AP-IL--ILX-IL Central Area Forecast Discussion, IL

000

FXUS63 KILX 151138

AFDILX

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE LINCOLN IL

638 AM CDT WED JUL 15 2015

.SHORT TERM...(TODAY)

ISSUED AT 329 AM CDT WED JUL 15 2015

A PLEASANT DAY IN STORE FOR CENTRAL AND SOUTHEAST IL COMPLIMENTS OF

WEAK HIGH PRESSURE OF 1018 MB OVER THE WESTERN GREAT LAKES WHICH

DRIFTS EAST INTO LOWER MI BY 00Z/7 PM AND RIDGES INTO IL. COOLER

HIGHS IN THE LOWER 80S OVER THE AREA WITH NE WINDS 5-10 MPH AND

MOSTLY SUNNY SKIES WITH SCATTERED CUMULUS AND CIRRUS CLOUDS. MORE

COMFORTABLE DEWPOINTS IN THE UPPER 50S TO MID 60S TODAY AND LOWEST

FROM I-74 NE.

.LONG TERM...(TONIGHT THROUGH TUESDAY)

ISSUED AT 329 AM CDT WED JUL 15 2015

592 DM 500 MB HIGH PRESSURE RIDGE OVER TEXAS WILL RIDGE INTO IL THIS

EVENING WHILE WEAK SURFACE HIGH PRESSURE 1018 MB OVER NORTHERN WI

AND UPPER MI SHIFTS EAST INTO SE ONTARIO BY DAWN THU. THIS WILL

ENSURE DRY CONDITIONS ACROSS MUCH OF CENTRAL AND EASTERN IL THROUGH

TONIGHT. 00Z MODELS HAVE TRENDED SLOWER AND FURTHER NORTH WITH SHORT

WAVE EJECTING FROM THE CENTRAL ROCKIES OVER TOP OF UPPER LEVEL RIDGE

INTO WI/NORTHERN IL THU. THIS TO BRING ISOLATED SHOWERS AND

THUNDERSTROMS TO FAR WESTERN IL AREAS FROM GALESBURG TO JACKSONVILLE

WEST LATE TONIGHT. THEN CHANCES OF SHOWERS/THUNDERSTORMS SPREADS

EAST INTO IL RIVER VALLEY THU. SPC CONTINUES TO HAVE MARGINAL RISK

OF SEVERE STORMS (5% RISK) THU OVER AREAS MAINLY WEST OF IL RIVER.

INCREASING SSE WINDS THU TO START TO BRING A BIT WARMER AND MORE

HUMID AIR BACK INTO CENTRAL IL. HIGHS THU IN THE LOW TO MID 80S WITH

WARMEST READINGS SW CWA AND DEWPOINTS CLIMBING INTO THE UPPER

60S/LOWER 70S BY THU AFTERNOON. CHANCES OF SHOWERS AND THUNDERSTORMS

WILL BE MAINLY NORTH OF I-72 THU NIGHT AND NE OF I-74 FRIDAY WITH

ISOLATED CHANCES ELSEWHERE...THOUGH SE IL LIKELY TO STAY DRY DURING

THIS TIME.

00Z FORECAST MODELS CONTINUE TO SHOW A HEAT WAVE RETURNING TO

IL FRIDAY THROUGH THIS WEEKEND AS HIGH HEAT AND HUMIDITY (HIGHS IN

LOWER 90S AND DEWPOINTS IN THE 70S) RETURNS WITH AFTERNOON HEAT

INDICES AROUND 100F ON FRIDAY AND 100-108F THIS WEEKEND WHEN HEAT

ADVISORYS MAY BE NEEDED AGAIN. AN UPPER LEVEL SUBTROPICAL HIGH

PRESSURE RIDGE WILL RETROGRADE BACK TO THE SOUTHERN PLAINS THIS

WEEKEND AND SHORT WAVES RIDGING OVER TOP OF THE RIDGE WILL GIVE

ISOLATED SHOWERS AND THUNDERSTORMS FRIDAY THROUGH SUNDAY WITH BEST

CHANCES FROM I-74 NORTH. A STRONGER SHORT WAVE AND FRONTAL BOUNDARY

WILL MOVE SE INTO IL OVERNIGHT SUNDAY NIGHT AND MONDAY BRINGING A

BETTER CHANCE OF ORGANIZED SHOWER AND THUNDERSTORM ACTIVITY AND

POSSIBLY STRONG TO SEVERE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)

ISSUED AT 638 AM CDT WED JUL 15 2015

VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HRS AT ALL TAF

SITES. SCATTERED CUMULUS CLOUD COVER EXPECTED TO DEVELOP BY LATE

MORNING AROUND 4 KFT AGL. CLOUD COVER WILL BE RELATED TO SURFACE

HEATING...SO WILL DISSIPATE AROUND SUNSET. INCREASING HIGH CLOUD

COVER WILL DEVELOP OVERNIGHT. WINDS E-NNE LESS THAN 10 KTS.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...

NONE.

&&

$$

SHORT TERM...07

LONG TERM...07

AVIATION...ONTON

Delivered by Weather Underground Inc. Wed Jul 15 2015 7:38AM EDT