624  
FXUS63 KDTX 181946  
AFDDTX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI  
346 PM EDT THU JUN 18 2026  
   
KEY MESSAGES  
 
- BREEZY TODAY WITH WESTERLY WIND GUSTS OF UP TO 35 MPH AND A FEW  
ISOLATED SHOWERS POSSIBLE THROUGH REMAINDER OF THE AFTERNOON.  
 
- DRY FRIDAY WITH SCATTERED SHOWERS AND ISOLATED GENERAL  
THUNDERSTORMS ON SATURDAY.  
 
- ADDITIONAL RAINFALL CHANCES FOCUSED ACROSS LOWER MICHIGAN SUNDAY  
EVENING INTO MONDAY.  
 
- SLIGHTLY BELOW NORMAL TEMPERATURES ARE EXPECTED INTO THE WEEKEND.  
 
 
   
DISCUSSION  
 
COOLER CYCLONIC FLOW OVER THE AREA TODAY WITH AN 115+ KNOT UPPER  
LEVEL JET EXTENDING OUT OF THE PACNW THROUGH THE EASTERN GREAT LAKES.  
THIS HAS SUPPORTED A HIGH COVERAGE OF CLOUDS ACROSS THE AREA THIS  
AFTERNOON. STEEPENED LOWER LEVEL LAPSE RATES HAVE ALSO SUPPORTED  
GUSTY WINDS TO AROUND 35 TO 40 MPH. GUSTY CONDITIONS SHOULD EASE THIS  
EVENING AS STABLE CONDITIONS DEVELOP WITH THE INBOUND SURFACE HIGH  
PRESSURE AND THE STRONGER LOWER LEVEL JET WINDS MOVE OFF TO THE EAST.  
WHILE THE ENVIRONMENT IS LACKING DEEPER MOISTURE, THE NORTHWEST FLOW  
AND WEAK CAA PRESENTS LOW END POPS FOR POSSIBLE ISOLATED SHOWER  
ACTIVITY THROUGH REMAINDER OF THE AFTERNOON. A CLOUD CLEARING TREND  
IS EXPECTED TONIGHT BRING MOSTLY CLEAR SKIES AND LOWS DOWN INTO THE  
LOW/MID 50S.  
 
SURFACE HIGH PRESSURE WITH LOW AMPLITUDE LOW LEVEL RIDGE WILL LEAD  
TO DRY CONDITIONS FOR TOMORROW. LESS CLOUD COVER AND SLIGHTLY WARMER  
850 MB TEMPERATURES SHOULD LEAD AFTERNOON HIGH TEMPERATURES  
GENERALLY AROUND THE MID 70S. A WEAK SHORTWAVE IS PROGGED TO PASS  
WITHIN THE NORTHWEST FLOW OF THE BROADER TROUGH AND ARRIVE LOCALLY  
ON SATURDAY. SLIGHT IMPROVEMENT IN MOISTURE WITH MARGINALLY IMPROVED  
INSTABILITY AND LAPSE RATES SHOULD BE ENOUGH TO SUPPORT SCATTERED  
SHOWERS AND ISOLATED THUNDERSTORMS. THE BETTER ENVIRONMENT FOR  
THUNDERSTORMS LOOKS FOCUSED NORTH OF I-69.  
 
STABLE CONDITIONS WILL MARK THE START OF SUNDAY AS A CONVECTIVE  
SYSTEM ORGANIZES UPSTREAM AROUND THE MID-MISSISSIPPI RIVER FORCED BY  
A MID-LEVEL WAVE PASSING THROUGH THE CENTRAL PLAINS, STRONG LOW  
LEVEL JET, AND MOISTURE CONVERGENCE. THE NORTHERN PERIPHERY OF THIS  
MCS LOOKS TO CLIP LOWER MICHIGAN SUNDAY EVENING INTO MONDAY.  
FORECAST SHOWS WEAK LAPSE RATES AND LITTLE TO NO INSTABILITY, SO A  
SEVERE WEATHER THREAT SHOULD BE LIMITED WITH HEAVY RAINFALL BEING  
THE MAIN FOCUS. THERE IS STILL ROOM FOR A SHIFT IN THE RAINFALL  
AXIS, BUT HEAVIEST RAINFALL IS CURRENTLY FORECAST TO SET UP ACROSS  
IN AND OH. TEMPERATURE FORECAST OVER THE WEEKEND INTO NEXT WEEK  
LOOKS SOMEWHAT STEADY WITH HIGHS IN THE 70S AND OVERNIGHT LOWS IN  
THE 50S.  
 
 
   
MARINE  
 
BREEZY WEST FLOW PERSISTS FOR THE REMAINING DAYLIGHT HOURS IN THE  
WAKE OF A DEPARTING LOW PRESSURE SYSTEM. WIND GUSTS RANGING BETWEEN  
20-30 KNOTS WILL BE LIKELY AND SMALL CRAFT ADVISORIES REMAIN IN  
PLACE THROUGH TONIGHT. A RIDGE OF HIGH PRESSURE WILL BUILD IN LATE  
TONIGHT THROUGH TOMORROW MORNING WHICH WILL RELAX THE PRESSURE  
GRADIENT AND WILL REDUCE WIND SPEEDS AND GUST POTENTIAL. AN UPPER-  
LEVEL DISTURBANCE QUICKLY PASSES THROUGH IN THE MORNING AND EARLY  
AFTERNOON WHICH WILL BRING CHANCES FOR RAIN SHOWERS AND A LOW CHANCE  
FOR AN EMBEDDED THUNDERSTORM. A WEAK AREA OF HIGH PRESSURE WILL THEN  
HOLD THROUGH THE WEEKEND BEFORE LOW PRESSURE ARRIVES OVER THE OHIO  
VALLEY EARLY MONDAY MORNING, BRINGING RAIN AND THUNDERSTORM CHANCES  
ALONG WITH ELEVATED WIND GUSTS, PARTICULARLY ACROSS THE SOUTHERN  
GREAT LAKES THROUGH LAKE ERIE AND LAKE ST. CLAIR.  
 
 
   
PREV DISCUSSION  
 
ISSUED AT 104 PM EDT THU JUN 18 2026  
 
AVIATION...  
 
WESTERLY WINDS GUSTING TO 30-35 KNOTS THIS AFTERNOON WILL DROP BELOW  
10 KNOTS TONIGHT, BEFORE RAMPING BACK UP FRIDAY WITH GUSTS PEAKING  
AROUND 25 KNOTS. DEEPER BOUNDARY LAYER MIXING THIS AFTERNOON SHOULD  
YIELD MOSTLY CLEAR SKIES THIS EVENING, BUT THERE IS SOME INDICATION  
FOR RENEWED VFR CLOUD DEVELOPMENT OVERNIGHT AND ESPECIALLY FRIDAY  
WITH STEEPENING LOW LEVEL LAPSE RATES FROM SURFACE HEATING.  
 
D21/DTW CONVECTION...NO THUNDERSTORMS EXPECTED.  
 
DTW THRESHOLD PROBABILITIES...  
 
* MEDIUM FOR CEILINGS AT OR BELOW 5 KFT THIS AFTERNOON AND THEN  
AGAIN TOMORROW AFTERNOON.  
 
* MEDIUM FOR CROSSWIND OPERATIONS THIS AFTERNOON.  
 
 
   
DTX WATCHES/WARNINGS/ADVISORIES  
 
MI...NONE.  
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LHZ421-422-  
441>443.  
 
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LCZ460.  
 
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LEZ444.  
 
LOW WATER ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LEZ444.  
 
 
 
 
 
DISCUSSION...AA  
MARINE.......AM  
AVIATION.....SF  
 
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