Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 281739
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1239 PM CDT WED SEP 28 2016

.UPDATE...
Issued at 1239 PM CDT Wed Sep 28 2016

Updated for the new 18Z Aviation Discussion below.

&&

.SHORT TERM...(Today through Thursday)
Issued at 325 AM CDT Wed Sep 28 2016

A stacked low over Lake Superior is finally departing, moving
south/southeast towards the Ohio Valley, which will result in
decreasing chances for rain and gradually clearing skies tonight into
Thursday. Temperatures will be on a warming trend for highs - in the
mid 50s to near 60 today, upper 50s to mid 60s Thursday - with
tonight the coolest night of the week as skies clear out and lows
fall into the upper 30s to low 40s, coolest across north-central
Minnesota.

On the synoptic scale the stubborn upper low is finally exiting
stage-right, but not without another cloudy day across the
Northland. Mid and low-level moisture looks to continue to wrap
around the low resulting in mostly cloudy skies today, but less wind
today compared to the breezy past two days. Highs will be warmer as
the coolest air aloft departs to the east and some breaks in the
clouds are possible. Across northwest Wisconsin and especially east
of the Bayfield peninsula showers/sprinkles will continue to be
possible through the day. Late today into tonight a mid-level ridge
will build in from the west aloft and a surface high centered near
Lake of the Woods builds leading to clearing skies and calm
conditions. Fog/stratus will be possible towards Thursday morning,
mainly across inland areas of northwest Wisconsin where the best
leftover boundary layer moisture will be located. If skies clear
earlier than anticipated some parts of northern Minnesota could
approach the mid 30s, but given the cloud coverage upstream do not
anticipate any kind of widespread frost - most locations will have
lows in the 40s with the coolest spots in the upper 30s. Warmer with
more sun on Thursday as high pressure continues to build in from the
west. Most of the warmth can be attributed to the solar heating as
temps aloft Thursday will be about the same as today (850mb temps
around +3 to +6C).

.LONG TERM...(Thursday night through Tuesday)
Issued at 325 AM CDT Wed Sep 28 2016

High pressure will initially nudge its way into the Upper Midwest
from Ontario as a cutoff low rotates along the Ohio River Valley.
This will bring dry and quiet weather for Friday. Low temperatures
will be in the 40s Thursday night. High temperatures on Friday will
be in the mid to upper 60s.

Cloud cover will increase on Saturday, mainly across NW WI, as the
cutoff low retrogrades from the Ohio River Valley into the central
Great Lakes. Expect the high to continue nudging into NE MN, which
should keep the clouds at bay. Due to the cutoff, increased to
chance POPs across far eastern portions on NW WI. Both the
GFS/ECWMF/GEM are in good agreement with the cutoff pushing
northeastward into the central/eastern Great Lakes. Highs on
Saturday and Sunday will be in the 60s with low temperatures in the
40s throughout the Northland.

After Sunday, the GFS/ECMWF/GEM synoptically are a little different
in kicking out the cutoff system with the GFS/GEM being more
progressive than the ECMWF. This system will eventually move into the
Northeast US while a trough digs and deepens across the Western half
of the US. Ahead of the trough, an area of low pressure will develop
in the Plains. This will bring the next chance of showers/storms for
Monday through Wednesday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1239 PM CDT Wed Sep 28 2016

The cool north-northeast flow across northeast Minnesota and
northwest Wisconsin will continue into tonight, while a high
pressure will slowly move into the region from the northwest. The
cool flow has helped develop widespread broken/overcast MVFR
cumulus ceilings across the Northland today, with conditions
further becoming cloudier than earlier forecasts. The HRRR and
4-km NAM have been doing really well in depicting the widespread
low-level cloud cover, where most other models have been much
clearer. The HRRR and 4-km NAM continue to maintain this cloud
cover through at least Wednesday, despite the high pressure
nudging into the region tonight and Wednesday. I trended the
aviation forecasts cloudier, adding longer periods of MVFR
ceilings today into tonight. May need to keep the MVFR even
longer, but there is still a bit of chance of enough scattering of
the cloud cover before sunset. Whatever cloud cover remains by
sunset will have a difficult time dissipating overnight.

Since it looks like tonight will be cloudier than earlier
forecast, the threat of fog developing later tonight does not
appear to be as much as before. However, wherever there are
pockets within the cloud cover overnight, fog could develop.
Therefore, kept some lower IFR/MVFR visibility later tonight to
suggest the possible fog.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  58  45  60  45 /   0   0   0   0
INL  57  41  61  41 /   0  10   0   0
BRD  60  42  64  45 /   0   0   0   0
HYR  58  45  63  43 /  20  10   0   0
ASX  58  48  61  45 /  30  10  10   0

&&

.DLH Watches/Warnings/Advisories...
WI...Beach Hazards Statement until 8 PM CDT this evening for WIZ001.

MN...Beach Hazards Statement until 8 PM CDT this evening for MNZ037.

LS...Small Craft Advisory until 4 PM CDT this afternoon for
     LSZ140>147.

     Small Craft Advisory until 10 PM CDT this evening for LSZ121-148.

&&

$$

UPDATE...Grochocinski
SHORT TERM...JJM
LONG TERM...WL
AVIATION...Grochocinski



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