197
FXUS63 KDTX 141947
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
347 PM EDT Sat Sep 14 2024

.KEY MESSAGES...

- Seasonably warm and dry conditions prevail through mid-week with
  patchy morning fog Sunday through Tuesday.

&&

.DISCUSSION...

Quasi-static synoptic state featuring a Rex Block across the region
exhibits only slight eastward adjustments of the resident upper
ridge into Georgian Bay while a remnant post-tropical low reverses
course over the Gulf states. Local PWATs around 0.75 inches reflect
perpetual column dryness while ThetaE convergence warps
anticyclonically around the Lower Peninsula and through the Upper
Midwest. Slightly more cirrus noted in afternoon GOES imagery than
yesterday as some high cloud generated off the subtropical jet
deflects southward. This poses minimal obstruction to diurnal
insolation while an influx of wildfire smoke persists aloft.
Southeasterly gradient flow generally holds AOB 15 mph each day
while trending near calm overnight. Another cool morning start
Sunday offers a repeat scenario for a couple hours of patchy ground
fog with lows/dewpoints near 60F.

The resident ridge begins shear/elongate eastward toward the
Atlantic Sunday, but latest progs suggest some stubbornness to the
closed high as the next potential (sub-)tropical disturbance tries
to organize off the Carolina coast and push northwest across The
Appalachians. H8 temps continue to hold in the 15-17C range Sunday
and again Monday maintaining highs in the low-mid 80s where the
warmest readings are mostly likely west of US-23. No major forecast
revisions needed this time before focus shifts to the coastal
Carolina low Wednesday. More NWP solutions now advertise a southern
Appalachia track, if not further northwest into the Ohio Valley.
Propagation into far southeast Michigan appears much less likely
(mainly GFS/GEFS/CMC), but given the broader trend in developing
such a system with inland integrity, will be monitoring this
possible opportunity for precipitation closely. For context, the
official Detroit Area precipitation total for this month stands at
0.06 inches of rain, all of which fell on September 6th. Thus far,
the Detroit areas is now tied for its sixth driest start to
September on record (for Sept 1-13).

&&

.MARINE...

High pressure continues to dominate conditions across the central
Great Lakes through at least the first half of next week. As such,
dry weather persists with southerly flow developing by Sunday that
then holds into early next week. Winds generally hold at or below
15kts.

&&

.PREV DISCUSSION...
Issued at 136 PM EDT Sat Sep 14 2024

AVIATION...

High amplitude, long wavelength ridging will remain centered over
the Great Lakes region throughout the period. Dry boundary layer
conditions and a strong capping inversion centered at 5.5 kft agl
will preclude low cloud today. Shallow ground fog will again be
possible at daybreak Sunday due to favorable radiative cooling
conditions.

For DTW/D21 Convection... Thunderstorms are not in the forecast for
the foreseeable future.

 DTW THRESHOLD PROBABILITIES...

* None.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

DISCUSSION...KGK
MARINE.......KDK
AVIATION.....CB


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