278
FXUS63 KGRR 250628
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
228 AM EDT Mon May 25 2026
.KEY MESSAGES...
- The only chance of rain with a backdoor cold front Wednesday
- Mild temperatures and dry conditions Thursday and beyond
&&
.DISCUSSION...
Issued at 228 AM EDT Mon May 25 2026
- The only chance of rain with a backdoor cold front Wednesday
The Dense Fog Advisory issued last evening is working out very well,
with most observations showing 1/4 mile visibilities, and the night
time microphysics satellite imagery showing lots of low clouds and
fog. This will burn off quickly after sunrise, so no concerns there.
Otherwise today and Tuesday, we should see a good deal of sunshine
with just a few high clouds expected. We will remain in between the
northern stream well north of the area, and the deeper and more rich
moisture just to our south.
The Northern stream will send a back door cold front down through the
forecast area on Wednesday. This is in response the the upper ridge
axis just west of the area, and the cold front to slide down
downstream of the ridge where NNE aloft dominates. It does look like
precipitation trends have increased a little with this front over
the last 1-2 days. Moisture and resultant instability will be
limited with deep moisture locked up just south of the state. The
best chance of rain with this weak front will be a bit inland from
Lake Michigan, which will stabilize the lakeshore a bit with a flow
from the SW.
- Mild temperatures and dry conditions Thursday and beyond
850 mb temperatures will fall from +15 to +16C on Tuesday, to
around +9C by Wednesday evening behind the front. Instead of max
temps inching up to the 80s, this cold front will keep highs in the
70s through the week. The upper ridge axis will end up just west of
the area and will block up the major weather features. For our area,
it means mild temperatures and a good deal of sunshine through the
end of the forecast period.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 128 AM EDT Mon May 25 2026
Dense fog has developed at all of the terminals quickly late last
evening/early this morning with nearly ideal conditions for its
development. Conditions will remain ideal through the night, so
have kept all sites at VLIFR conditions through 12z. Starting at
12z (due to early sunrises) we should start seeing improvement. We
have all sites going VFR by 14z. After that, just a few cumulus
clouds possible along with some thin high clouds will be about it
through this period. Winds will generally be from the SW up to 10
knots.
&&
.MARINE...
Issued at 228 AM EDT Mon May 25 2026
Night time microphysics satellite imagery this morning shows
widespread stratus/fog over the lake. This continues to justify the
Marine Dense Fog Advisory well. Chances are this will linger longer
over the lake due to less mixing, so it may need to be extended a
bit this morning.
Other than the Fog advisory, we continue to think that no other
wind/wave headlines will be needed over the next week. This comes as
we will only see one system move through (Wednesday) with limited
wind associated with it.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Dense Fog Advisory until 11 AM EDT this morning for MIZ037>040-
043>046-050>052-056>059-064>067-071>074.
MARINE...Dense Fog Advisory until 10 AM EDT this morning for LMZ844>849.
&&
$$
DISCUSSION...NJJ
AVIATION...NJJ
MARINE...NJJ
NWS GRR Office Area Forecast Discussion
