Area Forecast Discussion
Issued by NWS Gaylord, MI

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912
FXUS63 KAPX 270224
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
924 PM EST Sun Feb 26 2017

.UPDATE...
Issued at 922 PM EST Sun Feb 26 2017

Cold front just now moving into eastern Upper and on northern
Lower`s doorstep. Scattered snow showers ahead of the front have
intensified in large part due to southwest flow out ahead of the
front picking up additional moisture off Lake Michigan. Have seen
reflectivity exceeding 40 dBZ at times this evening with visibility
reduced to less than a mile in the heaviest snow showers. Low
level instability has been favorable as well thanks to fairly
steep low level lapse rates out ahead of the front, as per 00Z
KAPX and KGRB soundings. Still expecting the snow showers to
diminish towards midnight as temperatures drop and the cold front
pushes through, with drier air gradually building in behind the
front. Gusty winds will gradually subside once the front pushes
through later tonight. Starting to see clouds scouring out behind
the front across western Upper, and do expect this trend to
eventually manifest itself over the APX forecast area later
tonight. How much we clear out is still in question, but do
expect at least partly cloudy skies for most of the area by
daybreak. This combined with CAA behind the front will lead to a
substantial drop in temps overnight. Have therefore nudged down
low temps by a degree or two, as we`re already seeing some
readings in the teens across western Upper.

&&

.NEAR TERM...(Tonight and Monday)
Issued at 307 PM EST Sun Feb 26 2017

...Lingering light snow this evening...

High Impact Weather Potential: Nothing significant.

Pattern Synopsis/Forecast: Progressive flow on south side of Hudson
Bay centered gyre continues above the Great Lakes landscape.
Shortwave trough embedded in such racing across the northern reaches
of our area early this afternoon. Just enough lift and moisture
(some of the lake enhanced variety) to kick off some mostly light
snow showers. The most persistent of this activity has been found
along the shoreline of Lake Michigan into eastern upper Michigan.
Even there, however, snowfall amounts have remained light, largely
under two inches.

Flow regime has no signs of slowing down anytime soon, with current
shortwave expected to be to our east by this evening. Deep layer
flow actually becomes more southwest with time later tonight on into
the first half of the week as troughing reestablishes itself across
the Intermountain West. This will send another surge of above normal
temperatures up into our area, beginning as early as Monday.

Primary forecast concerns: Lingering light snow concerns this
evening and cloud/temperature trends right through Monday.

Details: Shortwave induced and lake enhanced snows look to end this
evening as forcing quickly departs and surface ridging builds into
the region. Any additional accumulations expected to remain under an
inch. Post-system airmass simply looks too dry to allow much, if any
lake effect to develop. May actually see skies scour out some
heading through the overnight, setting us up for at least a partly
sunny Monday. Center of surface ridge pushes off to the east, with
return southerly flow becoming increasingly well established through
the day. Combine this with some of that sunshine, and where looking
at temperatures exceeding freezing by several degrees, especially
south of the big bridge. Would not be surprised to see some areas
down near Saginaw bay make a run at the middle 40s.

&&

.SHORT TERM...(Monday night through Wednesday)
Issued at 307 PM EST Sun Feb 26 2017

...Another storm system arrives midweek...

High impact weather potential: Minimal with a bit of snow possible
early Tuesday and again Wednesday with rain sandwiched in between.

Pattern Forecast: By Monday night, weak upper-level ridging is
expected to be evident across the eastern two-thirds of the CONUS
out ahead of a buckle in the jet stream and resulting well-defined
wave diving from the Pac NW into the Rockies. As an open wave and
strung out energy ejects lee of the Rockies on Tuesday, surface
cyclogenesis gets underway with low pressure expected to pass from
the central Plains through the Great Lakes region by Tuesday night-
Wednesday.

Primary Forecast Concerns: Fairly tranquil conditions expected
Monday night with increasing clouds and near-normal low
temperatures...ranging from the mid-upper 20s. The period of main
concern lies from Tuesday through Wednesday and includes a myriad of
forecast challenges including precip timing, type, and amounts.
Return flow Monday night into Tuesday will help to gradually
increase deep layer moisture across northern Michigan...evident by
pwats rising from ~0.35" Monday night to 0.55" Tuesday morning.
Despite model disagreement continuing to some degree in terms of the
developing low pressure`s track, expecting a warm front to be draped
across central Lower Michigan by mid-Tuesday morning. This should
provide enough support to kick off at least a few scattered rain/
snow showers across portions of the area, which will transition to
all rain showers as the warm front continues to trek northward
throughout the day (above normal temperatures too - high temps
Tuesday ranging from near 40 north to the upper 40s south). Wouldn`t
be shocked to see precip remain fairly scattered in nature Tuesday
afternoon before the main surge of moisture arrives from the
southwest Tuesday evening. At this juncture, will continue to
feature the highest PoPs/QPF during the 00-06z Wed timeframe. For
the second half of Tuesday night, as low pressure continues to shift
eastward, dry slotting may strip out much of the mid-level moisture
resulting in a decrease in rain shower coverage (perhaps even just
periods of lingering drizzle). Expected rain amounts Tuesday through
Tuesday night on the order of 0.15-0.30".

Colder air begins to filter into the area from northwest to
southeast during the day Wednesday as low pressure departs toward
the eastern seaboard and cooler air wraps back into the Great Lakes.
Confidence is low with respect to the amount of lingering
precipitation vs. the arrival timing of cold air, but at least a
brief transition to snow showers and perhaps a minor accumulation
seems feasible before synoptic moisture wanes with lake effect
processes ramping up in its wake for Wednesday night into Thursday.

.LONG TERM...(Wednesday night through Sunday)
Issued at 307 PM EST Sun Feb 26 2017

Pattern looks to remain active through the extended. With low
pressure lifting through Canada and high pressure passing to our
west, lake effect snows will be likely into the weekend with NW/NNW
flow. Going into the weekend, the high pressure axis will have
cleared the area, bringing warmer temperatures and perhaps some warm
advection rain/snow over the weekend. After below normal temps
Thursday and Friday, we will see above normal temps for the rest of
the weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 656 PM EST Sun Feb 26 2017

A cold front will drop southeast across northern Michigan this
evening. Snow showers along this front are weakening as they
progress east, but KPLN would stand the best chance to be affected
through about 03Z. Ceilings are expected to remain VFR overnight,
but a few models hint at the possibility of MVFR here and there
later tonight. Think this is too pessimistic given the drier air
building in behind the front, so have continued with VFR. Gusty
winds will diminish this evening, but a few gusts to around 20
knots will be possible along the front. Winds will shift to NW
behind the front tonight, becoming light and variable Monday
morning and eventually turning south as a high pressure ridge
moves overhead.


&&

.MARINE...
Issued at 307 PM EST Sun Feb 26 2017

Current gusty southwest winds will subside overnight as they
veer northwest with time. Winds quickly become southerly on Monday
as high pressure pushes off to the east. These sub-advisory level
south to southeast winds are expected to continue right through
Tuesday.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY until 4 AM EST Monday for LHZ345>349.
LM...SMALL CRAFT ADVISORY until 4 AM EST Monday for LMZ323-341-342-
     344>346.
LS...NONE.
&&

$$

UPDATE...MEK
NEAR TERM...MSB
SHORT TERM...MJG
LONG TERM...ALM
AVIATION...MEK
MARINE...MSB



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