Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
FXUS63 KDTX 190742
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
342 AM EDT THU MAY 19 2016
A rather stagnant pattern is setting up over lower Michigan as
exiting trough stalls over the east coast while deepening closed low
remains stationary over the west coast. This is resulting in broad
ridging developing across much of the central plains while the
lingering thermal trough remains over the Great Lakes. As the west
coast system strengthens it will promote stronger ridge
amplification over the mountain west which will eventually release
eastward toward Michigan Sunday and into the next week. With
blocking pattern of troughs along east coast, flow across the Great
Lakes will be weak which will not favor any notable changes to the
resident airmass locked over the area through the end of this week.
High pressure at the surface will be centered over the area today,
before drifting just east enough to allow a southerly component to
the wind on Friday. Expect temperatures through this period to
slowly increase a degree or so each day due to cumulative effects of
diurnal heating each day. Today temperatures will rise into the
upper 60s and Friday many will hit 70.
On Saturday a southern stream system will eject through the Ohio
Valley while a northern stream trough pulls a back door cold front
through the eastern Great Lakes. Models have been in good agreement
over the last several runs in keeping the southern system south of
the state and washing out the cold front as it runs into ridging
both at the surface and aloft over the region. This should keep us
dry but we should expect some increase in cloud cover which will
keep highs in the low 70s.
The large west coast system will release northeastward Sunday into
the new week. This will allow the amplified ridge to slide into the
area bringing warmer southerly flow with it. Temperatures should
reach into mid to upper 70s for the first half of the new week. The
next shot of any precipitation will come mid week as a train of
shortwaves looks to track through a southwest flow pattern into the
region. This may result in periodic showers and thunderstorms
through that period.
Light and variable winds will be maintained throughout today and
Friday as a result of high pressure anchored across the Great Lakes
region. The center of the high pressure is forecast to slide into
Wisconsin on Saturday as low pressure lifts across the upper Ohio
Valley. This will result in a light north-northeast wind across
southern Lake Huron and Lakes Erie and St Clair. High pressure will
expand back eastward across the Great Lakes on Sunday as this low
weakens and lifts off the East Coast, which will reestablish light
and variable winds across the marine areas.
Issued at 1149 PM EDT Wed May 18 2016
VFR conditions will continue with high pressure positioned over the
area. Light/variable winds can be expected with just FEW-SCT diurnal
cumulus Thursday afternoon.
Aside from diurnal cumulus Thursday afternoon in the 7-8kft range,
expect clear skies this forecast as high pressure expands over the
area. Light/variable winds will become light southeast with lake
breeze(s) roughly 21z-00z.
//DTW Threshold Probabilities...
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
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