Flooding Continues in Arenac County Along the Rifle River

                        

344

ACUS01 KWNS 181952

SWODY1

SPC AC 181950



Day 1 Convective Outlook

NWS Storm Prediction Center Norman OK

0250 PM CDT Thu Sep 18 2025



Valid 182000Z - 191200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF

MISSOURI...



...SUMMARY...

Isolated severe storms are possible mainly from late afternoon into

tonight across Missouri into adjacent parts of the Lower Missouri

Valley and southern Plains. Isolated strong to severe storms may

also occur across southern California and the Lower Colorado River

Valley.



...20z Update...

The previous forecast remains on track. The primary adjustment was

an eastward expansion of 5% wind/hail probabilities into northwest

AR where pulse convection is developing within a very buoyant

(though weakly sheared) environment. Similar thermodynamic/kinematic

conditions have yielded sporadic wind/hail reports in recent days,

so at least a low-end severe threat is anticipated through early

evening (see MCD #2096 for additional details).



Elsewhere, the forecast remains on track. Convection is beginning to

deepen across northeast OK, far eastern KS, and far southwest MO,

which is expected to increase in coverage and intensity within the

Slight risk area through the evening based on recent environmental

data and CAM solutions. Further west, consideration was given for

removing risk probabilities across eastern TX into western OK;

however, surface convergence along a diffuse front is gradually

increasing with an attendant uptick in mid-level cumulus. Forecast

soundings and a couple of recent HRRR/RRFS solutions hint that

elevated convection along the boundary remains possible through

mid-evening, and deep-layer wind shear is sufficient for organized

convection. Across central OK, elevated thunderstorms developing

late tonight within a modest warm advection regime may pose a threat

for isolated large hail. See the previous discussion below and MCDs

#2097 and #2098 for additional details.



..Moore.. 09/18/2025



.PREV DISCUSSION... /ISSUED 1139 AM CDT Thu Sep 18 2025/



...Missouri and Lower Missouri Valley to southern Plains...

Generally isolated severe storms will be possible today regionally

ahead of the east/southeast-advancing front (and residual

convection/outflows), but a somewhat greater/semi-focused corridor

of severe potential, mostly in the form of damaging winds, appears

to exist across portions of Missouri. This will be influenced by

modestly stronger cyclonic flow aloft attendant to the

mid/upper-level trough, with a favorably warm/moderately unstable

boundary layer this afternoon. Bouts of damaging winds will be

possible regionally, with some hail as well.



...Southern California/Lower Colorado River Valley....

An anomalously moist airmass associated with the remnants of

tropical cyclone Mario continues to advect northward into and across

southern portions of California/Arizona. 12Z NKX sounding sampled a

1.95 PW value, which is well above the 90th percentile based on

daily SPC sounding climatology. Filtered heating is anticipated

within this moist environment, resulting in moderate buoyancy across

much of eastern southern California and southwest Arizona this

afternoon. Moderate vertical shear is anticipated as well,

particularly across southern California. Additional thunderstorm

development is expected during the afternoon, with a predominantly

multicellular mode. However, enough shear and instability are in

place to support organization with any more persistent updrafts, and

a few supercells capable of damaging gusts are possible. A

very-low-probability tornado threat may exist as well, particularly

in the Lower Colorado Valley vicinity where some guidance suggests

surface winds stay more southeasterly. Even so, the low-level flow

is weak and any tornado threat should be very localized.



...Eastern South Dakota/southeast North Dakota/western Minnesota...

In proximity to the upper low over the Dakotas, a relatively moist

environment, sufficient cloud breaks/heating, ample low-level CAPE,

and ambient vorticity near a weak surface low and nearby front could

be sufficient for some funnels this afternoon through around sunset.

A brief non-supercell tornado cannot be conclusively ruled out near

the boundary/surface low if stronger destabilization materializes,

but the overall potential/likelihood should remain limited.



$$






                

                        

268

ACUS02 KWNS 181732

SWODY2

SPC AC 181730



Day 2 Convective Outlook

NWS Storm Prediction Center Norman OK

1230 PM CDT Thu Sep 18 2025



Valid 191200Z - 201200Z



...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST NE

INTO WESTERN/CENTRAL KS...



...SUMMARY...

Isolated severe storms are possible across parts of the central

Plains on Friday. Isolated strong storms may also occur across parts

of the Southwest and from the ArkLaTex into the Upper Midwest.



...Synopsis...

A broad mid/upper-level trough will remain in place across parts of

the northern/central Plains and Upper Midwest on Friday. Multiple

embedded vorticity maxima will move traverse the larger-scale trough

through the period. Across the West, a midlevel shortwave trough

will move across parts of central/northern CA/NV, while a deeper

mid/upper-level trough offshore of southern CA will move slowly

eastward.



...KS/southern NE vicinity...

A somewhat conditional Marginal Risk has been added from southwest

NE into western KS, due to the potential for isolated supercells

within a northwest-flow regime.



Guidance has generally trended toward a more vigorous midlevel

shortwave trough and jet maximum moving southeastward from the

northern High Plains toward the lower MO Valley through the period.

In response to this system, a weak surface low is forecast to

develop across the central High Plains. Guidance continues to vary

somewhat regarding the placement of any surface boundaries and

extent of low-level moisture return during the day, but at least

isolated storm development will be possible by late afternoon from

southern NE into northwest KS.



Deep-layer shear will become favorable for organized convection

within the northwesterly flow regime along the southwest periphery

of the aforementioned shortwave trough. Buoyancy may remain

relatively modest (with MLCAPE of 500-1500 J/kg), but recent CAM

guidance depicts potential for isolated supercell development, which

could pose a threat for localized hail and gusty winds. A more

uncertain scenario is for convection directly associated with the

shortwave trough to intensify as it approaches southeast NE, but

there is considerable uncertainty regarding diurnal destabilization

in this area.



A strengthening low-level jet could support some storm clustering

and maintenance of elevated convection into late Friday night across

parts of KS. Longevity of the severe threat into Friday night is

uncertain, but isolated hail and strong gusts cannot be ruled out

within this nocturnal regime as well.



...Upper Midwest...

A midlevel shortwave trough initially over parts of IA/MO is

generally forecast to move north-northeastward toward MN/WI through

the day, as the trailing shortwave moves into the central

Plains/lower MO Valley. Scattered to numerous storms will be

possible across parts of the Upper Midwest/MS Valley, within a

relatively moist and uncapped environment. Midlevel lapse rates and

deep-layer shear are generally forecast to remain rather weak, so

any severe threat will likely be dependent on sufficient diurnal

heating/destabilization. Confidence in a mesoscale corridor of

organized severe threat is too low for probabilities at this time,

but a few strong storms will be possible.



...ArkLaTex into the lower/mid MS Valley...

Scattered storm development will be possible during the afternoon

from the ArkLaTex into the lower/mid MS Valley, though details

regarding heating/destabilization are somewhat uncertain, due to the

potential impact of upstream morning convection and related cloud

debris. While deep-layer flow/shear will generally be weak across

the region, a few strong storms will be possible if sufficient

heating occurs. Severe probabilities may eventually be needed if

confidence increases regarding stronger diurnal destabilization.



...Southwest...

Scattered to widespread storms will again be possible across parts

of the Southwest on Friday, within a relatively moist and moderately

unstable environment. Deep-layer shear will generally be modest,

resulting in uncertainty regarding any organized severe potential.

However, localized strong gusts and small to near-severe hail will

be possible with the strongest storms.



..Dean.. 09/18/2025



$$






                

                        

349

NWUS53 KAPX 182330

LSRAPX



Preliminary Local Storm Report

National Weather Service Gaylord MI

730 PM EDT Thu Sep 18 2025



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

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

            ..REMARKS..



0715 PM     Rain             1 SSW Manistee          44.23N 86.34W

09/18/2025  M1.03 Inch       Manistee           MI   Mesonet



            Mesonet station DW9113 Manistee.





&&



$$












                

                        

442

FXUS63 KAPX 182208

AFDAPX



Area Forecast Discussion

National Weather Service Gaylord MI

608 PM EDT Thu Sep 18 2025



.KEY MESSAGES...



- Shower/storm chances favoring areas south of M-32. Slight

  thunder potential as well, greatest chances near Saginaw Bay.



- Turning cooler Friday and Saturday with low shower chances at

  times. Better rain chances arrive later in the weekend as

  warmth and humidity return Sunday.



&&



.SHORT TERM /THROUGH FRIDAY/...

Issued at 232 PM EDT Thu Sep 18 2025



Pattern Synopsis/Forecast: Ridging overhead being somewhat

suppressed by a weak/subtle trough making headway just off to our

northeast. Backdoor cold front passed through northern MI from the

north-northeast this morning/midday with ample post-frontal moisture

struggling to release its grip on low clouds across parts of the

forecast area. More plentiful sun the father south one goes with

potential for a few pop up showers/storms this afternoon/early

evening. Otherwise, a return of higher surface pressures and

increasingly dry air gradually returns on Friday.



Forecast Details: Stubborn morning/midday cloud cover across the

northern half of the forecast area as pretty much dissipated

over the last hour or two. Southern areas (primarily south of

M-32) remain favored for continued convective processes this

afternoon/early evening, with the highest chances as you head

near M-55 where MUCAPE is progged as high as 1,000 J/kg. Any

scattered shower/storm development should largely dissipate

after sunset with the loss of diurnal heating.



Some stratus may redevelop tonight, favored across parts of eastern

upper and northeast lower. Lows generally spanning the upper 40s to

upper 50s area-wide.



For Friday, any low clouds tonight likely to be slow to improve on

Friday, but eventually more sunshine expected area-wide with high

temperatures cooler than the last several days for many areas --

ranging from the mid-60s to mid-70s area-wide, a touch cooler near

the Lake Huron shoreline given a prevailing east wind. Low

chances/confidence for a few additional pop up showers/storms during

the afternoon/evening, primarily in downsloping areas of northwest

lower (west of US-131).



&&



.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...

Issued at 232 PM EDT Thu Sep 18 2025



Pattern Forecast: High pressure remains centered to our northeast

Friday night through Saturday with a developing system upstream over

the Plains. At least initially, northern MI is sandwiched between

these two with relatively tranquil conditions anticipated. By later

Saturday, a warm front emanating from that upstream system will

introduce shower chances across parts of the forecast area with

better chances for more numerous showers/storms expected to arrive

by later Sunday into Monday.



Additional showery/unsettled weather potential continues into

Tuesday as moisture is slow to depart, and with increasingly colder

air aloft, may combine to kick of some diurnal instability driven

showers. Longer range guidance trends suggest cooler/drier air

builds in beyond this disturbance for the middle part of next week.



Forecast Details: Generally low end chances for scattered showers

and an isolated thunderstorm exist Saturday as a warm front tied to

low pressure upstream begins its approach. This boundary eventually

expected to cross south to north late Saturday night into Sunday

with a warmer and somewhat more muggy day on Sunday. Additional,

more numerous, shower and storm chances late Sunday, Sunday night

into early Monday as more favorable forcing aloft slides across the

western Great Lakes.



Showery conditions may linger at times for the second half of Monday

into Tuesday with a general drying trend anticipated heading toward

the middle of next week. Temperatures remaining on the mild side

through the entirety of the forecast period with daytime highs

largely in the upper 60s to mid-70s and no real sign of a return of

more fall-like temperatures on the horizon.



&&



.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...

Issued at 607 PM EDT Thu Sep 18 2025



Showers and a few storms lingering around Saginaw Bay and the Lake

Michigan shoreline south of the Manitou Islands will diminish with

time this evening into tonight. At least some remnant mid/high cloud

is expected to stick around tonight, decreasing confidence in FG/BR

development across northern lower Michigan compared to last night.

However, IFR and even LIFR CIGs are anticipated for a time later

tonight/early Friday morning across interior northern lower

Michigan -- and expected to remain outside of TAF sites at this

time. PLN and APN are expected to have MVFR CIGs settle in for

a time late tonight through Friday morning before eventually

lifting back to VFR for the remainder of the TAF period. MBL may

see patchy FG/BR, but aforementioned mid/high cloud leads to

low confidence in this materializing. Otherwise, VFR conditions

are anticipated at the remainder of TAF sites through the

issuance period.



&&



.APX WATCHES/WARNINGS/ADVISORIES...

MI...None.

MARINE...None.



&&



$$



SHORT TERM...MJG

LONG TERM...MJG

AVIATION...DJC






                

                        

206

ACUS11 KWNS 182304

SWOMCD

SPC MCD 182303

MOZ000-ARZ000-190100-



Mesoscale Discussion 2099

NWS Storm Prediction Center Norman OK

0603 PM CDT Thu Sep 18 2025



Areas affected...Missouri



Concerning...Severe Thunderstorm Watch 614...



Valid 182303Z - 190100Z



The severe weather threat for Severe Thunderstorm Watch 614

continues.



SUMMARY...Isolated wind/hail can be expected with convection as it

spreads east this evening.



DISCUSSION...A well-defined short-wave trough is advancing east

across NE/KS early this evening. In response to this short wave, a

weak surface boundary is serving as the focus for a broken line of

robust convection, currently extending from Livingston County

MO-Barry County MO-Crawford County AR. This activity is propagating

through a modestly buoyant corridor of instability characterized by

1000-1500 J/kg MLCAPE. Isolated severe winds and marginally severe

hail have been reported with these storms, but 0-6km shear is

seasonally weak and 500mb flow is on the order of 20-25kt. As a

result, gusty winds should be the primary threat with this frontal

convection as it propagates toward the eastern edge of ww614.



..Darrow.. 09/18/2025



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



ATTN...WFO...LSX...LZK...SGF...EAX...TSA...



LAT...LON   36489407 39449427 39449201 36499192 36489407



MOST PROBABLE PEAK WIND GUST...55-70 MPH

MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN