377
FXUS63 KAPX 060724
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
324 AM EDT Mon May 6 2024

.KEY MESSAGES...

- More frost potential tonight?

- Thunderstorm potential Tuesday/night.


&&

.SHORT TERM /THROUGH TONIGHT/...
Pattern Synopsis/Forecast: Northern Michigan lies at the upper-level
trough/ridge inflection point aloft with attendant subsidence
supporting surface high pressure squarely overhead early this
morning. Height rises anticipated today with mid-level ridge axis
draped across the state tonight in advance of vertically stacked low
pressure pinwheeling over the northern Plains that`ll eventually
send a warm front towards the western Great Lakes later Tuesday.

Forecast Details:

A chilly start for many across northern Michigan early this morning
with the coldest readings (low-mid 30s) as of 3:00 AM in the
typically cooler spots of both interior eastern upper and
northern lower. Some thin high clouds currently observed across
northern lower...most numerously near and south of M-72. That won`t
limit sun-filled skies in the day ahead as afternoon high
temperatures surge back into the mid-60s to mid-70s area-wide.
Light winds will promote lake breeze development resulting in
cooler temps at the lakeshores -- especially on the Lake Huron
side where midday lake breeze development may limit some
immediate lake side locales from rising out of the 50s.

Another round of chilly temperatures and more frost potential exists
for the night ahead, however riddled with uncertainty and less
confidence than the current night. While the aforementioned
ridge axis is expected to be overhead, surface high pressure
should be centered pretty well off the northeast. None the less,
trends favor winds decoupling again overnight with a period of
calm or very light southeast winds area-wide. Further
uncertainty around cloud cover with upstream convection over the
Plains and mid-upper MS Valley perhaps spilling some high
debris clouds into the western Lakes. Gut feeling following
latest trends is that it`ll be another fairly chilly night with
at least a period of decent radiational cooling and frost
potential -- once again favoring raw statistical guidance,
rather than blended probabilistic guidance, with some localized
lows falling into the low-mid 30s across the typically favored
interior spots.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
PATTERN SYNOPSIS/FORECAST:

Troughing continues to swing away from the Upper Great Lakes;
ridging building into the Upper Midwest in its wake attm, as
anomalous troughing continues to dig through the western US, aided
by upstream troughing/jet over the Pacific. Southerly flow picking
up across the high Plains, with a weakly-defined warm front
developing here. Shortwave trough in the southern stream of the flow
over the Mid MS Valley...along BCZ stretching from Quebec down
through the OH Valley, ultimately into TX, where it loops back up
along the lee of the Rockies. Anomalous moisture along and ahead of
this BCZ, with pwats ramping up into the 1.5+ inch range. Some high
clouds from this feature trying to sneak into the Great Lakes, but
struggling beneath strong subsidence over the region...with surface
high pressure nearly dead overhead.

High pressure expected to hang on across the Great Lakes today into
tonight...but will be looking for height falls across the Upper
Midwest late tonight into Tuesday...as that downstream system
spirals over the central US, with a lobe of PV swinging northward
into the region with a warm front Tuesday afternoon/evening. As the
PV max slips into the region Tuesday night, anticipate the primary
warm front will stall out...with a stationary boundary stretching
back into the central Plains along the perimeter of the upper low
over MT/WY. This should keep things relatively dreary going into
Wednesday, with the upstream upper low looking to eject eastward
into Wednesday night. This should allow another wave to develop
along the lingering boundary, and track somewhere through the OH
Valley, though the exact position and evolution with northern stream
energy over Ontario still a bit unclear. For now, though, signals
point toward the better rain chances remaining across
southern/central Lower MI going into Thursday. Ultimately looking
for a clipper to dig into the region late in the week...as the
upstream pattern tries to turn blocky. Still looking like we have a
shot at remaining generally troughy overall for Mother`s Day weekend
and beyond, though exactly how this occurs is still up in the air
(pun intended).

Primary Forecast Concerns:

Thunderstorm potential and hazards Tuesday/Tuesday night...
Antecedent dry airmass leftover from today, especially aided by
slightly stronger southeasterly flow ahead of the warm
front...should result in slower precip onset, as hinted at in
yesterday morning`s AFD. This may, in fact, also result in less
impressive QPF for the region, as the bulk of the deeper moisture
may be wasted in trying to saturate the atmosphere, rather than
precipitating out. Guidance still wants to try to stall that
boundary out over northern Michigan somewhere...which will play a
large role in how things evolve for our area...as the further north
it gets, the more into the warm sector we will get, and the greater
potential for seeing better parameters for severe weather. Do have
to wonder if more sunshine will allow for more destabilization,
and/or cause the warm front to jump further north than
expected...but think we will still have to contend with a decent cap
around 925-850mb or so...which could put the kibosh on anything
surface based, except for perhaps down toward the M-55
corridor/Manistee, where there is a slightly better shot at getting
into the warm sector.

Still looks like we could have enough deep forcing with the PV max
and warm front to get some elevated convection, particularly noting
some potential for steeper lapse rates aloft at times (though the
best of these may remain in the warm sector...and/or near MBL
again)...which could lend a marginal hail threat. Additionally, with
potential for some low-level surface based cape in the vicinity of
the warm front, along with potential for development of some kind of
weak low that may trek through the area...can`t rule out the
possibility of tornadoes, though this should be relatively
small...and the greater chance of this should remain to our south.
Also think damaging winds could be a threat in the warm
sector...particularly if the cap ends up being broken/overcome
(which is much more questionable for our area than points south
attm). Agree with the new Day 2 severe outlook, which for now keeps
the marginal risk just south of our area...though as has been
mentioned several times thus far, we will have to keep an eye on how
far north that warm front ends up getting Tuesday afternoon/evening.
Otherwise...with pwats floating around the top end of climo (around
an inch or so), particularly with a stalled boundary around, there
should be a threat for heavy rain/localized flooding, even north of
the warm front where surface based parameters may not be impressive.
Will also be something to keep an eye on as we draw nearer.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
VFR conditions under mostly clear/sunny skies through this taf
period. Light winds this morning, with local lake breeze
development expected this afternoon.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...Frost Advisory until 8 AM EDT this morning for MIZ016>018-
     021>024-027>030-032>035.
MARINE...None.

&&

$$

SHORT TERM...MJG
LONG TERM...FEF
AVIATION...MSB