Area Forecast Discussion
Issued by NWS Central Illinois

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KILX 061155
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
655 AM CDT WED MAY 6 2015

.SHORT TERM...(TODAY)
ISSUED AT 324 AM CDT WED MAY 6 2015

FRONTAL BOUNDARY EXTENDS FROM NEAR MACOMB TO PARIS ACROSS CENTRAL IL
THIS MORNING AND COOLER TEMPERATURES WITH HIGHER DEWPOINTS NORTH OF
THE BOUNDARY ARE RESULTING IN AREAS OF FOG...WITH OCCASIONAL DENSE
FOG OBSERVATIONS IN BLOOMINGTON...AND LASALLE AND PONTIAC TO THE
NORTH. 7Z HRRR MODEL IS DEPICTING WELL THE DENSE AREA AND HAVE
INCORPORATED PATCHY DENSE FOG IN GRIDS ACCORDING TO THIS. FOG SHOULD
DISSIPATE BY AROUND 8 AM WITH DAYTIME HEATING.

FOR TODAY...A 500 MB RIDGE AXIS ORIENTED NW-SE ACROSS IL WILL SHIFT
NORTHEASTWARD WHILE A SHORTWAVE OVER THE SOUTHERN PLAINS EJECTS
NORTHEASTWARD JUST WEST OF ILLINOIS. PRECIPITATION ASSOCIATED WITH
THE SHORTWAVE WILL APPROACH THE WESTERN SIDE OF ILLINOIS BUT WILL
LIKELY REMAIN JUST WEST OF THE CENTRAL IL FORECAST AREA. FORECAST
SOUNDINGS FOR CENTRAL IL INDICATE A WEAK SUBSIDENCE INVERSION AND
DRY AIR AT MID LEVELS WHICH SHOULD HELP TO PREVENT ANY SIGNIFICANT
CONVECTION...ALTHOUGH ENOUGH MOISTURE BELOW THE DRY SUBSIDENT LAYER
COULD BRING SCATTERED TO BROKEN SHALLOW CUMULUS. SOUTHERLY FLOW
AHEAD OF THE SHORTWAVE WILL PUSH THE FRONTAL BOUNDARY NORTHWARD WITH
WARM AIR BEHIND THE FRONT BRINGING HIGHS INTO THE MID OR UPPER 80S
ACROSS CENTRAL IL. SURFACE WINDS EXPECTED TO BE SOUTHERLY 8-15 MPH
WITH GUSTS 12-20 MPH...THE STRONGER WINDS TOWARD THE WESTERN SIDE OF
THE STATE.

.LONG TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 324 AM CDT WED MAY 6 2015

BRIEF DRY PERIOD WILL CONTINUE THROUGH THE OVERNIGHT HOURS WITH THE
WARM TEMPS. STORM/WAVE OVER THE SRN PLAINS WILL TRACK
NORTH/NORTHEAST BUT IS EXPECTED TO MOSTLY STAY TO THE WEST...BUT
SOME PRECIP CHANCES SNEAKING INTO WEST CENTRAL ILLINOIS ON THURSDAY,
WITH THE BEST CHANCES PUSHING INTO THE EVENING HOURS AND OVERNIGHT
FOR SHOWERS AND THUNDERSTORMS. BIGGER SYSTEM DIGGING INTO THE DESERT
SW OVER THE NEXT 36 HRS OR SO AND WILL KEEP THE WESTERN US UNDER A
TROF, AMPLIFYING THE PATTERN AND SETTING UP SOUTHWESTERLY FLOW FOR
THE MIDWEST. MANY SHORTWAVES TRACKING AROUND THE TROF AND UP INTO
THE MID MISSISSIPPI VALLEY/MIDWEST THROUGH THE END OF THE WEEKEND
AND INTO THE FIRST PART OF THE WORKWEEK.  PERIODS OF SHOWERS AND
THUNDERSTORMS KEEP HIGH CHANCE/LIKELY THREAT IN THE FORECAST THROUGH
MONDAY NIGHT UNTIL THE SYSTEM IS SLOWLY DRIVEN OUT OF THE REGION.
STILL SOME QUESTION AS TO WHERE THE BOUNDARY WILL PROVIDE THE BEST
FOCUS AND THE MODELS ARE FAIRLY DIFFUSE WITH THE CONVECTIVE
ACTIVITY.  TEMPERATURES REMAIN WARM WITH A PRETTY STUBBORN WARM
AIRMASS AND SOUTHERLY WINDS AT THE SFC KEEPING WAA GOING EVEN WITH
THE SHOWERS AND THUNDERSTORMS...AT LEAST UNTIL THE TROF FINALLY
EXITS NE AND ALLOWS COOLER TEMPS BACK INTO THE REGION BY DAY7/DAY 8.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 655 AM CDT WED MAY 6 2015

EASTERN PORTION OF FRONTAL BOUNDARY ACROSS CENTRAL IL HAS BEGUN TO
MOVE NORTHWARD AND IS NOW JUST SOUTH OF KPIA-KMQB WITH FOG
DISSIPATING OR ABSENT FROM ALL CENTRAL IL TAF SITES EXCEPT KPIA.
KPIA WILL CONTINUE IFR VSBY UNTIL 13-14Z AS A RESULT BEFORE VFR
CONDITIONS ARE IN PLACE ACROSS CENTRAL IL. EXPECT VFR CONDITIONS
TO CONTINUE FOR THE REMAINDER OF THE 24 HOUR TAF PERIOD WITH S
WINDS 6-12 KTS DEVELOPING. GUSTS TO AROUND 20 KTS CAN BE EXPECTED
FROM 18Z-00Z ALONG WITH SCT CLOUD COVER AROUND 5 KFT AGL.

&&

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

$$

SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...ONTON


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.