Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 172303
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
703 PM EDT Tue Apr 17 2018

.NEAR TERM...(Tonight through Wednesday)
Issued at 344 PM EDT Tue Apr 17 2018

...Brief respite between systems tonight/Wednesday...

High Impact Weather Potential...Minimal.

Pattern Synopsis/Forecast...Deep cyclonic flow remains across
Michigan this afternoon...as last vestiges of weekend storm move
away from the state.  Upper low centered over southeast Ontario with
several PV anomalies still rotating around it...one of which is
spinning southward across far eastern Upper at mid afternoon and
dragging some light spotty radar returns along with it.  Some hints
of thin horizontal roll convection over northwest Lower off Lake
Michigan...but nothing more than flurries with it.

Last of the disturbances with downstream cyclone will move away from
northern Michigan tonight.  Short wave ridging across the midwest
tries to build in for Wednesday...but never quite gets here as a
broad deformation/col region develops between the departing system
and another Pacific-origin short wave trough that will quickly move
into southern Wisconsin/Lower Michigan later Wednesday afternoon.
Associated surface low forecast to track from Missouri into
Indiana/Ohio by Wednesday evening.

Primary Forecast Concerns...Finally...not much in the near term.
Clouds will probably stick around tonight with plenty of moisture
upstream though could see some thin spots open up especially eastern
Upper.  Next system looks to be more of a Wednesday night issue...
and will be a battle between deformation zone and low level dry air
advection from the northeast meeting up with a narrow axis of
moisture/theta-e aloft (isentropic progs illustrate this nicely).
Will have increasing precip probabilities over southwest corner of
the forecast area by late afternoon (mixy/snow?).

&&

.SHORT TERM...(Wednesday night through Friday)
Issued at 344 PM EDT Tue Apr 17 2018

...Quick hitting light precip Wed night, then slowly clearing out...

High Impact Weather Potential...Minimal. Less than an inch of slushy
accumulation possible along/south of M-72 Wed night. Maybe some
patchy freezing drizzle for a brief time.

Pattern Synopsis/Forecast...A quick-moving system will pass by just
south of Michigan Wednesday night as the driving upper low opens up
and becomes absorbed into a broader trough/low over eastern North
America. As this happens, a shortwave will drop south across
northern Michigan but without much impact given a drier airmass
concurrently advecting in from the north. Winds will be a tad gusty
out of the NNW on Thursday behind this departing system and strong
high pressure building into the Upper Midwest. This high will
provide quiet weather for Friday and beyond.

Primary Forecast Concerns...Snow and potential for some freezing
drizzle across our southern counties Wednesday night.

Since yesterday, models have come into much better agreement on the
expected track of Wednesday night`s system, shunting it slightly
farther south. This keeps the bulk of its precipitation downstate...
or more locally, generally along and south of M-72. Not a lot of
precipitation for our area to deal with, as QPF amounts through the
first half of Wednesday night look to be around a tenth of an inch
or less in that area. The question is what form it will primarily
take, depending on how fast near-surface temperatures drop Wednesday
evening. Forecast soundings would support a rain/snow mix initially,
changing to all snow as temperatures fall. Likely less than an inch
of slushy snow accumulation from that. Further complicating the
forecast, however, will be a rapid drying of the column from aloft
and whether the resultant shallow moist layer near the surface can
remain cold enough for further ice production in the clouds. Thus,
wouldn`t entirely rule out some areas seeing a brief period of light
freezing drizzle overnight, but don`t anticipate it would be
anything impactful. The GFS, NAM and some hi-res guidance suggest
some patchy light snow showers may linger across a portion of
northeast Lower Thursday morning, but think the influx of drier air
will probably limit that possibility.

As high pressure builds in Thursday night, skies clear out and winds
diminish. Given the relatively fresh snowpack, would anticipate some
efficient radiational cooling. Went ahead and nudged Thursday night
min temps down a little farther, particularly for inland areas.

.LONG TERM...(Friday night through Tuesday)
Issued at 344 PM EDT Tue Apr 17 2018

High Impact Weather Potential...Minimal.

With high pressure overhead, moderating temperatures and precip free
conditions will prevail through the extended period. There is a bit
of a weak front that could pop off a few showers mid-week, but that
looks like the only thing for a while. Temperatures may finally make
a return to normal as we start next week, and by mid week we could
see above normal temperatures for the first time this month.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 703 PM EDT Tue Apr 17 2018

Aside from a few flurries tonight...cigs will remain MVFR and
vsbys will remain VFR thru the 24 hr TAF forecast period thanks to
plenty of low level moisture wrapping around the backside of
departing low pressure. N/NW winds will remain around 10 kts with
a few higher gusts possible.

&&

.MARINE...
Issued at 344 PM EDT Tue Apr 17 2018

Lingering Small Craft Advisories this evening within some of the
northern Lower nearshore zones...with winds/wave diminishing
overnight as gradient weakens. Winds will be increasing again from
the north Wednesday night into Thursday which will likely
necessitate another round of Small Craft Advisories.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY until midnight EDT tonight for LHZ347-348.
LM...SMALL CRAFT ADVISORY until midnight EDT tonight for LMZ323-342-
     344>346.
LS...NONE.
&&

$$

NEAR TERM...JPB
SHORT TERM...MK
LONG TERM...MK
AVIATION...MR
MARINE...JPB



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