649
FXUS63 KAPX 160000
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
700 PM EST Mon Dec 15 2025

.KEY MESSAGES...

- Lingering light precip/drizzle/freezing drizzle issues tonight/
Tuesday.

- Midweek warming trend ahead of a system expected to bring rain (!)
to northern Michigan Thursday...

-...then back to reality with another push of Arctic air
 Thursday night/Friday. Snow potential as well as flash freeze
 possibilities Thursday night.

- Additional precipitation chances for the weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 342 PM EST Mon Dec 15 2025

Pattern Synopsis/Forecast: Long wave trough is getting shunted
to the east today as Pacific air begins to flood into western
North America. Low amplitude ridging across the Pacific
Northwest/western Canada downstream of a Pacific-basin omega
block. Short wave trough zipping across the Great Lakes
today...assisting with the warm advection driven snow event
across the forecast area earlier today. Speaking of which: 850mb
0C isotherm pushing into Wisconsin... which is a harbinger of
what is to come later this week. Remnants of weekend Arctic high
(1038mb) centered along the Ohio River...weak low pressure
(1015mb) along the Minnesota/Dakotas border...surface
trough/shallow cold front extends northeast into northern
Ontario with a stubby warm front into southern Minnesota/Iowa.

Flow pattern expected to become a zonal Pacific-dominated one as the
week progresses with a couple of short wave troughs of note.  First
quick moving wave passes by Wednesday...while a stronger wave digs
into the Plains Thursday and lifts across the region Friday.  A
third system swings through for the coming weekend.  Surface
trough/cold front across northwest Ontario drops into Lake Superior
tonight but that is probably as far south at it will get as deep
layer warm air advection and subsequent height rises continue across
the Great Lakes.  850mb temperatures warm above freezing for the
first time in what seems like forever by Tuesday morning...and surge
to +8C by evening.  A true Alberta Clipper associated with
Wednesday`s short wave trough will slide by well to the north of
Michigan...its associated cold front will try to edge its way into
the state from the north Wednesday.  Probably won`t make it very far
south given the low amplitude nature of its parent short wave
trough.  More substantial system...really another Clipper but
developing farther south across the northern Plains...will take aim
on the Great Lakes in the Thursday time frame.  This system looks
like it will whiplash from warm to cold...so definitely some impacts
to think about.  Another weaker system may impact the state this
weekend.

Primary Forecast Concerns:

Lingering light precip/drizzle/freezing drizzle issues tonight/
Tuesday: Starting out this afternoon with some lingering west/
southwest flow light snow/flurries as mid level moisture strips
out...CBL depth is shallow given warm advection.  What is
interesting however is bottom part of the inversion is
saturated...and at temperatures at or above -10C.  So while it is
still cold enough for a bit of a lake response...some questions
about ice nucleation potential raise the question of whether we can
squeeze out some flurries and/or light freezing drizzle at least
this evening.  Couple of recent PIREPS over northwest Lower
reporting riming...would prefer to see some reports of clear/mixed
icing to better corroborate this idea but at least the icing reports
indicating small supercooled cloud droplets.

During the day Tuesday a band of mostly mid level moisture crosses
the forecast area...along with steeper mid level lapse rates but
with a dry layer of air below that should preclude much in the way
of measurable precipitation.  But there are indications of shallow
instability within southwest flow off Lake Michigan...and now
definitely at temperatures that should preclude ice nucleation. So
wondering if there is still a chance for some drizzle/freezing
drizzle along the Lake Michigan shoreline (surface temperatures will
be close to or maybe above freezing).

Midweek warming trend ahead of a system expected to bring rain (!)
to northern Michigan Thursday...:  Rather remarkable stretch of cold
weather (unless you hate winter like myself):  last time we saw a
high temperature above normal was the day before Thanksgiving (26
November)...and we haven`t been close to a normal high temperature
since.  But that is expected to change over the next several days
(normal highs for mid December range from 30 to 34 degrees);
consensus forecast highs for Wednesday are still in the 30s even
with a quick shot of colder air so have tempered those down a bit
especially across eastern Upper as highs may stay in the 20s.
Thursday looks to be the warmest day for certain with strong
southerly flow ahead of the approaching upstream system...
temperatures expected to be within several degrees either side
of 40. Nice surge of moisture with precipitable water values at
or above 0.75 inch which is a +2 to +3 sigma standardized
anomaly for mid December. So a widespread rain-on-snow event
will unfold Thursday...there is a non-zero probability that
precipitation could start as freezing rain in the race between
above freezing surface temperatures and precipitation starting.
This is not expected to be hydrologically significant given the
next bullet in the long term section below...

&&

.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 342 PM EST Mon Dec 15 2025

Primary Forecast Concerns:

     back to reality with another push of Arctic air Thursday night/
Friday. Snow potential as well as flash freeze possibilities
Thursday night: The return to cold weather is forecast to arrive
Thursday night...cold frontal passage will be accompanied by
strong north/northwest winds and temperatures plummeting quickly
through 20s and into the teens by Friday morning. This brings
up a real concern for a flash freeze event with wet roads icing
up as temperatures drop...and add in some windblown snow to help
polish things up. Wind gusts 20-30mph inland and 30-40mph along
the Lake Michigan shoreline look likely at this point. Have
already dropped this mention into the Hazardous Weather Outlook
this morning. Snow/snow showers continue into Friday with
temperatures back in the upper teens/ 20s.

The short nature of the rainfall and the cold air "locking up" any
snowmelt/runoff should preclude a sharp hydrologic response to this
event.  But with ice already on area river and the thaw-freeze cycle
will continue to present a threat for backwater flooding where ice
jams do develop.

Additional precipitation chances for the weekend: Temperatures should
moderate Saturday but as usual the push of warm air will be
accompanied by some precipitation (snow). Colder air likely
makes a comeback on Sunday along with lake convection.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 657 PM EST Mon Dec 15 2025

Snow flurries will persist across parts of northern Michigan this
evening with low chances for patchy freezing drizzle. MVFR CIGs are
expected across all TAF sites through Tuesday morning aside from APN
where VFR conditions are anticipated through the period. Low to
medium chances exist for IFR CIGs to work into the other TAF sites
Tuesday morning -- with CIU being the most likely site to see IFR
CIGs for a time. Otherwise, southwest winds will increase to 10-15
kts this morning into this afternoon with gusts to 25-35 kts through
the end of the period.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory from 11 AM Tuesday to 5 PM EST Wednesday
     for LHZ345>349.
     Gale Warning from 11 AM Tuesday to 5 AM EST Wednesday for
     LMZ323-341-342-344>346.
     Small Craft Advisory from 5 AM Tuesday to 5 PM EST Wednesday
     for LSZ321.
     Small Craft Advisory from 11 AM to 11 PM EST Tuesday for
     LSZ322.

&&

$$

SHORT TERM...JPB
LONG TERM...JPB
AVIATION...DJC