748 FXUS63 KILX 161114 AFDILX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 614 AM CDT TUE JUL 16 2013 .DISCUSSION... ISSUED 330 AM CDT TUE JUL 16 2013 SHORT TERM...TODAY THROUGH FRIDAY FORECAST CONCERN IS THE HEAT WAVE THROUGH FRIDAY AND HOW HIGH AFTERNOON HEAT INDICES WILL GET. THEN LOOKING AT INCREASING CONVECTION CHANCES LATE THIS WEEK AS A COLD FRONT MOVES SOUTH THROUGH IL FRI NIGHT/SAT. 00Z MODELS ARE IN GOOD AGREEMENT INTO THIS WEEKEND...THEN DIVERGE EARLY NEXT WEEK. LEANED ON THE ECMWF MODEL FOR THE WX FORECAST EARLY NEXT WEEK. STRONG 600 DM 500 MB HIGH PRESSURE THE NEAR IN/OH/KY BORDER TO RETROGRADE WESTWARD INTO CENTRAL/SE IL DURING MID WEEK AND BRING THE LONGEST HEAT WAVE OF THE SUMMER TO THE REGION. HIGHS IN THE LOWER 90S TODAY AND LOW TO MID 90S WED THRU FRI COMBINED WITH DEWPOINTS OF 70-75F TO GIVE HEAT INDICES OF IN THE UPPER 90S TO NEAR 100F THIS AFTERNOON...98-103F WED AFTERNOON AND 100-106F THU/FRI AFTERNOON. THIS IS BELOW HEAT ADVISORY CRITERIA OF 105F BUT WILL ISSUE A SPECIAL WEATHER STATEMENT TO ADDRESS THIS HEAT WAVE. OUR HOTTEST DAY OF THE YEAR SO FAR WAS JUNE 12 WITH LOW TO MID 90S BUT THAT ONLY LATEST ONE DAY. THIS HEAT WAVE WILL BE 4 DAYS LONG. A SUTTLE SHORT WAVE TRACKS NW ACROSS MO/SW IL THIS AFTERNOON AND COULD DEVELOP ISOLATED CONVECTION SW OF JACKSONVILLE DURING THE AFTERNOON AS AIRMASS IS UNSTABLE WITH CAPES OF 2000-3000 J/KG. SCATTERED TO BROKEN CUMULUS CLOUDS TO DEVELOP AGAIN THIS AFTERNOON BUT MOST AREAS WILL STAY DRY TODAY WITH LITTLE OR NO LIFTING MECHISMS AROUND AND SOME CAP DEVELOPING WITH APPROACHING STRONG UPPER LEVEL HIGH PRESSURE RIDGE. SIMILAR WEATHER EXPECTED WED THROUGH THU NIGHT AS GENERALLY DRY... HOT AND HUMID CONDITIONS PREVAIL WITH STRONG UPPER LEVEL HIGH PRESSURE NEARLY OVERHEAD. BROUGHT IN 20-30% CHANCE OF CONVECTION OVER NORTHERN AND EASTERN AREAS FRI AFTERNOON WITH COLD FRONT PUSHING SOUTH THROUGH SOUTHERN WI TOWARD NORTHERN IL. FRIDAY COULD BE EVEN HOTTER AND MORE HUMID WITH COMPRESSIONAL HEATING AHEAD OF COLD FRONT TO OUR NORTH IF WE SEE ENOUGH SUNSHINE ESPECIALLY FROM I-72 SOUTH. LONG TERM...FRIDAY NIGHT THROUGH TUESDAY BEST CHANCES OF THUNDERSTORMS WILL BE FRIDAY NIGHT AND SAT AS COLD FRONT PUSHES SOUTHWARD THROUGH IL WITH UPPER LEVEL RIDGE WEAKENING AND SHIFTING SOUTHWARD INTO TN VALLEY. FAIRLY STRONG UPPER LEVEL LOW/TROF DIGS SE FROM CANADA INTO THE GREAT LAKES REGION LATE THIS WEEK AND THIS TO BRING SOME RELIEF FROM THE HIGH HEAT THIS WEEKEND. CONVECTION CHANCES MAINLY SHIFT SOUTH OF CENTRAL IL DURING SAT NIGHT AND SUNDAY AS COLD FRONT PUSHES SLOWLY THROUGH THE OHIO VALLEY. A NORTHERN STREAM SHORT WAVE/TROF TO TRACK INTO THE WESTERN GREAT LAKES REGION EARLY NEXT WORK WEEK AND RETURN A CHANCE OF SHOWERS AND THUNDERSTORMS TO CENTRAL IL MON OR TUE. 07 && .AVIATION... ISSUED 605 AM CDT TUE JUL 16 2013 OTHER THAN SOME PATCHY FOG EARLY THIS MORNING AND AGAIN AFTR 08Z WEDNESDAY...VFR CONDITONS WILL PREVAIL. HIGH PRESSURE AT THE SFC AND ALOFT WILL DOMINATE THE WEATHER ACROSS THE FORECAST AREA OVER THE NEXT COUPLE OF DAYS. FORECAST SOUNDINGS CONTINUE TO INDICATE A RAPID INCREASE IN THE CU FIELD AGAIN TODAY...HOWEVER WITH THE LACK OF ANY FORCING/LIFT...ANY TSRA WILL BE ISOLATED AT BEST SO WILL CONTINUE TO KEEP OUT OF ANY TAF SITE. WITH THE ABUNDANT LOW LEVEL MOISTURE AND INSTABILITY PRESENT...IT APPEARS WE MAY SEE A PERIOD OF BROKEN CU WITH BASES FROM 4000-5000 FEET. ONCE AGAIN...ANY BKN CIGS SHOULD SCATTER OUT AFTR 23Z WITH A MAINLY CLEAR SKY OVERNIGHT...WHICH AGAIN WILL LEAD TO SOME PATCHY GROUND FOG BY WED MORNING. WINDS WILL BE QUITE LIGHT AGAIN TODAY OUT OF THE SOUTH WIND SPEEDS OF 10KTS OR LESS. A SOUTHERLY WIND AT OR LESS THAN 5 KT CAN BE EXPECTED TONIGHT. SMITH && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$