textproduct: Detroit/Pontiac

KEY MESSAGES

- Seasonably average temperatures return for the midweek period with little to no rain chances.

- Much above normal temperatures possible by next Sunday.

DTW THRESHOLD PROBABILITIES

* Low for cigs aob 5000 feet Wednesday morning.

PREV DISCUSSION

Issued at 243 AM EDT Tue Oct 6 2026

DISCUSSION...

Progressive shortwave ridging will carry the center of the surface anticyclone out of Southeast Michigan to over the Mid Atlantic states by this evening. Strength and positioning of the surface high will result in the development of a notable southwest gradient wind with gusts later today of approximately 15 to 25 mph, highest speeds north of I 69 particularly near Saginaw Bay. Not surprisingly the forecast soundings show good mixing through 5.0 kft agl with highs today in the middle to upper 60s. Persistent gradient tonight yields warmer overnight temperatures with lows in the 50s areawide.

Exit region to next Pacific upper level jet packet will support troughing into the western and northern Great Lakes Wednesday. Very good model signal for the development of a cold front with a little warm thetae surge in advance of the feature here Wednesday. Convective allowing models suggest rain shower potential tonight in the moisture transport corridor especially north of Metro Detroit. Forecast models suggest that perhaps best case 500 J/kg MUCAPE will be possible. The real problem and limiting factor will be the amount of stability that is projected to remain in the 6.0 to 14.0 kft agl layer. Will be an interesting all or nothing scenario perhaps for a shower or a rumble of thunder, with some favorable cloud top cooling processes likely required to help steepen midlevel lapse rates. The forecast currently resides dry for tonight. Warm and mild Wednesday afternoon with temperatures reaching the lower to middle 70s. A good little setup for some overachievement. Rapid expansion of the wavelength of the troughing may cause a disjointed frontal structure with the NAM suggesting active downward vertical motion through the 800-900mb layer already by 19-20z. This lower level subsidence combined with very stable midlevel limits any potential for measurable precipitation later Wednesday.

Moisture lean midlevels and a stable midlevel carries out dry weather through the end of the week. Near to below normal temperatures are expected Thursday and Friday with highs in the 60s. Very impressive ridging continues to be advertised for the weekend and beginning of next week. Could be looking at a possibility for temperatures to make a run at 80 degrees for Sunday and Monday dependent on cloud. One item to watch for will be the possiblity of Gulf moisture to make a direct run at Southeast Michigan late Sunday. If that were to develop and clip Southeast Michigan there would be high rainfall rates based on climatology.

MARINE...

Influence of high pressure quickly wanes today as low pressure slides across northern Ontario resulting in strengthening south- southwest wind locally. Typical uncertainty wrt to thermal stability given active warm advection. Forecast soundings advertise borderline neutral conditions near the lake surface when the strongest gradient arrives early tonight. A few gusts to gales are possible over the north-central waters given the favorable long fetch but local probabilistic guidance continues to downplay a multi-hour period of gales (<20% chance). Running forecast still favors peak gusts in the low 30kt range with no Gale headlines, though Small Advisories are effect for the Saginaw Bay/tip of the Thumb into Wednesday morning. Surface cold front eventually crosses Wednesday flipping flow to the northwest with persistent James Bay troughing maintaining moderate gusts (20-30kts) through Thursday.

DTX WATCHES/WARNINGS/ADVISORIES

MI...Frost Advisory until 8 AM EDT this morning for MIZ047>049-053>055- 060>063.

Lake Huron...Small Craft Advisory from 8 PM this evening to 10 AM EDT Wednesday for LHZ421-422-441.

Lake St Clair...None. Michigan waters of Lake Erie...None.