Saint Ignace, Michigan Weather Forecast Discussion

130
FXUS63 KAPX 260718
AFDAPX
Area Forecast Discussion
National Weather Service Gaylord MI
Issued by National Weather Service Marquette MI
318 AM EDT Fri Sep 26 2025
.KEY MESSAGES...
- Isolated showers possible today.
- Prolonged stretch of warm and dry weather this weekend and
  into next week.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 257 AM EDT Fri Sep 26 2025
Early this morning an upper level low was sitting over the Hudson
Bay with ridging over the central U.S into the Canadian prairies
and northwest flow overhead. A surface low pressure was over the
eastern U.P with a cold front stretching through northern WI
into the central U.P and eastern Lake Superior. Not too much in
the way of precipitation was accompanying the front, with just
some weak radar returns over the eastern U.P near Sault Ste.
Marie but much of the precipitation was likely not reaching the
ground. Temperatures had fallen into the 50s across the north
and 40s to near 50 over the south, where fog had developed
under clear skies and light winds.
A weak shortwave will track through Wisconsin today and the
aforementioned cold front will push south through northern
lower Michigan this morning bringing northerly winds into the
area and slightly cooler temperatures over the north. Highs
today will range from the 60s north to mid 70s south. The
shortwave and front could trigger a few light showers today,
maintained low PoPs along the front.
The chance for showers will go away around sunset tonight with the
loss of daytime heating. Patchy fog will be possible again with
light winds and clear skies. Lows will fall into the upper 40s
north to low 50s south.
Saturday will be dry with mainly sunny skies and light winds.
Temperatures will warm well into the 70s for much of the area
though it will be slightly cooler, near 70 over the far north
and eastern U.P. Deep mixing should help to lower RH Saturday
afternoon to near 40% and potentially down into the 30s. The
deterministic NBM seems too high with dewpoints/RH, opted to use
the NBM 25th percentile for Saturday afternoon to reflect the
lower dewpoints and RH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 257 AM EDT Fri Sep 26 2025
The main story through much of the extended remains the
building ridge and stretch of dry weather. Saturday into next
week guidance supports a prolonged period of quiet conditions
with temperatures trending above normal. Highs are expected to
run in the 70s through the weekend, with some locations flirting
with 80 Saturday through Monday. NBM guidance may be too high
with the dewpoints and RH into early next week, model soundings
suggesting RH could fall into the 20-30% range Sunday into
Monday but did not deviate from the NBM at this time.
Ensemble guidance favors ridging holding firm into early next
week, though we`ll be under a somewhat fast west-to-east flow
aloft-- meaning can`t rule out a weak shortwave sneaking through
at some point sparking light showers but overall confidence
leans strongly toward a warm and dry forecast. A potential back
door front mid to late next week could bring some subtle pattern
shifts-- cooler easterly flow across parts of northern Michigan
and perhaps an uptick in cloud cover. Still, even that,
precipitation chances remain quite low.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 132 AM EDT Fri Sep 26 2025
A cold front over the central and western UP will progress into
northern Lower Mi during the course of the day, aided by enhanced
mid level west-northwest flow. The frontal boundary is forecast to
weaken/wash out as it heads toward southern Lower Mi Fri evening.
Ample low level moisture along and in advance of the associated
frontal convergence and the development of a shallow post frontal
low level inversion will support areas of MVFR based clouds with
some IFR. Diurnal mixing during the afternoon and dry air nudging in
from upper Michigan will result in gradually lifting cloud bases
with partial to full clearing Fri evening.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
SHORT TERM...NL
LONG TERM...NSC/NL
AVIATION...JZ

NWS APX Office Area Forecast Discussion