409
FXUS63 KDLH 271733
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1233 PM CDT Sat Apr 27 2024

.KEY MESSAGES...

- Showers and a few thunderstorms will continue this morning
  before tapering off this afternoon.

- Brief lull in the action before another system enters from the
  south bring showers and a few thunderstorms. Rain chances will
  increase through Sunday morning with widespread rainfall
  across the region expected by the early evening hours. Second
  system departs Monday evening.

- Active weather continue with another system passing west to
  east on Tuesday once again brining rain and some
  thunderstorms.

&&

.DISCUSSION...
Issued at 402 AM CDT Sat Apr 27 2024

Current conditions/Today:

Scattered showers and some embedded thunderstorms continue to impact
the Northland this morning as a low pressure moves across southern
MN. We have seen a few lightning flashes overnight as we still have
a small bubble of MUCAPE over the region. We will maintain this
instability through the mid morning hours. Thereafter,
embedded thunderstorm chances quickly taper off across the
region. However, as the Low pressure moves into NW WI we could
see some isolated storms in the afternoon hours. CAMs are not
overly excited about the potential for stronger storms with an
overall consensus of rain tapering off in the afternoon.

Second System Sunday/Monday:

There will be a brief lull in the action as another Colorado Low
gears up to make a run at the Great Lakes region later tonight.
Following a somewhat similar track as the previous low, we
expect precipitation to begin filtering in from the south Sunday
morning. Widespread rain showers will envelop the Northland by
the early evening hours. Thunderstorm chances increase a bit
Sunday night as the low moves into western WI. But similar to
the last system the amount of available instability to tap into
is very limited. Severe weather is not expected. Additionally,
as the low approaches the increased pressure gradient will lead
to some breezy east to northeast winds Sunday night through
Monday morning. Wind speeds have decreased a bit with this
forecast package but areas along the shore line (especially the
North Shore) could see some wind gusts upwards of 45 mph.

Lake Shore Flooding Potential Sunday/Monday:

One other consideration may be Lake Shore flooding for the Twin
Ports. Lake levels are currently at 602ft which is not quite
the height we typically associate with lake flooding but not
entirely out of the question. The prolonged northeasterly gales
are expected to cause wave height of 11-16 ft with occasional 20
ft. If gales can maintain there speeds for over 24 hrs we could
see the levels rise to the point of needing a Lake Flood
Advisory.

Third System Tuesday:

The system begins to occlude on Monday as rain chances begin to
diminish in the evening. However, the region is not quite done
with the active pattern. An upper level low moving along the
International Border will draw another system out of the
Northern Plains for Tuesday afternoon and evening. As the cold
front pushes across the region expect some rain and some
isolated thunderstorms once again.

Extended Forecast:

At the midweek point we see some significant divergence in model
guidance lower confidence. For now, we are carrying
intermittent PoPs of 20-40% as the general set up is a slow
moving upper level low across Ontario with a baroclinic zone
over the region. The main ingredient in question is if we have
enough moisture to trigger any precipitation as some on the
deterministic guidance show some pretty decent dry air through
period.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1233 PM CDT Sat Apr 27 2024

MVFR ceilings are expected to be common through the period as
one low pressure system departs this afternoon and another one
arrives on Sunday. There is a slight possibility (20-30% chance)
that some VFR conditions could happen briefly tonight as there
may be some patches of clearing amongst the low clouds. In the
next 2-4 hours, visibility will be mostly VFR but occasionally
MVFR as showers continue to pass through. The general trend will
be for showers to end and visibility to improve as low pressure
departs. Visibility is expected to remain VFR tonight through
Sunday morning after rain moves away. Breezy conditions this
afternoon, but winds briefly become light tonight, switching
direction from northwesterly to northeasterly ahead of the next
low pressure system. Direction will be more variable this
afternoon at HYR closer to the low pressure center. Breezy
conditions redevelop Sunday morning along with rain chances
returning (30-50% chance) late Sunday morning from south to
north.

&&

.MARINE...
Issued at 402 AM CDT Sat Apr 27 2024

A Colorado Low moving across southern MN and towards the Great
Lakes region today is bringing widespread rain showers with a
few embedded thunderstorms. This activity will decrease this
afternoon. Winds are currently breezy but will weaken and back
to out of the northwest this afternoon. However, another system
right on its heels will increase winds once again tonight.
Another round of showers and thunderstorms will be possible
Sunday as well as gales.

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...Gale Watch from Sunday morning through Monday morning for
     LSZ121-140>143-146>148-150.
     Small Craft Advisory until 4 PM CDT this afternoon for
     LSZ140>147-150.
     Gale Watch from Sunday morning through Monday morning for
     LSZ144-145.

&&

$$

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