466
FXUS63 KAPX 291848
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
248 PM EDT MON JUN 29 2026
KEY MESSAGES
- EXTENDED PERIOD OF HOT AND HUMID CONDITIONS, HOTTEST LIKELY
TUESDAY THROUGH THURSDAY.
- PERIODIC SHOWER AND THUNDERSTORM CHANCES THROUGHOUT THE WEEK,
SEVERE STORMS POSSIBLE WITH HEAVY RAIN, LARGE HAIL AND DAMAGING
WIND.
DISCUSSION
ISSUED AT 241 PM EDT MON JUN 29 2026
THE HEAT IS ON. A 596 DAM UPPER HIGH BUILDS OVER THE SOUTHEAST
CONUS EARLY THIS WEEK WITH ANOMALOUSLY WARM AND MOIST AIR
EXTENDING NORTHWARD INTO THE GREAT LAKES. AT THE SAME TIME,
HEIGHT FALLS WITH AN UPPER TROUGH DEEPENING ACROSS THE
INTERMOUNTAIN WEST. THE UPPER HIGH WILL SLOWLY DRIFT EASTWARD
THROUGHOUT THE WEEK, WITH A NUMBER OF SHORTWAVES RIDING THE
PERIPHERY OF THE RIDGE RESULTING IN SHOWER/STORM CHANCES. THE
CONVECTION WILL CERTAINLY "MUDDY" THE TEMPERATURE FORECASTS FROM
DAY TO DAY OVER NORTHERN MICHIGAN, WITH CLOUD COVER AND
SHOWER/STORM THREATS LARGELY CONTROLLING MAX TEMPERATURES.
DESPITE THE UNCERTAINTY ON TEMPERATURES, IT WILL BE HOT AND VERY
HUMID AS DEEPER MOISTURE SURGES INTO THE GREAT LAKES WITH
DEWPOINTS OVER 70F. I WILL TRANSITION THE EXTREME HEAT WATCH TO
A HEAT ADVISORY FOR ALL OF NORTHERN MICHIGAN FOR TUESDAY, WITH
GREATER THAN TRIPLE DIGIT HEAT INDICES LIKELY IN MANY AREAS.
EVEN IN AREAS THAT MAY NOT QUITE REACH CRITERIA, IT WILL BE
QUITE HOT AND HEAT STRESS WILL BE AN ISSUE. CHECK ON THOSE MOST
SENSITIVE TO HEAT INCLUDING THE ELDERLY, YOUNG CHILDREN,
OUTSIDE WORKERS AND PETS. WILL HANDLE THE HEAT HEADLINES DAY BY
DAY GIVEN THE UNCERTAINTY IN CONVECTIVE EVOLUTION.
SEVERAL CONVECTIVE THREATS THROUGHOUT THE WEEK WITH DEVELOPING
SOUTHWEST FLOW ACROSS A VERY MOIST/UNSTABLE AIRMASS ACROSS THE GREAT
LAKES. ANY MINOR PERTURBATION COULD ACT AS THE TRIGGER GIVEN THE
HIGH INSTABILITY, WITH LEFTOVER CONVECTIVE OUTFLOWS/BOUNDARIES
ACTING AS FOCUSING MECHANISMS FOR STORMS. ON TUESDAY, STORMS MAY
FIRE OVER PORTIONS OF NORTHERN WISCONSIN AND WESTERN UPPER MICHIGAN
WITHIN AN EXTREMELY UNSTABLE CORRIDOR, THEN SHIFT EAST FOR THE
AFTERNOON OR EVENING. MODERATE SHEAR AND POTENTIALLY EXTREME
INSTABILITY COULD PRODUCE A DAMAGING WIND AND LARGE HAIL THREAT,
WITH BOWING SEGMENTS POSSIBLE INTO PARTS OF NORTHERN MICHIGAN.
ADDITIONAL SHORTWAVES OVER A GRADUALLY FLATTENING RIDGE TOWARD
THE END OF THE WEEK MAY BRING ADDITIONAL SHOWER/STORM CHANCES.
THE UPPER LEVEL PATTERN BECOMES LESS AMPLIFIED HEADING INTO THE
HOLIDAY WEEKEND BUT STILL QUITE WARM AND REMAINING ACTIVE WITH
SHOWER/STORM CHANCES.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 130 PM EDT MON JUN 29 2026
SHOWERS WITH EMBEDDED THUNDERSTORMS ARE SEEN ON RADAR SLOWLY
TRACKING WEST TO EAST ACROSS THE REGION. MAINLY VFR CONDITIONS
EXPECTED TO PERSIST, WITH DROPS IN CATEGORIES POSSIBLE AS
STRONGER STORMS CONTINUE, MAINLY ACROSS PLN. WINDS WILL DECREASE
TONIGHT WITH BR/FG/LOW STRATUS BECOMING LIKELY IN THE MORNING
HOURS (DROPPING CONDITIONS TO IFR TO EVEN LIFR AT TIMES), BUT
SHOULD BURN OFF AS WE HEAD INTO THE AFTERNOON, RETURNING TO VFR.
APX WATCHES/WARNINGS/ADVISORIES
MI...HEAT ADVISORY FROM NOON TO 8 PM EDT TUESDAY FOR MIZ016>018-
020>036-041-042-086>088-095>099.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
LHZ345>348.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR LMZ323-341-342-
344>346.
DISCUSSION...JK
AVIATION...NSC
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