Area Forecast Discussion Issued by NWS Duluth, MN
000
FXUS63 KDLH 150557
AFDDLH
Area Forecast Discussion
National Weather Service Duluth MN
1257 AM CDT Fri Mar 15 2024
.KEY MESSAGES...
- Near critical fire weather conditions Friday from the
Brainerd Lakes through the St. Croix Valley and the Pine
Barrens of northwest Wisconsin.
- Rain changing to snow is expected across the Arrowhead, Iron Range
and along the International Border Friday evening into Saturday.
New snowfall accumulations will be an inch or less.
- Strong northwest winds Friday night and Saturday with widespread
gusts in excess of 30 mph.
- Lake-effect snow showers persist into the new week along the
South Shore, but most areas remain dry with near to slightly
below normal temperatures.
&&
.DISCUSSION...
Issued at 334 PM CDT Thu Mar 14 2024
Quiet conditions are forecast across the Northland tonight into
Friday morning before a clipper system impacts the area Friday
evening into Saturday. Westerly winds in the warm sector of the
clipper on Friday will support a relatively mild day with high
temperatures in the 40s for most locations, with a few 50s not
out of the question. In regards to fire weather, near critical
fire weather conditions are likely (>80% chance) from the
Brainerd Lakes area through the St. Croix Valley and across the
Pine Barrens of northwest Wisconsin on Friday. Good mixing with
westerly winds around 10-15 mph will support relative humidity
levels falling to around 25-30% for these areas where sunny
skies through the afternoon are expected.Near the International
Border and into the Iron Range, cloud cover will be on the
increase through the day. This will help to keep relative
humidity levels from falling as far. However, this will have to
be closely monitored should clouds arrive later than expected as
west-southwest winds will be stronger for these areas at 15-20
mph.
Precipitation with the clipper will spread across the Borderlands,
Iron Range and Arrowhead of northeast Minnesota through Friday
evening, with lesser chances (30-50%) for areas further to the
south. Precipitation will start as rain, and slowly mix with
more and more snowflakes as colder air advects in through the
night and into Saturday morning. New snowfall accumulations will
generally be an inch or less for the Borderlands, Iron Range
and Arrowhead with little to no accumulation immediately at the
coast.
The other main story with this clipper will be strong west turning
northwest winds Friday night and Saturday across the region. All
ingredients for strong winds are there with a strong pressure
gradient, steep low level lapse rates in cold air advection, and
isallobaric forcing with 35-40kts at the top of the mixed layer.
Thus, widespread wind gusts in excess of 30 mph are likely (>80%
chance) Friday night and Saturday, with localized gusts in excess of
40 mph for the higher terrain areas of the Iron Range, North Shore
and Bayfield Peninsula.
Lake effect snow in northwest winds is expected for favored
South Shore snow belts Saturday night into Monday morning.
Given the long duration of the setup, there is a 20-40% chance
of amounts exceeding 4 inches. However, given the late season
and temperatures near freezing during the day, this adds
uncertainty to how well snow will accumulate.
&&
.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1257 AM CDT Fri Mar 15 2024
VFR conditions predominate across the region, but there are some
pockets of MVFR to IFR stratus around Lake Superior. Another
area of MVFR stratus is approaching the Northland from the
northwest. Expecting this MVFR stratus to spread across the
region overnight and then lift back to VFR through the day
Friday. As an area of low pressure approaching Friday evening,
more clouds are expected to filter in with MVFR conditions
returning to INL. Some rain showers will also be possible at INL
and HIB Friday evening as well, but shouldn`t impact VSBYs.
Winds will become breezy Friday afternoon and evening eventually
becoming northwesterly in the wake of a cold front with gusts to
20 to 30 knots. A brief period of low level wind shear will work
across the region late in the period as well with the cold
front. Have left out for now, but will need to reevaluate for
future updates.
&&
.MARINE...
Issued at 334 PM CDT Thu Mar 14 2024
Extended the Small Craft Advisory for Silver Bay to Duluth and
most of the South Shore until 7PM this evening for continued
northeast wind gusts to 25kts. The Advisory continues for the
Outer Apostle Islands and Oak Point to Saxon Harbor until 11PM
where stronger winds and higher waves will continue longer. Did
issue a Gale Watch for all western Lake Superior nearshore
waters for Friday night through Saturday evening as strong low
pressure moves across southern Canada. Southwest gales Friday
night will turn to the northwest on Saturday. Conditions
hazardous to small craft are likely (70-90% chance) to continue
into Sunday as winds slowly decrease.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Gale Watch from this evening through late Saturday night for
LSZ121-140>148-150.
&&
$$
DISCUSSION...PA
AVIATION...BJH
MARINE...PA