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000
FXUS63 KAPX 191856
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
256 PM EDT Mon Apr 19 2021

.NEAR TERM...(Through Tonight)
Issued at 252 PM EDT Mon Apr 19 2021

...Much colder air arrives...

High impact weather potential: Another freeze expected across our
vulnerable fruit growing areas of northwest lower Michigan tonight.
Lingering gales.

Pattern synopsis and forecast:

Sharp shortwave trough rotating across the northern Great Lakes
early this afternoon, with its attendant surface low pressure
pivoting east across northern Ontario. Cold front extends south from
this low, making steady east progress across Lake Huron. Gusty west
winds ushering in a shot of much colder air behind this front, with
falling temperature into the 30s across the western Great Lakes
(with wind chill values several degrees colder yet). While most
widespread and organized showers have now exited off to our east,
burgeoning lake processes and "wrap around" moisture are resulting
in increasing snow shower activity across the snow belts of central
and western upper Michigan.

Winter-like airmass will continue to spill into the area
tonight...bringing more hard freeze concerns and light lake effect
snow showers as it does so.

Primary forecast concerns/challenges:

Main emphasis is on temperature trends, attendant freeze concerns,
and light lake effect snow potential tonight.

Details:

Expect lake effect snow showers to increase in coverage and
intensity into the snow belts of eastern upper Michigan later this
afternoon and evening as H8 temperatures fall into the negative
teens across Lake Superior and synoptic moisture contribution
increases. Limited inversion heights (just a bit over 5kft) and a
relatively short window for most organized snow showers (best
parameters exit east quickly later this evening) should keep snow
amounts light, on the order of an inch or two. Much less favorable
conditions across Lake Michigan, with more limited synoptic
contribution, even lower inversion heights, and a noted inverted-v
signature on guidance derived soundings. Can`t rule out a few lake
effect snow showers into northwest lower Michigan, but both coverage
and intensity will be minimal.

Much more impactful concern tonight will be temperatures. Despite
completely unfavorable radiational cooling conditions with gusty
winds and lake clouds, simple magnitude of cold air advection will
result in temperatures falling below freezing across the area (wind
chill readings in the teens and 20s!). Freeze warning already issued
for our vulnerable fruit growing areas along the northwest lower
coastline. Unfortunately, next couple night look as cold, if not
even a few degrees colder.

&&

.SHORT TERM...(Tuesday through Thursday)
Issued at 252 PM EDT Mon Apr 19 2021

High impact weather potential: Freeze conditions possible.

Broad upper-level troughing will continue over the Great Lakes
region although surface high pressure will build into the forecast
area along with drier air. This will produce mostly quiet weather
throughout this forecast period...with partly to mostly cloudy skies
and cool weather as a generally north to northwesterly wind
continues to usher in cooler air from Canada. With -10 to -12C still
at 850mb, lingering moisture, and lake temperatures around 3C, we
can expect lake clouds to be a nuisance through at least late
Wednesday. Thursday will get a bit warmer as warmer air begins to
wrap around the top of the ridge and spill into northern Michigan.
As mentioned above, mostly north to northwesterly flow will continue
to usher in cold temperatures through Wednesday, producing daytime
temperatures well below normal for this time of the year...some
locations will continue to run about 10-15 degrees below normal,
only reaching into the mid 30s to low 40s. Temperatures will
continue to only reach into the low 20s to low 30s at night...with
the possibility of getting colder if clouds diminish and winds stay
down in intensity. Will have to protect sensitive vegetation since a
lot has blossomed and/or bloomed already...which is way too early,
we still have a lot of cold nights in store for the next several
weeks.

&&

.LONG TERM...(Thursday night through Monday)
Issued at 252 PM EDT Mon Apr 19 2021

A rather progressive weather pattern will continue, but no "big
storms" at the moment. Forecast models are in fairly good consensus
of northern Michigan seeing more dry weather with mostly high
pressure overhead and only a couple of periods with a weak
disturbance moving through, producing some chances of precipitation.
More seasonable temperatures should return for the long term
forecast period as a more southerly flow develops.
Overnight temperatures will drop into the 30s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 128 PM EDT Mon Apr 19 2021

MVFR to low end VFR CIGS will be common through tonight, with
much colder air and growing overlake instability, possibly leading
to scattered lake effect rain and snow showers that would
primarily impact TVC/PLN. No serious VSBY impacts expected from
the showers. Some improvement in cigs is expected heading through
Tuesday morning.

Gusty west to northwest winds expected to continue through the
period.

&&

.MARINE...
Issued at 252 PM EDT Mon Apr 19 2021

A tight pressure gradient and unstable over-water thermal regime
will continue to bring advisory and low end gale force winds to the
nearshore waters tonight...with some advisory winds lingering right
through Tuesday. Expect wind speeds to decrease below advisory
levels Tuesday night as the pressure gradient slackens.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING from 10 PM this evening to noon EDT Tuesday for
     MIZ020-021-025-026-031-099.
LH...SMALL CRAFT ADVISORY until 6 AM EDT Tuesday for LHZ348-349.
     GALE WARNING until 6 AM EDT Tuesday for LHZ345>347.
LM...SMALL CRAFT ADVISORY until 6 AM EDT Tuesday for LMZ323-344>346.
     GALE WARNING until 6 AM EDT Tuesday for LMZ341-342.
LS...SMALL CRAFT ADVISORY until 5 PM EDT Tuesday for LSZ322.
     GALE WARNING from 8 PM this evening to 6 AM EDT Tuesday for
     LSZ321.
&&

$$

NEAR TERM...MB
SHORT TERM...TL
LONG TERM...TL
AVIATION...MB
MARINE...MB