Area Forecast Discussion
Issued by NWS Central Illinois

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000
FXUS63 KILX 302346
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
646 PM CDT THU JUL 30 2015

.SHORT TERM...(TONIGHT)
ISSUED AT 322 PM CDT THU JUL 30 2015

ASIDE FROM A FEW HIGH/THIN CLOUDS DRIFTING ACROSS MAINLY THE
SOUTHERN KILX CWA THIS AFTERNOON AND EVENING...SKIES WILL BE CLEAR
ACROSS CENTRAL ILLINOIS THROUGH TONIGHT.  WINDS WILL BECOME WESTERLY
AND DIMINISH TO 5 MPH OR LESS AFTER SUNSET...WHILE OVERNIGHT LOW
TEMPERATURES DROP INTO THE LOWER TO MIDDLE 60S.

.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 322 PM CDT THU JUL 30 2015

BROAD UPPER LEVEL RIDGING IN THE WESTERN HALF OF THE COUNTRY AND
BROAD UPPER LEVEL TROUGHING IN THE EAST WILL EVOLVE INTO HIGHER
AMPLITUDE FLOW BY LATE IN THE WEEKEND. THIS COULD RESULT IN A RETURN
TO A WETTER PATTERN FOR CENTRAL AND EASTERN IL NEXT WEEK. HOWEVER...
DUE TO SOME MODEL UNCERTAINTY WITH THE SPECIFICS OF THIS TRANSITION
THE UNCERTAINTY LEVEL IS HIGH.

IN THE SHORTER TERM...SHORTWAVE TROUGHING IS EXPECTED TO ROTATE INTO
THE GREAT LAKES REGION FROM THE NW...ALLOWING A WEAK FRONT TO MOVE
TOWARD CENTRAL IL BY LATE TOMORROW AFTERNOON. THIS BOUNDARY WILL
PROVIDE THE FOCUS FOR A FEW THUNDERSTORMS. HOWEVER...WEAK
INSTABILITY/LOW LEVEL MOISTURE LEVELS WILL RESULT IN FAIRLY
ISOLATED COVERAGE FROM LATE AFTERNOON INTO THE EVENING HOURS. WILL
STICK WITH SLIGHT CHANCE POPS FOR THIS POTENTIAL. OTHERWISE...A
WEST WIND AND GENERALLY AMPLE SUNSHINE SHOULD GIVE US HIGHS IN THE
UPPER 80S FRI.

SOMEWHAT DRIER AIR WILL FILTER INTO OUR REGION SATURDAY RESULTING IN
PLENTY OF SUN AND TEMPERATURES IN THE MID TO UPPER 80S. AN
INCREASING LOW LEVEL WIND FIELD SATURDAY NIGHT SHOULD RESULT IN AT
LEAST SCATTERED ELEVATED CONVECTION IN THE ILLINOIS RIVER VALLEY AND
POSSIBLY AS FAR EAST AS BMI. BETTER CHANCES FOR RAIN ACROSS
CENTRAL AND EASTERN IL LOOK TO BE SUNDAY AS MCS REMNANTS FROM OUR
WEST MOVE INTO THE AREA. THE PRESENCE OF SCATTERED THUNDERSTORMS
AND ASSOCIATED CLOUDS SHOULD KEEP TEMPERATURES DOWN IN THE LOWER
TO MID 80S FOR SUNDAY.

FORECAST UNCERTAINTY STARTS TO PLAY A ROLE FROM LATER MONDAY THROUGH
MIDWEEK AS MODEL INCONSISTENCIES AND DIFFERENCES APPEAR. THE GFS IS
MUCH FARTHER EAST WITH THE UPPER TROUGH AXIS THAN THE EUROPEAN
MODEL. THEY BOTH SHOW A FRONT SLOWLY APPROACHING AND EVENTUALLY
MOVING THROUGH ILLINOIS. HOWEVER THE GFS IS QUICKER AND THE EUROPEAN
MUCH SLOWER BECAUSE OF THEIR RELATIVE POSITIONS OF THE EASTERN UPPER
TROUGH AXIS. THIS BOUNDARY WOULD SERVE AS THE FOCUS FOR PERIODS OF
SHOWERS AND T-STORMS MUCH OF NEXT WEEK. WILL LEAN TOWARD A BLEND OF
THESE TWO MODELS FOR THE FORECAST NEXT WEEK. HOWEVER...CONFIDENCE IS
LOW AS THE PATTERN EVOLVES AND THE MODELS DEAL WITH CONSISTENCY
ISSUES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 645 PM CDT THU JUL 30 2015

VFR CONDITIONS WILL PREVAIL UNTIL EARLY AFTERNOON FRIDAY AS HIGH
PRESSURE PROVIDES CLEAR SKIES AND LIGHT WINDS. A WEAK FRONTAL
BOUNDARY WILL APPROACH FROM THE NORTHWEST TOWARD MIDDAY
FRIDAY. ISOLATED THUNDERSTORMS WILL BE POSSIBLE ALONG THE FRONTAL
BOUNDARY WITH POTENTIAL FOR LOCAL MVFR CONDITIONS. PREDOMINANT VFR
CONDITIONS STILL EXPECTED...HOWEVER...SO HAVE ONLY INCLUDED VCTS
AND FEW CB IN TAFS AT THIS POINT. WINDS W 4-8 KTS UNTIL FRIDAY
AFTERNOON...BECOMING WNW 10-12 KTS WITH GUSTS TO 18-20 KTS.

&&

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

&&

$$

SHORT TERM...BARNES
LONG TERM...MILLER
AVIATION...ONTON



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