEN AREA CAN EXPECT COOLER TEMPS
AS HIGH PRSS BUILDS IN FOR TUESDAY. CLOUDS AND PCPN COULD KEEP
TEMPS A LITTLE COOLER FOR NEXT TWO DAYS AS WELL...BUT WILL STAY
JUST BELOW MOS GUIDANCE FOR NOW.

LONG TERM...TUESDAY NIGHT THROUGH SATURDAY

DRY WEATHER WILL CONTINUE FOR TUE NIGHT THROUGH WED NIGHT. THEN A
WARM FRONT DEVELOPS OUT WEST AND MOVES NORTH TOWARD THE AREA FOR
LATER PART OF THE WEEK. SOME UNCERTAINTY AS TO WHETHER THERE WILL
BE PCPN AS THE WARM FRONT LIFTS NORTH SO WILL JUST HAVE SILENT
20PCT IN GRIDS FOR THUR THROUGH FRIDAY NIGHT FOR NOW. ZFPILX WILL
HAVE A DRY FORECAST.

TEMPS WILL STAY AROUND NORMAL MOST OF THE WEEK BUT BEGIN TO WARM
BACK UP FRIDAY...REACHING THE UPPER 80S TO AROUND 90 BY SATURDAY.

AUTEN
&&

.AVIATION...
ISSUED 1246 PM CDT SAT JUN 15 2013

MAINLY VFR CONDITIONS AGAIN NEXT 24 HOURS OUTSIDE OF
THUNDERSTORMS. CURRENT COMPLEX AFFECTING PARTS OF CENTRAL IL THIS
AFTERNOON WILL PRODUCE BRIEF VSBY REDUCTIONS DOWN TO 4SM AND
POSSIBLY BRIEFLY LOWER IN HEAVIER TSRA. NEXT BATCH OF STORMS
EXPECTED TO FORM OVER IA AND NRN MO LATER THIS AFTERNOON AND SHIFT
OVER THE TAF SITES THIS EVENING AND HAVE TEMPO GROUPS FOR MOST
LIKELY TIME OF OCCURRENCE. AFTER THIS SYSTEM PUSHES THROUGH MUCH
OF THE ACTIVITY SHOULD BE SUPPRESSED TO OUR SOUTH/EAST FOR SUNDAY
MORNING. CHANCE OF SOME VSBY REDUCTIONS AFTER 06Z IN LIGHT WIND
REGIME AND WITH WET GROUND AND HAVE TRENDED THIS DIRECTION FOR
MOST SITES.

25
&&

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

$$