Freeze Warning 2, NWS Detroit, MI

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1214 PM EDT Mon May 8 2017

.AVIATION...

Dry airmass in place will support clear skies and VFR through the
period. Nothing more than a patch of diurnal cu around 7kft
expected. Steady northwest wind around 10 kts may briefly gust to
around 18 kts this aftn before diminishing to calm or variable for
the balance of the night this evening.

//DTW THRESHOLD PROBABILITIES...

* None.

&&

.PREV DISCUSSION...
Issued at 315 AM EDT Mon May 8 2017

DISCUSSION...

Slow evolving pattern as upper level low over southern Quebec is
reluctant to break down and exit. Dry upper level northwest
confluent flow/general subsidence over the Central Great Lakes Today
and Tuesday, with 1000-5000 mb mean RH bottoming out around 15
percent Tuesday morning. 00z DTX revealed a 545 DAM height at 500 MB,
and heights will rise over the next couple days, supporting a
moderating airmass. Although, dry low level airmass will lead to wide
diurnal swings. Full sunshine today expected to yield maxes in the
upper 50s, but dew pts holding in the 20s setting the stage for
another cold night tonight, mins around freezing, which should be
conducive for frost formation with winds going calm. With current
cold readings/Freeze warning headline still in effect, will defer to
the day shift to issue the frost/possible Freeze headline for
Tonight.

Upper level energy exiting the northern Rockies today, with upper
level PV filament tracking through the region on Tuesday. However,
with surface low washing out and tracking southeast into the Ohio
Valley, and good 925/850 MB FGEN remaining displaced off to the
southwest, should be able to maintain dry conditions, but some mid
clouds likely spilling over, leading to minor impact on maxes,
holding around 60 degrees per guidance, still over 5 degrees below
normal.

Upper level shortwave ridging on Wednesday expected to maintain dry
conditions, with temps climbing into the low to mid 60s based off
850 mb temps slightly above 3 C. Shortwave trough tracking through
Wednesday Evening/Night, but surface low and moisture expected to
reside mainly south of the Michigan border and should continue to
remain dry. Airmass will cool off for the end off the work week,
mainly in the mid levels, with 500 mb temps falling into the
negative lower 20s. Could be enough diurnal/surface based
instability around by the time we get to Friday to support scattered
showers, but low level convergence looks to reside mainly over
western lower Michigan, with weak northeast winds over southeast
Michigan helping to temper maxes slightly with flow off Lake Huron.

MARINE...

Moderate northerly wind will continue over marine areas today,
especially early and over the open waters of Lake Huron. Wind
conditions over nearshore areas will become increasingly influenced
by a lake breeze component as the pressure gradient weakens during
the afternoon. A narrow ribbon of high pressure will then settle
over Lake Huron and Lower Michigan tonight through Tuesday before
broadening and weakening Wednesday. This process will produce light
and variable wind over the region through mid week before the next
low pressure system brushes the region Wednesday night and Thursday.
The wind response will become light northerly as this system is
projected to track far enough south through the Ohio valley to
produce only a minor impact on the Great Lakes through Friday.

&&

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

AVIATION.....JVC
DISCUSSION...SF
MARINE.......BT

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

Hazardous Weather Outlook
National Weather Service Detroit/Pontiac MI
341 AM EDT Mon May 8 2017

MIZ047>049-053>055-060>063-068>070-075-076-082-083-090815-
Midland-Bay-Huron-Saginaw-Tuscola-Sanilac-Shiawassee-Genesee-Lapeer-
St. Clair-Livingston-Oakland-Macomb-Washtenaw-Wayne-Lenawee-Monroe-
341 AM EDT Mon May 8 2017

This hazardous weather outlook is for southeast Michigan.

.DAY ONE...Today and Tonight

Clear skies and calm winds will allow temperatures to fall to around
freezing once again late Tonight, leading to frost formation.
Another frost or freeze headline will likely be needed.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today and tonight.

LCZ460-LEZ444-LHZ361>363-421-422-441>443-462>464-090815-
Lake St. Clair-
Michigan Waters of Lake Erie from Detroit River to North Cape MI-
Lake Huron from 5NM east of Mackinac Bridge to Presque Isle Lt
beyond 5 NM off shore-
Lake Huron from Presque Isle Light to Sturgeon Point MI beyond 5NM
off shore-
Lake Huron from Sturgeon Point to Alabaster MI beyond 5NM off shore-
Outer Saginaw Bay SW of Alabaster to Port Austin MI to Inner Saginaw
Bay-Inner Saginaw Bay SW of Point Au Gres to Bay Port MI-
Port Austin to Harbor Beach MI-Harbor Beach to Port Sanilac MI-
Port Sanilac to Port Huron MI-
Lake Huron from Port Austin to Harbor Beach beyond 5NM Off Shore-
Lake Huron from Harbor Beach to Port Sanilac beyond 5NM Off Shore-
Lake Huron from Port Sanilac to Port Huron beyond 5NM Off Shore-
341 AM EDT Mon May 8 2017

This hazardous weather outlook is for portions of Lake Erie, Lake
Huron and Lake St Clair.

.DAY ONE...Today and Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today and tonight.

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

SF