063
FXUS63 KDLH 211509
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1009 AM CDT Fri Jun 21 2024

.KEY MESSAGES...

- Chances for showers and thunderstorms increase today,
  especially over northwest Wisconsin, with chances continuing
  into Saturday. Little rainfall is expected over far northern
  Minnesota today.

- There will be a threat for heavy rain today into Saturday
  morning, although it has decreased and shifted south again.
  Portions of northwest Wisconsin have the highest chance at
  seeing 1-2"+.

- The threat for severe storms has diminished Saturday but there
  remains a Marginal Risk (1/5) from east-central Minnesota into
  much of northwest Wisconsin. The window for severe is narrow
  and dependent on sufficient clearing to build instability.

&&

.DISCUSSION...
Issued at 358 AM CDT Fri Jun 21 2024

A stalled frontal boundary remained well south of the Northland
this morning and the latest guidance has it moving slightly
north into southern Minnesota into southern Wisconsin today.
Showers and thunderstorms were moving along and north of this
front early this morning from eastern South Dakota through
southern Minnesota and northern Iowa. This activity will
continue to move east-northeast and most of the heavy rain this
morning will remain south of the Northland. However, high PWAT
air will move north with values over the southern half rising
to 1.5-1.8" today into tonight. 850-700MB FGEN will increase
through the day and combine with a shortwave to provide lift for
showers/storms further north into northern Minnesota.
Instability will be meager at best today and tonight with the
RAP forecasting a few hundred j/kg over the south half of the
Northland. The threat for severe storms today/tonight is low and
the SPC keeps the Marginal Risk just south of northwest
Wisconsin. Confidence is not very high on POPS, especially
tonight. CAM guidance suggests showers/storms will move north
today especially over northwest Wisconsin and we have the
highest POPS there. Most then bring a lull in coverage this
evening before another shortwave moves in later tonight and the
surface low lifts northeast. We didn`t buy in completely to the
majority of the CAM guidance given the very moist airmass and
FGEN but it trends hold, we may be able to reduce chances later
this afternoon/tonight, especially over central into northern
Minnesota.

We do have more confidence that the heavy rain threat has
shifted south but does remain over portions of northwest
Wisconsin. HREF 24 hour QPF does show the potential for a narrow
band of 1-2" from Washburn to Price Counties in northwest
Wisconsin today into tonight and the WPC has a Slight Risk of
excessive rainfall in that area. The ECMWF ensemble guidance
paints a more bullish picture for heavy rain with probabilities
of 60-90% for rainfall of 2" or greater from east-central
Minnesota into northwest Wisconsin. However, we think the ECMWF
is too far north with the surface low/warm front. The latest
guidance does show it has shifted south compared to 24 hours ago
and we think that trend will continue so feel it`s too high on
its QPF.

We have chances for showers/thunderstorms continuing Saturday,
highest over northwest Wisconsin and in the morning. Instability
is again meager, especially in the morning. Thunderstorm
coverage will be low over central to northern Minnesota. CAM
guidance suggests a lull in shower/storm coverage will develop
Saturday morning overnight/early morning convection moves off.
It`s possible we may too high with POPS Saturday morning. The
threat for heavy rain is low on Saturday and the Northland has
been removed from the latest excessive rain outlook. We remain
in a Marginal Risk (1/5) for severe thunderstorms Saturday over
east- central Minnesota into northwest Wisconsin and the main
threat will be hail to 1" in diameter and damaging wind to 60
mph. The window for severe will be narrow and dependent on some
clearing occurring to boost CAPE.

Winds today into Saturday will be off Lake Superior and they
will be stronger Saturday compared to today. There will be a
HIGH risk for rip currents on Saturday.

A shortwave in northwest flow aloft will bring more chances for
showers/thunderstorms Sunday. Widespread heavy rainfall and
severe storms are not expected. There will be periodic chances
for more showers/storms next week but the upper flow will be
more progressive diminishing the heavy rain threat. The best bet
for a dry day will occur Wednesday with high pressure over the
region.

Temperatures will trend warmer Sunday-Tuesday then cool
slightly.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 623 AM CDT Fri Jun 21 2024

Morning radar showed rain and some embedded thunderstorms moving
toward east-central Minnesota and northwest Wisconsin with more
scattered activity further west moving toward KBRD. Chances for
showers/storms will occur periodically through the period and
be greatest from east-central Minnesota into northwest
Wisconsin. We targeted a mention of showers/storms where
confidence was highest and future updates/amendments will
continue to refine the timing.

Ceilings will lower to MVFR/IFR today into tonight over all but
far northern Minnesota. Some may ceilings dip even lower. There
will also be some fog with mainly MVFR visibility.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 1007 AM CDT Fri Jun 21 2024

With this update, Small Craft Advisories have been issued for
most nearshore zones for Saturday with gusty northeast winds to
25 kt and wave heights 2 to 5 ft expected. No other changes
since the last update.

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...Small Craft Advisory from 7 AM to 7 PM CDT Saturday for
     LSZ142>147-150.

&&

$$

DISCUSSION...Melde
AVIATION...Melde
MARINE...JDS