180
FXUS63 KAPX 070116
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
916 PM EDT Mon May 6 2024

.KEY MESSAGES...

- A few areas may see frost tonight, mainly inland.

- Rain showers/thunder Tuesday/Tuesday night...lingering
  showers Wednesday especially north.

- Shower chances mainly Lower Michigan Thursday.

- More shower chances for the weekend?

.UPDATE...
Issued at 913 PM EDT Mon May 6 2024

Nothing to really add to that which was inherited. A quiet and
seasonably chilly night, with just some passing thin upper level
clouds. Lows tonight will range from the middle 30s to middle
40s.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 334 PM EDT Mon May 6 2024

Pattern Synopsis and Forecast:

Cool night expected as high pressure slides into and to the east of
Lake Huron. Pressure gradient mildly tightens on Tuesday in advance
of the next system aloft with mildly breezy southeast winds. Large
expansive upper low digs in across the center of the country, with a
lobe of energy pinwheeling into northern Michigan from the
southwest. Thus showers, and occasional thunderstorms, will be
possible as lower pressure/sfc boundary moves into the region
on Tuesday.

Primary Forecast Concerns:

Generally light winds tonight and could be a splotch of high level
clouds try and work in tonight briefly. That being said, still
expecting cool temperatures, dipping into the 30s across some areas.
Previous fcst leaned on statistical guidance for low temps, followed
suit with a couple of spots across the interior approaching the mid
30s or so. Thus, have patchy frost in the interior, but overall
not too confident nor is this expected to be expansive or
significant with perhaps just a few brief hours in the 30s.

Cloud cover will be on the increase Tuesday as low pressure system
spins across the Dakotas with mildly breezy southeast winds
expected. Warm moist advection lifts into the region resulting in an
initial band of showers likely, with a chance for embedded/isolated
thunderstorms during the afternoon hours. Best potential for
thunderstorm development looks to be across southwest northern
lower, as the low level moisture increases and thus instability as
well (at least thru Tuesday afternoon). Convective activity will
continue into Tuesday night, read on for details.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 334 PM EDT Mon May 6 2024

Pattern Forecast: Anomalous upper low moving into the central
Rockies today (-2 to -3 sigma 500mb standardized height anomalies)
will spin slowly northward across the High Plains through
midweek...while kicking some height falls into the Great Lakes to
start the long term forecast cycle.  Short wave ridging will bridge
over the top of this upper low...almost cutting it off but the end
result will be some general "bagginess" to the upper level pattern
across Michigan into Thursday and possibly lingering on Friday as
well.  Upper level ridging becoming better estabilished this weekend
will send some additional short wave energy into the Great Lakes/Ohio
Valley Saturday.

Occluding low over western North Dakota will push an elongated
occluded front into Lower Michigan Tuesday afternoon along with a
short wave trough Tuesday night/Wednesday.  Elongated mostly latent
PV axis left behind running east-west across southern Ontario/Lower
Michigan/Wisconsin Wednesday as upper short wave trough lingers...
general weakness in the surface pressure pattern though start to get
rising pressures into the upper Lakes Wednesday night.  As the upper
trough begins to shift east Thursday looks like a couple of short
wave troughs will move through the state...one crossing Lower
Michigan/Ohio Valley...a second that is forecast to drop out of
northeast Ontario and across the forecast area Thursday night.
Another short wave trough digs southeast out of central Canada and
across the Great Lakes in the Saturday time frame.

Primary Forecast Concerns:

Rain showers/thunder Tuesday night...lingering showers Wednesday
especially north: Northward lifting occluded front will have some
dynamic support with it as a PV anomaly and the left exit region of
a 100kt jet streak across southern Lower...weakening stability as
well with some elevated CAPE.  Precipitation chances may let up
along the M-55 corridor overnight...but overall highest QPF across
the Tip of the Mitt and eastern Upper (0.50" to 0.75") from 00z-12z
Wednesday.  Elevated CAPE will also allow for thunderstorm chances
mainly across northern Lower/Straits region.  On Wednesday deeper
moisture lingers across Upper Michigan along a 700mb trough axis...
so light rain chances will continue across eastern Upper and the
Straits region...with more sun probable the farther south you go.

Shower chances mainly Lower Michigan Thursday: Actually there is a
chance we could get some rain into northern Lower Wednesday
night...but short wave trough moving across far southern Lower/
northern portions of Indiana and Ohio with what should be
deformation band of precipitation setting up across a good portion
of Lower Michigan Thursday into Thursday night.  Will have a north-
south PoP gradient across the forecast area though three days out
uncertain as to how far north precipitation chances might get.

More shower chances for the weekend?: After a respite on Friday next
short wave digging southeast into the Great Lakes should bring more
shower chances for the weekend...right now overall probabilities are
pretty low but the better chance appears to be Saturday.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 735 PM EDT Mon May 6 2024

VFR conditions under just some passing high clouds through at
least the first half of Tuesday. Expect lowering cigs and
increasing shower chances to spread in from west to east later
Tuesday, potentially bringing MVFR conditions to KTVC and KMBL.
Light winds tonight expected to become a bit gusty out of the
southeast on Tuesday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

UPDATE...MSB
SHORT TERM...JLD
LONG TERM...JPB
AVIATION...MSB/JLD