Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 211122
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
622 AM CDT Mon May 21 2018

.SHORT TERM...(Today through Tuesday)
Issued at 359 AM CDT Mon May 21 2018

Surface high pressure remained in place across the Upper Midwest
early this morning while a closed upper low was centered over
central South Dakota. Thin cirrus has streamed northward across
our southern forecast zones during the past few hours, but the
moon and stars are visible through the veil. Scattered rain
showers were noted on regional radar over southeast South Dakota,
northern Iowa, and southern Minnesota, and were tracking generally
northward.

Have increased cloud cover across my southern zones today in an
attempt to capture the cirrus shield which will remain in place
today. The closed low is forecast to fill as it lifts
northeastward into Minnesota this afternoon. Height falls are
forecast over central Minnesota into northern Wisconsin as the
trough approaches. An area of low- and mid-level frontogenesis
will lift into central Minnesota and northern Wisconsin this
afternoon ahead of the trough. Southerly flow into the frontal
zone, combined with the height falls, should be sufficient to
spread scattered showers northward into northwest Wisconsin. A few
showers may reach the Brainerd Lakes later this morning and
linger into the afternoon, as well. The high cirrus is not
expected to have a significant impact on afternoon temperatures.
Look for highs to reach the upper 60s to upper 70s. A lake breeze
will likely move into the Minnesota Arrowhead once again today
keeping temperatures along and within a few miles of the shore in
the low to upper 60s. A weaker lake breeze may move into northern
Wisconsin, but the affects will be more subtle. Think we`ll see
efficient mixing similar to yesterday, and have kept afternoon
humidity on the drier side of the bias-corrected guidance. This
includes areas in northwest Wisconsin and central Minnesota where
mainly cloudy skies are indicated. Think the clouds will be thin
enough to permit plenty of insolation. With very dry airmass in
place and aloft, even shallow mixing should result in very dry
humidity values.

Shortwave trough moves off to the east tonight, ending the shower
chances while clouds are slow to depart. Overnight lows will not
be as cool with readings from the upper 30s north to the upper 40s
south.

Tuesday looks quiet once again with highs in the upper 60s to
upper 70s. Partly cloudy skies will linger across the south during
the morning with increasing sun for the afternoon. Northwest
winds will bring in a little more moisture. Was not as aggressive
with afternoon humidity, with low 20 percent values in the BWCAW
to the 30 to 40 percent range elsewhere.

.LONG TERM...(Tuesday night through Sunday)
Issued at 359 AM CDT Mon May 21 2018

Tuesday night and Wednesday upper level ridging over the area is
expected to gradually weaken and slide east across the area,
allowing a warm air advection wing to push into the area at 850mb
by Wednesday afternoon and evening. With this feature moving in,
there are increasing chances for showers and thunderstorms
Wednesday night and Thursday. These POPs are going to depend upon
moisture return into the area, which has been rather anemic
lately, with spring leaf-out running nearly two weeks later than
normal, I anticipate the models do not have a good handle on how
much evapotranspiration is actually going on for areas around
here. Temperatures will begin a warming trend for Wednesday and
Thursday as more warm air moves into the area.

The main upper low moves across the area Thursday night through
Friday into Saturday, bringing significant chances for showers and
thunderstorms. Temperatures Thursday and Friday will be on the
warm side, followed by cooling again for Saturday as the upper low
gets east of us and allows some cooler air to move in from the
north, along with cloud cover. Have begun the process of
increasing POPs, and expect we may get rainfall amounts between
half an inch and an inch of much needed precipitation.

After Saturday we turn dry and remain cool for Sunday and Monday,
with upper level ridging building in once again and a surface
ridge sliding across the area as well.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 622 AM CDT Mon May 21 2018

High pressure has led to initial VFR conditions as of issuance
time. As this area shifts to the east, a shortwave will begin to
move across the region. This will lead to increasing clouds,
especially over areas south of highway 2. This will lead to some
MVFR CIGS at KBRD and KHYR beginning around 05z...spreading to
KDLH around 08z. Ceilings at KHYR to lower to IFR after 08z as
well. Shower activity on Monday afternoon and evening looks to
remain south of the terminals. Winds are expected to remain light
through the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  70  47  75  50 /  10  10   0   0
INL  76  43  77  47 /   0   0   0   0
BRD  67  47  75  51 /  20  10   0  10
HYR  72  48  75  51 /  20  10   0   0
ASX  70  45  76  47 /  10  10  10   0

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&

$$

SHORT TERM...Huyck
LONG TERM...LE
AVIATION...LE



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