000
FXUS63 KMQT 230846
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
446 AM EDT Tue Apr 23 2024

.KEY MESSAGES...

-For the north half of the UP, today`s weather features rain
 turning to snow and breezy conditions, though little to no
 accumulation is expected.
-For the south half of the UP, clearing skies early will allow
 for thunderstorm potential to build for the afternoon along
 with breezy conditions, though chances of severe weather are
 below 5%.
-Dry weather in the midweek under high pressure.
-Active weather pattern returns this weekend and continues into
 next week and looks wet.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 445 AM EDT Tue Apr 23 2024

GOES-16 WV imagery shows a secondary push of moisture pushing
through the central UP from west to east this morning. This is
associated with a secondary shortwave aloft following the initial
frontal passage earlier in the overnight period. RAP analysis shows
a 996mb surface low at the very northernmost point on Lake Superior
with the upper low spinning along the MN/Canada border. The HREF
shows that after this secondary surge of moisture, dry-slotting will
allow for a break in the precipitation until the mid-morning hours.
The low dropping southeast will be the forcing mechanism for showers
today, with the main impacts to the forecast being precipitation
type in the north and thunderstorm potential in the south.

In the north, the HREF shows that PoPs reenter the forecast around
15Z as the low moves over eastern Lake Superior and wraparound
moisture is lifted by the low and enhanced by the terrain of the
western and northern UP. As the winds turn northerly through the
morning and cool Canadian air surges south, rain showers will
changeover to snow. The HREF suggests that there`s a 50-90% chances
that all of the UP north of US-41 and west of Marquette will see 0.5
inches worth of 10:1 snowfall. However, actual accumulations are
expected to be less than that given the springlike temperatures
lately having warmed the ground, so actual sticking snow should
be minimal. This warm ground will also protect from any rain-to-
snow freezing surface threats.

Further south, the clearing skies in the dry slot will allow for
surface temperatures to climb well into the 60s, and the NBM
suggests a 10% chance of reaching 70 in Menominee today. This
heating will allow for surface instability to build, with HREF 25th-
75th percentile SBCAPE this afternoon building to 300-900 J/kg. As
the low drops south and surface convergence increases, HREF
simulated reflectivity paintball plots exceeding 35 dBZ become quite
colorful beginning around 17Z through 00Z for much of the US-2
corridor. Mean SRH values around 100 m2/s2 should limit the
organization of these storms somewhat. Given the deep inverted V
soundings and freezing levels above 700mb, sub-severe hail and
isolated strong winds are possible today, though probabilities of
severe weather threats in any given 25-mile radius zone in the UP
are below 5% today.

&&

.LONG TERM /TONIGHT THROUGH MONDAY/...
Issued at 250 AM EDT Tue Apr 23 2024

Upper air pattern consists of a 500 mb trough in the lower Great
Lakes 00z Wed. This trough moves away and is replaced by a shortwave
ridge in the upper Great Lakes 12z Fri. Snow showers should end
early this evening and then dry weather most of tonight into
Thursday night. Looked at fire weather concerns for Wed and Thu and
the strong winds are not there along with cold temperatures.
Relative humidities are the only thing there, but not sure how wet
the fuels are.

In the extended, the GFS and ECMWF show a broad 500 mb trough in the
western U.S. with a ridge in the east. In this trough there is a
shortwave that is negatively tilted in the central plains 12z Fri.
This trough then heads northeast into the upper Mississippi Valley
12 Sat. Next wave comes out of the trough into the central plains
12z Sun and then heads into the upper Great Lakes 12z Mon and into
the lower Great Lakes 12z Tue. Active pattern in this forecast
period and temperatures go from above normal to near normal for this
period. Also looks wet with storm track over the area or just to the
south.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 124 AM EDT Tue Apr 23 2024

VFR will continue through the early morning hours across all TAF
sites as rain showers slowly overspread the area.  It will take a
bit though for the environment to become saturated, thus will hold
off on any MVFR conditions until after Tue 15Z with the second round
of rain showers in association with disturbance moving through Upper
Michigan.  At that point, brief periods of IFR can also not be ruled
out into the early afternoon along with a transition from rain to
snow showers. In addition, southwesterly winds will eventually back
to the northwest in the wake of the aforementioned disturbance and
will strengthen again by early afternoon with gusts back up to 25
kts.

&&

.MARINE...
Issued at 250 AM EDT Tue Apr 23 2024

Winds increase by late morning as a strong cold front drops down
from the north, bringing with it north-northeasterly gales up to 35
knots across the central and eastern lake today. As the cold air
advection ceases by this evening, expect the winds to die down,
eventually becoming 20 knots or less by Wednesday morning as a high
pressure sets up over the lake. This high pressure keeps the winds
light across the lake through Thursday. Stronger winds don`t look to
show up again until Thursday night, when an approaching front brings
southeast winds of 20 to 25 knots back across the lake. As it`s
parent low approaches from the Southern Plains Friday, expect the
winds to increase to 20 to 30 knots from the southeast. As the low
moves into Lake Superior Saturday, expect winds to turn northerly to
25 to 30 knots behind the low`s center from west to east across the
lake.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Small Craft Advisory from 8 AM EDT /7 AM CDT/ this morning to
     8 AM EDT /7 AM CDT/ Wednesday for LSZ240>242.

  Gale Warning from 8 AM this morning to 8 PM EDT this evening
     for LSZ243>245-263>266.

  Small Craft Advisory from 8 PM this evening to 10 AM EDT
     Wednesday for LSZ243>245.

  Small Craft Advisory from 10 AM this morning to 6 AM EDT
     Wednesday for LSZ246-247.

  Small Craft Advisory from 10 AM this morning to 1 PM EDT
     Wednesday for LSZ248>251.

  Gale Warning from 2 PM this afternoon to 2 AM EDT Wednesday
     for LSZ267.

Lake Michigan...
  Small Craft Advisory from 1 PM this afternoon to 11 AM EDT
     Wednesday for LMZ221.

  Small Craft Advisory until 8 AM EDT Wednesday for LMZ248-250.

&&

$$

SHORT TERM...GS
LONG TERM...07
AVIATION...TDUD
MARINE...07