Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 271949
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
249 PM EST Sun Nov 27 2016

.NEAR TERM...(Tonight)
Issued at 247 PM EST Sun Nov 27 2016

High impact weather potential:

Pattern synopsis and forecast:

High amplitude pattern out there this afternoon, with troughing off
the Atlantic coast, as well as over the Rockies where an associated
area of low pressure was deepening in the central plains and the
Dakotas. A warm front extended eastward from the low and strong
southerly winds were starting to drag deeper low level moisture in
off the Gulf of Mexico, around the backside of high pressure on the
east coast. When combined with strong forcing, headlined by a strong
LLJ and strong left exit region upper divergence on the nose of a
140+kt jet, showers have developed along the warm front and in
another band north of there within a zone of DPVA. In nrn Michigan,
many areas were still under the influence of persistent stratus and
high elevation fog with trapped low level moisture under a still
lowering inversion. However, low level winds were deepening out of
the south, and there is some cloud level drier air across southern
lower Michigan that is advecting northward.

Forecast concerns: Can we redevelop some fog/near sfc stratus this
evening? Is there any chance for continued Lake stratus? Timing and
evolution of rain tonight into Monday.

Upper troughing to our west deepens into the srn Rockies with a
closed off low wrapping into the Dakotas. Our ridging will gradually
work it`s way eastward with deepening southerly flow into Monday
morning. The low level drier air will initially advect into our area,
and combined with increasing subsidence, stratus will have a real
good chance at eroding out. There will still be some marginal
shallow overlake instability that could try and withstand the
drying, impacting south flow regimes. Low level winds do ramp up
tonight, but maybe some spotty near sfc stratus and fog can
redevelop for a period this evening. Doubt there is much chance
later into the night as some mixing arrives with much stronger winds
just above the sfc. We will see that band of rain showers associated
with the DPVA trying to work it`s way into nrn Michigan, but by the
time it gets here, the DPVA is much weaker and total -divQ will be
minimal. The main weather looks to be be the increasing/deepening
low level moisture that is currently seen from TX to MO. After some
deeper mid and upper level moisture strips out Monday morning,
forecast soundings show the potential for drizzle at times, in the
return of the dreary low clouds. If the timing is right, the strong
forcing associated with the upper divergence and LLJ, as well as
stronger DPVA arrives late in the day for much better chances for
showers.

Temperatures may be able to dip this evening if there is some
clearing, but as winds strengthen through the night temperatures may
even rise. Clouds Monday will keep potential highs down. Looking for
mid to upper 30s for lows and highs Monday in the low to middle 40s.

&&

.SHORT TERM...(Monday and Tuesday)
Issued at 247 PM EST Sun Nov 27 2016

...Wet and windy through early Tuesday/Mild into midweek...

High Impact Weather Potential: Strong southeast winds off Lake Huron
into southeast Upper and northeast Lower shoreline areas Monday
through Tuesday morning.  Decent rainfall event on tap for Monday
night through early Tuesday...at this point not expecting significant
hydrology issues unless observed rainfall comes in much heavier
than forecast.

Pattern Synopsis/Forecast: Upper level troughing being carved out by
several pieces of short wave energy crossing the intermountain west
this afternoon...short wave ridging out ahead of it spanning the
Mississippi Valley.  Lead short wave trough/170kt jet streak lifting
northeast out of the Four Corners with a second wave digging south
across California/Nevada...and yet a third piece of energy just off
the British Columbia coast.  Lead wave will track into the northern
Plains where it will continue to deepen/close off over the Dakotas
Monday...while second short wave trough whips around the south side
of the developing upper low and impacts Michigan Tuesday.  Once this
system closes off it is going to be slow to move...system will begin
to fill by Wednesday but is not likely to drift across the Great
Lakes until trailing short wave trough over the northeast Pacific
finally makes its way through the base of the trough.

High pressure ridge extending north from the mid Atlantic/Southeast
across the lower Great Lakes...low pressure in the lee of the
northern/central Rockies with a return moisture feed developing
between these features across Texas/Oklahoma/Kansas (precipitable
water 0.75-1.00+ inch)...though a wide swath of dry air exists
across the northern Plains/midwest/upper Great Lakes.  Large area of
3-4mb/3h pressure falls coincident with and east of the lee-side low
indicative of development...which will continue apace as the low
emerges across the central Plains and into the eastern Dakota
Monday(probably sub-980mb).  Tight pressure gradient ahead of this
deepening cyclone will overspread Wisconsin/Michigan Monday...which
will be reinforced by a secondary (weaker) surface wave that will be
a reflection of second short wave trough approaching Michigan
Tuesday morning.  Gradient will relax a little with passage of this
surface wave...with winds shifting to southwesterly.  Not a big push
of cold air with this system being as wrapped up as it will be...
will begin to see some cooler air leak into Michigan in the
Wednesday time frame.

Primary Forecast Concerns: Second round of rainfall will be the main
QPF event with this storm...spreading in from the south late Monday
afternoon/Monday night.  Decent push of moisture (precipitable water
0.75-1.00 inch) on nose of 50+kt low level jet pushing into Lower
Michigan...widespread rainfall expected Monday night...tapering to
more spotty showers with dry slotting as Tuesday morning progresses
with forecast trend suggesting a decrease in cloud cover later
Tuesday.  Though instability will be lacking for much of the
event...wouldn`t rule out a few rumbles of thunder Tuesday morning
along leading edge of dry slot where steepening mid level lapse
rates intersect northeast retreating low level theta-e ridge axis
and strongest dynamic forcing.  Still a pretty good signal for
rainfall amounts 0.50-1.00 inch in the 00z-12z Tuesday time
frame...and appears that there is hydrologic capacity in the system
to be able to absorb this amount of rain.

Brisk southeast winds will be ongoing Monday night...and will
strengthen off Lake Huron during the night with secondary surface
wave lifting northeast into Lower Michigan.  Wind gusts near the
lake of 30-40+mph anticipated from Drummond Island west toward the
Straits...and much of the northeast Lower shoreline (borderline Wind
Advisory criteria).  As the surface wave passes winds should let up
on Lake Huron as flow veers around to southwest.  Winds will still
be gusty Tuesday...this time off Lake Michigan with gusts 20-30mph
especially during the afternoon.

No big impact weather expected beyond Tuesday...elongated potential
vorticity anomaly moves into Lower Michigan Wednesday...likely
inducing another surface response and focusing some light
precipitation.

&&

.LONG TERM...(Tuesday night through Sunday)
Issued at 247 PM EST Sun Nov 27 2016

Chances for rain and/or snow continue through the extended. With a
strong low stalled over MN/WI, a second low will develop in the deep
troughing extending to the Gulf. The track of this second low looks
to remain to out SE, but could get close enough to bring some
rain/snow. Additional precip chances will come as the upper low
pivots through the Great Lakes, as well as lake effect late in the
week as the occluded front lifts out. Mid-week thermal profiles
support more of rain during the day switching to snow overnight,
while late week and into the weekend will see mainly snow for
most.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1228 PM EST Sun Nov 27 2016

MVFR Stratus will finally be eroding out this afternoon and into
this evening, as increasing subsidence/drying from a lowering
inversion and cloud layer drier air work northward into the
airports. A period of mostly clear skies is at least possible for
awhile tonight until higher level clouds arrive from deepening low
pressure to the west. Late tonight and into Monday morning, an
arcing band of rain showers is expect to be decaying as it enters
MBL/TVC. Forcing is rather weak and not expecting much QPF, but
low level moisture will be quickly overtaking nrn Michigan with
likely MVFR/IFR CIGS and VSBYS and drizzle at times.

Light S/SE winds into this evening, before Low level winds will
be increasing tonight for the development of LLWS.


&&

.MARINE...
Issued at 247 PM EST Sun Nov 27 2016

Sub advisory SE winds will ramp up through the night and remain
strong into Monday night, as the pressure gradient tightens ahead of
a warm front. Widespread advisory level winds can be expected along
with gales, which will generally be felt across Lake Huron and
Whitefish Bay. The warm front passes Tuesday, but it is expected to
still have some very shallow overlake instability for advisory level
winds into Tuesday evening.

Periods of light rain/Drizzle can also be anticipated late tonight
into Monday, before heavier rains move in Monday night into Tuesday
morning.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...GALE WATCH from Monday evening through Tuesday morning for
     LHZ346>349.
     SMALL CRAFT ADVISORY from 7 PM this evening to 7 AM EST Tuesday
     for LHZ345>349.
LM...SMALL CRAFT ADVISORY from 7 PM this evening to 7 AM EST Tuesday
     for LMZ323-341-342-344>346.
LS...GALE WATCH from Monday evening through Tuesday morning for
     LSZ322.
     SMALL CRAFT ADVISORY from 7 PM this evening to 7 AM EST Tuesday
     for LSZ322.
     GALE WARNING from 7 AM Monday to 7 AM EST Tuesday for LSZ321.
&&

$$

NEAR TERM...SMD
SHORT TERM...JPB
LONG TERM...ALM
AVIATION...SMD
MARINE...SMD



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