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Area forecast discussion
National Weather Service Gaylord Michigan
1221 PM EST Wed Nov 20 2019

Update...
issued at 1025 am EST Wed Nov 20 2019

Large area of high pressure stretches from the Great Lakes to the
Gulf of Mexico late this morning...keeping much of the eastern
half of the US relatively quiet weather-wise. Stubborn low clouds
continue to hang over most of our County Warning Area...but latest satellite and
surface obs do show some relatively large breaks in the clouds
especially across NE lower Michigan. Areas of fog are also holding
over much of our County Warning Area...but vsbys are steadily improving as daytime
mixing progresses. Diurnal heating will continue to slowly mix out
our remaining fog and lift our cigs...but expect our general sky
conditions will remain partly to mostly cloudy throughout the
balance of the day. A look at upstream satellite images shows
plenty of low clouds extending westward thru the western Great
Lakes...with the leading edge of the mid/upper level cloud shield
from upstream developing low pressure now entering Wisconsin and
Illinois. Temps will be close to normal this afternoon...with
highs in the upper 30s and lower 40s.

&&

Near term...(today through tonight)
issued at 239 am EST Wed Nov 20 2019

Impactful weather: minimal.

Pattern synopsis and forecast:

A weak ridge of sfc high pressure is poking up into nrn Michigan
early this morning, while a weak shortwave is driving southeast through the
western Great Lakes, on the backside of exiting upper troughing. The
wave is not bringing any precipitation, but weak westerly flow and
Overlake instability is continuing to result in wintry lake effect
precipitation over parts of far northwest lower Michigan. Skies were
variably cloudy, with some clear areas, despite decent bl moisture
still all around. Where it has cleared, some locally dense fog has
been common. Quite hectic for weather that bring minimal impacts to
the region. Upstream, mid level ridging was dominating the middle of
the country, while a more impressive shortwave was ejecting out of a
closed upper low over California. In response, low pressure was developing
in the Lee of The Rockies.

There is still some uncertainty into how long the nuisance wintry
lake effect will linger, due to differing fcst soundings through
this morning. However, the overall idea will be for the sfc ridge to
slide east through the day, allowing slightly warmer low level air
to work in from SW to NE, gradually resulting in diminishing
Overlake instability and lowering inversion heights. Winds backing
more SW through the day, which would shove any light precipitation
(which would be rain/drizzle by afternoon) up into eastern
upper/straits. Attm, have all precip ending by afternoon though.

The aforementioned sfc low from the Lee of The Rockies then tracks
into the mid and upper Mississippi Valley through tonight, and
strong warm air advection ensues, via a 45-50kt SW low level jet. No les concerns whatsoever.
Sfc temperatures that reach highs of the upper 30s to lower 40s,
will drop very little through the night, due to increasing winds and
thickening cloud cover. Lows are likely not to fall below freezing.
The strong warm air advection will combine with some initial shortwave
activity/DPVA and some anticipated right entrance region upper jet
dynamics, to result in saturating the entire atmospheric column for
the far western cwa, and the beginning of the rain expected for
primarily Thursday. Areas further east are still expected to be dry
below 10kft for any chance of rain by daybreak Thursday.

&&

Short term...(thursday through friday)
issued at 239 am EST Wed Nov 20 2019

High impact weather potential: Lakeshore flooding possible Thursday
night into early Friday.

A deepening low pressure system over the Central Plains will
continue it's trek towards the Great Lakes region Thursday morning.
Winds will continue to strengthen ahead of this system...with
southerly flow veering as we transition from the warm sector to
cooler air filtering in on northwest winds by Thursday night/Friday
morning. Moisture will also be on the increase ahead of this
system...with a steady rain beginning Thursday morning (with
pwats of just over an inch in forecast soundings) and lasting
through the late afternoon/early evening hours until we transition
to more of showery precipitation and a cooler air mass producing
light snow showers with wrap around moisture and marginal lake
effect parameters perhaps enhancing this precipitation a bit over
portions of northwest lower and eastern upper. High pressure and
drier air then builds into the forecast area behind the departing
storm system...although there is a bit of lingering moisture and
850mb temperatures of around -10c that could continue some light
lake effect snow showers for portions of the forecast area...mainly
northwest lower. High pressure continues to build into the Great
Lakes region from the Central Plains and will produce a break from
precipitation and mostly clear to partly cloudy skies Friday night
through Saturday. High temperatures will be in the low to mid 40s
Thursday with warm air advection on southerly winds ahead of the aforementioned
storm system and only reach into the low 30s Friday with the cooler
air filtering in behind the departing system. Temperatures will
rebound a bit...reaching into the upper 30s with sunshine Saturday.
Low temperatures will generally be in the low to mid 20s. There is a
bit of concern with Lakeshore flooding possibilities Thursday night
into early Friday with northwesterly gusty winds and 5-8 foot waves
forecast. This would cause concern along the Lake Michigan shoreline
of northwest lower Michigan.

Long term...(friday night through tuesday)
issued at 239 am EST Wed Nov 20 2019

..seasonable temperatures with little to no precipitation...

High impact weather...none is expected.

Fairly quiet weather is expected during the long term portion of the
forecast. Nearly zonal flow aloft this weekend into early next week
should lead to seasonable temperatures with little to no
precipitation. Just some slight chance pops Sunday through Monday
night for a couple of weak short waves moving through the flow and
on Tuesday for the approach of another possible system. There may be
a more organized storm system just beyond the scope of this forecast
toward the middle of next week. Something to keep and eye on since
it would be during Holiday travel.

&&

Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1221 PM EST Wed Nov 20 2019

Low pressure will lift NE out of the Central Plains and into the
western Great Lakes region over the next 24 hours. Widespread
precipitation will develop along and ahead of this system...
arriving across northern Michigan very late tonight and Thursday.
Some snow will mix with the rain during the onset...but most of
the precip that reaches the ground will be plain rain. Overall
conditions will remain MVFR thru the 24 hr forecast period...but
could drop to IFR within some of the heavier downpours of rain on
Thursday. Low level wind shear will develop overnight into Thursday as southerly
winds just off the deck strengthen ahead of this system. Surface
winds will strengthen to 15 to 25 kts with higher gusts expected.

&&

Marine...
issued at 239 am EST Wed Nov 20 2019

A weak pressure gradient is expected to keep wind speeds below
advisory levels through this evening, before the next low pressure
system lifts through the western Great Lakes Thursday. This will
provide potential quit-hitting gales over portions of lakes Michigan
and Huron, with advisory speeds elsewhere. Cold air advection Thursday night into
Friday morning will bring potential continued gales for at least
Lake Huron, otherwise widespread advisories continue. The low
pressure system will bring widespread rain, which will change over
to lake effect.

&&

Apx watches/warnings/advisories...
Michigan...none.
LH...Small Craft Advisory from 6 am Thursday to 6 am EST Friday for
lhz345>347.
Gale watch from Thursday morning through Thursday afternoon for
lhz348-349.
Lm...Small Craft Advisory from midnight tonight to 6 am EST Friday
for lmz323-341-342-344.
Gale watch from Thursday morning through Thursday afternoon for
lmz345-346.
Ls...Small Craft Advisory from 6 am Thursday to 6 am EST Friday for
lsz322.
Small Craft Advisory from midnight tonight to 6 am EST Friday
for lsz321.
&&

$$

Update...mr
near term...smd

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