Flooding Continues in Arenac County Along the Rifle River

                        

004

ACUS01 KWNS 140102

SWODY1

SPC AC 140100



Day 1 Convective Outlook

NWS Storm Prediction Center Norman OK

0800 PM CDT Thu Aug 13 2026



Valid 140100Z - 141200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF

NORTH-CENTRAL ILLINOIS INTO SOUTHWEST OHIO...



...SUMMARY...

Thunderstorms with severe wind gusts and hail will be possible

tonight from parts of north-central Illinois into southwest Ohio.

Severe gusts and hail will be possible in parts of the central

Plains. A few severe gusts may also occur in parts of the

Intermountain West.



...Mid Mississippi and Ohio Valleys/Southern Great Lakes...

The latest water vapor imagery shows a mid-level anticyclonic flow

pattern over the central U.S., with west-northwesterly flow located

over the eastern U.S. At the surface, a quasi-stationary front is

analyzed from northeast Missouri to northern Kentucky. Surface

dewpoints along and to the south of the front are in the 70s and low

80s F, which is contributing a west-northwest to east-southeast axis

of strong instability. The RAP has MLCAPE along this axis in the

3000 to 5000 J/kg range. To the north of the instability axis,

short-term model forecasts move a subtle shortwave trough

east-southeastward through the Midwest tonight. Large-scale ascent

associated with the trough coupled with increasing low-level flow

will likely result in the development of a line of strong storms.

This is forecast to take place late this evening, with the line

moving southeastward from north-central Illinois across central

Indiana and into southwest Ohio. Severe wind gusts will be possible

with this line segment.



...Central Plains...

Southwesterly mid-level flow is currently in place over much of the

southwestern and central U.S. An embedded mid-level shortwave trough

appears to be moving into the central High Plains. Ahead of this

feature, the RAP has an axis of moderate instability located from

northern and western Kansas into northeastern Colorado, along which

MLCAPE is estimated in the 1500 to 2500 J/kg range. Scattered

thunderstorms were ongoing near the instability axis early this

evening in eastern Colorado with another cluster in central Kansas.

Increasing low-level flow from this evening into the overnight

period will likely sustain convective development. Hail and isolated

severe wind gusts will be possible with the stronger cells.



...Intermountain West...

On water vapor imagery, multiple shortwave troughs appear to be

moving through the Intermountain West. Ahead of these features,

scattered thunderstorms are ongoing across much of Nevada and Utah.

The RAP is currently analyzing an axis of instability from southeast

Nevada into north-central Utah along which MLCAPE is estimated to be

in the 750 to 1000 J/kg range. Near the instability axis, the RAP

also has low to mid-level lapse rates in the 7.5 to 8.5 C/km range.

This thermodynamic environment should support an isolated potential

for severe wind gusts this evening.



..Broyles.. 08/14/2026



$$






                

                        

052

ACUS02 KWNS 131732

SWODY2

SPC AC 131730



Day 2 Convective Outlook

NWS Storm Prediction Center Norman OK

1230 PM CDT Thu Aug 13 2026



Valid 141200Z - 151200Z



...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL

HIGH PLAINS EASTWARD INTO PARTS OF THE MIDWEST...OHIO VALLEY...AND

MID-ATLANTIC...



...SUMMARY...

Isolated strong to severe storms are possible from the central High

Plains into parts of the Midwest, Ohio Valley, and Mid-Atlantic on

Friday.



...East-central Plains into the Midwest...

Isolated severe potential will be possible with early morning

elevated storms within a warm advection regime. These storms will

generally diminish with time given the weakening low-level jet. An

MCV will likely emanate from the central High Plains and impact the

Mid-Missouri Valley during the afternoon. This MCV will track along

the periphery of the upper ridge that will be building into the

Plains/Midwest. Model guidance varies with regard to how organized

this MCV and associated surface reflection will be. Moderate to

strong instability is expected to develop near the effective surface

boundary by the afternoon despite some expected cloud cover. The

timing of convective development is quite uncertain. The HRRR

suggests strong enough convergence at the surface that storms will

form by late afternoon. Many other CAMs suggests development after

00Z as the low-level jet increases again. Storms that do develop

will likely have supercell characteristics initially, but weak flow

above 500 mb will tend to lead to outflow dominance and clustering.

Should confidence in late afternoon development increase, there may

be greater severe potential than currently expected.



...Ohio Valley into parts of the Mid-Atlantic...

Convection will likely be ongoing across portions of the Ohio Valley

into the central Appalachians early Friday morning. Model guidance

generally suggests that an MCV feature will be associated with this

activity, though the strength of the MCV varies. Regardless of how

strong the MCV is, there is a consistent signal for cloud cover

limiting destabilization/low-level lapse rates across much of these

regions. Stronger mid-level winds will also be displaced from the

larger buoyancy values in the Carolinas. Given the timing of the

MCV, it appears likely that wind damage potential will be spatially

limited. There will be a small corridor of stronger heating in

southeast Virginia/northeast North Carolina which could see locally

stronger storms.



...CO Front Range into the central High Plains...

Moist east/southeasterly surface winds into the higher terrain will

again promote scattered storm development within the Front Range.

Deep-layer shear will not be overly strong, but a few storms will be

capable of isolated hail and severe winds. Additional storms are

expected in the hotter, well-mixed environment to the south and

east. These storms will be capable of severe winds. There will be

some increase in the low-level jet during the evening. The strongest

850 mb winds will be focused farther east, however. If a cluster can

form, it may persist farther eastward into later in the evening.



..Wendt.. 08/13/2026



$$






                

                        

718

FXUS63 KAPX 132359

AFDAPX



Area Forecast Discussion

National Weather Service Gaylord MI

759 PM EDT Thu Aug 13 2026



.KEY MESSAGES...



- Increasing shower/storm chances this weekend, especially Saturday

  night.



.DISCUSSION...

Issued at 207 PM EDT Thu Aug 13 2026



Upper ridge currently extending through the Plains with downstream

west/northwest flow aloft across the Great Lakes. Convective

complexes continue to ride along the primary instability axis

to our south and west. The upper ridge will gradually shift east

into this weekend, deamplifying a bit as a shortwave trough

moves through. Upper ridge will flex again to our west early

next week, with northwest flow resuming over the Great Lakes.



Fairly benign weather through Friday with increasing influence of

drier and more stable air, as high pressure builds in from the

northwest.  A small chance of an early evening shower over northeast

lower along a lake breeze boundary, but any activity would be

isolated and dissipate quickly.  Some patchy fog again tonight,

although decreasing soil moisture and an overall drier atmosphere

should limit the extent.  Quiet weather continues on Friday, despite

another shortwave passing to our east, with limited moisture making

any shower development difficult.



Unsettled weather still in store for the weekend, although more

recent model runs are further south with the shortwave energy

and surface reflection. Although deeper moisture on the backside

of departing high pressure will push toward the area on

Saturday, it will initially have to fight a relatively dry

airmass. Eventually, the deeper moisture (PWATs 200% of normal)

will win out and surge northward into our area Saturday night

into early Sunday, which is when we will see the best chance of

precipitation. The trends have been drier overall in recent

model runs and the heavy rain threat looks to be focusing more

over central/southern Michigan. Unfortunately, this could keep

much needed steadier rains out of northern Michigan. Cold front

sweeps across the area by later Sunday with deep layer drying.



Additional shortwave energy in fast moving northwest upper flow will

bring unsettled weather and shower chances back to the area for

Tuesday and Wednesday. Temperatures a little cooler from Sunday into

early next week, although still comfortable 70s for most areas.



&&



.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...

Issued at 753 PM EDT Thu Aug 13 2026



Predominantly VFR aviation weather conditions expected across

the northern Michigan terminals through the 00Z TAF valid time.

Patchy fog is expected overnight, which may locally reduce

visibility to MVFR or IFR levels for a time. Winds will

generally be light through the period.



&&



.APX WATCHES/WARNINGS/ADVISORIES...

MI...None.

MARINE...None.



&&



$$



DISCUSSION...JK

AVIATION...PBB






                

                        

726

ACUS11 KWNS 140130

SWOMCD

SPC MCD 140130 COR

KSZ000-NEZ000-COZ000-140300-



Mesoscale Discussion 1973

NWS Storm Prediction Center Norman OK

0830 PM CDT Thu Aug 13 2026



Areas affected...portions of eastern Colorado...northwest Kansas and

southwest Nebraska



Concerning...Severe potential...Watch possible



Valid 140130Z - 140300Z



CORRECTED FOR TYPO



Probability of Watch Issuance...40 percent



SUMMARY...Several clusters of strong to occasionally severe storms

may gradually move into a more unstable air mass this evening. Some

potential for MCS development and a subsequent severe wind gust risk

is evident. Confidence is low, but a Watch is possible.



DISCUSSION...As of 0100 UTC, regional radar imagery showed several

clusters of strong to occasional severe storms ongoing from southern

WY, across eastern CO into southwestern KS. Driven in part by a

broad post-frontal upslope flow regime, convective coverage has

steadily increased this evening. With numerous storms ongoing, some

cold pool amalgamation has been noted. Recent CAM guidance shows

this continuing with a potentially more organized cluster or MCS

evolving later this evening.



The air mass to the north of the front is still relatively warm and

moist which is supporting moderate buoyancy (MLCAPE 1500-2500 J/kg).

Deep-layer shear is more modest between 25-35 kt, but slightly

elongated mid and upper-level hodographs are supportive of some

organization of multicells and clusters. Overall shear profiles are

also expected to increase later this evening with the nocturnal

low-level jet.



The primary uncertainty remains the storm-scale organization of the

cold pool and how that may influence the severe risk. With the

environment more than supportive of strong updrafts and current

storm maintenance, further clustering and eventual organization is

possible, especially where low-level convergence is maximized along

and north of the front. Given this potential, some severe risk could

evolve later this evening and overnight. The need for a watch is

very uncertain, but conditions will be monitored.



..Lyons/Hart.. 08/14/2026



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



ATTN...WFO...GID...LBF...DDC...GLD...PUB...BOU...CYS...



LAT...LON   41020262 41330103 41260030 41029977 40699947 39209938

            38769992 38490030 37840140 37830153 37780215 38200293

            38720380 39220407 40060413 40840285 41020262



MOST PROBABLE PEAK WIND GUST...65-80 MPH

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