FXUS63 KDTX 262248

AFDDTX



Area Forecast Discussion

National Weather Service Detroit/Pontiac MI

648 PM EDT Thu Jun 26 2025



.KEY MESSAGES... 



- Yet another round of thunderstorms is likely Friday as a cold 

front moves through Lower Michigan. There is a Marginal Risk of 

severe intensity during the afternoon and evening. 



- High temperatures increase back to the upper 80s to 90 degrees 

Friday and Sunday after a brief cool down Saturday.



&&



.AVIATION...



Disorganized, scattered showers and thunderstorms, mostly around 

FNT/PTK airports this evening should be dissipating late in the 

evening with the loss of daytime heating. With surface dew pts in 

the low to mid 70s and frontal boundary hanging around I-69 

corridor, it appears likely MVFR low clouds and/or fog will develop, 

with a good chance for a period of IFR over MBS where temp is cooler 

and higher surface dew pts will make inroads overnight with very 

light southerly winds. Lowest confidence in low cigs and visibility 

restrictions over southern site (YIP/DTW/DET).



Another round of showers and thunderstorms appears likely tomorrow 

afternoon as cold front arrives during peak heating. Southwest wind 

gusts ahead of the front will likely reach into the 20-25 knot range 

in the afternoon, in addition to the stronger/gustier winds in any 

thunderstorm. 



For DTW/D21 Convection...



 THRESHOLD PROBABILITIES...



* Low for thunderstorms this evening, moderate tomorrow afternoon.



* Low in ceilings aob 5000 feet through evening. Moderate late 

  tonight and tomorrow afternoon.



&&



.PREV DISCUSSION...

Issued at 417 PM EDT Thu Jun 26 2025



DISCUSSION...



An interesting progression of thunderstorm development from this 

morning continues to unfold across the area this afternoon and 

evening. Broad scale support for nocturnal/elevated convection late 

last night resulted in storms grazing the Tri Cities and Thumb 

around sunrise this morning. The larger scale support, mainly near 

the entrance region upper jet circulation, helped the 850-700 mb 

theta-e ridge percolate over southern Lower Mi all morning until 

becoming surface based toward noon. A messy multicell convective 

mode dominated since then and which has migrated south of the Ohio 

border after forecast issuance. Lingering severe potential, for 

mainly damaging wind and heavy rainfall, has shifted farther north 

to the hybrid marine layer/surface front. This has released new 

storms where MLCAPE projections show a 2000 J/kg instability axis 

through early evening. In all cases, precip loaded damaging wind 

gusts are the primary severe hazard followed by heavy rainfall. Hail 

is a distant third given the deep moisture profile and low CAPE 

density in the mid levels. 



The ongoing storms across Lower Mi are expected to dissipate with 

the loss of heating tonight, in time to look toward the Midwest 

where another low pressure system is interacting with the resident 

surface front across the Great Lakes. Surface based storms out there 

are also expected to diminish/dissipate on the downward side of the 

heating cycle followed by a new transition to low level jet forced 

convection tonight. The surface low moves into NW WI while pulling 

the front back north into northern Lower Mi late tonight and Friday 

morning. This presents a dry warm sector scenario for SE Mi and a 

more favored nocturnal MCS track north of the Tri Cities late 

tonight into Friday morning.



Yet another round of thunderstorms is likely for SE Mi Friday 

afternoon as the WI surface low continues into northern Ontario 

while dragging a cold front across Lower Mi. The solid warm sector 

in place over the area is HREF projected to build SBCAPE up to 

around 2000 J/kg ahead of the front. Bulk shear is also advertised 

to be on the low side, however a deeper dive into model soundings 

indicates unidirectional mid level flow around 35 knots with some 

dry air around the 500 mb level. The big CAPE helps with the lower 

end wind field for storms evolving into line segments along the 

front with damaging wind potential the primary hazard, as good or 

better than SPC's Marginal Day 2 outlook for our area into Friday 

evening. 



The Friday cold front ushers weak high pressure into the area for 

Saturday, slightly cooler and a little less humid. This reverses 

Sunday as the next low pressure system moves into the Great Lakes 

and brings highs back up near 90. The front associated with this 

system leads to a larger scale pattern shift resulting in at least 

lower humidity with greater staying power next week.



MARINE...



Marine conditions remain unsettled in terms of thunderstorms this 

afternoon through Friday while wind and waves are otherwise subdued 

outside of the storms during this time. The current center of low 

pressure in the Midwest moves eastward along a frontal zone that has 

been wavering across Lake Huron and Lower Michigan over the last 

couple days. The low moves across the Straits Friday and pulls a 

weak cold front southward through Lower Michigan and into the Ohio 

valley Friday night. Light wind and favorable weather follow with 

weak high pressure Saturday followed by another low pressure system 

entering the northern Great Lakes during Sunday through Sunday 

night. This system brings a stronger cold front into Lake Huron and 

Lower Michigan to start next week.



&&



.DTX WATCHES/WARNINGS/ADVISORIES...

MI...None.

Lake Huron...None.

Lake St Clair...None.

Michigan waters of Lake Erie...None.

&&



$$



AVIATION.....SF

DISCUSSION...BT

MARINE.......BT





You can obtain your latest National Weather Service forecasts online

at www.weather.gov/detroit.

