645
FXUS63 KLOT 080734
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
134 AM CST SUN FEB 8 2026
KEY MESSAGES
- MILDER TEMPERATURES EXPECTED FOR MUCH OF THE UPCOMING WORK
WEEK.
DISCUSSION
ISSUED AT 134 AM CST SUN FEB 8 2026
SNOW ASSOCIATED WITH A REGION OF STOUT LOW-LEVEL FRONTOGENESIS
CONTINUES TO SHIFT EAST EARLY THIS MORNING AND IS ENDING IN OUR
FORECAST AREA. SOME LINGERING MID-LEVEL MOISTURE ASSOCIATED WITH
THE PRIMARY 700 MB SHORTWAVE WILL DRIFT OUT OF SOUTHERN
WISCONSIN, BUT ADDITIONAL PRECIPITATION APPEARS UNLIKELY WITH
THIS THROUGH DAYBREAK. THE PRESSURE GRADIENT WILL STEADILY
INCREASE ACROSS THE AREA THIS MORNING AS A MODEST SURFACE LOW
CURRENTLY ACROSS EASTERN SOUTH DAKOTA DRIFTS EASTWARD AND SLOWLY
FILLS. THIS WILL LEAD TO INCREASING SOUTHEASTERLY BREEZES
TODAY, AND SOME ADDITIONAL MID-LEVEL CLOUD COVER WILL LIKELY
DEVELOP WITH TIME. PERSISTENT ONSHORE FLOW WILL ALSO LEAD TO AN
EXPANSION OF LOW STRATUS MAINLY ACROSS PARTS OF LAKE COUNTY, IL,
BUT CLOUD DEPTHS APPEAR TOO LIMITED TO SUPPORT MUCH A
PRECIPITATION THREAT.
WARM ADVECTION WILL INCREASE LATE TONIGHT INTO MONDAY MORNING AS
ANOTHER SURFACE LOW SPINS UP ACROSS SOUTH DAKOTA. IN RESPONSE,
MOISTURE WITHIN THE 925-800 MB LAYER IS FORECAST TO INCREASE A
BIT INTO EARLY MONDAY MORNING. AT THIS POINT, SUSPECT THAT THE
NAM IS SUFFERING FROM ITS TYPICAL MOIST BIAS, WITH LIMITED
SUPPORT FOR THE DEGREE OF SATURATION IT'S ADVERTISING ACROSS THE
REST OF THE GUIDANCE SUITE. AS A RESULT, PRECIP CHANCES DON'T
APPEAR NECESSARY AT THIS TIME.
THE AFOREMENTIONED LOW IS FORECAST TO SCOOT EAST INTO IOWA ON
MONDAY AFTERNOON. AS THIS OCCURS, BOUNDARY LAYER FLOW ACROSS
NORTHERN ILLINOIS WILL BEGIN TO TURN SOUTHERLY AND EVENTUALLY
SOUTHWESTERLY MONDAY NIGHT. THIS IN TURN WILL DRIVE A WARMER
AIRMASS NORTHWARD, WITH HIGHS ON MONDAY LOOKING LIKELY TO PUSH
WELL INTO THE 40S ACROSS THE SOUTHWEST THIRD OF THE FORECAST
AREA, WITH MID/UPPER 30S EXPECTED TO LINGER ACROSS FAR NORTHEAST
ILLINOIS AND NORTHWEST INDIANA.
EVENTUALLY, A COLD FRONT WILL SHIFT ACROSS THE REGION EITHER
VERY LATE MONDAY NIGHT OR TUESDAY MORNING. THE SIGNAL FOR ANY
PRECIPITATION WITH THIS FRONT/TROUGH ISN'T PARTICULARLY ROBUST,
LIKELY DUE TO PROGGED LIMITED LOW-LEVEL MOISTURE. THAT SAID,
SOME GUIDANCE LOOKS CLOSE TO SUPPORTING DRIZZLE (UKMET AND NAM
AND PARTICULAR), ALTHOUGH AGAIN THIS DOESN'T HAVE A LOT OF
SUPPORT ACROSS THE REST OF THE GUIDANCE SUITE AT THIS TIME, SO
DID NOT SEE A REASON TO INTRODUCE A WEATHER MENTION AT THIS
POINT. IN THE WAKE OF THIS FRONT, A BRIEF PERIOD OF COLD
ADVECTION WILL DIMINISH THROUGH THE AFTERNOON WHICH SHOULD ALLOW
TEMPERATURES TO PUSH BACK INTO THE 40S ACROSS MUCH OF THE AREA.
HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH WEDNESDAY
NIGHT. THEREAFTER, SEVERAL DISTURBANCES ARE FORECAST TO TRACK
ACROSS THE CENTRAL CONUS AND MIDWEST. SOME POTENTIAL FOR WINTRY
PRECIPITATION IS EVIDENT, BUT SIGNIFICANT SPREAD ACROSS THE
DETERMINISTIC AND ENSEMBLE MODEL SUITE EXISTS LEADING TO LOW
CONFIDENCE IN THE FORECAST EVOLUTION THURSDAY INTO NEXT WEEKEND.
CARLAW
AVIATION /06Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 1048 PM CST SAT FEB 7 2026
KEY MESSAGES FOR THE 06Z TAFS:
- NARROW NW-SE BAND OF SNOW EXITING THE CHICAGO TERMINALS EARLY
IN THE TAF PERIOD. BRIEF MVFR/IFR DURING THIS SNOWFALL.
A NARROW NORTHWEST-SOUTHEAST BAND OF LIGHT SNOW OVER ORD/MDW/GYY
JUST PRIOR TO TAF ISSUANCE WILL MOVE QUICKLY EAST OF THE
TERMINALS WELL BEFORE DAYBREAK. GYY MAY STILL EXPERIENCE SNOW
AT 06Z, WHILE ORD AND MDW MAY SEE SNOW END AROUND THE START OF
THE PERIOD. WILL SEE QUICK IMPROVEMENT FROM IFR/MVFR TO VFR
CONDITIONS AS SNOW MOVES EAST.
OTHERWISE, VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD, ALONG
WITH EAST-SOUTHEAST TO SOUTHEAST WINDS AROUND 10 KTS AS A WEAK
AREA OF LOW PRESSURE PASSES WELL SOUTH OF THE REGION.
RATZER
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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