606
FXUS63 KMQT 091908
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
308 PM EDT Thu May 9 2024

.KEY MESSAGES...


- Clipper system brings chances for thunderstorms to the far
  western areas of Upper Michigan Friday afternoon and Friday
  evening.

- Chances for thunderstorms return on Sunday for the west and Sunday
  night central portions of the Upper Peninsula.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 216 PM EDT Thu May 9 2024

Deeper moisture associated with a midlevel trough pivoting
through the Lower Great Lakes continues to settle south of the
forecast area. Meanwhile, a shortwave ridge axis extends
northeastward from eastern MT to near Hudson Bay. Strong
subsidence between these features continues to spread into the
UP, and surface ridging will continue to build in overnight.
Very dry airmass evident on low- level water vapor imagery
supports model forecast PWATs falling to around 0.25 inches, or
-1 to -2 standard deviations tonight. Diurnal cu/sc exist in
various areas across the UP this afternoon, including along a
convergence boundary where better low-level moisture still
exists on the inland side of the Lake Michigan lake breeze
circulation. These should quickly dissipate with the loss of
diurnal heating tonight, leaving mostly clear skies aside from
possibly a bit of midlevel cloudiness over the eastern UP. It
looks like an ideal setup for radiational cooling, especially
over the western half where the high will be centered, so took
low temps down a couple of notches by blending in METMOS
guidance. This should yield upper 20s over the west half and
low/mid 30s elsewhere.

&&

.LONG TERM /FRIDAY THROUGH THURSDAY/...
Issued at 308 PM EDT Thu May 9 2024

Upper air pattern consists of a 500 mb closed low over the Rockies,
a shortwave across Manitoba and western Ontario 12z Fri. The
shortwave drops southeast into the upper Great Lakes 00z Sat and
into the lower Great Lakes on Sat. Looks to be a possibility of some
thunder Fri afternoon and evening in the west. Overall, did not make
too many changes to the going forecast.

In the extended, the GFS and ECMWF show a 500 mb closed low over
northern Ontario 12z Mon with a trough over the central plains and a
shortwave over the northern Rockies. Upper pattern moves slightly to
the east 12z Tue and to the northern plains 12z Wed and upper Great
Lakes 12z Thu. Manual sfc progs show a front stalling out over the
area 12z Mon through 12z Thu with a clipper type system moving
through on Wed into Thu. Temperatures look to remain above normal
for this forecast period. Thunderstorms are possible again Sunday
into Sunday night.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 153 PM EDT Thu May 9 2024

VFR conditions are expected to prevail throughout the TAF period. A
patch of SCT/BKN stratocu around 3.5kft will likely linger through
the evening, but clear skies will return overnight. Northerly to
northeasterly winds will continue to gust around 20 kt for the
remainder of the daylight hours before becoming light and variable
overnight.

&&

.MARINE...
Issued at 308 PM EDT Thu May 9 2024

North winds below 20 kts will continue tonight across the lake.
Winds likely will remain below 20 kts into Saturday night.
Some thunderstorms over the far western portions of the lake are
also possible with a passing cold front Friday afternoon and
evening. Winds increase to around 15-25 kts on Sunday as another
cold front passes over the lake; some thunderstorms over the west
half of the lake are possible with this cold front as well. Winds
otherwise hold around 10-20 kts into the early parts of next week.

&&

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

&&

$$

SHORT TERM...Thompson
LONG TERM...07
AVIATION...Thompson
MARINE...07