302
FXUS63 KDLH 061956
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
256 PM CDT Mon May 6 2024

.KEY MESSAGES...

- Rain moves into the area late tonight with strong storms
  potential Tuesday Afternoon with the chance for gusty winds
  and small hail.

- Drier conditions arrive Wednesday with the chance for a
  potent lake breeze each day.

- Rain chances increase late this week and into the weekend due
  to a few shortwaves dropping out of Canada.

&&

.DISCUSSION...
Issued at 239 PM CDT Mon May 6 2024

Short Term:

Beautiful Spring conditions are in place across much of the
Northland and will persist into this evening. Highs will top off in
the upper 60s (near the lake) to low 70s (inland) with mostly clear
skies and a light SE wind to top it all off. Late this evening and
into early tomorrow is when our weather will drastically change for
the messier. At the synoptic level, a negatively tilted upper level
trough will exit the Southern Plains this afternoon leaving much of
the Plains and Great Lakes in strong SW flow at 500mb. This will
contribute to the development of sub 980mb surface low across the
Northern High Plains. While the surface low itself wont be close to
our CWA, an occluded front that will stretch from Dakotas through
Minnesota and down into the Southern Great Lakes will be the focus
of our precipitation tomorrow morning. The front will be orientated
NW-SE and be moving perpendicular to its orientation towards the
NE. The frontal boundary will give us rain showers starting in
Central Minnesota before overspreading towards NW Wisconsin and
towards the Arrowhead. Rainfall at times could be heavy with 6hr
rainfall totals reaching upwards of 0.5 along the I-35 corridor and
up towards the North Shore. This band should slowly weaken and drift
towards the US/Canadian Border through the day allowing for some
clearing behind it through the afternoon. Some instability will
develop with up to 1000J/kg of MUCAPE developing in NW Wisconsin
with lesser amounts as one heads further NW towards the MN/WI border
and into Minnesota. With bulk shear in the 20-40kt range, we could
see some convective elements with any storms that can fire Tuesday
Afternoon. The SPC has placed the entire area in a General
Thunderstorm Risk with a few of our counties in NW Wisconsin in a
marginal risk (level 1 out of 5). Those counties would have the best
chance of seeing stronger storms capable of gusty winds and small
hail (20-30%). Should we see slightly more clearing, theres a non-
zero chance that we get cold air funnels due to the presence of
adequate 3CAPE and low-level vorticity.

Extended Range:

By Wednesday morning most of the precipitation will
have ended as the system finally leaves our region. Following its
exit, our region will be placed in a northerly flow in tandem with
another system developing across the Southern Great Lakes late on
Wednesday. Within this northerly flow, a strong lake breeze will
form with temperatures near the lake in the upper 40s/lower 50s
while inland areas will see their highs closer to 62-67 degrees.
Thursday will be similar with temperatures likely a few degrees
warmer than the prior day. As we head into the weekend, a series of
shortwaves will move SE out of Canada and into our vicinity. We
should see elevated precipitation chances for each of the days with
no specifics set in stone at this point.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1245 PM CDT Mon May 6 2024

The pressure gradient continues to strengthen today, leading to
increasing southeasterly winds and gusts. Look for 18-25 knot
gusts this afternoon and evening, highest at BRD. Even with
these gusty surface winds, LLWS will be a concern late this
evening and tonight as a south-southeasterly low-level jet of
40-50 knots moves over the Northland. Winds turn even stronger
out of the east late tonight into Tuesday, with some gusts up to
30-35 knots at times, particularly in northeast Minnesota.

VFR conditions persist until later tonight when light to
moderate rain moves into BRD around 07-08Z from the southwest
and spreads northeast across the Northland into Tuesday morning
on the leading edge of a warm front. There may even be some
embedded thunder at BRD overnight into Tuesday morning (10-20
percent chance), but confidence was too low to include in the
TAF at this time. Expect MVFR visibility in the rain, while
ceilings quickly drop through MVFR to IFR as the main band of
rain moves over the terminals.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 239 PM CDT Mon May 6 2024

Northeast winds are beginning to increase out on Lake Superior
this afternoon, with Small Craft Advisories going into effect
this afternoon as both winds and waves increase. A low pressure
system advancing toward the area will push rainfall into the
area overnight tonight and Tuesday, keeping the trend of
increasing winds and waves going through the daytime on Tuesday.
Winds may diminsh for a short time this evening before
increasing again during the early morning hours of Tuesday, but
the longer fetch of the wind will keep waves building. We may
have a period on Tuesday from late morning through the afternoon
where we may get some gale force gusts along the North Shore
north of Two Harbors. Currently, the certainty on this is not
very high and this potential may not affect a very large area or
for very long, so have not upgraded to a Gale Warning at this
time. After Tuesday, northeast winds continue into Wednesday and
even Thursday before backing into the north. We may need
additional Small Craft Advisories for all or parts of the lake
and for the time frame through Thursday.

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 from 7 AM Tuesday to 4 AM CDT Wednesday
     for LSZ140-147-150.
     Small Craft Advisory from 4 AM Tuesday to 4 AM CDT Wednesday
     for LSZ141-142.
     Small Craft Advisory until 4 AM CDT Wednesday for LSZ143>146.
     Small Craft Advisory from 10 AM to 4 PM CDT Tuesday for LSZ148.

&&

$$

DISCUSSION...LE/KP
AVIATION...Rothstein
MARINE...LE