National Weather Service - Area Forecast Discussion

000
FXUS63 KAPX 191042
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
542 AM EST Wed Dec 19 2018

.NEAR TERM...(Today through Tonight)
Issued at 248 AM EST Wed Dec 19 2018

High impact weather potential: Minimal. Outside shot at a little
light freezing rain in portions of NE lower.

Pattern synopsis and forecast:

Early this morning, a weak mid level trough in the Central Plains
was connected to more of a closed circulation spinning in TX, while
somewhat shallow/broad ridging stretched from the Great Lakes down
into the SE states. Weak shortwave energy was ejecting into into nrn
Michigan and resulting in a fairly good amount of higher level
cloud. At the sfc, high pressure was over much of the eastern CONUS,
while low pressure was moving into Central Canada. In between,
including nrn Michigan, the pressure gradient was decently tight,
resulting in continued gusty winds up to 20 mph.

Not a lot of exciting things to talk about through tonight. Some
stronger shortwave energy from western Canada will drop into the
troughing in the Central Plains down into the more closed
circulation from TX. This sharpens the overall troughing, and we do
start to see sfc troughing and a cold front start to move closer to
the western Great Lakes late this afternoon through tonight. Mid and
higher level cloud will be thickening over this, and there is even a
suggestion of some possible low level cloud that arrives. However,
there is a decently sized dry pocket of air between 2-8kft, while
overall forcing will be on the weak side of things. There continues
to be the idea that the dry pocket of air can be overcome enough for
a chance of light precipitation. For most of the region, the thermal
situation is warm enough for the precipitation to be in the form of
light rain. That said, low temperatures tonight might threaten at or
just below freezing in portions of NE lower to result in light
freezing rain. Not confident in that scenario, as the expectation is
for a solid mid and upper level deck of clouds to keep temperatures
from getting that cold. Something to watch for though.

The pressure gradient stays fairly tight for gusts into the upper
teens to lower 20 mph range, despite minimal mixing in stable near
sfc conditions.

Highs today will be around 40F/lower 40s, while lows tonight in the
low to mid 30s.

&&

.SHORT TERM...(Thursday through Friday)
Issued at 336 AM EST Wed Dec 19 2018

...Rain/snow shower chances Thursday into Friday...

High Impact Weather Potential...Low.

Primary Forecast Concerns...Pops and precipitation type.

The complex storm system with dying energy passing by to our north
and deepening low pressure moving by to our south and east looks to
unfold Thursday into Friday. Northern Michigan is kind of left in
between both systems so will continue with chance pops for rain
showers Thursday morning with high end chance to low end likely pops
Thursday afternoon as models are in general agreement about a
moisture push moving up from the south. There is even a chance for
some wet snowflakes to mix in with any rain later Thursday
afternoon. Cooler air behind a surface cold front moving through
Thursday evening will lead to more chance pops for a mix of rain and
snow showers Thursday night and mainly just snow shower chances
Friday (especially eastern zones) as marginally colder air advects
in from the northwest. Am not expected much in the way of snow
accumulation (generally an inch or less).

.LONG TERM...(Friday night through Tuesday)
Issued at 336 AM EST Wed Dec 19 2018

...A couple of chances for light snow...

High Impact Weather Potential...None expected.

Cooler air Saturday will give way to colder air Sunday into early
next week as a cold front moves across the region Saturday night.
This is good news for anyone wishing for a white Christmas. So with
the cold air in place and a short wave moving across the region
Sunday and warm advection/over running Tuesday, there will be a
couple of chances for mainly light snow. Unfortunately, extended
models vary on the placement and timing of these two weak systems.
In addition, it`s seemingly cold enough for lake effect snow
showers, though winds appear light and moisture is somewhat lacking.
Although a white Christmas is not a slam dunk, at least there is
still a chance across a majority of the area. Temperatures look to
be near climatological averages.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 541 AM EST Wed Dec 19 2018

Low pressure crossing central Canada and high pressure over the
eastern CONUS has continued to result in a tight enough pressure
gradient for some lower end gusty S/SW winds, which may continue at
times through tonight. This low pressure and associated cold front
approach the western Great Lakes tonight, resulting in a small
chance for light rain.

More LLWS will be possible tonight, if sfc winds can decouple
enough.

&&

.MARINE...
Issued at 248 AM EST Wed Dec 19 2018

Low pressure crossing central Canada and high pressure over the
eastern CONUS has continued to result in a tight enough pressure
gradient for advisory level winds for much of Lakes Michigan and
Huron. The gradient will remain tight through tonight, before the
low pressure relaxes winds as it pushes through the nrn Great Lakes
Thursday into Thursday night, which will also result in increasing
chances for rain. Current advisories will hold through tonight. Cold
advection Thursday night will lead to the next round of marine
headlines.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY until 5 AM EST Thursday for LHZ348-349.
LM...SMALL CRAFT ADVISORY until 5 AM EST Thursday for LMZ323-341-342-
     344>346.
LS...NONE.
&&

$$

NEAR TERM...SMD
SHORT TERM...AS
LONG TERM...AS
AVIATION...SMD
MARINE...SMD

NWS APX Office Area Forecast Discussion