Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 301800 AAB
AFDDLH

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
100 PM CDT TUE AUG 30 2016

.UPDATE...
Issued at 100 PM CDT Tue Aug 30 2016

updated aviation discussion below for the 18z taf issuance.

&&

UPDATE Issued at 619 AM CDT Tue Aug 30 2016

The cold front is just about to exit the Wisconsin portion for the
forecast area. The remaining mid and high clouds, and patchy fog, will
erode allowing for a mostly sunny to sunny sky. No big changes.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 239 AM CDT Tue Aug 30 2016

At 07Z/2am, the cold front was moving through the region and was
located from Grand Marais southwestward to just east of Brainerd.
The last of the rain was exiting the far southern edge of the
Wisconsin forecast area. Behind the front, high pressure was
building across the region. Some cirrus was drifting into the area
from the Southwest and covered two thirds of the region. Low and mid
clouds were found from the north shore of Lake Superior, through the
Twin Ports, down the I35 corridor and points East. As the high
pressure continues across the region this afternoon, the morning
clouds will give way to mostly sunny to sunny skies.

The high pressure affects the region tonight and Wednesday. Mostly
clear to clear skies are on tap. Much cooler and drier air will
accompany the high. Minimum temps will be in the 40`s and lower 50`s
tonight. Highs Wednesday from the upper 60`s over the tip of the
Arrowhead, to the 70`s elsewhere. Dewpoints on Wednesday will be in
the 50`s.

.LONG TERM...(Wednesday night through Monday)
Issued at 239 AM CDT Tue Aug 30 2016

Sunny and seasonable through the work week with chances for storms
returning for the Labor Day weekend.

On the synoptic scale a broad mid/upper level ridge will build
across the Plains/Canadian Prairie into the Midwest/northern Ontario
through the work week with a resultant sfc high pressure building
over the Northland Thursday into the upper Great Lakes/northern
Ontario Friday. The 500mb ridge axis moves across the upper MIdwest
Friday morning with south-southwest flow through the vertical column
Friday through the weekend. Usually this would lead to a warm-up,
but because of the cooler airmass affecting the eastern two-thirds
of the country mid-week there won`t be the usual warm airmass to the
south/southwest to advect into the upper Midwest. There will be a
gradual increase in low level moisture, but doesn`t look like a
strong warm front will precede a cold front anticipated to approach
from the west late Saturday into Sunday. There will be some elevated
instability ahead of the front, but only on the order of 500-1500
j/kg MUCAPE - enough for a few strong storms, but not to the extent
that would warrant concern for widespread severe storms at this
point. Looks like the best chance for precipitation will be Sunday
into Monday - guidance has been on a gradual slowing trend with the
arrival of the best instability and cold front. Certainly some
potential for heavy rainfall Sunday night into Monday not unlike
this past Sunday into Monday.

Highs in the low to mid 70s through the long term period, except
slightly cooler along the north shore. Lows cooler in the 40s inland
Wednesday and Thursday night, but warmer into the weekend given the
expected (albeit not strong) warm air advection and cloud cover.

Looking beyond the long-term, the longwave mid-level trough stays
parked over the Desert Southwest with a ridge over New England
leading to a continued south/southwest flow supporting the
likelihood of another few mid-level disturbances moving across the
Upper Midwest with near normal temperatures.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 100 PM CDT Tue Aug 30 2016

While the cold front has cleared the entire area, the moisture
gradient behind the front continues to lag the wind shift, and
this is supporting a rather expansive area of mvfr ceilings across
northwest Wisconsin, including KHYR where an MVFR ceiling has
been persistent much of the morning. While broken ceilings at
KHYR are likely to persist for maybe another hour or two, we
expect conditions to improve to VFR by 20z at the latest.
Otherwise, northwest flow from 5-10 knots and clear skies will
persist at all other TAF sites through 18z Wed. The combination of
light winds, clear skies, moist ground, and slightly longer night
time hours may lead to some fog formation at the favored KHIB/KHYR
sites tonight and Wed morning, and a tempo group has been
introduced for MVFR fog conditions at those two TAF sites with
this issuance.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  74  53  73  51 /   0   0   0   0
INL  73  49  73  46 /   0   0   0   0
BRD  75  53  75  52 /   0   0   0   0
HYR  76  52  73  48 /  10   0   0   0
ASX  74  53  74  51 /   0   0   0  10

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...None.
LS...None.
&&

$$



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