Expert Forecast Opinion

742
FXUS63 KDTX 110757
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
357 AM EDT Fri Oct 11 2024

.KEY MESSAGES...

- Above normal temperatures and breezy with gusts around 25 mph,
isolated 30-35 mph.

- A Red Flag Warning is in effect across the Tri-Cities and Thumb.

- A cold front will move across late tonight into tomorrow morning,
bringing the slight chance (10-20%) for an isolated shower.

- Periods of rain expected late Saturday night into Sunday. An
isolated thunderstorm possible along or south of I-94.

&&

.DISCUSSION...

Return flow from a departing high pressure system, which will wash
out across the Appalachia late today, will veer and then maintain
southwest flow across the Great Lakes which will advect the warmer
Great Plains air upstream into Michigan. The 00Z DTX RAOB recorded
an 850mb temperature of 6.2C, with projected model guidance
forecasting a value near 15C by 18Z today. The surface impacts will
be temperatures that rise into the mid to upper 70s for a daytime
high while warm sector mixing depths, which fall just shy of h850,
maintain breezy conditions within the warm sector. Peak gusts around
25 mph are expected for most locations, isolated 30-35 mph in spots,
mainly across the Tri-Cities and Thumb. While minimum RH values are
not out of the ordinary for this time of year, the breezy conditions
in conjunction with dry fuel has prompted an upgrade to a Red Flag
Warning for the Tri-Cities and Thumb. Please see the fire weather
forecast and synopsis for additional details.

A second high pressure system will push into the Midwest through the
afternoon and will drive a cold front across SE MI from north to
south this evening through the overnight hours, roughly 00Z - 08Z.
Isolated showers will be possible ahead of the front, but overall
moisture quality remains pretty anemic with almost no instability to
work with. Low chance PoPs (10-20%) will reside across the Tri-
Cities and Thumb, where moisture quality is slightly better relative
to surrounding locations, but otherwise this is expected to be a dry
frontal passage for most locations. Within the near-wake of the
front, there will be a narrow window of steeper low-level isentropic
downglide/subsidence that can bring a quick pop of wind gusts of 25-
35 mph, after the nocturnal stable layer has formed. Breezy
conditions are not expected to be long-lived through the remaining
morning hours as low-level stable conditions quickly redevelop.

The cold front is expected to clear the state by 12z, settling over
Ohio/Indiana, bringing cooler conditions with highs ranging from the
low 60s (Tri-Cities, Thumb), to upper 60s (near the MI/OH border).
Most locations remain dry through the day, with rain chances then
increasing initially across southern Michigan (I94 south) from
overrunning along the stalled frontal boundary. Rain chances then
expand northward through the morning first from low pressure which
will move across southern Lake Michigan, allowing the front to nudge
back into Michigan, while more elevated activity attempts to filter
in across northern lower MI and across the Tri-Cities and Thumb,
ahead of an upper-level trough. The expanding upper-level trough
will reinforce low pressure over the Great Lakes and will support
scattered to numerous shower activity across the cwa Sunday
afternoon through early Monday morning.

This low pressure system will strengthen and occlude over the
Continental Northeast where an expansive and strong thermal trough
then fills in across the Great Lakes Monday through the midweek
period. This will bring the coolest Fall weather of the season Mon-
Tue with highs in the low 50s and lows hitting or nearing the
freezing mark. This also bring the chance for lake effect rain
showers Monday and Tuesday as cooler air filters over the warmer
waters of the Great Lakes.

&&

.MARINE...

Milder air builds into the area today with west to southwest winds
gusting up to 25 to 30 knots across central Lake Huron during the
day. Small Craft Advisories remain in effect for Saginaw Bay and the
Lake Huron nearshore waters to Harbor Beach through the day. A
strong cold front then drops across the central Lakes late this
afternoon into tonight, bringing scattered showers with winds
veering to the northwest. Gusts to 35 knot gales are forecast to
develop across northern and central Lake Huron in the wake of the
front, and a Gale Warning is in effect from 6 PM to midnight.
Elsewhere, gusts of 25 to 30 knots are expected through early
Saturday morning, resulting in a building wave field across southern
Lake Huron. High pressure then builds into the region on Saturday
allowing winds and waves to subside. A passing low pressure system
will bring increasing north to northeast winds in the late Sunday to
Monday time frame with additional marine headlines possible.

&&

.PREV DISCUSSION...
Issued at 1148 PM EDT Thu Oct 10 2024

AVIATION...

A cold front will advance across the northern lakes on Friday, while
high pressure over the eastern lakes gets suppressed to the south.
This will result in an increasing southwest gradient during the
course of the day. Ample dry air and daytime heating will result in
steep low level lapse rates which will lead to gusty southwest winds
during the afternoon on Friday. Model soundings are supportive of
gusts around 20 knots across Detroit to 25-30 knots at MBS. The cold
front will move south across the area Saturday night and will be
marked by a wind shift to the north. The lack of low level moisture
will cloud based mainly VFR along the front.

For DTW/D21 Convection... No thunderstorms today or tonight.

DTW THRESHOLD PROBABILITIES...

* None


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Red Flag Warning from 8 AM this morning to 8 PM EDT this evening
for MIZ047>049-053>055.

Lake Huron...Gale Warning from 6 PM this evening to midnight EDT tonight for
LHZ361-362.

Small Craft Advisory until 4 PM EDT Saturday for LHZ421-441.

Small Craft Advisory until 4 AM EDT Saturday for LHZ422.

Small Craft Advisory from 4 PM this afternoon to 4 PM EDT Saturday
for LHZ442-443.

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

$$

DISCUSSION...AM
MARINE.......TF
AVIATION.....SC


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.