Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
FXUS63 KDTX 232338
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
738 PM EDT SUN OCT 23 2016
A quick hitting shortwave is now tracking out of Wisconsin and the
Upper Peninsula of Michigan into the central Great Lakes region.
Overwhelmingly, the bulk of the dynamics and support for ascent will
track north of the M 59 corridor. Despite very good structure of the
shortwave and satellite signature, the most favorable of the
dynamics will exist below 700 mb. The low level fgen and system
relative isentropic ascent is forecasted to spread west to east from
the Saginaw Valley to Port Huron between the 23-02Z timeframe. Deep
layer moisture is lacking and virtually nil midlevel isentropic
ascent puts a limit on the amount of widespread or measured rainfall
amounts. Surface reporting sites so far have been void of RA, but
given the integrity of the reflectivity there is definitely
precipitation reaching the ground. The valid question now is
whether or not all of the activity will occur east of the TAF sites.
The altostratus shield has been substantial this evening down
through Detroit. Expecting midlevel cloud for a good chunk of
tonight before lower tropospheric stratus takes hold in the cold
advection regime with moisture trapped below the inversion. Bulk of
the guidance supports keeping a BKN stratocumulus deck at minimum
throughout the afternoon Monday.
For DTW...Clouds and precipitation are expected to push north and
east of the terminal. Center of weak low pressure pushing across the
DTW terminal will bring a period of variable wind this evening
becoming northerly between 03-05Z. Moisture will become trapped
below a subsidence inversion which will support stratus or
stratocumulus tonight through Monday.
//DTW Threshold Probabilities...
* High confidence in cigs aob 5kft tonight and Monday.
Issued at 325 PM EDT Sun OCT 23 2016
Compact strong dynamical wave currently centered over east central
Wisconsin will continue its fast path southeastward across Michigan
this evening and early night. Very strong lift occurring north of
the track however moisture is quite limited with very dry air in the
lower and mid levels. Decent amount of radar returns is seen but
amount reaching ground is quite light and limited. Expect the best
chance for measurable rainfall to occur this evening and early
tonight along and north of the surface low track which looks to go
from Milwaukee to lansing to Detroit. Lows will be slightly on the
mild side tonight in the lower 40s as more seasonable airmass won`t
start advecting in til morning behind departing surface low. High
pressure behind the departing wave will bring clearing trend Monday
starting from far southern counties to the Thumb region by evening.
High pressure will continue in control through Wednesday morning
with a fair amount of clear skies and seasonable
Low pressure traversing east from the Central Plains into Michigan
will bring the likely chance for precipitation Wednesday afternoon
into Thursday. While off to a projected chilly start Wednesday
morning with lows in the lower 30s, mainly north of I-69,
precipitation is not expected to move in until temperatures rise
into the mid to upper 40s, keeping everything as rain. Low pressure
will move over Lake Ontario Thursday into Friday. Precipitation
chances will be renewed Friday and into the weekend as a second low
from the North Central Plains travels east, dragging along with it a
cold front which will bring additional chances for rain.
Small craft advisories remain in effect for the nearshore zones of
Lake Huron as westerly winds this afternoon veer to northwest and
ramp up as colder air moves across the waters. Hazardous waves will
be accompanied by near-gales over the open waters. Gusty northwest
winds will persist through Monday before easing Tuesday and
Wednesday with the area in between two low pressure systems. The
next low will arive Wednesday night into Thursday bringing with it
the potential for a period of strong east winds.
Lake Huron...Small Craft Advisory from 1 AM to 10 PM EDT Monday FOR LHZ421-
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
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