530
FXUS63 KMQT 151936
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
336 PM EDT Sat Jun 15 2024

.KEY MESSAGES...

- Dry through today before the return of showers and
  thunderstorms tonight with next system.

- Possible strong to severe thunderstorms Sunday and Monday.

- Warmer than normal with frequent chances for showers and
  thunderstorms through next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 121 PM EDT Sat Jun 15 2024

Clouds pressed into the forecast area this morning, accompanied by
some light rain/sprinkles, thanks to a weak impulse emanating out
of a more vigorous shortwave lifting northeast through Minnesota.
Despite this cloud cover many locations were able to warm into the
upper 60s and low 70s across the west half by 12 EDT while the east,
Keweenaw, and areas near the Lake Michigan only topped out in the
low 60s. Both areas should continue warming this afternoon, with mid
70s in the west and low 70s in the interior east/Lake Superior
lakeshores. Lakeshore areas near Lake Michigan should remain in the
60s given the prevailing off-lake flow. Expect cloud cover to
persist as well, with increasing cloud cover expected across the
interior west as the aforementioned shortwave upstream presses
closer to the region.

&&

.LONG TERM /SUNDAY THROUGH SATURDAY/...
Issued at 335 PM EDT Sat Jun 15 2024

Expect an active period starting this evening across our area as
troughing deepens over the western U.S. and ridging amplifies over
the Eastern Seaboard next week. This pattern will cycle very warm
and moist air over us early next week, in addition to many chances
for showers and thunderstorms throughout. With strong shearing and
abundant CAPE in the atmosphere, some severe weather could occur
early this week. More details follow below.

Showers and a few thunderstorms begin making there way into the U.P.
this evening as a shortwave low lifting from the Northern Plains
into northern Ontario tonight brings isentropic ascent across our
area. Given the lack of shear and CAPE across the area during the
overnight hours, thunderstorms will have a hard time forming and
staying together. That being said, with ensemble guidance showing
PWATs exceeding 1.50 inches (which is just below the 99th percentile
of modeled climatology), we could see some heavy rainfall tonight.
The heavy rainfall threat continues over the area Sunday while the
showers and thunderstorms look to slowly leave our area from west to
east by the afternoon hours. Looking at the newest 12z guidance, the
chance for severe weather Sunday seems to have gone down as the much
better CAPE comes into the region behind the showers and
thunderstorms due to the cloud cover breaking up behind them.
However, with a 45 to 65 kt LLJ still moving across the east half
Sunday, we could see a strong or severe storm or two pop up over the
east if there is enough forcing with the shortwave`s passage. Behind
this initial wave of showers and storms, expect mostly sunny skies
and muggy conditions, with high temperatures getting into the low to
mid 80s in the interior west to low to mid 70s in the interior east.
With cloud cover sticking around until the afternoon hours over the
west and late afternoon in the east, the high temperatures have
likewise been reduced by a few degrees in this forecast package.
More showers and thunderstorms could make there way into Upper
Michigan come Sunday night as a secondary shortwave moves through
Lake Superior. With a strong and supportive hodograph for updraft
tilting, sufficient 0-6 km bulk shear, and ample MUCAPE, some
elevated strong to severe thunderstorms are possible. However, there
is some doubt that thunderstorms and showers will fire over our
area, with some CAMs showing the convection too far to our south and
west to effect our area. In addition, given that the severe weather
would happen during the overnight hours, this somewhat limits the
severe potential given the lack of daytime heating. Should any
severe weather occur, the primary threat would be hail. The west has
the best chance for seeing severe weather Sunday night.

Rain and thunderstorm chances continue across Upper Michigan next
week as very warm and muggy conditions also continue across the area
via the troughing over the western U.S. slowly crawling eastward.
Expect to see dewpoints get above 70 degrees in some spots Monday
and Tuesday, with highs getting into the 80s Monday and possibly the
90s Tuesday; it`s not out of the question that we could set a heat
record or two come Tuesday as ensemble guidance shows temperatures
around the 99th percentile of modeled climatology. Severe weather
chances continue into Monday and possibly Tuesday of next week too,
as there will be plenty of CAPE and shear to work with given that we
will still be under the influence of the warm, moist Gulf of Mexico
airmass and with synoptic-scale frontogenesis setting up shop just
to our west in the Upper Mississippi Valley and Northland/Duluth
CWA. Models have us possibly being drier and warmer next Tuesday as
the convection becomes more focused over Duluth`s CWA atop the
synoptic-scale frontogenesis zone. As this frontal boundary crawls
eastward over us Tuesday night through possibly Thursday, expect
additional rain shower and thunderstorm chances, with temperatures
cooling close to normal. As more zonal flow moves over us with weak
high pressure setting up shop over northern Ontario and the Northern
Plains, expect to see the rain and thunderstorm chances continue as
shortwaves continue to ride the upper-level flow across our area.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 121 PM EDT Sat Jun 15 2024

VFR conditions this afternoon will deteriorate overnight into Sunday
morning as a system spreads rain into the region. Expect all sites
to fall to MVFR by morning, maybe IFR at KCMX and KIWD. Wind shear
will also be possible at all terminals overnight. Gusty winds will
develop by morning at all sites.

&&

.MARINE...
Issued at 335 PM EDT Sat Jun 15 2024

Some southeast becoming southerly winds of 20 to 25 knots over the
central lake this afternoon and evening eventually dies down to 20
knots or less before ramping up to 30 knots from the southeast to
south Sunday morning to afternoon over the central lake once again.
In addition, some southerly gusts up to 30 knots will be possible
along the south Lake Superior nearshores throughout the day, with a
few gale force gusts up to 35 knots being possible near Grand Marais
and Munising during the afternoon hours. Winds weaken to 20 knots or
less by late Sunday afternoon/evening and remain that way until
possibly next Tuesday, when some southerly winds of 20 to 25 knots
could be seen along the south nearshores. Light winds of 20 knots or
less returns Tuesday night and could remain through the rest of the
week.

Thunderstorms are possible across the lake beginning late tonight,
with chances continuing through the middle of next week. Some severe
weather is possible over the lake, particularly the west, from
Sunday through Tuesday as a zone of frontogenesis sets up near
Duluth; the primary severe threat is hail, followed by winds. In
addition, while significant wave heights look to be generally 4 feet
or less over the next several days, we could see wave heights get up
to 4 to 6 feet over the eastern half Sunday given the stronger
southeast to southerly winds.

&&

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

&&

$$

SHORT TERM...JTP
LONG TERM...TAP
AVIATION...JTP
MARINE...TAP