393
FXUS63 KAPX 041929
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
329 PM EDT Sat Oct 4 2025

.KEY MESSAGES...

- Late convection this afternoon?

- Fire danger concerns Sunday amid potential record warmth.

- High rip current risk on Lake Michigan Sunday.

- Rain chances return Sunday night/Monday.

- Cool down starting Tuesday through the rest of the week...frost
potential Wednesday morning/Thursday morning.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 309 PM EDT Sat Oct 4 2025

Pattern Synopsis/Forecast: Broad upper ridging encompasses much of
the eastern half of the CONUS (with a weak disturbance trapped over
Mississippi/Alabama)...with a split long wave trough across western
North America with a southern branch upper low moving through the
southern Great Basin.  Mid level anticyclone centered over the Ohio
Valley/mid Atlantic...some moisture circulating around the west/
north side of that high (1200Z APX sounding precipitable water 1.06
inches)...it is drier both in a relative and absolute sense from the
mid Atlantic into Missouri which may play a part in fire weather
issues Sunday (more on that later).  Speaking of 1200Z APX
sounding...steep lapse rates below 650mb atop a stable surface layer
with a decent residual layer up to about 825mb.  Lifting most
unstable parcel (850mb/theta-e 333K) yields near 200J/kg MUCAPE...
just enough to drive a small area of convection from Grand Traverse
Bay northeast through the Tip of the Mitt this morning.  At the
surface: 1001mb surface low over northwest Ontario with the upper
Lakes well in the warm sector of this cyclone (obviously)...cold
front extends southwest from the low into South Dakota.  1028mb high
over the mid Atlantic with southerly boundary layer flow into the
Great Lakes.

Cold front upstream will be slow to push east Sunday as a frontal
wave developing over South Dakota will ride the front northeast into
northwest Ontario Sunday.  Stronger height falls Sunday night will
push the cold front into Upper Michigan/Wisconsin by Monday morning.

Primary Forecast Concerns:

Late convection this afternoon?: Moderate Cu streamers have
been developing across interior northern Lower...not surprising
given above mentioned 1200Z APX sounding which mixed for mid
80s/upper 50s yielded an uncapped 500+ J/kg MLCAPE. Not much in
the way of reflectivity above -10C just yet...satellite imagery
suggests some ice at cloud top so will have to watch for
developments over the next several hours. This process may be
aided by lake breeze convergence along the Lake Huron shoreline
from the Straits southeast to Thunder Bay.

Fire danger concerns Sunday amid potential record warmth:  Another
day of deep boundary layer mixing expected Sunday...as a result will
be a breezy/windy day from the south.  Strongest winds should be
across western Mackinac county (actually should be an east-west
gradient in winds across eastern Upper)...where wind gusts of 25-35+
mph probable during the afternoon.  Wind gusts across northern Lower
more in the 20-30mph range.  The drier air wrapping around the mid
level high mentioned earlier should play a role in allowing for
lower dew points Sunday afternoon than today (dew points in the 50s
and lower 60s this afternoon)...probably more like 50-55F for
minimum dew points.  Reluctant to go too hog wild with the drying
given upstream dew points.  High temperatures Sunday will still be
in the 80s...may be a degree or two cooler than today but will still
threaten some records (more on that below).  But as discussed
yesterday will need to see dew points in the mid 40s to get Red Flag
criteria relative humidity values.  So definitely another elevated
fire danger day in the works.

High temperature records for Sunday include 81 ANJ (2005)/82 GLR
(2005)/84 PLN (2005)/85 APN (2005)/87 TVC (1922)/88 HTL (1922).  TVC
and HTL may be safe...but the others will be close.

High rip current risk on Lake Michigan Sunday: While we are
technically out of beach hazard season...will go ahead and
issue a Surf Zone Forecast and a Beach Hazard Statement with
several Lake Michigan counties with a moderate to high swim risk
on a day where warm temperatures will likely draw late season
beachgoers.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 309 PM EDT Sat Oct 4 2025

Days 2-3 (Monday-Tuesday): Approaching cold front will be on our
doorstep Monday morning...and should be accompanied by a band of
what looks to be mostly post-frontal/anafront precipitation.  Could
see some afternoon convection ahead of the front across about the
southeast half of the forecast area.  Northwest-southeast oriented
thermal gradient across the forecast area Monday afternoon...with
temperatures likely falling into the 50s across Upper Michigan...
while highs near Saginaw Bay will likely warm into the lower 80s.

This anafront nature to the precipitation will keep rain chances
going for most of the forecast area Monday night and into Tuesday
morning...looks like a solid 0.25-0.50+ inch of rain expected over
areas where D1 (Moderate Drought) is encroaching northward.  Back to
more typical early October temperatures for Tuesday (highs in the
60s).

Days 4-5 (Wednesday-Thursday): High pressure builds into the Great
Lakes for midweek...which should dry things out but set up the
potential for frost development Wednesday and especially Thursday
morning.

Days 6-7 Outlook (Friday-Saturday): Trends still suggest shower
chances return to end the week along with seasonable
temperatures.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 132 PM EDT Sat Oct 4 2025

VFR. Strong low pressure over northwest Ontario and strong high
pressure over the Hampton Roads area will work together to drum
up persistent S to SSW flow across the region today, with some
15 to 20 kts gusts possible through sunset. Winds subside a bit
this evening into tonight, with just some high cloud. Despite
that, anticipating a period of LLWS at both CIU and PLN tonight
with weaker surface flow and stronger flow aloft. Surface winds
crank back up into Sunday, with gusts of 25 to 30 kts certainly
on the table by late morning and into the afternoon.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from Sunday morning through Sunday
     evening for MIZ025-031-095.
MARINE...Small Craft Advisory from 2 PM Sunday to 8 AM EDT Monday for
     LHZ345.
     Small Craft Advisory from 10 AM Sunday to 5 PM EDT Monday for
     LMZ323-342-344>346.
     Gale Watch from Sunday evening through late Sunday night for
     LMZ341.

&&

$$

SHORT TERM...JPB
LONG TERM...JPB
AVIATION...HAD