Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 241708

Area Forecast Discussion
National Weather Service Duluth MN
Issued by National Weather Service TWIN CITIES/CHANHASSEN MN
1208 PM CDT Wed May 24 2017

Issued at 1207 PM CDT Wed May 24 2017

Updated to include 18Z aviation discussion below.


.SHORT TERM...(Today through Thursday)
Issued at 313 AM CDT Wed May 24 2017

A mid-level shortwave situated over southern Iowa this morning will
continue to dive to the south and east today, allowing a mid- to
upper-level ridge to develop from the west. There is a lingering
ribbon of positive vorticity advection in the 500 mb progs, which
will help to focus some small precipitation chances over a small
portion of northwest Wisconsin this afternoon, mainly over Price
county. Not expecting much in terms of accumulation from this
precipitation, as only light rain showers/sprinkles are expected.
Otherwise, once this PVA ribbon moves off to the east, drier
conditions will prevail through much of the day Thursday. Some areas
of fog are possible overnight tonight into Thursday morning,
especially from the Twin Ports and southeast across northwest
Wisconsin. Some of the guidance is a bit more aggressive on the fog
tonight, given the development of a low-level inversion as shown in
the NAM soundings. Favorable dewpoint depressions, along with light
winds, will create conditions suitable for fog development in these

Sfc low pressure center will slowly translate over the Ohio River
Valley today and Thursday, along with sfc high pressure over Hudson
Bay, Canada, maintaining a northeast flow over Lake Superior, so
temperatures will be cooler along the lake today and tomorrow, with
highs today into the lower to mid 50s along Lake Superior and into
the lower to mid 60s further inland. Temperatures inland should be a
bit warmer for Thursday compared to today as winds become more
southerly, with highs inland into the 60s, with some mid 50s still
expected along Lake Superior.

A mid-level shortwave trough will develop over the Intermountain
West and advance eastward over southern Saskatchewan and Manitoba
Canada tonight and Thursday, bringing another chance of rain
showers, from west to east across much of the area Thursday
afternoon and into the evening hours. Again, not expecting much of
accumulations through the afternoon. This precipitation looks to be
supported by a push of 850-700 mb warm air advection ahead of the

.LONG TERM...(Thursday night through Tuesday)
Issued at 313 AM CDT Wed May 24 2017

The extended period will be somewhat unsettled through Tuesday. At
this point, the models do not indicate any major storm systems but a
series of shortwaves will move through the forecast region,
keeping a chance of showers and occasional thunderstorms. A slow
moving low pressure area will move through southern Canada
spinning off the shortwaves through the weekend. There will be a
chance for thunderstorms Sunday and Monday afternoon as stronger
impulses move through the region. Temperatures will be at or a
little above normal through the extended forecast period.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1207 PM CDT Wed May 24 2017

Weak surface ridge to the northeast will slide away through the
period as a trough of low pressure approaches from the west. There
are currently a few showers with the more robust cu field over
mainly the northern portion of the area, so a brief shower or few
sprinkles can`t be ruled out, but ceilings have climbed into the
VFR range pretty much everywhere at this point. We will see some
warm advection associated with that feature work into the western
portion of the area toward the end of the period, with an increase
in mid/high clouds. KHIB could see a slightly lower deck toward
the tail end of the period, but still looks to be VFR. The LAMP
guidance is bullish on some low ceilings overnight for many
locations, but don`t see much in the raw output from the various
guidance to support it, and previous forecasts also didn`t buy
into the idea. So, left any mention of that out of the forecasts
for now.


DLH  57  39  60  45 /  10   0   0  40
INL  66  40  67  49 /   0   0  30  40
BRD  62  44  68  51 /   0   0  30  20
HYR  61  39  70  50 /  10   0  10  40
ASX  55  36  60  44 /  10   0   0  30




LONG TERM...Stewart
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