002
FXUS63 KDLH 252007
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
307 PM CDT Tue Jun 25 2024

.KEY MESSAGES...

- Mainly dry today, with some scattered showers and a couple
  embedded thunderstorms in the Borderlands this evening into
  tonight and other portions of the Northland (20% chance)
  tonight.

- Isolated showers lingering Wednesday morning.

- Larger area of low pressure moves through the region late this
  week, with some heavy rainfall/flooding potential. Some strong
  to severe storm potential on Friday, ahead of the cold front,
  as well.

- Another active period of weather for early next week. There
  are some hints of additional heavy rainfall and severe
  potential next Monday and Tuesday, although details are still
  a bit fuzzy.

&&

.DISCUSSION...
Issued at 306 PM CDT Tue Jun 25 2024

Rest of Today - Tonight:

Mostly sunny to partly cloudy weather and quiet weather
continues through this afternoon as a brief area of high
pressure sits in the region, allowing afternoon high
temperatures to top out in the upper 70s to mid 80s with
decreasing dewpoints and gusty west to northwest winds. We will
begin to see increasing cloud cover later this afternoon and
evening as another cold front approaches from our north in
association with low pressure over northern Quebec. Shortwave
energy moving through the Northland in conjunction with the
southward advancing cold front will kick off scattered shower
activity this evening in far Northern MN, with this shower
activity sagging southeast into NE MN tonight into early
Wednesday. Short-term models also show some shower activity
clipping the Brainerd Lakes into east-central MN tonight. Can`t
rule out a rumble of thunder or two tonight, mainly across far
northern MN, but no severe weather will occur given very little
in the way of instability. Precipitation amounts will be light,
on the order of 0.1-0.25" across far Northern MN, and less than
0.10" elsewhere.

Wednesday:

A few of these showers/storms linger through Wednesday morning,
but on a much more isolated basis. High pressure builds into the
area late under northwest flow aloft, bringing clearing skies
later in the day into at least Wednesday night. Temperatures
will be more mild in the mid-60s to mid-70s.

Thursday - Saturday:

Surface high pressure begins to depart to our east on Thursday,
as a feed of Gulf moisture begins to advect north into the
Upper Midwest, raising PWATs into the 1.5-1.8" range (90+
percentile of late June sounding climatology) Thursday night
into Friday. A stronger upper-level trough moving east across
the northern U.S. Rockies and northern High Plains Thursday
night through Friday will kick off a deepening surface low
pressure over the northern High Plains, with the low passing
through the Northland Friday afternoon-evening. Showers and
thunderstorms start in the Northland Thursday evening/night in
association with the warm front ahead of the approaching low.
Current indications are for the warm front to set up somewhere
near or just north of the International Border, but the location
will still likely waiver a bit as this system approaches, and
could be a focus for moderate to heavy rainfall given high
PWATs. Additionally, there is a window of time Friday afternoon
and evening in the warm sector ahead of the cold front with
this system where potentially 1000-2000 J/kg of MUCAPE combined
with 0-6km shear of 40-50 knots could provide the focus for
strong to severe thunderstorm potential along with moderate to
heavy rainfall associated with the thunderstorms. However, it
should be noted that this severe potential will be contingent on
how long earlier day convection lingers, as well as the
strongest upper-level forcing being located farther west than
the best instability. In addition to the severe potential, one
other thing we will be continuing to watch closely is the heavy
rain and flooding potential due to the very wet soils and
elevated streamflows across much of the Northland.

The main shortwave trough slides through the Northland on
Saturday, leading to lingering showers to start the weekend
before conditions briefly dry out late Saturday into Sunday as
surface high pressure moves through the Upper Midwest again.

Sunday - Next Wednesday:

The high pressure settling in briefly for Sunday will be
accompanied by high temperatures around the 70 degree mark for
most of the Northland. Things look to change as we head into
Monday. As a result of an increasing mid-level jet through this
period, a series of mid-level shortwave troughs look to impact
the area resulting in yet another active pattern for our region.
That being said, there is increasing potential for severe
weather with the CSU Machine Learning probabilities highlighting
both the Monday and Tuesday timeframe for severe weather
potential. SPC convective outlook discussions for Monday and
Tuesday corroborate this. In addition, Gulf moisture will be
pulled up from the Gulf of Mexico. The GFS IVT shows this well
with a strong return of moisture being advected into the area
in the July 1st and July 2nd timeframe (next Monday and
Tuesday). It is too early to determine exactly where this setup
plays out. However, when looking at the CSU Machine learning
Probabilities for excessive rainfall, our region is highlighted
once again. This is certainly something to keep an eye on as
moist soils are already saturated and rivers are still running
high. It wouldn`t take much more rainfall to exacerbate the
ongoing flooding across the area. However, this is still several
days out so the forecast can and likely will change as this
early next week timeframe approaches.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1244 PM CDT Tue Jun 25 2024

VFR and dry conditions through this evening with gusty daytime
westerly winds gusting to 20 to 25 knots before turning light
and veering northwesterly tonight. Clouds will increase this
evening and tonight, with ceilings gradually lowering to MVFR
late tonight into Wednesday morning as some scattered showers
move into the Northland. Can`t rule out some brief IFR at
KHIB/KDLH late tonight into early Wednesday morning, but chances
are only 30-40% so left ceilings as MVFR for now. Shower
chances are low (20-30%), and have VCSH mention for most
terminals aside from a brief -SHRA at KINL and dry conditions
for KHYR. There may be an isolated thunderstorm across far
northern Minnesota (10% chance). Winds turn northerly Wednesday
morning, with some gusts up to 15 knots during the mid to late
morning.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 306 PM CDT Tue Jun 25 2024

Westerly winds of 10-15 knots with gusts to 20 to 25 knots will
continue through very late this afternoon before winds veer to
northeasterly this evening and weaken to less than 15 knots,
with lingering conditions hazardous to small craft until early
this evening. Small Craft Advisories are in effect. Winds
briefly increase early to mid-Wednesday morning with gusts to
20 knots mainly in the head of the Lake and around the South
Shore before turning light the remainder of the day into
Wednesday night as high pressure moves in. Winds turn south to
easterly on Thursday on the back side of the high pressure, with
gusts up to around 15 knots during the afternoon.

Isolated showers and perhaps a thunderstorm for tonight into
mid-Wednesday morning. No severe weather is expected.

For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 8 PM CDT this evening for LSZ121-
     140>148-150.

&&

$$

DISCUSSION...Rothstein/CJM
AVIATION...Rothstein
MARINE...Rothstein