394
FXUS63 KDLH 131736
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1236 PM CDT Tue Aug 13 2024

.KEY MESSAGES...

- Areas of fog this morning are expected to clear out by mid morning.
  Additional fog will be possible again tomorrow morning.

- A few showers and sprinkles again in the afternoon today mostly
  over the Arrowhead and into NW WI.

- Widespread rain is expected to spread in from the west late
  Wednesday with chances lingering into Friday. Rainfall may be
  moderate to heavy at times with a few embedded thunderstorms.

&&

.DISCUSSION...
Issued at 314 AM CDT Tue Aug 13 2024

Current Conditions/Today:

Areas of fog this morning will erode by the mid morning hours.
Surface high pressure over much of the region today bringing in some
increased subsidence and drier air. Models hang onto a ribbon
of moisture spanning from the Arrowhead and into portions of NW
WI. Diurnal heating through the day could once again result in
some isolated showers and storms in the afternoon across this
ribbon. Lack of overall shear as we saw in the previous day will
result in the same interactions. Any storms that do manage to
blossom will not last long and collapse on themselves
occasionally producing gusts of 30 mph with some outflow
boundaries.

Tomorrow:

Surface high pressure moves off to the east on Wednesday as
southerly flow returns to the Northland. Temperatures will warm to
the upper 70s and low 80s. Cloud cover will also be increasing
through the day out ahead of our next weather system. Upper level
troughing works across the Northern Plains with a surface low
strengthening and moving east across the Central Plains. A warm front
will surge in from the south spreading showers and storms Wednesday
evening through Thursday. Confidence has increased on the overall
onset time as the 00Z suite of deterministic guidance has come into
good agreement.

Storm Chances:

Some embedded thunderstorms can`t be ruled out with MUCAPEs of
a couple hundred J/kg. Bulk shear profiles vary between guidance
ranging from 15-30 kts. The better dynamics for severe weather
look to be off to the west and south, which seems reasonable
given the low track is expected to traverse across southern MN.

Heavy Rain Chances:

The primary concern with this incoming system will be some moderate
to heavy rainfall at times. Model variance on QPF still remains on
the highs side with plumes not having favorable clustering. It
is interesting that both operational models of the Euro and GFS
are on the low side for QPF when compared to the rest of their
ensemble members. The overall dynamics at play show deep
saturation in the lower levels with warm cloud depth of 10-12k
ft. At this juncture the system is not expected to stall out so
concerns for flash flooding are on the low end.

Friday-Weekend:

By Friday evening the system deepens into a cut off low over the
Great Lakes Region. This will throw us back into the regime we`ve
seen the past couple days. Cyclonic flow aloft with diurnal heating
in the afternoon leading to showers and isolated storms popping up.
Expect this pattern to hold though the weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1236 PM CDT Tue Aug 13 2024

VFR conditions are expected this afternoon into tonight. Scattered
showers are possible in the tip of the Arrowhead and north-central
WI this afternoon, possibly impacting HYR. Fog development is
possible tonight (30% chance), which could reduce visibility to at
least IFR. Confidence in fog development is highest in HYR and HIB.
Light and variable winds today through tonight will be shifting to
the southeast tomorrow ahead of approaching low pressure.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 314 AM CDT Tue Aug 13 2024

Areas of fog this morning will dissipate by late morning. Winds will
generally be light today with high pressure gliding across the
region. Areas of fog will once again develop tonight and erode
the following morning. Easterly winds increase tomorrow with
speeds of 10-15 kts expected. Some funneling at the head of the
Lake could see these speeds further increase in the afternoon.


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...None.

&&

$$

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