432
FXUS63 KLOT 051712
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1212 PM CDT THU JUN 5 2025
KEY MESSAGES
- VISIBILITY REDUCTIONS AND POOR AIR QUALITY IN HAZE AND SMOKE
EXPECTED FOR PORTIONS OF THE AREA TODAY.
- SHOWER AND THUNDERSTORM CHANCES RETURN OVER THE WEEKEND.
UPDATE
ISSUED AT 1050 AM CDT THU JUN 5 2025
SURFACE OBSERVATIONS AS WELL AS GOES VISIBLE SATELLITE IMAGERY
SHOW SMOKE CONCENTRATIONS HAVE INCREASED ACROSS PORTIONS OF THE
AREA THIS MORNING. THIS HAS RESULTED IN VISIBILITY REDUCTIONS IN
THE 3-5 MILE RANGE ACROSS THE CHICAGO METRO AND SUSPECT THIS
WILL CONTINUE FOR MUCH OF THE DAY IN ADDITION TO CONTINUED POOR
AIR QUALITY. RIGHT ALONG THE IMMEDIATE LAKESHORE AND OVER THE
NEARSHORE WATERS OF LAKE MICHIGAN VISIBILITY MAY DIP BELOW 1
MILE AT TIMES, LIKELY AUGMENTED BY LINGERING MORNING FOG.
PETR
DISCUSSION
ISSUED AT 322 AM CDT THU JUN 5 2025
THROUGH FRIDAY:
EARLY MORNING GOES NIGHTTIME RGB IMAGERY SHOWS AN AREA OF FOG
DEVELOPING ROUGHLY ALONG THE I-80 CORRIDOR FROM THE SOUTHWEST
CHICAGO SUBURBS WEST INTO NORTH CENTRAL IL. KVYS AND KJOT ARE
BOTH DOWN TO M1/4SM, THOUGH ADMITTEDLY KJOT AWOS IS IN A LOW
SPOT THAT FREQUENTLY FOGS. WEBCAMS ALONG I-80 IN WILL COUNTY DO
SHOW DENSE FOG AS WELL, SO OPTED TO HOIST A DENSE FOG ADVISORY
UNTIL 9 AM THIS MORNING. SUNRISE IS ONLY A COUPLE OF HOURS AWAY
AND WITH THE HIGH SUN ANGLE I'D ANTICIPATE THIS DENSE FOG TO
BURN OFF WITHIN A COUPLE OF HOURS OF SUNRISE.
ALSO SEEING SOME DENSE MARINE FOR DEVELOP WITH WEBCAMS SHOWING
IT OOZING INLAND JUST A BIT IN SPOTS ALONG THE IL SHORELINE. THE
INLAND EXTENT IS VERY LIMITED AND ONLY SEEMS TO BE SPREADING
INLAND SO FAR IN VERY LOCALIZED SPOTS, SO GOING TO HOLD OFF ON A
DENSE FOG ADVISORY NEAR THE LAKE FOR NOW. IF THE MARINE FOG
PERSISTS INTO THE LAKE MORNING OR AFTERNOON, THEN IT IS POSSIBLE
THAT THE FOG COULD REACH JUST SLIGHTLY INLAND AS ONSHORE FLOW
PICKS UP DIURNALLY, THOUGH FOG WILL BE FIGHTING HIGH SUN ANGLE
AND LIKELY CONFINED TO AREAS WITHIN A QUARTER MILE OF SHORE.
OTHERWISE, FAIRLY BENIGN WEATHER IS EXPECTED TODAY THROUGH
FRIDAY. THE FRONTAL BOUNDARY HAS PUSHED WELL SOUTH OF OUR AREA
AND MAY SAG A BIT FARTHER SOUTH THROUGH TONIGHT. UPSTREAM
SHORTWAVE THAT WE HAD BEEN WATCHING FOR ANOTHER ROUND OF RAIN
FOR OUR SOUTHERN CWA FRIDAY NOW LOOKS TO BE LESS AMPLIFIED AND
MORE SUPPRESSED TO OUR SOUTH, SO HAVE LOWERED POPS CONSIDERABLY
FRIDAY.
FINALLY, OBSERVATIONS AROUND THE REGION SHOW VERY LITTLE
EVIDENCE OF MEANINGFUL NEAR SFC SMOKE. SATELLITE IMAGERY
WEDNESDAY AFTERNOON/EARLY EVENING SHOWED SMOKE FAR LESS DENSE
APPEARING THAN IT HAD BEEN. THE HRRR, WHICH ADMITTEDLY HASN'T
DONE A GREAT JOB WITH ITS HANDLING OF NEAR SFC SMOKE, SHOWS
FAIRLY LOW NEAR SFC SMOKE CONCENTRATIONS TODAY. CAN'T RULE OUT A
SLIGHT SMELL OF SMOKE IN THE AIR TODAY, BUT NOT SEEING ANYTHING
THAT WOULD SUGGEST A SIGNIFICANT ENOUGH AMOUNT OF NEAR SFC
SMOKE TODAY TO LEAD TO MEANINGFUL VSBY RESTRICTIONS.
- IZZI
FRIDAY NIGHT THROUGH WEDNESDAY:
CONSENSUS FORECAST GUIDANCE HAS BECOME INCREASINGLY PHASED WITH
A PAIR OF TROUGHS OVER THE CENTRAL ROCKIES FRIDAY NIGHT, WHICH
HAS WEAKENED A WESTERN GREAT LAKES RIDGE AND HASTENED THE
DEPARTURE OF AN ASSOCIATED SURFACE HIGH EARLY THIS WEEKEND.
WHILE THE BULK OF MID/UPPER-LEVEL FORCING VIA THE STACKED TROUGH
AND RIGHT ENTRANCE OF AN UPPER JET STREAK SHOULD FAVOR THE
HIGHEST RAIN CHANCES ACROSS CENTRAL ILLINOIS, HAVE INCREASED
POPS ACROSS THE FORECAST AREA IN THE AFTERNOON. AN UPPER-LEVEL
LOW OVER THE FAR NORTHERN GREAT LAKES WILL THEN PUSH A COLD
FRONT WITH THE POTENTIAL FOR SHOWERS AND SOME STORMS ACROSS THE
AREA SUNDAY AFTERNOON AND EVENING. WILL NEED TO MONITOR FOR A
LOW-END SEVERE STORM RISK WITH GUSTY WINDS AS DECENT EFFECTIVE
SHEAR COUNTERACTS MARGINAL MID-LEVEL LAPSE RATES.
THE UPPER-LEVEL LOW WILL SETTLE OVER THE FAR NORTHERN GREAT
LAKES REGION EARLY NEXT WEEK. A SERIES OF EMBEDDED COMPACT WAVES
ROTATING AROUND THE LOW COULD BRING DIURNALLY-ENHANCED SHOWERS
MONDAY AFTERNOON AND POSSIBLY TUESDAY AFTERNOON, CONDITIONAL ON
COINCIDENT TIMING OF THE WAVES WITH PEAK HEATING. A
DEAMPLIFYING MID-LEVEL RIDGE IS THEN PROGGED TO CROSS THE REGION
MIDWEEK, SUPPORTING DRIER AND MORE SEASONABLE CONDITIONS.
KLUBER
AVIATION /18Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 1212 PM CDT THU JUN 5 2025
THE MAIN AVIATION WEATHER CONCERNS FOR THE 18Z TAF PERIOD
INCLUDE:
* A PERIOD OF MVFR CIGS AT MDW AND GYY THIS AFTERNOON
AN MVFR CLOUD DECK IS SLOSHING WESTWARD ACROSS THE SOUTHERN
REACHES OF THE LAKE AS OF NOON LOCAL. MVFR HAS TAKEN HOLD AT GYY
IS EXPECTED TO MOVE OVER MDW RIGHT AROUND 1730Z. CONFIDENCE IN
THE BEHAVIOR OF THE MVFR IS LOW, ESPECIALLY AT MDW VS GYY, AND
CIGS MAY END UP SCATTERING BEFORE LONG. OTHERWISE, THIS LOWER
DECK SHOULD PULL AWAY FROM THE TAF SITES DURING THE LATTER PART
OF THIS AFTERNOON. VFR CAN THEN BE EXPECTED THROUGHOUT THE
PERIOD.
MEANWHILE, NE WINDS WILL CONTINUE TO GUST TO AROUND 20 KT
THROUGH EARLY EVENING BEFORE SUBSIDING TO BETWEEN 5 AND 10 KT
OVERNIGHT. DIRECTION MAY BACK TO NNW FOR A TIME TONIGHT WHILE
REMAINING LIGHT. EXPECT NE WINDS DURING THE DAY TOMORROW TO
AROUND 10 KT.
DOOM
LOT WATCHES/WARNINGS/ADVISORIES
IL...AIR QUALITY ALERT UNTIL MIDNIGHT CDT TONIGHT FOR ILZ005-ILZ006-
ILZ012-ILZ013-ILZ020-ILZ021-ILZ103-ILZ104-ILZ105-ILZ106-
ILZ107-ILZ108.
IN...AIR QUALITY ALERT UNTIL MIDNIGHT CDT TONIGHT FOR INZ001-INZ002-
INZ010-INZ011.
LM...DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR WINTHROP
HARBOR TO NORTHERLY IS. IL.
VISIT US AT WEATHER.GOV/CHICAGO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page