346 FXUS63 KILX 160151 AFDILX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 851 PM CDT THU MAR 15 2012 .DISCUSSION... ISSUED 847 PM CDT THU MAR 15 2012 SCT CONVECTION ACROSS CENTRAL ILLINOIS MAINLY DIURNALLY DRIVEN AND WITHOUT SYNOPTIC BOUNDARY TO INTERACT WITH FOR THE MOST PART. HAVE SPREAD OUT THE CHANCE POPS A BIT TO ACCOUNT FOR SCT SHOWERS POPPING UP ALONG OUTFLOWS. MOST CONVECTION IS COMING DOWN SHORTLY AFTER GOING UP WITH THE EXCEPTION OF A FEW STRONGER STORMS PRODUCING QUARTER SIZED HAIL. ACTIVITY DECREASING THROUGH THE EVENING HOURS AS THE BOUNDARY LAYER STABILIZES. MINOR UPDATES TO THE HOURLY TEMPS AND SOME TWEAKS TO THE POPS. OTHER THAN THAT...FORECAST IN GOOD SHAPE. HJS && .AVIATION... ISSUED 600 PM CDT THU MAR 15 2012 S/SWRLY WINDS CONTINUE WITH HIGH PRESSURE TO THE EAST...SCT STORMS ACROSS THE AREA LOSING VERTICAL GROWTH QUICKLY WITHOUT DIURNAL HEATING. VCTS MENTION FOR SPI THROUGH THE EVENING. SAME STORY TOMORROW WITH SCT/BKN CU THROUGH THE AFTERNOON. MENTIONED A CB FOR THE AFTERNOON TO COVER ANY SCT CONVECTIVE GROWTH...BUT NOT ENOUGH CERTAINTY TO PUT IT ANYWHERE IN PARTICULAR. HJS && .PREV DISCUSSION... ISSUED 301 PM CDT THU MAR 15 2012 MODELS IN VERY GOOD AGREEMENT WITH OVERALL PATTERN GOING FROM SOUTHWEST FLOW TO RIDGING ACROSS THE EASTERN HALF OF THE US...WITH A LARGE TROUGH IN THE WEST. THIS PATTERN WILL CONTINUE THE WELL ABOVE NORMAL TEMPS THROUGH THE WEEKEND AND INTO NEXT WEEK. SMALL SHORT WAVES WILL ALSO MOVE NORTHEAST THROUGH THE FLOW AND BRING SOME CHANCES OF PCPN TO A PART OF THE CWA IN THE SHORT TERM. LONG TERM CONCERN IS THE LARGE TROUGH DEVELOPING OUT WEST AND WHEN THE RESULTING PCPN WILL ARRIVE IN THE CWA NEXT WEEK. LONG TERM MODELS ACTUALLY LOOK SIMILAR IN THIS FORECAST AND COULD SEE SEVERAL PERIODS OF PCPN TOWARD MIDDLE OF NEXT WEEK. SHORT TERM...TONIGHT THROUGH SUNDAY SFC HIGH PRSS WILL REMAIN ANCHORED OFF THE EAST COAST THROUGH THE PERIOD...ALLOWING WARM AND MOIST AIR TO BE ADVECTED INTO THE AREA FROM THE SOUTH. THIS WILL KEEP EARLY SUMMER-LIKE CONDITIONS IN THE AREA REST OF THE WEEK AND THROUGH THE WEEKEND. SEVERAL MINOR SHORT WAVES ARE SEEN IN THE WATER VAPOR LOOP TODAY AND THESE WILL MOVE EAST-NORTHEAST THROUGH THE PERIOD...BRINGING SMALL CHANCES OF PCPN TO PORTIONS OF THE CWA. HIGHEST CHANCES...THOUGH STILL SMALL...WILL BE IN THE SOUTH FOR TONIGHT AND TOMORROW. WILL MAINTAIN A SLIGHT CHC IN-BETWEEN WAVES TOMORROW NIGHT...FOLLOWED BY A CHANCE AGAIN SAT AND SAT NIGHT...AND IN THE EAST SUNDAY. FOR NOW...WILL JUST KEEP POPS IN CHANCE CATEGORY SINCE A SFC FEATURE WILL NOT BE ASSOCIATED WITH THE PCPN THROUGH THE PERIOD. TEMPS WILL REMAIN WELL ABOVE NORMAL AND SEE NO CHANGE IN THAT AT THIS TIME. EXPECTING RECORD TEMPS THROUGH MOST OF THE PERIOD. LONG TERM...SUNDAY NIGHT THROUGH THURSDAY WITH THE PATTERN BECOMING ONE OF A STEEP TROUGH IN THE WEST AND RIDGING IN THE EAST...BELIEVE WARM AND MOIST CONDITIONS WILL CONTINUE INTO THE BEGINNING OF NEXT WEEK. INITIALLY DRY CONDITIONS WILL BE THE RULE...BUT AS THE TROUGH GETS CLOSER...CHC POPS WILL BE INTRODUCED IN THE EXTREME WEST FOR MON AND THEN AGAIN ON TUE. GFS AND ECMWF MODELS FORECAST THE TROUGH DEVELOPING INTO A CUTOFF LOW IN THE MID LEVELS. THIS WILL SPLIT THE FLOW AND THE UPPER LVL LOW WILL SLOWLY MOVE EAST OR BECOME STATIONARY. THIS SLOW MOVEMENT WILL KEEP MOIST AIR ADVECTING INTO THE AREA FOR MIDDLE OF THE WEEK. SO WILL HAVE TO KEEP CHC POPS IN THE FORECAST FOR TUE NIGHT THROUGH THURSDAY. WELL ABOVE NORMAL TEMPS WILL CONTINUE FOR THE BEGINNING OF THE WEEK BUT BELIEVE TEMPS WILL COOL SOME...THOUGH STILL REMAIN ABOVE NORMAL...FOR MIDDLE OF THE WEEK AS CLOUDS AND PCPN AFFECT THE AREA. EXPECTING RECORD TEMPS TO CONTINUE AT THE BEGINNING OF THE WEEK. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$