Flooding Continues in Arenac County Along the Rifle River

                        

487

ACUS01 KWNS 120524

SWODY1

SPC AC 120523



Day 1 Convective Outlook

NWS Storm Prediction Center Norman OK

1223 AM CDT Mon May 12 2025



Valid 121200Z - 131200Z



...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE SOUTHEAST

AND NORTHEAST MT/NORTHWEST ND...



...SUMMARY...

Isolated severe thunderstorms are possible across parts of the

Southeast today. A tornado or two, localized damaging winds, and

hail are possible. Isolated severe gusts are also possible in

northeast Montana to northwest North Dakota around early evening.



...Southeast...

The vertically stacked mid/upper low that has been nearly stationary

over the Sabine Valley will finally pivot northeastward towards

western TN through early Tuesday. A jetlet of strong mid-level

southerlies over the northeast Gulf and FL Panhandle will dampen

somewhat as it becomes centered on north FL to southeast GA vicinity

this afternoon. More probable diurnal thunderstorm development is

anticipated from the left-exit region of this jetlet westward

towards the cold-core of the stacked low. Deep-layer vertical shear

will relax with westward extent, yielding more of a pulse

strong-storm environment from Middle TN to western AL and MS.

Despite the meridional deep-layer wind profile, effective values

should be sufficient for multicell clusters and transient updraft

rotation centered on eastern AL and GA into north FL. Pockets of

modest buoyancy should support a mix of small to marginally severe

hail and strong gusts capable of isolated damaging winds. Along the

eastern periphery of this activity, a tornado or two is possible

where there remains some overlap with the western belt of enhanced

low-level flow, shifting east along the South Atlantic Coast.



Farther south, a more nebulous convective scenario is anticipated

amid extensive ongoing convection across the FL Peninsula and Keys.

Guidance differs markedly with the degree of destabilization, as

adequate boundary-layer heating will be required amid poor mid-level

lapse rates near 5 C/km. Some guidance suggests south FL has the

best chance at recovery by afternoon. As such, have opted to

maintain the level 1-MRGL risk through the entire region, mainly

driven by wind.



...Northeast MT to northwest ND...

Another day of rather deeply mixed thermodynamic profiles is

expected across this portion of the Upper MO Valley. Convective

coverage off the higher terrain of southern MT should be

substantially less than in recent days, amid deep-layer

southwesterly wind profiles. Some guidance suggests very isolated

storms could develop as low-level convergence increases in the early

evening. Should this occur, potential will exist for a few dry

microbursts producing localized severe gusts.



..Grams/Lyons.. 05/12/2025



$$






                

                        

127

ACUS02 KWNS 120530

SWODY2

SPC AC 120528



Day 2 Convective Outlook

NWS Storm Prediction Center Norman OK

1228 AM CDT Mon May 12 2025



Valid 131200Z - 141200Z



...NO SEVERE THUNDERSTORM AREAS FORECAST...



...SUMMARY...

The risk for organized severe thunderstorms remains limited across

the U.S. Tuesday through Tuesday night.



...Synopsis...

A gradual amplification of the upper-level trough currently over the

Pacific Northwest is expected over the next 48 hours across the

western CONUS. This will maintain a southwesterly flow regime across

the central and northern Rockies, which will promote steady lee

troughing and modest moisture return across the Plains through

Tuesday night. The eastward advection of a stout EML will result in

strong capping across the southern Plains where moisture return will

be the greatest. A few isolated high-based thunderstorms are

possible along the surface trough late afternoon/early evening, and

may produce strong downdrafts given deep boundary-layer mixing, but

the overall convective signal remains too limited to warrant risk

probabilities. Additional elevated convection is possible early

Wednesday morning across the Dakotas as a cold front begins to push

east across the northern Plains.



Across the East, the upper low currently over the lower MS River

Valley is expected to gradually de-amplify and lift to the

northeast. Rich low-level moisture already in place ahead of this

feature, coupled with daytime heating and limited inhibition, will

maintain scattered thunderstorm chances for most areas east of the

MS River to the central Appalachians. Loosely organized convection

is possible across eastern NC Tuesday afternoon in the vicinity of a

weak surface low/trough where low-level winds may be sufficiently

backed to elongate hodographs. However, disparity in recent guidance

regarding the overall convective environment and convective coverage

in the wake of widespread early-morning precipitation precludes

highlights. Similarly, somewhat organized convection may materialize

across parts of MS/western AL Tuesday evening at the eastern

periphery of the EML where capping will be weaker. While hodographs

will be favorable for organized convection, weak forcing for ascent

should limit the probability for sustained, robust storms.



..Moore.. 05/12/2025



$$






                

                        

066

FXUS63 KAPX 120310

AFDAPX



Area Forecast Discussion

National Weather Service Gaylord MI

1050 PM EDT Sun May 11 2025



.KEY MESSAGES...



- Warm and very dry Monday. Fire danger continues.



- Shower/storm chances return at times this Tuesday through the

  remainder of the week.



&&



.UPDATE...

Issued at 1046 PM EDT Sun May 11 2025



Current forecast remains on track. Temperatures do not drop as

much as the previous night, however, did blend some MOS

guidance in to lower some of the values, especially across the

cooler locations and in the vicinity of the Straits and Lake

Huron due to the combination of a select few locations popping into

the 40s. Moisture does increase tonight however, with dewpoints in

the upper 30s to lower 40s, putting a cap on how cold things will

get. There is a chance some of these locations see temps much colder

than the current fcst tonight. Otherwise, precipitation free weather

is anticipated on Monday with generally light to a few mildly breezy

winds and very dry conditions once more. Moisture advection Monday

evening and overnight will end the fire weather concerns for the

time being and usher in the threat for showers and thunderstorms

Tuesday through the end of the week.



&&



.SHORT TERM /THROUGH MONDAY/...

Issued at 325 PM EDT Sun May 11 2025



Pattern/synopsis: Surface high pressure will move east away from

Lake Huron, though a ridge will extend west into lower MI. This

ridge stretches into southern lower MI tonight, before migrating

north on Monday. Aloft, a w-e oriented 500mb ridge axis starts

in the southern lakes, then pushes north into our neck of the

woods.



Forecast: Quiet, excepting fire wx concerns. Ongoing clouds

over far eastern upper MI will gradually get displaced eastward.

Late on Monday, mid and high clouds will push northward into

southern parts of our area. Otherwise, little cloud cover in the

short term period, with increasing ridging surface and aloft.

Winds will decouple tonight, but not as emphatically as last

night; there is an increasing wind field off the surface,

especially in the north half of the forecast area. Between that

and a warmer start, temps will not drop nearly as far as last

night. Lows will be mainly in the 40s.



Winds available to mix down will decrease on Monday, as the

surface ridge axis drifts north, and the pressure gradient

relaxes with time. Expect to mix down 20 mph wind gusts in the

afternoon in the interior of northern lower MI. Warmest day of

the year thus far; highs mid-upper 70s in eastern upper, low-

mid 80s in the interior of northern lower MI. NBM10Pct guidance

is still appropriate for dew point progs, which mixes out min

RH values deep into the teens (plenty of mid teens in the

interior). Don`t have enough winds to result in high-end fire wx

concerns, but dry fuels, low RHs, and an incomplete spring

green-up will definitely keep some concerns going.



&&



.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...

Issued at 325 PM EDT Sun May 11 2025



Midlevel pattern remains the same at longwave ridging over the

southern Canadian Providences continues warm and dry conditions

until troughing from the pushes returns atmospheric moisture to the

northwoods. This weak wave of energy will move a cut-off surface

level low to the midwest and return showers as soon as Tuesday to

northmen Michigan. Rounds of showers and storms will linger through

the remainder of the week as this trough stalls and becomes more

disheveled and falls apart. Another trough currently over the

Pacific Northwest will finally push this sytem to the northeast at

the end of the week, finally ending this drearier pattern for

the Great Lakes region and returning widespread subsidence

around the late Saturday/Sunday timeframe.



Even with an incoming pattern chance to the region compared to

current "high and dry" weather, not a lot of impactful weather is

expected for most of the week. Only a few isolated showers are in

the forecast this Tuesday, especially across mid Michigan as the

southern parts of the CWA will see a few convectively driven showers

generating maybe a tenth or so of QPF. Otherwise most areas will

remain mostly cloudy south of M-32 and mostly sunny north of the

Bridge. This pattern of on and off scattered shower accompanied by

thunder will continue through midweek as this system lingers across

the region. Best chance of heavier showers and some stronger storms

will be Thursday night as a cold front attached to the Pacific NW

trough drags across the CWA. Most recent guidance is hinting at the

potential of one or two severe storms Thursday night as dew points

spike into the 60s with moderate amounts of instability. Frontal

timing appears to be overnight which is not ideal, but moderate

lapse rate and enough CAPE should support severe level amounts of

hail or even strong downdraft winds. Some showers may linger into

the weekend but subsidence returns to the region this Sunday, thus

returning a drier pattern by then end of the week/early next week.



&&



.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...

Issued at 1046 PM EDT Sun May 11 2025



VFR conditions are expected through the period with FEW250 at

times. Winds aloft increase for KPLN & KCIU resulting in LLWS

for a period tonight into Monday morning. Otherwise dry with south

to southeast winds at about 10 KTs on Monday with increasing clouds

late. Lake breezes will develop during the afternoon as well.







&&



.APX WATCHES/WARNINGS/ADVISORIES...

MI...None.

MARINE...None.



&&



$$



UPDATE...JLD

SHORT TERM...JZ

LONG TERM...SJC

AVIATION...JLD






                

                        

638

ACUS11 KWNS 120449

SWOMCD

SPC MCD 120448

NDZ000-120545-



Mesoscale Discussion 0771

NWS Storm Prediction Center Norman OK

1148 PM CDT Sun May 11 2025



Areas affected...northwest North Dakota



Concerning...Severe Thunderstorm Watch 246...



Valid 120448Z - 120545Z



The severe weather threat for Severe Thunderstorm Watch 246

continues.



SUMMARY...Severe thunderstorm watch 246 will expire at 05Z.



DISCUSSION...The severe threat has mostly ended across northwest

North Dakota. Thunderstorms continue across the region, but

instability continues to decrease as the boundary layer cools. A few

strong to occasionally severe wind gusts have been reported in the

last 1 to 2 hours. An isolated strong to severe gust is possible

past 05Z, but any continued threat should be brief and isolated as

the overall threat continues to wane amid decreasing instability.



Severe thunderstorm watch 246 will be allowed to expire at 05Z.



..Bentley.. 05/12/2025



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



ATTN...WFO...BIS...GGW...



LAT...LON   47630387 48420404 48680387 48810310 48860213 48470065

            47720028 46800027 46610130 47290286 47630387



MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH