439
FXUS63 KDLH 181127
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
627 AM CDT Fri Oct 18 2024

.KEY MESSAGES...

- Warm today with a cold front moving in from the west bringing
  a chance for showers to the Northland today into Saturday.
  Significant rainfall is unlikely for most.

- Dry conditions return Sunday and Monday with temperatures
  well above normal.

- Rainfall chances return Tuesday/Tuesday night but significant
  rainfall is unlikely. Much cooler temperatures arrive
  Wednesday.

&&

.DISCUSSION...
Issued at 258 AM CDT Fri Oct 18 2024

Gusty southerly winds continue early this morning with a tight
pressure gradient and 925mb winds of 40-50 knots overhead. A
cold front was off to the west through the Red River Valley into
south central South Dakota as of 07Z. Humidity values were still
quite low across the area with current temperatures around what
normal highs are for this time of year. The cold front will
move into northwest Ontario and extend southwest through
northeast Minnesota into eastern South Dakota by 00Z Saturday. A
chance for showers will develop through the day along the front.
Gusty winds this morning will decrease over central to north-
central Minnesota as the gradient weakens along the front. Ahead
of the front, including northwest Wisconsin and far eastern
Minnesota, gusty winds will continue through the day. Highs will
again be above normal with lower sixties to lower seventies
forecast.

The front will move very slowly to the east tonight into
Saturday before lifting north as a warm front Saturday night.
An upper trough will be over the Rockies this morning with a
cut-off low over AZ. The northern portion of the upper trough
will aid in moving the front east but the front will not make
it through the Northland. It will stall Saturday then return
north as a warm front Saturday night. Chances for showers will
continue tonight then diminish through the day Saturday.
Rainfall amounts will be less than a quarter inch for most today
into Saturday. However, the HREF was forecasting some very
narrow localized higher amounts of a 0.5-1". This is reasonable
given a narrow plume of PWAT values around 1" are forecast which
is above the 90th percentile and there is some low to mid level
FGEN around the frontal boundary. Just where the localized
higher amounts materialize is still uncertain. The latest NBM
only has 10-20% chance for 24hour rainfall amounts exceeding
0.25" but the HREF is higher at 20-40%.

The cut-off low in AZ will start to move northeast Sunday with
upper ridging developing over the Northland. Upper ridging will
continue into Monday as the upper low moves into Nebraska by
00Z Tuesday. Dry weather will return Sunday and continue into
Monday with highs 15-25F above normal.

Chances for light showers return Tuesday as the upper low opens
up into a trough and a northern stream trough arrive. Rainfall
amounts will be on the light side with this system. The global
models as well as most of the ensemble members of the ECMWF show
the rain departing by Wednesday afternoon.

Colder air will move in as the upper trough and surface low
depart and Wednesday will feature temperatures closer to
normal.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 627 AM CDT Fri Oct 18 2024

VFR conditions today with low level wind shear this morning
affecting KHYR. Gusty southerly winds of 20 to 25 knots will
occur this morning but into the afternoon in northwest
Wisconsin. A cold front will move into the Northland late today
into tonight bringing with it a chance for showers. Coverage of
the showers are not expected to be widespread and we again made
use of VCSH with targeted TEMPO mentions as well. Confidence
remains higher for KINL so a period of prevailing showers
continues there.

Ceilings will lower behind the front to MVFR or IFR. Low level
wind shear will also return at KHYR this evening then end later
Friday night.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 258 AM CDT Fri Oct 18 2024

Southerly winds will continue today and be strongest this
morning before gradually diminishing this afternoon and evening.
Gusts to around 25 knots will aid in creating hazardous
conditions and Small Craft Advisories remain in effect. A cold
front will move over Lake Superior tonight where it will stall.
Winds tonight will be at or less than 15 knots with a few higher
gusts along the South Shore. Wind direction will vary across
western Lake Superior depending on exactly where the front ends
up. We expect a period of northerly winds along the North Shore
tonight with all areas becoming southerly again Saturday at or
less than 15 knots.

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 until 4 PM CDT this afternoon for LSZ121-
     140-141-148.
     Small Craft Advisory until 10 AM CDT this morning for
     LSZ142>147-150.

&&

$$

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