146
FXUS63 KDLH 241124
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
624 AM CDT Fri May 24 2024

.KEY MESSAGES...

- Windy with rain showers entering from the south. Chances for
  some strong to severe storms increase in the afternoon. The
  best chances for severe storms will be in NW WI.

- Another round of showers and storms will be possible Saturday
  late afternoon and evening.

- Active weather continues for the Northland as a low pressure
  system moves into southern WI for Sunday.

&&

.DISCUSSION...
Issued at 339 AM CDT Fri May 24 2024

Current conditions:

A surface low pressure is currently along the border of the North
and South Dakota this morning with it`s associated warm front edging
its way north into our CWA. Light rain showers can be seen on radar
moving north across north central MN. This rain activity is expected
to dissipate over the next few hours before the next wave
associated with the warm front pivots in from the south.

Today:

The aforementioned low pressure is expected to deepen as it
continues its northeast track towards Manitoba. GEFS climatology
is giving a return interval of 1 in 5 years for the pressure
anomaly so I opted to increase the winds a bit with this
forecast package. The strongest winds will be across northern MN
closet to the Low in the afternoon hours. High res guidance is
giving the area a 40-50% chance of reaching Wind Advisory
criteria. There still remains some discrepancies with how much
can mix down to the surface. This is due to the low maturing as
a robust low level jet (winds in excess of 50kts at 2000 ft)
throttles in from the southeast.

Rain chances will increase through the late morning hours and
persist into the evening as the warm front surges north. Some
embedded thunderstorms will be possible at times. The better chances
for storms will be in NW WI. The warm sector out ahead of the cold
front is expected to brush NW WI this afternoon and evening and
could generate some strong to severe storms. With the strong low
level jet in place we will already have ample amounts of bulk shear.
The main ingredient in question will be how much instability will
the area generate before the cold front sweeps through. A few of the
deterministic models suggest a couple hundred J/kg of MLCAPE will be
possible. Meanwhile, the RAP is advertising over 1000 J/kg,
certainly and outlier, but some of the CAMs do show some rather
strong returns. SPC has a marginal threat (1 out of 5) outlined
across a small portion of our SE counties. All modes of severe
remain possible. Primary threats would be large hail up to 1
inch in diameter, 70 mph, and a possible tornado.

Friday night/Saturday:

The cold front will exit to the east this evening with most of the
precipitation tapering off. The exception to this will be across far
northern MN where wrap around moisture from the parent low now over
Manitoba will lead to some persistent showery activity. The
first half of Saturday looks to be quiet with increasing clouds
through the day and highs in the 60s and 70s. A baroclinic zone
over the region could see rain and storm chances return in the
late afternoon and evening (20-40%). SPC has the area in a
general risk for thunderstorms but this may need to be increased
to marginal if trends hold. Some of the 00Z guidance is showing
a corridor of instability within the baroclinic zone with
strong bulk shear in excess of 40 kts.

Sunday/Early next week:

Sunday continues active weather for the Northland as a low pressure
moves across southern WI. Our region will stay on the northern
periphery of this system allowing NW WI to see another round of
moderate rain. Current estimates are around 0.25-0.50 inches of rain
with the bulk of it falling Sunday afternoon and evening. The
progression of this low into next week shows some variance among
ensembles but in general we can expect some additional wrap around
showers to impact portions of the Northland through the early
portions of the work week.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 624 AM CDT Fri May 24 2024

A low pressure system moving up through the Red River Valley this
morning has a warm front bringing showers and thunderstorms in from
the south. As this low continues it`s northeast trajectory we will
see and increased low level jet that could induce some low level
wind shear. One challenge with this forecast package is trying to
determine if these strong winds will be able to mix down to the
surface as we head through the day. More showers and a few
thunderstorms will be possible through the day as a cold front
pivots across the region. Expect degrading flight conditions as we
head into the afternoon hours.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 339 AM CDT Fri May 24 2024

A strong low pressure moving from the Northern Plains into Manitoba
today will increase the pressure gradient throttling northeast winds
across Lake Superior. Gale Warnings are out for the North Shore and
there is potential that they may need to be expanded to the Outer
Apostle Islands depending on how the winds ramp up this morning. A
few of the high res models are hinting at stronger winds by 11 AM.
Gales are not expected to last for long but Small Craft
Criteria will still remain until Saturday due to increased
winds and waves.

Additionally, rain showers will enter from the south this afternoon
with the chances for some thunderstorms. Severe weather is not
anticipated for Lake Superior at this time.

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

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Beach Hazards Statement through this evening for MNZ037.
WI...Beach Hazards Statement through this evening for WIZ001.
MARINE...Small Craft Advisory until 4 AM CDT Saturday for LSZ121-145-
     148.
     Small Craft Advisory until 10 AM CDT this morning for
     LSZ140>144.
     Gale Warning from 10 AM this morning to 7 PM CDT this evening
     for LSZ140>144.
     Small Craft Advisory until 1 PM CDT Saturday for LSZ146-147-
     150.

&&

$$

DISCUSSION...Britt
AVIATION...Britt
MARINE...Britt