880
FXUS63 KDLH 201137
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
637 AM CDT Thu Jun 20 2024

.KEY MESSAGES...

- Some light showers will occur today over portions of the
  Northland.

- Chances for showers and thunderstorms ramp up tonight into
  Saturday. There will continue to be a risk for both severe
  storms (Saturday) and heavy rain (mainly Friday night into
  Saturday).

- There has been a slight southward shift in the greatest risk
  for heavy rain.

&&

.DISCUSSION...
Issued at 350 AM CDT Thu Jun 20 2024

High pressure was over the Northland this morning and it`s
forecast to slowly slide east today. Area radars showed light
showers/virga moving north into the southwest quarter of the
Northland early this morning and chances(20-40%) for light
showers will occur over mainly southern portions, from the
Brainerd Lakes east northeast to the Twin Ports and northwest
Wisconsin today. 00Z Soundings showed plenty of dry air present
and that will take some time to saturate. We only expect light
rainfall amounts today.

The surface high will only move slightly further east tonight
but warm air/moisture advection and FGEN with the baroclinic
zone lifting north will provide forcing for showers/storms.
PWAT values will increase to about 1.6" by 12Z Friday over
southern portions of the Northland. There are some limiting
factors though for strong storms/heavy rain tonight. Instability
is lacking with only ~130j/kg per the RAP with the GFS/ECMWF
lower. There isn`t much of a low level jet either with the core
of the stronger 850MB winds well off to the southwest in
Nebraska. Although the CAMS offer different solutions with
placement of showers/storms tonight they mostly agree on
keeping any of the stronger storms just south of the Northland.
We increase POPS further on Friday, keeping the highest values
of 60-90% over the southern half of the Northland. The warm
front is forecast to stay in southern Minnesota into central
Wisconsin through the day. However, 850MB FGEN will exist over
the Northland along with a weak upper shortwave. The CAMS are
not as bullish on shower/thunderstorm coverage as our current
POPS suggest, especially in the afternoon, but forcing and PWAT
values ~1.5" support higher chances. The HREF 24 hour QPF does
forecast a narrow band of 1-1.75" of rainfall tonight into
Friday over parts of northwest Wisconsin. The ECMWF ensemble and
NBM probabilities for 2" of rain or greater are rather low at
15% or lower.

A stronger shortwave will cause the surface low to move toward
southwest Minnesota by Saturday morning with the low continuing
northeast into Wisconsin or Upper Michigan or northern Minnesota by
Saturday evening. Confidence in the low track is low as seen in
the global model forecasts and from the smattering of low
locations from the ECMWF ensemble members. The best chance for
heavy rain will occur Friday night into Saturday with plenty of
moisture and some increase in instability, especially Saturday.
The low level jet is again not very strong and is more
southwest, especially on Saturday versus southerly like what
occurred earlier this week. Depending on the low track, there
will be a severe threat as well on Saturday and the SPC has a
Slight Risk (2/5) from east central Minnesota into much of
northwest Wisconsin with a Marginal Risk (1/5) over all be
western portions of the Northland. The risk of rainfall of 2" or
more for a 48 hour period ending Sunday morning is 30-75% from
the Brainerd Lakes to the Twin Ports and northwest Wisconsin,
with the highest values from east-central Minnesota into
northwest Wisconsin. Our total rainfall from today through
Saturday night has diminished for most slightly and ranges from
0.75 to 2.5", greatest over northwest Wisconsin. If stronger
thunderstorms do develop, there will likely be smaller areas
that receive greater amounts. Given soils are saturated in spots
and many rivers/streams are running high or will already be in
flood, there will be a risk of more flash flooding.

There will be periodic chances for more showers/storms beyond
this weekend but the upper level flow will favor systems that
are more progressive.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 637 AM CDT Thu Jun 20 2024

VFR conditions were occurring early this morning with scattered
showers in the Brainerd Lakes to near Hinckley on northeast
toward the Twin Ports. These showers will continue for several
more hours and move east. Ceilings are expected to remain VFR
with the showers.

Tonight, ceilings will lower to MVFR and possibly IFR. This will
be most likely over southern portions of the Northland. There
will also be a chance for more showers and possibly a few
thunderstorms.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 350 AM CDT Thu Jun 20 2024

East to northeast winds will occur through Saturday becoming
west to northwest Saturday night into Sunday. Speeds today into
Friday will be from 5 to 15 knots, with some higher gusts, and
be strongest in the Twin Ports area. Winds will be a bit
stronger Saturday, mostly from 10 to 20 knots. There will be a
chance for thunderstorms Friday into Saturday. Some of the
storms Saturday could be strong to severe.

An area of low pressure will move through the region and turn
winds to west or northwest Saturday night into Sunday.

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...Melde
AVIATION...Melde
MARINE...Melde