185
FXUS63 KDTX 071114
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
614 AM EST Thu Nov 7 2024

.KEY MESSAGES...

- Dry weather with temperatures at or slightly above early November
normals today through Saturday.

- The next chance of rain arrives Sunday as a large low pressure
system reaches the Midwest.

&&

.AVIATION...

Any lingering morning stratus left in the wake of an overnight cold
frontal passage will vacate the area as drier air arrives in modest
northwest flow. A limited coverage of VFR diurnal cu will then
emerge for the latter half of the day. Winds gradually veering from
northwest to westerly today, with some increase in speed. VFR
conditions persist overnight in prevailing westerly flow.

DTW THRESHOLD PROBABILITIES...

*  None

&&

.PREV DISCUSSION...
Issued at 341 AM EST Thu Nov 7 2024

DISCUSSION...

Post-frontal drier air has settled in with sfc dew points at this
hour reading about 15 degrees lower than this time 24 hours ago.
Still some remnant stratus hanging on beneath the frontal inversion
but the arrival of deeper subsidence is already working to erode
this layer across the north. This clearing will work south through
the morning leaving a mostly sunny afternoon with temperatures a
touch higher than normal - mainly mid to upper 50s for a high. A
ridge of high pressure will become positioned along the northern
Ohio Valley promoting benign conditions into tonight.

A clipper system tracks from northern Alberta this morning toward
James Bay tonight, strengthening considerably during this period.
Its surface low pressure tracks well to our north and delivers a
glancing blow from a dry cold front that will mainly result in a
breezier day Friday. With closer proximity to the low/gradient, the
Thumb should see the highest gusts - up to around 25-30 mph.
Otherwise, conditions will be similar to today with mostly sunny
skies and temps slightly above normal in the mid to upper 50s. The
post-frontal colder air will settle in Friday night along with clear
skies and diminishing winds, bringing lows down into the 30s.

A deep cutoff low meandering over the Four Corners today into
tomorrow will eject northeast into the central Plains by Saturday,
resulting in a period of amplified ridging over the Great Lakes.
This allows broad high pressure to pass over the region to maintain
the dry and mostly sunny streak. After the chilly start to the day,
highs will come in near climatological normals. Clouds will be
increasing by late in the day as elevated moisture transport tied to
the Plains low works in from the southwest.

The low will track across the Midwest Saturday night into Sunday
morning and present the next chance of rain as its warm advection
wing directs a deeper moisture plume with Gulf connections north
into the local area. Brief residence time of the nose of the LLJ as
it quickly veers over the area suggests the main slug of moisture
will be shunted across the Ohio Valley, but fgen over the local area
beneath jet exit region should still bring a good chance of rain
Sunday morning. The stacked low then tracks across the northern
Great Lakes Sunday night with additional lighter showers likely to
persist, especially across the north. High pressure builds in during
the early week before being quickly ushered out by the next system
set to move in during the mid-week. Mild temperatures ensure this
system also brings liquid rain.

MARINE...

A ridge of high pressure will briefly build into the Great Lakes
through the morning which will support lighter winds as wind
direction backs from the northwest to the west. A low pressure
system will then quickly fill in from the western Canadian
provinces, moving over the James Bay by tomorrow morning. This will
rapidly strengthen the pressure gradient over the Great Lakes, while
drawing cooler air over the northern Great Lakes in the wake of the
passing low. The result will be brisk westerly flow building into
the region throughout the morning hours tomorrow.

Latest model guidance continues to promote gust potential peaking in
the 20-30 knot range for Lake Huron and the Saginaw Bay. A Small
Craft Advisory has been issued for portions of the Lake Huron
shoreline. Some sporadic gust potential to gales will be possible
across northern Lake Huron, but most guidance at this time holds
gust potential to sub-gales. A secondary high pressure system then
builds over the Great Lakes through Saturday, diminishing wind
speeds and gust potential.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 10 PM this evening to 10 AM EST Friday
     for LHZ421-422-441.

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

$$

AVIATION.....MR
DISCUSSION...TF
MARINE.......AM

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