076
FXUS63 KMKX 312323
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
623 PM CDT MON AUG 31 2026
KEY MESSAGES
- HEAT & HUMIDITY CONTINUES THROUGH MIDWEEK. AFTERNOON HEAT
INDICES IN THE LOW-MID 90S EXPECTED EACH DAY THROUGH
WEDNESDAY, WITH UPPER 90S TO NEAR TRIPLE DIGITS POSSIBLE IN
AREAS EXPERIENCING MORE SUNSHINE. WARM TEMPERATURES LINGER
INTO THE WEEKEND, WITH HEAT INDEX VALUES IN THE UPPER 80S TO
LOW 90S THURSDAY THROUGH SUNDAY.
- ISOLATED THUNDERSTORMS POSSIBLE THIS EVENING AND AGAIN
TUESDAY AFTERNOON AND EVENING.
- AREAS OF FOG EXPECTED OVERNIGHT TONIGHT, WITH POTENTIAL FOR
PATCHY DENSE FOG IN LOW LYING AREAS.
- SCATTERED STORM CHANCES RETURN LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING, ESPECIALLY FOR CENTRAL WISCONSIN.
ADDITIONAL SCATTERED STORMS WILL OCCUR ON AND OFF WEDNESDAY
THROUGH FRIDAY.
UPDATE
ISSUED 625 PM CDT MON AUG 31 2026
FORECAST REMAINS LARGELY ON TRACK EARLY THIS EVENING. MCV-
AFFILIATED LIFT CONTINUES TO MOVE ACROSS SOUTHERN WISCONSIN,
THOUGH AN ABSENCE OF SURFACE BOUNDARIES & STOUT EML-AFFILIATED
CAPPING ARE KEEPING ANY PRECIPITATION WIDELY SCATTERED & OF
MOSTLY BENIGN INTENSITY. WITH A SYNOPTIC COLD FRONT STILL WELL
NORTH OF THE AREA & AN OUTFLOW BOUNDARY FROM EARLIER AFTERNOON
STORMS REMAINING OVER NORTHERN ILLINOIS, ANTICIPATING THESE
TRENDS TO CONTINUE INTO THE SECOND HALF OF THE EVENING ACROSS
THE MAJORITY OF THE AREA. CURRENT 15-25% PRECIP PROBS THUS
APPEAR REASONABLE, WITH NO INTERMEDIATE CHANGES NEEDED AT THIS
TIME. WHILE MEAN WESTERLY STEERING FLOW & CONSIDERABLE CAPPING
OFF THE SURFACE FRONT SHOULD HOLD ACTIVITY NORTH OF THE REGION,
WILL BE MONITORING FOR ANY CLOSER CALLS BETWEEN ISOLATED COLD
FRONTAL STORMS & OUR NORTHERN COUNTIES THROUGH MID-EVENING. IF
AN ISOLATED STORM SNUCK IN, IT COULD PRODUCE SOME SMALL HAIL OR
GUSTY WINDS.
QUIGLEY
SHORT TERM
ISSUED 336 PM CDT MON AUG 31 2026
TONIGHT THROUGH TUESDAY NIGHT:
A STRONG CAPPING INVERSION WITH 200-250 J/KG OF CIN HAS
PREVENTED SCATTERED THUNDERSTORMS FROM NUDGING OVER THE BORDER
INTO WISCONSIN THIS AFTERNOON. AN ISOLATED THUNDERSTORM IS STILL
POSSIBLE, BUT BECOMING LESS LIKELY. ISOLATED TO SCATTERED
SHOWERS ARE EXPECTED THROUGH THIS EVENING, ENDING AROUND SUNSET.
HIGHS IN THE MID 80S ARE EXPECTED, WITH HEAT INDEX VALUES IN
THE LOW 90S.
AFTER SUNSET, TEMPERATURES WILL FALL INTO THE LOW 70S AND WINDS
CALM AS A FRONTAL FEATURE STALLS OVER CENTRAL WISCONSIN. WITH
DEWPOINTS ALSO IN THE UPPER 60S TO LOW 70S, WIDESPREAD FOG IS
EXPECTED, WITH PATCHY DENSE FOG POSSIBLE IN LOW-LYING AREAS.
FOG IS EXPECTED TO BURN OFF SHORTLY AFTER SUNRISE ON TUESDAY AS
SOUTHWESTERLY WINDS INCREASE AGAIN. WITH WAA THROUGH ALL LEVELS
AND A MORNING BREAK IN THE CLOUD COVER, EXPECTING HIGH
TEMPERATURES TUESDAY TO REACH THE UPPER 80S TO 90 DEGREES. HEAT
INDEX VALUES ARE EXPECTED TO BE IN THE MID 90S IN CENTRAL
WISCONSIN WHERE MORE CLOUD COVER PERSISTS, AND IN THE UPPER 90S
FARTHER SOUTH. NEAR THE WI/IL BORDER, HEAT INDEX VALUES MAY
BRIEFLY REACH 100 DEGREES.
TUESDAY AFTERNOON INTO TUESDAY EVENING, AN ADDITIONAL PERIOD OF
ISOLATED TO SCATTERED THUNDERSTORMS IS POSSIBLE (20-30% CHANCES).
EXPECTING LIGHTNING TO BE THE PRIMARY THREAT, BUT CANNOT RULE
OUT AN ISOLATED STORM BECOMING SEVERE. WITH MUCAPE AROUND 2500
J/KG AND BULK SHEAR OF 35 TO 40 KT. A CAP REMAINS IN PLACE,
ALBEIT WEAKER (APPROXIMATELY 100 J/KG OF CIN), BUT A STRONG
TRIGGER IS LACKING FOR ADEQUATELY ORGANIZED STORMS. MAIN TRIGGER
WILL BE BROAD WAA ALOFT, WHICH WOULD LEND CREDENCE TO MORE OF A
SCATTERED THUNDERSTORM THREAT THAN AN ORGANIZED SEVERE THREAT.
LATE TUESDAY NIGHT INTO WEDNESDAY, AN 850 LLJ NOSES INTO CENTRAL
WISCONSIN WHERE THE WEAK FRONTAL BOUNDARY LINGERS, BRINGING
MORE CONFIDENCE FOR SCATTERED STORMS, BUT STILL LOW CONFIDENCE
FOR SEVERE ACTIVITY (20-40% CHANCES).
MH
LONG TERM
ISSUED 336 PM CDT MON AUG 31 2026
WEDNESDAY THROUGH MONDAY:
WISCONSIN REMAINS ON THE NORTHERN EDGE OF 500 MB RIDGING THROUGH
THE END OF THE WORK WEEK, WITH CHANCES FOR CONVECTION/RIDGE
RIDING MCSS THROUGH FRIDAY AND LINGERING HIGH HEAT AND HUMIDITY
THROUGH THURSDAY. INDIVIDUAL 500 MB SHORTWAVES AND LLJS WILL BE
THE DRIVING FORCE FOR STORMS THROUGH THE WEEK, WITH EXACT
TIMING AND PLACEMENT LIKELY NOT BECOMING CLEAR UNTIL 24 HOURS
FROM THE EACH EVENT. CURRENTLY, HIGHEST CONFIDENCE IN WIDESPREAD
STORM DEVELOPMENT FOR SOUTHERN WISCONSIN IS WEDNESDAY NIGHT
INTO THURSDAY, AS BROAD LOW PRESSURE DEVELOPS IN THE CENTRAL
PLAINS AND BRINGS A STRONGER, MORE FOCUSED LLJ TO EASTERN IOWA
AND SOUTHWESTERN WISCONSIN. THIS WOULD SUPPORT A SEVERE THREAT
DUE TO THE ENHANCED CAPE, MOISTURE, AND MORE FOCUSED TRIGGER AND
TEND TO LIKE THE NBM 50-70% POPS GOING INTO THURSDAY MORNING.
AS LOW PRESSURE DEEPENS IN THE NORTHEAST U.S. ON FRIDAY, HIGH
PRESSURE BUILDS INTO ONTARIO, BRINGING DRIER, NORTHEASTERLY FLOW
TO THE GREAT LAKES AND BRINGING A RETURN TO DRIER CONDITIONS AND
MORE SEASONABLE TEMPERATURES FOR THE WEEKEND INTO MONDAY (HIGHS
IN THE LOW 80S).
MH
AVIATION
ISSUED 625 PM CDT MON AUG 31 2026
VFR FLIGHT CATEGORIES PREVAIL ACROSS SOUTHERN WISCONSIN EARLY
THIS EVENING. WIDELY SCATTERED RAIN SHOWERS WILL LINGER THROUGH
THE FIRST HALF OF THE EVENING, PARTICULARLY IN EAST-CENTRAL
WISCONSIN AND NEAR THE WISCONSIN-ILLINOIS STATE LINE. HAVE THUS
INTRODUCED TEMPO -RA GROUPS THROUGH 02Z AT SBM AND JVL IN THE
00Z FORECAST. WHETHER/NOT STATE LINE ACTIVITY PERSISTS LONG
ENOUGH TO REACH THE VICINITY OF ENW REMAINS UNCERTAIN, WITH
RADAR TRENDS BEING MONITORED FOR POSSIBLE TEMPO GROUPS INTO THE
MID-EVENING HOURS. STILL ANTICIPATING AREAS OF FOG DEVELOPMENT
OVERNIGHT, WITH SHORT-TERM MODEL GUIDANCE HINTING AT THE
GREATEST POTENTIAL FOR VIS REDUCTIONS ACROSS THE WEST WHERE
CLOUD COVER IS FORECAST TO BE THINNER. HAVE THUS CONTINUED VIS
REDUCTIONS & BR MENTIONS AT MSN AND JVL DURING THE PREDAWN HOURS
IN THE 00Z FORECAST. GREATER ANTICIPATED CLOUD COVERAGE FURTHER
EAST CASTS SOME UNCERTAINTY REGARDING FOG POTENTIAL CLOSER TO
LAKE MICHIGAN, SO HAVE FOR THE TIME-BEING REMOVED ANY BR
MENTIONS AT EASTERN FIELDS GIVEN LOWER FORECAST CONFIDENCE.
WILL BE CLOSELY MONITORING VIS TRENDS FOR ANY CHANGES TO VIS
FORECASTS THROUGH THE OVERNIGHT.
QUIGLEY
MARINE
ISSUED 336 PM CDT MON AUG 31 2026
LOW PRESSURE OF 29.5 INCHES OVER THE CANADIAN PRAIRIES WILL LIFT
NORTHEASTWARD INTO THE HUDSON BAY THROUGH TUESDAY, BRINGING
CONTINUED BREEZY SOUTHWEST WINDS TO LAKE MICHIGAN THROUGH
TUESDAY. A SMALL CRAFT ADVISORY IS IN EFFECT THROUGH THIS
EVENING FOR GUSTY SOUTHWEST WINDS FROM PORT WASHINGTON
SOUTHWARD. WITH A WARM, MOIST AIRMASS MOVING NORTHWARD, PATCHY
DENSE FOG IS ALSO EXPECTED OVERNIGHT INTO TUESDAY MORNING. A
FRONT FROM THE CANADIAN LOW WILL SETTLE OVER THE LAKE TONIGHT,
LINGERING THROUGH THE WEEK AND ALLOWING FOR ON- AND-OFF
THUNDERSTORMS THROUGH FRIDAY. MEANWHILE, HIGH PRESSURE AROUND
30.0 INCHES OF THE SOUTHEAST U.S. WILL KEEP WINDS GENERALLY
SOUTHERLY THROUGH WEDNESDAY. THURSDAY, LOW PRESSURE FINALLY
EXITS INTO THE CANADIAN MARITIMES, BRINGING THE FRONT INTO THE
OHIO VALLEY AND ALLOWING WINDS TO SHIFT TO NORTHEASTERLY,
REMAINING NORTHEASTERLY THROUGH FRIDAY.
MH
MKX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
LM...NONE.
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