795
FXUS63 KMQT 140638
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
238 AM EDT Tue May 14 2024

.KEY MESSAGES...

- Dry weather continues through Wednesday, then periods of
  showers expected with a few embedded t-storms possible
  Thursday through the weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 234 AM EDT Tue May 14 2024

Sprawling high pressure remains centered around Hudson Bay today,
with light NW winds slowly veering more N/NE today as the high
slowly slides eastward. Another sunny day is expected, though smoke
from upstream wildfires drifting through may make our skies look a
bit hazy. Otherwise, some lake breeze development is expected off of
Superior, which should cause winds near it to back more to the N/NW.
Winds may also become somewhat elevated along the lake breeze,
gusting to around 15mph particularly throughout the eastern UP. Amid
northerly background flow, the lake breeze may be able to move
rather far inland. Temperatures peak well into the 50s and lower 60s
across much of the UP, and perhaps into the mid 60s closer to the WI
border. However, along the Superior shoreline and especially behind
the lake breeze, temperatures may struggle to reach even the lower
50s.

Meanwhile, as mixing deepens with daytime heating, expect dewpoints
to drop back during the afternoon. Much of the interior UP should see
dewpoints falling to the upper 20s to lower 30s, with some spots in
the interior-western UP even reaching the mid 20s. This should yield
RH values crashing into the mid and upper 20s across much of the
western UP, away from the Superior shoreline. The mitigating factor
for wildfire spread, however, remains our fairly light winds.

Temperatures quickly fall back into the 30s overnight with mostly
clear skies, light winds, and a dry airmass leading to a good
radiational cooling night.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 443 PM EDT Mon May 13 2024

Mid-level ridging in central Canada will support sfc high pres over
Hudson Bay for the next few days. This high extends ridging s across
the Northern Plains and Upper Mississippi Valley through Wednesday.
Northerly flow off the Lake on Tuesday results in a north-south temp
gradient with temps around 50F near Lake Superior to mid 60s
farthest from the lake. Lighter easterly flow on Wednesday allows
for deeper mixing and warmer temps approaching 60F near Lake
Superior and 70F across the interior. Models have broad agreement on
troffing progressing into the central U.S. bringing the next rain
chances, mainly on and after Thu. Thereafter, model spread rapidly
increases into and thru the weekend due to major differences in
timing/amplitude of waves rounding a ridge just off of the W Coast.
These differences translate to a very uncertain progression and
amplitude of waves downstream to the Great Lakes region. At this
time, a return to a pattern characterized by frequent rain chances
is favored. Ensemble guidance also indicates a chance for a system
to bring a period of widespread steady rain early next week. Temps
during the last half of the week should tilt toward above normal,
but that will depend on the amount of cloudiness and precipitation.
Next week, ensembles suggest temps will generally be on the cool
side of normal under fairly widespread negative height anomalies
across a good portion of the northern half of the Lwr 48.

Beginning tonight thru Tue night, aforementioned sfc high pres
extends south across the Upper Great Lakes region. Fcst soundings
suggest mainly clear nights tonight and Tue night and a mainly sunny
day on Tue. With sfc high pres ridge more firmly over the area Tue
night, Tue night will likely be the cooler night though there may be
some high clouds to contend with. Precipitable water is not
especially low to really enhance the cooling potential. Still, with
precipitable water running 55-70pct of normal, will favor the lower
side of available guidance, especially Tue night. Expect min
temps ranging thru the 30s F tonight, coolest interior w half.
Tue night should be a little cooler with mins at traditional
interior cold spots having a better shot at slipping just blo
30F. A gradient onshore wind enhanced by the lake breeze
component on Tue will lead to cool conditions along Lake
Superior. Expect highs in the upper 40s F there. Temps will
range up to the mid 60s F well inland interior w half. Drier air
aloft mixes down to the surface during the aftn resulting in RH
falling to 20-30pct interior w half, but lighter winds not
gusting above 15mph will limit fire weather concerns.

Sfc high pressure slides east across Ontario resulting in dry
easterly flow downsloping off the Canadian Shield. Increasing upper
level clouds and Canadian wildfire smoke/haze may limit warming, but
lighter winds should allow temps to warm to at least the upper 50s
near Lake Superior. Temps are only expected to be a few degrees
warmer across the interior where highs approach 70F.

A low amplitude mid-level trof tracking across the Northern Plains
on Wed approaches the Upper Great Lakes on Thu and shortwaves
pivoting around the trough bring periodic rain chances. Shra
associated with this feature could spread into western Upper MI late
Wed night, then progress eastward on Thu. The forecast package
continues to trend toward a later arrival of rain, especially across
the east where rain chances don`t arrive until Thursday night (e.g.
RGEM/NAM). Given the magnitude of antecedent dry air, this trend may
continue but the warm/moist air mass eventually moves in bringing
rain chances. There is fair agreement that Fri will be a drier day,
but not necessarily dry everywhere all day. Almost daily shortwave
passages suggest a return to a pattern similar to April 26 - May 4
when 7 of 9 days had measurable rainfall at WFO MQT. Fcst reflects
schc/chc of rain showers over the weekend and while widespread or
soaking rain is not expected, there will be rain chances in the
area. Warmer night time lows and damp conditions suggests bug spray
season has arrived.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 109 AM EDT Tue May 14 2024

Despite haze from upstream Canadian wildfires, VFR conditions will
prevail for the duration of the TAF period with light north to
northeast winds.

&&

.MARINE...
Issued at 443 PM EDT Mon May 13 2024

Sfc high pressure over Hudson Bay extends ridging south across the
Northern Plains and Upper Mississippi Valley today. Ridging drifts
east across the Upper Great Lakes thru Wed. As a result, expect
winds mostly under 20kt, except for NE winds gusting up to 25kt over
far western Lake Superior on Wednesday. Winds will continue to be
mostly under 20kt Thu/Fri as a broad trough tracks over the region,
bringing warmer temperatures and stable conditions to Lake Superior.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

SHORT TERM...LC
LONG TERM...EK/Rolfson
AVIATION...TDUD
MARINE...EK/JTP