560
FXUS63 KGRR 081911
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
311 PM EDT SUN JUN 8 2025
KEY MESSAGES
- SHOWERS AND EMBEDDED STORMS THIS EVENING AND MONDAY AFTERNOON
- BRIEF DRY PERIOD MID-WEEK
- SEASONABLE TEMPERATURES AND UNSETTLED END OF WEEK AND WEEKEND
DISCUSSION
ISSUED AT 311 PM EDT SUN JUN 8 2025
- SHOWERS AND EMBEDDED STORMS THIS EVENING AND MONDAY AFTERNOON
WHAT WAS ONCE A FORMIDABLE LINE OF SHOWERS WITH EMBEDDED STORMS
OVER WISCONSIN EARLIER, HAS DIMINISHED A BIT OVER THE LAST FEW
HOURS AS IT APPROACHES LAKE MICHIGAN. THIS HAS BEEN EXPECTED TO
OCCUR AND IT IS NOW COMING TO FRUITION. THE ATMOSPHERE IS JUST NOT
LINING UP WELL FOR GOOD ORGANIZATION TO OCCUR. DEEP LAYER SHEAR IS
MORE THAN SUFFICIENT TO HELP THE CAUSE WITH VALUES 35-40 KNOTS.
INSTABILITY IS THE PROBLEM WITH NO INSTABILITY OVER THE FORECAST
AREA AS OF 18Z, AND INSUFFICIENT LOW LEVEL FLOW TO ADVECT
SIGNIFICANT MOISTURE OVER THE AREA BEFORE THE FRONT ARRIVES HERE.
THERE WILL BE JUST ENOUGH TO KEEP THE SHOWERS GOING, AND MAYBE AN
EMBEDDED STORM THIS EVENING. THERE MAY BE A BRIEF UPTICK IN THE
COVERAGE OVER THE EASTERN PORTION OF THE FORECAST AREA AS BETTER
MOISTURE IS PRESENT THERE, LINGERING FROM THE LIGHT RAIN LAST
NIGHT. ALL SHOWERS AND STORMS WILL WEAKEN TO LINGERING SHOWERS
OVERNIGHT.
WE WILL SEE CLEARING TAKE PLACE THEN OVERNIGHT AND ON MONDAY
MORNING AS WE WILL BECOME UNDER THE INFLUENCE OF THE DRY SLOT
BETWEEN THE FRONT AND THE UPPER LOW DURING THIS PERIOD. THEN, THE
UPPER LOW WILL ARRIVE MONDAY AFTERNOON DURING PEAK HEATING.
INSTABILITY WILL BE WEAK AGAIN WITH A FEW HUNDRED J/KG OF CAPE.
THE STRONGER WAVE WILL HELP TO COMPENSATE FOR THIS A BIT, AND
PRODUCE SCATTERED TO NUMEROUS SHOWERS AND A FEW STORMS MONDAY
AFTERNOON AND EARLY EVENING BEFORE DISSIPATING.
- BRIEF DRY PERIOD MID-WEEK
TUESDAY WILL SEE LESS OF A CHANCE FOR RAIN SHOWERS AS THE UPPER
LOW SETTLING IN ON MONDAY WILL BE LIFTING OUT ON TUESDAY. WE WILL
BE CLOSE ENOUGH TO THE WEAKENING LOW THAT WE COULD SEE ONE MORE
WEAK SHORT WAVE PUSH THROUGH. FOR THIS REASON, WE ARE KEEPING A
SLIGHT CHANCE OF RAIN SHOWERS FOR TUESDAY AFTERNOON.
MODEL ENSEMBLE MEANS ARE KEEPING WEDNESDAY GENERALLY DRY ACROSS
THE AREA WITH SEASONABLE TEMPERATURES. THE UPPER JET WILL BE
POSITIONED FAR ENOUGH NORTH OVER CANADA THAT WE WILL NOT SEE THE
DIRECT IMPACTS FROM IT. HOWEVER, A WEAK COLD FRONT TRAILING SW OF
IT WILL PASS THROUGH THE STATE WEDNESDAY AFTERNOON. THIS FRONT IS
SHOWN TO BE MAINLY DRY WITH JUST A VERY SMALL CHANCE OF A SHOWER
WITH IT. THERE IS NO MOISTURE FOR IT TO WORK WITH.
- SEASONABLE TEMPERATURES AND UNSETTLED END OF WEEK AND WEEKEND
EVEN THOUGH THE FRONT IS EXPECTED TO MOVE THROUGH DRY ON
WEDNESDAY, IT WILL BECOME THE FOCUS FOR SMALL, BUT OCCASIONAL CHANCES
OF SHOWERS AND A FEW STORMS FROM THURSDAY THROUGH SATURDAY.
THE FRONT WILL WILL SLOWLY SINK TO ABOUT THE MICHIGAN/INDIANA
BORDER BY THURSDAY AFTERNOON BEFORE STALLING OUT AS IT ALIGNS WITH
THE UPPER FLOW. WE WILL THEN SEE SHORT WAVES EMBEDDED IN THE UPPER
FLOW HELP SUPPORT WAVES OF SHOWERS AND STORMS ALONG THE STALLED
OUT FRONT. THE HIGHEST PROBABILITY OF SHOWERS AND STORMS WILL BE
ACROSS THE SOUTH, CLOSER TO THE FRONT. ALL OF THE AREA WILL SEE
RAIN CHANCES THOUGH DURING THIS TIME FRAME. SEVERE WEATHER CHANCES
WILL LIKELY BE FOCUSED JUST SOUTH OF THE AREA WHERE THE MUCH
BETTER INSTABILITY IN THE WARM SECTOR WILL BE FOUND.
THE MODEL ENSEMBLES ARE IN FAIRLY GOOD AGREEMENT IN SHOWING HIGH
PRESSURE ACROSS ONTARIO HELPING TO PUSH THE STALLED FRONT A BIT
FURTHER SOUTH BY SUNDAY. THIS WOULD RESULT IN THE WAVES ALONG THE
FRONT STAYING FAR ENOUGH SOUTH THAT WE WOULD END UP LOSING OUR
RAIN CHANCES. THIS WOULD ALSO RESULT IN TEMPERATURES COOLING OFF A
LITTLE BIT.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 140 PM EDT SUN JUN 8 2025
THE MAIN FOCUS OF THIS SET OF AVIATION FORECASTS IS ON THE LINE OF
SHOWERS AND EMBEDDED STORMS OVER WI AND IL THIS AFTERNOON THAT
WILL MOVE THROUGH THE TERMINALS THIS EVENING.
THE CLOUDS AND SHOWERS FROM LAST NIGHT HAVE MOVED OUT, AND ALLOWED
FOR SKIES TO CLEAR OUT. WE WILL SEE THESE CONDITIONS CONTINUE
UNTIL JUST PRIOR TO THE ARRIVAL OF THE FRONT AND BAND OF SHOWERS
AND STORMS. THE SHOWERS AND STORMS WILL MOVE IN AT KMKG AROUND 22Z
OR SO, AND MOVE EASTWARD THROUGH ABOUT 02-03Z AT KJXN BEFORE
MOVING OUT. SHOWERS ARE EXPECTED WITH SOME EMBEDDED THUNDER IN IT,
AND HAVE ELECTED TO USE PROB30 FOR THE THUNDER CHANCES. CONDITIONS
WILL BE MAINLY VFR, WITH SOME ISOLATED IFR UNDER THE HEAVIER
SHOWERS/STORMS.
THE THUNDER THREAT SHOULD BE GONE AFTER 2-3 HOURS, AND SHOWERS
LINGERING A FEW MORE HOURS. ONCE THE SHOWERS MOVE OUT, SKIES
SHOULD CLEAR OUT AGAIN BY DAYBREAK MONDAY MORNING. THESE
CONDITIONS ARE EXPECTED TO THEN HOLD THROUGH THE END OF THIS
FORECAST PERIOD AT 18Z MONDAY.
MARINE
ISSUED AT 311 PM EDT SUN JUN 8 2025
IT IS LOOKING LESS LIKELY THAT WE WILL SEE THE NEED FOR A SMALL
CRAFT ADVISORY WITH AND BEHIND THE INCOMING FRONT. WINDS WILL COME
UP IMMEDIATELY AHEAD OF THE FRONT AND BEHIND THE FRONT, BUT THEY
LOOK MORE LIKELY TO STAY AT OR BELOW 20 KNOTS OVER THE COOLER WATER.
MUCH OF THE WEEK THEN SHOULD SEE WINDS BELOW 20 KNOTS AND WAVES
BELOW 3 FT. THE NEXT BEST CHANCE FOR ELEVATED WINDS AND WAVES WILL
BE AROUND THE FRIDAY TIME FRAME, BUT THOSE LOOK TO BE OFFSHORE.
GRR WATCHES/WARNINGS/ADVISORIES
MI...NONE.
MARINE...NONE.
DISCUSSION...NJJ
AVIATION...NJJ
MARINE...NJJ
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