956

ACUS01 KWNS 060538

SWODY1

SPC AC 060537



Day 1 Convective Outlook

NWS Storm Prediction Center Norman OK

1137 PM CST Fri Dec 05 2025



Valid 061200Z - 071200Z



...NO SEVERE THUNDERSTORM AREAS FORECAST...



...SUMMARY...

Severe thunderstorms are not expected today.



...Discussion...



Mean long-wave trough is expected to remain centered across the

eastern Plains/MS Valley through the day1 period. Negligible height

changes are expected across lower latitudes which will result in a

synoptic front oscillating across the northern/central FL Peninsula.

This boundary will serve as the primary focus for the potential for

isolated thunderstorm development. Latest model guidance is not

particularly aggressive in air mass destabilization across the

Peninsula, but showers and a few thunderstorms should develop

along/north of the boundary as deep westerly flow provides weak lift

atop the frontal zone. While deep-layer shear is strong, weak

buoyancy and poor lapse rates do not support robust or organized

severe updrafts.



..Darrow/Thornton.. 12/06/2025



$$






                

                        

431

ACUS02 KWNS 060542

SWODY2

SPC AC 060541



Day 2 Convective Outlook

NWS Storm Prediction Center Norman OK

1141 PM CST Fri Dec 05 2025



Valid 071200Z - 081200Z



...NO SEVERE THUNDERSTORM AREAS FORECAST...



...SUMMARY...

Aside from the possibility of a couple of thunderstorms across the

central Florida Peninsula, the risk for thunderstorms appears

negligible across much of the U.S. Sunday through Sunday night.



...Discussion...

Models continue to indicate that mid/upper ridging may rebuild

offshore of the British Columbia and Pacific Northwest coast, while

being maintained across and inland of coastal areas through this

period.  Downstream flow may not change appreciably on the

larger-scale, but one embedded vortex emerging from the Hudson Bay

vicinity may redevelop southeastward through central Quebec, while

at least a couple of short wave perturbations consolidate within

another branch of cyclonic flow across the central/southern Great

Plains through Southeast.



This latter development may be accompanied by modest mid-level

height falls as far south as the central Florida Peninsula by late

Sunday night, along with a reinforcing intrusion of cooler/drier air

across the Gulf coast into northwestern Gulf Basin.  Downstream, a

weak low may begin to develop along the initial stalled/slow moving

frontal zone, east of the Florida Peninsula.



...Florida...

Relatively warm layers in mid/upper levels, associated with

subtropical ridging centered over the Caribbean and adjacent western

Atlantic, may tend to suppress convective potential, particularly

across the southern into central peninsula through at least Sunday

evening.  However, beneath a belt of modest west-southwesterly

low-level flow (20-30 kt around 850 mb), an initially drier boundary

layer over the interior into eastern peninsula may moisten and

become potentially unstable by late Sunday afternoon into evening.

It is possible that this could become supportive of a period of

thunderstorm development, mainly focused along/ahead of the cold

front as it advances into and across the Interstate 4 corridor.



At least some machine learning guidance suggests that the

environment could become supportive of low probabilities for severe

weather, mainly in the form of a generally brief, weak tornado or

two.  With sufficient boundary-layer moistening, forecast soundings

do depict the development of modest low-level hodographs, and strong

deep-layer shear beneath 40-50+ kt flow around 500 mb.  At this

point, however, this potential still appears too conditional to

introduce a categorical severe risk, based on latest HREF and other

model guidance. But trends will continue to be monitored.



..Kerr.. 12/06/2025



$$






                

                        

689

NWUS53 KAPX 050429

LSRAPX



Preliminary Local Storm Report

National Weather Service Gaylord MI

1129 PM EST Thu Dec 4 2025



..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...

..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....

            ..REMARKS..



1040 PM     Non-Tstm Wnd Gst 2 S Naubinway           46.09N 85.45W

12/04/2025  M40 MPH          Mackinac           MI   Public



            Naubinway Marina.





&&



$$



JZ








                

                        

748

FXUS63 KAPX 060545

AFDAPX



Area Forecast Discussion

National Weather Service Gaylord MI

1245 AM EST Sat Dec 6 2025



.KEY MESSAGES...



- Snow/snow showers remain through this weekend.



- Below zero temps Sunday night into Monday morning across the

  interior.



- A medium potential (~40-70%) exists for at least 4" of snow later

  Monday into Tuesday for locations adjacent to the Lake MI shoreline.



- Another system bears watching for more accumulating snow mid next week.



&&



.SHORT TERM /THROUGH TONIGHT/...

Issued at 1213 AM EST Sat Dec 6 2025



Pattern Synopsis and Forecast:



Any significant snows from last night will dwindle to mainly light

lake induced snow showers through the day as H850 temps drop into

the mid teens below zero. That being said, best potential for a

burst of snow today will be across northern portions of Chippewa

county, with a quick few inches not out of the question for a small

subset of the county assuming banding shifts far enough south. Some

progged fcst soundings flirt with with a patch or brief instance of

freezing drizzle as well, so cannot rule it out across the area.



Today, potent complex trough will be spinning to the north across

Ontario, center slowly meandering across the southern portion of

Hudson Bay. Meanwhile, a positively tilted short wave on the

backside of the trough will swing to the southeast tonight across

the Upper Midwest. There will be additional short waves/pieces of

energy displaced to the south within the general flow aloft. The

combination of the pieces of energy aloft, general sfc troughing,

and sufficiently cold low levels will produce snow showers/light

snow across the region beginning late tonight into early Sunday for

most. Generally speaking though, impactful weather through tonight

remains relatively low (outside of a rogue lake effect band in

Chipp) with instances of snow and minor accums. Daytime temps in the

20s and lows in the teens for most.



&&



.LONG TERM /SUNDAY THROUGH FRIDAY/...

Issued at 1213 AM EST Sat Dec 6 2025



Day 2-4 (Sunday - Tuesday):



Mid level impulse, seen at H500 & H700, and general sfc troughing

will aid in light snow development across the region through the day

on Sunday. An inch to three of accumulation will be possible, with a

relatively thick and saturated DGZ making for efficient, fluffy

accumulation. Some of the CAMs show convergent snow bands and the

potential for meso vortex formation near the LM, LH, LS

shorelines, but most keep these features predominantly offshore.

We`ll hedge towards that solution at this time but refinement

will be needed. Another place to keep an eye on will be near

Whitefish/ E UP, with a little more lake inducement/mesoscale

processes possible, but this will be spatially sensitive as

well. All this being said, this should be a light snow event for

most, if not all, but some subtle details make this event worth

monitoring.



The story heading into the overnight will be the cold advection with

high pressure settling in from the north. Widespread single digits

are expected across northern MI Sunday night into Monday with

portions of the interior seeing values below zero (first time this

season?).



Interesting setup heading into the early portions of this week.

Relatively vigorous short wave trough digs into N MN & WI later

Monday and Monday night. Sfc low pressure development expected

within the vicinity of this feature. Flow around the low level

circulations will lead to southwest flow across Lake MI, likely

leading to a decent SSW lake effect/enhanced event Monday night into

Tuesday. Snow showers expected across the rest of northern MI on

Tuesday as the trough aloft swings on through. This is seen pretty

well in the LREF probabilities, with medium probs (40 to 60%) for at

least 3" (10:1 ratio, it might be close to double that in

reality) across western Mack, Beaver Island, parts of the LM

coast. Model_Certainty tool verifies the ENS, with moderate

snows showing up within some of the deterministic guidance and

blends. Something to monitor and fine tune in the coming days

for sure. Next system will be right on its heels Tuesday night.



Days 5-7 (Wednesday - Friday):



Another system is expected to move west to east Tuesday night into

Wednesday with sfc low pressure system progged to track across the

Upper Midwest and then into MI. A couple to several inches of snow

would be possible with this system, albeit this will likely be a

quick mover. In the ENS, there`s a subtle shade towards more

QPF/snow across the central and southern portions of the state, but

being this far out these details will likely change. Colder behind

this system late next week with the potential for lake effect snow

showers to some degree.



&&



.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...

Issued at 1142 PM EST Fri Dec 5 2025



Light snow continues early overnight (though much less so APN

than elsewhere). IFR conditions common tonight at the other TAF

sites. Snow exits, and conditions improve to MVFR late

overnight, and in some spots VFR Saturday afternoon.



Somewhat breezy sw to w winds.



&&



.APX WATCHES/WARNINGS/ADVISORIES...

MI...Winter Weather Advisory until 5 AM EST early this morning for

     MIZ016-020-025-031.

MARINE...Small Craft Advisory until 4 PM EST this afternoon for

     LHZ345>348.

     Small Craft Advisory until 5 AM EST early this morning for

     LHZ349.

     Small Craft Advisory until 4 PM EST this afternoon for LMZ323-

     341-342-344>346.

     Small Craft Advisory until 4 PM EST this afternoon for LSZ322.

     Small Craft Advisory from 4 AM early this morning to 4 PM EST

     this afternoon for LSZ321.



&&



$$



SHORT TERM...JLD

LONG TERM...JLD

AVIATION...JZ






                

                        

867

ACUS11 KWNS 030113

SWOMCD

SPC MCD 030112

MEZ000-NHZ000-030715-



Mesoscale Discussion 2249

NWS Storm Prediction Center Norman OK

0712 PM CST Tue Dec 02 2025



Areas affected...coastal northern New England



Concerning...Heavy snow



Valid 030112Z - 030715Z



SUMMARY...Moderate to heavy snow rates on the order of 1/2 to 1+

inches per hour are possible across southern Maine this evening,

with heaviest rates most probable near Down East coastal areas

closer to and after Midnight EST, as strengthening and gusty winds

contribute to reduced visibilities and blowing/drifting.



DISCUSSION...A deepening surface cyclone is forecast to continue an

east-northeastward migration, generally south through east of the

Cape Cod vicinity through mid to late evening.  This will be

accompanied by a zone of strengthening lower/mid-tropospheric

frontogenetic forcing to its north through northeast.  At

mid-levels, the Rapid Refresh indicates that this will shift across

southern Maine through southern New Brunswick, where forecast

soundings indicate that  strengthening lift in (roughly) the 600-500

mb layer may coincide with temperatures most conducive to large

dendritic ice crystal growth (around -15 C).



There is notable spread within and among the various model output

concerning these details, and potentially varying rates of cyclone

and upward vertical motion intensification.  However, in the

presence of sub-freezing thermodynamic profiles, guidance generally

indicates snow rates on the order of 1/2 to 1 inch per hour are

possible this evening across much of southern Maine.  Heaviest rates

appear most probable near immediate coastal areas of Maine,

particularly across Down East coastal Maine closer to and after

05-06Z, when strengthening and gusty east-northeasterly surface

winds may contribute to considerable blowing/drifting and reduced

visibilities.



..Kerr.. 12/03/2025



...Please see www.spc.noaa.gov for graphic product...



ATTN...WFO...CAR...GYX...



LAT...LON   43277133 44757076 45456714 44046610 43626951 43127081

            43277133