540
FXUS63 KDLH 302027
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
327 PM CDT Thu May 30 2024

.KEY MESSAGES...

- The next round of rainfall and thunderstorms moves in from
  west to east this evening and lasts into Friday morning to
  bring a tenth to a half-inch of rainfall to the region.

- Scattered showers and thunderstorms Saturday gives way to
  heavy rainfall and severe weather chances (15-30%),
  especially in the southern half of the Northland, Sunday
  afternoon and night.

- A third round of moderate to heavy rainfall may occur next
  Tuesday into Tuesday night.

&&

.DISCUSSION...
Issued at 250 PM CDT Thu May 30 2024

Mid-level high pressure under a high-amplitude ridge exits the
Northland this afternoon ahead of an incoming frontal boundary
moving through the Upper Midwest and creating showers and
thunderstorms in northwest Minnesota so far today. The deepest
moisture plume overspreads north-central Minnesota around 00Z
this evening and works east-southeastward through tonight. While
there are a couple of hundred J of surface based CAPE yet this
afternoon to work with in the Brainerd Lakes region, any later
evening or overnight thunderstorms are most likely along and
south of US Hwy 2 in northeast Minnesota and through the far
northwest Wisconsin counties; severe weather is not expected
tonight. There is a 60-80% chance of at least 1/4 of an inch of
precipitation west of US Hwy 53 in northeast Minnesota tonight,
with 40-50% chance for northwest Wisconsin. There is even a 60%
chance for around or slightly above a 1/2 inch of rainfall
tonight for the Brainerd Lakes into east-central Minnesota.

This currently-progressive boundary is expected to stall out
closer to the North Shore and southward along the MN/WI
stateline Friday. Southwesterly flow with plenty of moisture
advection along this low-level convergence zone supports
continued rain shower and thunderstorm chances throughout the
Friday daytime and Friday night time period in far eastern
Minnesota and across northwest Wisconsin. A mid-level vort max
lifts northward into the region Friday night to create a period
of moderate rainfall under thunderstorms in northwest Wisconsin.

The troughing that was responsible for the stalled boundary
creating the showers and storms through Saturday morning finally
exits the region Saturday daytime, but still with isolated
storms and showers across the eastern half of the forecast area.

Dry weather Saturday night into Sunday morning coincides with
increasing moist southerly flow to create warm temperatures
around 10 degrees above normal, around 80 F, in most inland
locations.

A deepening Canadian trough draws an even more moist airmass
(deterministic guidance progged at 1.3-1.6 inches of
precipitable water) into the region by the afternoon hours.
There is a 15-30% chance of severe weather setting up in the
Brainerd Lakes region and into east-central Minnesota by Sunday
afternoon and into the evening hours as mid-level lapse rates
around 8 C/km, 0-6km shear to 40 knots and 1500-2000 J/kg of
CAPE support the SPC Outlook for severe weather in this southern
half of the northeast Minnesota side of the forecast area. There
is a 30-50% chance for at least 1" of rainfall in northeast
Minnesota and 20-30% in far northwest Wisconsin and a 10-20%
chance for around 2" of rainfall mainly in northeast Minnesota.
The severe threat lessens by later Sunday night as shear breaks
down and storm structure support aloft dissipates, although high
rainfall rate showers could continue through Monday morning. At
this point, ponding of water in intersections, high flows in
drainage ditches, and elevated creek flows are looking somewhat
likely Sunday evening and into Monday with saturated soils being
shown across the region per satellite-derived imagery. Check
with the National Water Prediction Services and the hydrologic
ensemble forecast system hydrographs as well to keep up-to-date
on the potential for mainstem river flow forecasts with these
next few rounds of rainfall.

Drier weather later Monday afternoon and night gives way to
another low pressure system moving into the central US by
Tuesday to create a potential (40-50% chance) third round of
moderate to localized heavy rainfall in the region into next
Wednesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1239 PM CDT Thu May 30 2024

VFR conditions prevail till 00Z-03Z Friday as a line of showers
and isolated thunderstorms moves into north-central Minnesota
this evening. A few popup rain showers may (20% chance) occur
though in the Brainerd Lakes region this afternoon. Breezy
southerly winds ahead of the line of showers veers southwesterly
along and behind the front before becoming more west-
southwesterly into Friday early morning as the cold front exits
the region east of HYR. Low level wind shear around 35 knots may
occur for a few hour period at terminals right ahead and along
the front, but is not expected to linger and the borderline
magnitude kept those conditions out of the TAF for now. Showers
last into northwest Wisconsin and east-central Minnesota Friday
daytime.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 215 PM CDT Thu May 30 2024

Easterly winds gusting to 20 knots at the head of the lake this
afternoon decrease in the later evening hours today as winds
back southerly tonight. An incoming cold front creates the next
round of thunderstorm chances over the lake late tonight into
the pre-dawn hours early Friday morning. A stationary boundary
sets up along the North Shore Friday daytime to keep widely
scattered shower and storm chances for the head of the lake and
mainly South Shore into Friday night.

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...NLy
AVIATION...NLy
MARINE...NLy