Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 170456

Area Forecast Discussion
National Weather Service Gaylord MI
1156 PM EST Mon Jan 16 2017

Issued at 1002 PM EST Mon Jan 16 2017

Tough forecast from a precipitation type and amount for the rest
of tonight into Tuesday morning. Band of waa precipitation
continues to advance north, albeit very slowly given very deep
dry wedge evident on our 00z sounding. Per obs and spotter
reports, elevated warm nose is doing its job, with mostly liquid
or sleet reaching the surface. Problem is very dry low level air
is resulting in surface cooling as precipitation begins, with
freezing rain being the result. Further north, temperatures
dropped rather rapidly into the 20s, although slight recovery is
beginning as thicker overcast arrives. Damage has been done,
however, with road temperatures likely several degrees below
freezing. As for the rest of tonight, expect band of precipitation
to continue to advance north, likely reaching the straits region
by sunrise. More sleet and snow should mix in on leading edge of
this precipitation as it advances north, although still suspect
increasing warm nose aloft will result in a changeover to
primarily liquid along and south of M-32 by morning. Surface
temperatures will be slow to recover given dry air, that despite
warming processes from freezing and transfer of warmer air from
aloft. Thus, more freezing rain expected, particularly across
northeast lower and interior regions. Even if warming is more
aggressive than currently anticipated, cold road surfaces will
allow freezing to continue for several more hours after
temperatures go above freezing. Kicked around the idea of an ice
storm warning given upstream trends and uptick in model qpf. Have
raised ice accumulations some, but do believe guidance qpf progs
are running hot given just how much dry air has to be overcome.
Advisory remains for now, with many roads expected to become ice
covered and very slippery by morning.


.NEAR TERM...(Tonight and Tuesday)
Issued at 245 PM EST Mon Jan 16 2017

...Mixed Precipitation starts this evening continues into
Tuesday morning...

High Impact Weather Potential...While there will be mixed
precipitation, the highest impact will be the ice accumulation
through the overnight into Tuesday morning.

Pattern Synopsis/Forecast...Low pressure is off to the southwest
of the region, in the C Plains, developing with the 500 mb low.
Warmer air is moving north, and the warm advection is producing
clouds and some precipitation south of the forecast area. At this
point the MRMS radar data is showing the snow or rain/snow line is
south of M-55, trying to push up against the drier air, as
dewpoint depressions have been around 10F through the afternoon
over most of N Lower, except near M-55 where the depressions are
around 5F.

As the moisture continues to stream north, and the precipitation
makes some inroads north of M-55, will expect temperatures will
cool back to freezing or below as the wet bulb temperatures are at
or below 32F. This should let the precipitation to start off as a
period of light snow, before we start to see any mixing. Then the
warm air aloft should begin to push north into the forecast area
and produce some sleet, and then freezing rain. The sfc warm air
takes a little longer, with the temperatures at or above freezing
through most of the night. However, after 12z, will expect a
change over to begin as the sfc temperatures begin to warm. Looks
like dry air begins to get into the mid levels, and begins to put
a damper on the rain as the temperatures warm. However, drizzle
will become more likely as we go through the afternoon.

Primary Forecast Concerns...Main concern is again p-type as the
the soundings are showing some indications that this will be the
trouble area. Some soundings show that that we only warm up to +1C
or less in the profile, but the depth of the warm air may be
enough to change the snow to freezing rain early, or it may stay
snow, albeit very wet snow. Then there is the case of the dry air
moving into the region, we may switch to patchy drizzle or
freezing drizzle earlier than expected as dry air in the model
soundings is showing up sooner than expected. However, it evolves
through the night into Tuesday, expect a mess.


.SHORT TERM...(Tuesday night through Thursday)
Issued at 245 PM EST Mon Jan 16 2017

...Lingering patchy drizzle/freezing drizzle possible Tue night...

High Impact Weather Potential: Perhaps a bit of drizzle/freezing
drizzle Tuesday night leading to a few lingering slick spots.

Pattern Forecast: Upper-level low and associated surface reflection
rolls across the southern Great Lakes on Tuesday, exiting to the
east of the region Tuesday night. Zonal flow prevails for the
midweek timeframe with gradually warming temperatures across a large
portion of the country`s midsection. Our next weather-maker begins
to take shape over the central plains as upper level energy ejects
out of the desert southwest Wednesday into Thursday, although any
impacts from that won`t likely be felt until Friday-Saturday.

Primary forecast concerns: The main forecast issues revolve around
any lingering precip Tuesday night. Boundary layer temperatures
begin to cool Tuesday evening and despite mid-level moisture
stripping out of the area in conjunction with departing low
pressure, low-level moisture remains intact. This combined with weak
lingering synoptic support is expected to allow for a bit of patchy
drizzle in spots. Once again, surface temperatures will be right
around the freezing mark, causing concern that some areas may see
freezing drizzle...especially as you head inland from the Great
Lakes. Any drizzle/freezing drizzle that were to fall would be
awfully light, but may renew concern for slick spots during the
overnight hours Tuesday.

Another subtle wave races across southern Ontario late in the day
Wednesday; however, with very little moisture, the only concern
would be for a couple of rain/snow showers across far northern
sections of eastern Upper late in the day Wednesday-Wednesday
evening, but gut feeling is that most locations stay precip-free.
Otherwise, mainly quiet conditions are expected with gradually
warming temperatures. High temps Wednesday in the mid-30s north to
near 40 south and even a touch warmer for Thursday with highs a
couple degrees on either side of 40...some 14-20 degrees above

.LONG TERM...(Thursday night through Monday) Issued at 245 PM EST
Mon Jan 16 2017

High Impact Weather Potential...

High Impact Weather Potential: Rain in some locations over the
weekend could create some slick spots. Another wintry mix possible

Things look pretty quiet for most through the weekend. Guidance is
struggling a bit with a blocky pattern. Starting to see more
solutions with a fairly anomalous H5 high in the vicinity of James
Bay over the weekend, which is pushing an occluding low further west
and limiting impacts for us. Well above normal temperatures will
continue through the period, but the current location of the H5 high
may limit the WAA somewhat as it will induce more easterly flow. But
given the warmth and likely above freezing dew points, we should see
declining snowpack over the weekend. A more robust low tracking into
the area early in the week could bring another wintry mix.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1153 PM EST Mon Jan 16 2017

Wintry mix of precipitation (including freezing rain) and
attendant low cigs/IFR conditions will continue to slowly push
north through the overnight, with IFR conditions in low cigs and
light precipitation continuing through today. Not expecting
significant amounts of freezing rain or sleet/snow, but enough to
likely cause some impacts at the taf locations. Precipitation is
expected to gradually change over to light rain later today as
surface temperatures warm. Light winds through this taf cycle.


Issued at 245 PM EST Mon Jan 16 2017

Even with the sfc low moving into the southern part of Michigan on
Tuesday, the winds remain below small craft criteria, and thus the
waves as well. That is, until Wednesday afternoon, then as the sfc
high moves south of the region, we get into a decent gradient on
the back side of the high, producing more return flow. Wind gusts
look like they would be marginally small craft, in the later
afternoon over N Lake Michigan. Waves also begin to heap up by
that time.


MI...WINTER WEATHER ADVISORY until noon EST Tuesday for MIZ020-025-
     WINTER WEATHER ADVISORY until noon EST Tuesday for MIZ016>019-


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