764
FXUS63 KMQT 101905
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
305 PM EDT Mon Jun 10 2024

.KEY MESSAGES...

- Chilly and dry again tonight with high pressure overhead.
  Patchy frost is possible.

- A more active period is expected Tuesday afternoon through
  Thursday night. This will be accompanied by generally warmer
  than normal temperatures that continue into the weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 305 PM EDT Mon Jun 10 2024

Upper air pattern consists of a 500 mb trough in the ern U.S. with a
shortwave in the northern Rockies and a ridge over the northern
plains. This upper ridge moves into the upper Great Lakes by 12z
Tue. Put out a frost advisory for tonight for most places as
temperatures drop to the lower to mid 30s. The sky will be clear and
with light winds, ideal radiational cooling conditions will set up
so widespread frost will be likely well inland away from the warmer
shorelines of the Great Lakes.

&&

.LONG TERM /TONIGHT THROUGH SUNDAY/...
Issued at 440 AM EDT Mon Jun 10 2024

Mid level ridging and sfc high pressure will be shifting over the
Upper Great Lakes tonight, continuing the dry period. Near calm
conditions, PWATs ~0.35" (below the NAEFS 10th climatological
percentile), and clear skies sets up the UP for another radiative
cooling night. Lows are expected in the mid 30s to mid 40s, warmer
near the lakeshores. This leaves some potential for patchy frost.
Meanwhile, midlevel troughing will be approaching from the west.

Tuesday through Tuesday night, a mid level trough moves east from
Manitoba to Ontario, with pretty robust positive theta-e advection
out ahead of it as southerly flow tightens up. A shortwave rotating
around the trough from southern Manitoba to far northern Ontario
will support the sfc low along a similar track. Resulting isentropic
ascent, coupled with some weak PVA rippling out ahead of the
approaching trough, could touch off some showers and storms across
the western UP as early as Tuesday afternoon. However, most
convection holds off until the evening as the associated cold front
moves through. With latest model guidance indicating bulk shear ~30
kts and not much CAPE by then (6/10 0Z LREF mean CAPE around 50-
100j/kg with a max of 400 J/kg), strong storms are not likely and
severe storms are not expected as the cold front moves through. As
the cold front and isentropic ascent weakens Tuesday night, showers
and any storms begin to diminish as they continue eastward across
the UP. Dry weather returns to the west half around midnight.

Wednesday likely should see mostly dry weather until the afternoon.
WAA from low level southwest becoming south flow will help bring
warmer than normal temps into the 70s with some spots in the
interior west possibly reaching into the low 80s. Some diurnal
showers and storms are possible as we reach convective temps, mainly
in the east and along Lake Superior where there could be some
support from a lake breeze and/or weak PVA from the trough moving
east through northern Ontario. Bulk shear will be ~40 kts with the
6/10 0Z LREF plotting mean CAPE of around 300-500 J/kg; the NAM is
the strong outlier with up to ~1000-1500 J/kg of CAPE. Some stronger
storms are possible if the NAM setup is favored, but with
uncertainty in forcing and location of showers/storms, left as
slight chance PoPs (15-24%) for now.

A sfc low over southern Manitoba tracks east to just north of Lake
Superior Wednesday night into Thursday. While there still is some
significant spread in the model guidance thanks to poor resolution
of the mid level trough, this sfc low is expected to bring a cold
front across the area into Thursday morning bringing additional
chances for shower and storms. This will quickly be followed by a
southerly push of the mid level trough through Thursday night,
likely yielding the last chances for showers and storms this
work week.

There is some agreement on ridging with sfc high pressure moving
over the area for the early part of the weekend, but as this starts
to slide east out of the Upper Great Lakes late in the day Saturday
through Sunday, some PoPs do sneak in. Given uncertainty regarding
timing this far out, opted to leave NBM PoPs as is after Friday.
Temperatures will feel more summer-ey the rest of the week, with
highs ranging well into the 70s for most of the area Thursday
through Sunday and lows in the 40s and 50s.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1220 PM EDT Mon Jun 10 2024

High pressure will result in VFR conditions for the duration of the
TAF period.

&&

.MARINE...
Issued at 440 AM EDT Mon Jun 10 2024

With high pressure over Lake Superior through Tuesday morning, winds
are mainly expected below 20 kts. The exception to this would be for
some channeling northwest winds in whitefish bay, possibly gusting
up to 25 kts. The next potential for winds to exceed 20 kts is
Tuesday night into Wednesday over the west half of the lake when a
low pressure system tracks through far northern Ontario. That said,
chances of winds exceeding 20 kts are low (20-40%) given the
stability over the lake. Another low pressure system tracking just
north of Lake Superior Wednesday night through Thursday brings
similar chances for the eastern half of the lake. High pressure
returns calmer conditions below 20 kts for the start of the weekend.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Frost Advisory from 2 AM EDT /1 AM CDT/ to 8 AM EDT /7 AM CDT/
     Tuesday for MIZ002>007-009>014-084-085.

Lake Superior...
None.
Lake Michigan...
None.

&&

$$

SHORT TERM...07
LONG TERM...Jablonski
AVIATION...07
MARINE...Jablonski