FXUS63 KAPX 282339

Area Forecast Discussion
National Weather Service Gaylord MI
739 PM EDT Sat Mar 28 2020

.NEAR TERM...(Through Sunday)
Issued at 338 PM EDT Sat Mar 28 2020

...Rain and a few thunderstorms tonight...

High Impact Weather Potential: A few thunderstorms possible later
this evening into the overnight hours. Stronger storms could
produce hail.

Pattern Synopsis/Forecast: Rather impressive early spring storm
system continues to develop across the Plains/Midwest. Deepening
short-wave/closed upper low is located over eastern Nebraska
with a strong upper jet core extending from Texas up through the
Midwest and across the Great Lakes and pronounced upper
diffluent/divergence axis spreading into central Midwest region.
18Z surface analysis has attending surface low just into SW Iowa
and warm front stretching eastward across Illinois/Indiana and
Ohio. Strong low level backed flow coincident with building
instability through that region has set the stage for severe
weather over the next several hours.

Meanwhile, axis of widespread warm advection forced rainfall
across the region earlier in the day has largely diminished, save
for a few pockets of showers and perhaps a touch of drizzle.
But...warm conveyor/moisture surge ahead of the deepening low
has/is leading to our next expanding area of showers/storms up
into the Midwest and lower lakes region.

Details: Short-wave impulse and attending surface low on track to
further deepen/occlude while lifting up through the Midwest and
into central Wisconsin by Sunday morning. Associated strong warm
conveyor and upper level divergence forcing will spread widespread
rainfall up into northern Michigan tonight along with the potential
for some thunderstorms as elevated instability axis along and
ahead of the occluding front pivots up through the region.

Severe weather potential tonight: No changes from the late morning
update. Latest SPC Day One outlook maintains a marginal risk for
elevated severe storms across roughly the southern third of the
CWA, with the main threat large hail. That seems reasonable given
limited/no surface based instability tonight but respectable
0-6KM deep layer shear in excess of 70 knots in the presence of
some elevated instability.

Occluded boundary, pronounced dry slot and sharp cutoff to the
precip will be swinging through the region early Sunday morning
bringing a brief lull in precip for a few hours...save for spotty
drizzle. Stacked surface and upper level low and associated
vorticity center is expected to track across northern Lower
Michigan/Straits region through the day and will bring another
round of widespread showers across the region.


.SHORT TERM...(Sunday night through Tuesday)
Issued at 338 PM EDT Sat Mar 28 2020

High impact weather potential: Perhaps a few slick spots developing
by early Monday morning as lingering rain showers mix with and
transition to snow showers, especially across eastern upper and the
higher terrain of northern lower.

Pattern synopsis/forecast: By Sunday evening, well-advertised
vertically stacked low pressure is expected to be situated across
far northeast lower/northern Lake Huron...continuing to progress
eastward into Ontario overnight and eventually into Quebec Monday
morning. Lingering wrap around moisture bringing continued precip
chances will be the rule through Sunday night before deep layer
drier air returns as high pressure tries to gradually ooze into the
region from the northwest. As a result, much more tranquil
conditions expected locally to begin to the new work week.

Primary forecast concerns/challenges: Lingering precip chances
Sunday night, including a possible transition to light snow.
Temperature/cloud trends Monday into Tuesday.

As was alluded to above, wrap around moisture and continued synoptic
support on the backside of the departing system should prove to be
enough for lingering rain showers across the majority of the
forecast area at the start of the period Sunday evening. Primary
concern through the Sunday night time frame is the potential for a
transition to snow showers as the column cools, primarily after
midnight across parts of eastern upper and the interior highlands of
northern lower. Not expecting much in the way of accumulation
(perhaps a few tenths of an inch) given sfc temperatures near
freezing or a degree or two above, but can`t entirely rule out some
slick spots developing by Monday morning. Latest trends suggest
overall precip chances wane early Monday morning as a result of
decreased support aloft and drying through the mid-upper levels.
However, there may be enough shallow moisture (sub -10C) to continue
a few spotty showers or drizzle through mid-late morning before
model soundings take on a more inverted-V flavor through the low
levels, likely eventually resulting in just lingering low clouds
through the remainder of the day. High temperatures Monday expected
to fall some 10 or so degrees below Sunday`s readings...ranging from
near 40 to the low 40s across the forecast area.

Relatively tranquil weather returns across all of northern Michigan
for the remainder of the forecast period through midweek. Will keep
the inherited dry forecast going for now, although there are some
signs that this weekend`s system eventually stalls over the
Northeast before washing out with lingering mid-level energy perhaps
retrograding a bit late Tuesday. This may bring a bit of deeper
moisture back into the region from the east, perhaps resulting in a
few showers/drizzle across parts of the area, but confidence in this
idea is low at this time. High temperatures Tuesday climb a few
degrees over Monday...in the mid 40s for most.

.LONG TERM...(Tuesday night through Saturday)
Issued at 338 PM EDT Sat Mar 28 2020

High impact weather potential: Minimal for now, although sporadic
snow chances look possible at times mid-late week as renewed
troughing across the center of the CONUS brings below normal temps.

Initial precip chances through the extended arrive late in the day
Wednesday/Wednesday night as mid-level energy and an attendant
surface reflection barrel across the northern plains into the
northern Great Lakes. Currently, this system looks to fall as
primarily rain, but wouldn`t be surprised to see some snow mix in
during the overnight hours across the typically cooler areas/higher
terrain. Trends beyond this suggest renewed troughing across the
Great Lakes becomes prevalent through the remainder of the forecast
period with below normal temperatures and any weak perturbations
rippling through the flow bringing the possibility of rain/snow


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 740 PM EDT Sat Mar 28 2020

Lower cigs continue to gradually work northward into northern
lower MI. All TAF sites are expected to become IFR or low-end MVFR
for tonight and Sunday. Worst conditions (perhaps dipping into
LIFR) expected overnight and Sun morning at APN/PLN. Occasional
rain and showers will persist thru the forecast, though starting
to diminish very late Sunday.

Current gusty e to se winds will veer s and sw Sunday afternoon.
Some LLWS tonight.


Issued at 338 PM EDT Sat Mar 28 2020

Gusty SE winds will continue to ramp up tonight into Sunday
morning as a storm system deepens and tracks into Wisconsin. Winds
veer southwesterly a weaken a bit on Sunday as the system moves
through the tip of the mitt/Straits region. But winds further
veer northwesterly and increase again Sunday night.

Small craft advisories are in effect through Sunday morning to
address gusty SE winds. Additional small craft advisories will
likely be needed Sunday night into Monday.


MI...LAKESHORE FLOOD ADVISORY from midnight tonight to noon EDT
     Sunday for MIZ088-096-097.
LH...SMALL CRAFT ADVISORY until noon EDT Sunday for LHZ345>349.
LM...SMALL CRAFT ADVISORY until 6 PM EDT Monday for LMZ323-341-342-
LS...SMALL CRAFT ADVISORY from 11 PM this evening to noon EDT Sunday
     for LSZ322.
     SMALL CRAFT ADVISORY from 11 PM this evening to 6 PM EDT Monday
     for LSZ321.



NWS APX Office Area Forecast Discussion