FXUS63 KDTX 261725

AFDDTX



Area Forecast Discussion

National Weather Service Detroit/Pontiac MI

125 PM EDT Thu Jun 26 2025



.KEY MESSAGES... 



- Scattered to numerous thunderstorms again this afternoon as warm 

and humid air builds back into Lower Michigan. 



- There is a Marginal Risk of severe weather as storms may produce 

damaging down burst winds. Localized flooding will also be possible 

due to very moist airmass and saturated soils from recent storms 

this week. 



- A chance of thunderstorms continues Friday into the weekend as an 

active pattern holds across the Great Lakes. 



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

today through the weekend with heat indices up into the mid to upper 

90s at times.



&&



.AVIATION...



Moderately unstable, uncapped environment over southeast Michigan, 

with frontal boundary/dew pt gradient near the I-69 corridor. 

Disorganized strong thunderstorms should continue, but location is a 

bit challenging as outflow boundaries serve to focus additional 

redevelopment.  None-the-less, multiple rounds of showers/storms 

across southern TAF sites looks reasonable, and will be maintaining 

the tempo TS group through the afternoon, although concerned with 

the latest drift to the south with the bulk of the activity.

As low pressure enters the Western Great Lakes this evening, the 

surface boundary over Lower Michigan will attempt to lift north, 

providing better focus over MBS/FNT for the evening hours. With the 

elevated low level moisture/high surface dew pts over southeast 

Michigan tonight, much better chance for low clouds and/or some fog,

depending on how thick mid/high clouds from upstream activity over 

the Western Great Lakes advances east. However, with today's 

rainfall, enough confidence in MVFR stratus and/or fog development to

include in tafs, with very light southerly winds tonight, IFR not 

out of the question, especially at MBS. 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...Bulk of storms over southern Lower Michigan 

are showing signs of prograging southeast, away from terminal. Thus 

lower confidence for the rest of the afternoon. None-the-less, would 

expect enough destablization to trigger addtional storms late this 

afternoon, and will keep much of the inherited taf intact. 



 THRESHOLD PROBABILITIES...



* Low to medium for thunderstorms this afternoon and evening.



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

  and tomorrow afternoon.



&&



.PREV DISCUSSION...

Issued at 331 AM EDT Thu Jun 26 2025



DISCUSSION...



We remain on the northwestern edge of the large ridge across much of 

the SE conus today. The ridge is slowly weakening though still 

remains around 590 dam. This ridge continues to steer a very moist 

airmass up through the Plains and across lower MI with PWATs still 

hovering around 1.75 to 2+ inches which will carry through the end 

of the week. Surface dewpoints took a hit across much of the area 

when the cold front dropped through Tuesday, but remain around 70 

across the far south and 60s for the rest of the area. This has lead 

to showers/storms being very efficient rain makers the last couple 

days with the uncapped, high CAPE, low shear environment with a few 

areas developing localized flooding. This will remain a main concern 

through the end of the week until Friday when a stronger system 

passes through the Great Lakes and pushes the moisture south. We 

remain in a Marginal Risk of Excessive Rainfall for both days to end 

the week. 



Will be hard pressed to remove chances of showers/storms during any 

period through Friday as the persistent frontal boundary will 

continue to meander about the region with the slightest ripple in 

along the elevated front producing showers. The main difference 

between today/Friday vs the previous two days of convection though 

will be that we'll have some more notable synoptic waves tracking 

through the region through this main moisture axis bringing a couple 

periods of more targeted pops. 



The first wave is ongoing at press time, traveling through northern 

MI and pulling the 850mb front back up through the area with 

convection already firing along it over GRR. The surface front will 

also get drawn northward this morning building north and east with 

time allowing more unstable air (MUCAPE >2000 J/kg) back into a 

larger portion of the CWA. Will keep chance pops at least through 

the day with another period of scattered to numerous storms expected 

with peak heating and the main instability gradient in the vicinity 

of I-69. Localized flood risk with these storms along with wind 

threat from precip loaded downbursts. Some small hail will be 

possible with some storms. The second wave will again track through 

northern MI Friday pulling the warm frontal surface farther north 

through the whole CWA early in the morning with a chance of 

convection firing along it as we get a bit more of the 850mb low 

level jet (25-30 knots) over the area helping provide a bit better 

forcing locally. We'll be warm sectored most of the day allowing for 

another unstable day with CAPE >2000 J/kg, but the warm sector will 

provide a little cap to deal with. The cold front will get pulled 

into the area in the afternoon/evening bringing another round of 

more widespread convection. 



Temperatures will make a run at 90 for our southern portion of the 

CWA the next two days and when combined with the low-mid 70 

dewpoints may result in heat indices in the mid to upper 90s, 

possible touching 100 for a short period. With the expected cloud 

cover and scattered convection, we will hold off on any heat 

advisories at this time.



MARINE...



Warm front has lifted north into northern Lower Michigan this 

morning, leading to stronger (25+ knots) easterly winds over the 

northern Lake Huron. A wave of low pressure coming out of the Midwest 

will trigger numerous strong to possibly severe thunderstorms. 

Another round of strong storms on Friday before the low exits east. 

Light northwest flow follows the low for Friday night into Saturday 

before winds become light southerly for the second half of the 

weekend with mainly dry conditions.



HYDROLOGY...



A front wavering north and south across Lower Mi will be focus for 

showers and thunderstorms today through Friday, and possibly through 

the weekend. Showers and storms area ongoing this morning as the 

front moves back northward. The front becomes the focus for yet 

another round of storms in the afternoon which spread across the 

area in warm and humid air returning to the region. All of this 

occurs in a deep/high moisture environment that promotes heavy 

rainfall rates that could lead to localized flooding. Typical urban, 

small stream, and flood prone areas are most at risk but also any 

location that experiences repeated rounds of showers and 

thunderstorms, which could happen anywhere across SE Michigan during 

the mid to late week period.



&&



.DTX WATCHES/WARNINGS/ADVISORIES...

MI...None.

Lake Huron...None.

Lake St Clair...None.

Michigan waters of Lake Erie...None.

&&



$$



AVIATION.....SF

DISCUSSION...DRK

MARINE.......SF

HYDROLOGY....DRK





You can obtain your latest National Weather Service forecasts online

at www.weather.gov/detroit.

