998
FXUS63 KLOT 151744
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1144 AM CST SAT NOV 15 2025
KEY MESSAGES
- UNSEASONABLY WARM WEATHER AGAIN TODAY.
- GUSTY TODAY AND TONIGHT, THEN DRY AND MUCH COLDER FOR SUNDAY.
- PRECIPITATION CHANCES RETURN MONDAY NIGHT INTO TUESDAY.
DISCUSSION
ISSUED AT 219 AM CST SAT NOV 15 2025
IT'S A MILD START TO THE DAY WITH TEMPERATURES SITTING IN THE
UPPER 50S EARLY THIS MORNING. SIMILAR TO YESTERDAY, WARM
ADVECTION OUT AHEAD OF A NORTHERN GREAT LAKES LOW WILL BRING
ANOTHER MILD DAY TO THE AREA WITH HIGHS FORECAST IN THE MIDDLE
60S TO 70 IN SOME OUTLYING SPOTS. THE STORM'S COLD FRONT WILL
MOVE ACROSS BETWEEN LATE MORNING AND EARLY AFTERNOON TODAY. THE
COLD ADVECTION WON'T BE ALL THAT AGGRESSIVE IMMEDIATELY IN ITS
WAKE AND WE SHOULD CONTINUE TO SEE TEMPERATURES CLIMB BEHIND THE
FRONT INTO THE AFTERNOON. A MUCH COOLER AIRMASS WILL THEN
ADVECT INTO THE AREA FROM THE NORTHERN PLAINS TONIGHT DRAGGING
LOW TEMPERATURES INTO THE LOWER AND MIDDLE 30S.
A FEW SPRINKLES OR LIGHT SHOWERS WILL BE POSSIBLE OFFSHORE AND
TOWARD WESTERN LOWER MICHIGAN WITH THE FRONTAL PASSAGE. THE NAM
SUITE HAS BEEN A BIT AGGRESSIVE IN WANTING TO TRACK LIGHT PRECIP
ACROSS OUR CWA, BUT A LARGE WEDGE OF LOW LEVEL DRY AIR AND
GENERAL LACK OF SUPPORT OTHERWISE SHOULD KEEP THE LOCAL AREA DRY
TODAY. ADDITIONALLY, A STRONG LOW LEVEL JET IS CURRENTLY MOVING
OVERHEAD. AS THE BOUNDARY LAYER DEEPENS AFTER SUNRISE, IT'S
LIKELY THAT WE'LL MIX SOME OF THOSE STRONGER WINDS DOWN TO THE
SURFACE AND SEE GUSTS TO 25 TO 30 MPH THROUGH THE MORNING,
OCCASIONALLY HIGHER, THEN SUBSIDING A TAD BUT REMAINING GUSTY
FOR THE AFTERNOON. THE GUSTINESS WILL CONTINUE THROUGH TONIGHT
THANKS TO THE POST-FRONTAL COLD ADVECTION KEEPING THE BOUNDARY
LAYER WELL-MIXED.
HIGH PRESSURE WILL SETTLE INTO THE REGION BEHIND THE COLD FRONT
BRINGING SUNNY BUT COOLER AND VERY DRY CONDITIONS TO TOMORROW.
HIGHS TOMORROW ARE FORECAST IN THE UPPER 40S TO LOWER 50S WHILE
AFTERNOON DEWPOINTS ARE PROGGED IN THE TEENS TO AROUND 20
DEGREES. THIS WILL YIELD AFTERNOON RHS BETWEEN 25 AND 30%. WITH
MARGINALLY GUSTY NW WINDS EXPECTED AND GIVEN RECENT DRY
CONDITIONS, SUNDAY MAY SEE A MARGINALLY ELEVATED FIRE WEATHER
RISK.
ATTENTION THEN TURNS TO AN EARLY WEEK ROCKY MOUNTAIN LOW THAT
WILL TRACK ACROSS CENTRAL ILLINOIS BRINGING US OUR NEXT CHANCES
FOR RAIN. THE SYSTEM WILL DEVELOP OUT IN THE PLAINS EARLY MONDAY
BEFORE THE UPPER WAVE LOSES AMPLITUDE INTO THE MIDWEST AND THE
SURFACE LOW TRACKS IMMEDIATELY SOUTH OF OUR CWA ON TUESDAY.
THERE'S A CHANCE THAT WE COULD SEE SOME SNOW MIX IN WITH THE
RAIN, ESPECIALLY EARLY IN THE EVENT MONDAY EVENING AND NIGHT
WHEN DRIER LOW LEVEL AIR WILL PROMOTE SOME WET BULB COOLING. BUT
IT'S A VERY TOUCHY SETUP WITH SOUNDINGS EXHIBITING A NEARLY-
ISOTHERMAL LAYER THROUGH THE LOWEST COUPLE OF HUNDRED MILLIBARS
STRADDLING THE FREEZING LINE. THE EURO IS NOTABLY WARMER THROUGH
THE LOW LEVELS THAN THE GFS AND OFFERS LITTLE IN THE WAY OF
MIXED OR FROZEN PRECIP. THE EURO HAS BEEN FAR MORE CONSISTENT
RUN BY RUN WITH THE STORM'S TRACK THAN THE GFS WHICH HAS BEEN ON
A STEADY NORTHWARD TREND. THE LATEST ITERATIONS OF THE TWO SHOW
VERY SIMILAR STORM TRACKS NOW, BUT THE BIG QUESTION IS HOW FAR
NORTH THE LOW LEVEL WARM SECTOR/BAROCLINIC ZONE WILL EXTEND EAST
OF THE LOW. LOOKING AT ENSEMBLE SOUNDINGS, THERE IS STRONG
SUPPORT IN THE ENS SUITE FOR THE LOW LEVELS TO BE ABOVE FREEZING
WHILE THERE IS MORE SPREAD AMONG GEFS MEMBERS. THIS ADDS
FURTHER CONFIDENCE TO THE EURO'S WARMER SOLUTION. A NUMBER OF
OTHER MEDIUM-RANGE CAMPS SUCH AS THE RDPS, ICON, AND UKMET ALSO
FAVOR A WARMER SOLUTION SIMILAR TO THAT OF THE EURO. THE NBM
POPULATED THE FORECAST WITH ALL LIQUID PRECIP, WHICH WAS
MAINTAINED AS THAT APPEARS TO BE THE FAVORED OUTCOME. INSTANCES
OF A WINTRY MIX WILL STILL BE POSSIBLE THOUGH, PARTICULARLY
MONDAY NIGHT, BUT WOULD NOT CONTRIBUTE TO ANY IMPACTS ASIDE FROM
PERHAPS SOME ADDED VISIBILITY REDUCTIONS.
A POOL OF RICH GULF MOISTURE WILL TRACK AHEAD OF THE LOW. THE
1"+ PWATS LOOK TO STAY JUST OUT OF REACH TO OUR SOUTH, BUT AS
MANY AS 0.7-0.8" OF PWAT WILL WORK INTO OUR CWA. A WIDESPREAD
COUPLE TO FEW TENTHS OF AN INCH OF PRECIP IS ON THE TABLE MONDAY
NIGHT THROUGH TUESDAY. THE NE QUADRANT OF THE STORM WILL ALSO
PROVIDE THE OPPORTUNITY FOR LOW LEVEL DEFORMATION AND LOCALIZED
SWATHS OF HEAVIER RAINFALL UP TO AROUND A HALF INCH IN TOTAL.
THIS POTENTIAL FOR BANDED PRECIP IS PORTRAYED IN SOME MODEL QPF
OUTPUT AS WELL.
ANOTHER LOW WILL SPIN UP OFF THE LEE OF THE NEW MEXICO ROCKIES
LATE WEDNESDAY AND TRACK ACROSS THE REGION THURSDAY INTO FRIDAY.
THE WARM SECTOR LOOKS TO BE LADEN WITH GULF MOISTURE WITH PWATS
PROGGED AT OVER 1", MAYBE EVEN NEAR 1.5". THIS SORT OF MOISTURE
IN CONJUNCTION WITH LIKELY STRONG DYNAMIC FORCING AHEAD OF THE
HIGH-AMPLITUDE TROUGH WILL PRESENT AN OPPORTUNITY FOR WIDESPREAD
SOAKING RAIN. THERE'S PLENTY OF UNCERTAINTY STILL IN WHERE THE
STORM AND HEAVIEST PRECIP WILL TRACK, BUT MEDIUM RANGE GUIDANCE
IS PRETTY EXCITED ABOUT A SIZABLE SWATH OF 1-2" PRECIP TOTALS
SOMEWHERE AROUND THE REGION. GIVEN THE RICH MOISTURE AND FAIRLY
STEEP MID LEVEL LAPSE RATES, SOME ELEVATED THUNDERSTORMS MAY
EVEN BE IN THE CARDS THURSDAY INTO FRIDAY.
DOOM
AVIATION /18Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 1144 AM CST SAT NOV 15 2025
KEY MESSAGES:
- GUSTY WESTERLY TO NORTHWESTERLY WINDS ARE EXPECTED THROUGH
MUCH OF THE TAF PERIOD.
A COLD FRONT IS TRACKING ACROSS THE AREA FROM WEST TO EAST AT
PRESS TIME, WITH WINDS SHIFTING TO A WESTERLY DIRECTION BEHIND
IT. WINDS WILL GRADUALLY TURN MORE NORTHWESTERLY GOING INTO
TONIGHT AND THEN LARGELY REMAIN FROM A 300-330 DIRECTION
THROUGH THE DAY TOMORROW.
GUST MAGNITUDES THIS AFTERNOON SHOULD AVERAGE OUT AROUND 25
KTS, THOUGH STRONGER GUSTS TO NEAR AND IN EXCESS OF 30 KTS WILL
BE POSSIBLE AT TIMES EARLY TONIGHT AS A LOW-LEVEL JET
STRENGTHENS AND THE BOUNDARY LAYER STRUGGLES TO DECOUPLE IN THE
POST-FRONTAL COLD AIR ADVECTION REGIME. THERE COULD THEN BE A
RELATIVE LULL IN THE GUSTINESS LATER TONIGHT (ESPECIALLY AWAY
FROM ORD AND MDW), BUT GUSTS TO NEAR AND IN EXCESS OF 20 KTS
ARE OTHERWISE EXPECTED TO RESUME DURING THE DAYTIME TOMORROW.
WHILE PATCHY MVFR CEILINGS COULD LINGER AT/NEAR GYY UNTIL 19Z,
VFR CONDITIONS ARE OTHERWISE EXPECTED TO PREVAIL THROUGHOUT THE
TAF PERIOD.
OGOREK
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM CST SUNDAY FOR WINTHROP HARBOR
IL TO GARY IN.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 9 AM CST MONDAY
FOR GARY TO BURNS HARBOR IN-BURNS HARBOR TO MICHIGAN CITY
IN.
VISIT US AT WEATHER.GOV/CHICAGO
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