Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
FXUS63 KDLH 161820

Area Forecast Discussion
National Weather Service Duluth MN
120 PM CDT SUN OCT 16 2016

Issued at 120 PM CDT Sun Oct 16 2016

Updated for the new 18Z Aviation Discussion below.


.SHORT TERM...(Today through Monday)
Issued at 417 AM CDT Sun Oct 16 2016

Weak ridge of high pressure nosing into northern Minnesota early
this morning, with the cold front from yesterday now well off to our
east.  Skies have cleared for the most part, and have allowed fog to
develop over mostly northwest Wisconsin so far this morning.  Drier
air to the northwest has prevented fog development in Minnesota for
the most part.  Today this surface ridge to slowly shift east across
the area, allowing southeast flow to develop over the land by this
afternoon.  A surface low will be developing out over eastern
Montana, which is going to cause a strong east to northeast wind to
develop over Lake Superior.  As a result, while we should get into
the 60s for most land locations, it will stay in the 50s near Lake
Superior, especially along the north shore, though this is going to
depend on when the easterly flow sets in.   This low pressure that
develops over eastern Montana today will shift into western North
Dakota by this afternoon, with a decent shortwave aloft and warm air
advection going on at 850mb. These features to generate a band of
warm air advection driven showers and a few thunderstorms that
develop over eastern North Dakota this afternoon, and move across
northern Minnesota early this evening.  Warm and humid air will be
streaming into this system from the south, and by this evening some
thunderstorms should also develop in the warm sector ahead of a cold
front and spread northeast tonight.  In fact, we have not only
general thunder over the area tonight, but SPC has placed a marginal
risk of severe storms over the southern third of the forecast area.
Instability is somewhat marginal, but the dynamics of the system are
strong enough to make the most of the limited instability.  The
timing and placement of convective initiation this afternoon/evening
is uncertain, but should be generally in west central or central
Minnesota, then spreading east-northeast tonight.  After this wave
moves through, an 850mb baroclinic zone will remain draped across
the area, and another upper level wave will move along it, bringing
another round of showers and thunderstorms that should develop in
the afternoon over western Minnesota and spread northeast across the
forecast area once again.  There is some uncertainty in timing and
extent with this wave as the initial wave is going to set up some
critical features for tonight.  Conditions will be relatively warm
through Monday, with above normal temperatures.

.LONG TERM...(Monday night through Saturday)
Issued at 417 AM CDT Sun Oct 16 2016

A good consensus between the latest model guidance initially in the
long term. A shortwave trough will slide northeastward from the
Northern Plains late Monday evening, into Quebec by late on Tuesday.
Ahead of the trough an area of low pressure will develop along a
stalled out front in southern MN or WI. The GEM is a bit slower and
weaker with this feature moving through, but think the GFS/ECMWF and
NAM have a good handle on the situation. With strong 900 hPa to 700
hPa frontogenesis occurring ahead of the developing low, expect
showers and thunderstorms to develop as the low strengthens. This
will combine with a few hundred J/kg of MLCAPE and 70-80 kts of 0-6
km bulk shear confined over northern WI. So there will be a
potential for strong thunderstorms as highlighted in the latest Day
2 SPC Outlook for Monday evening into early Tuesday morning.
Overnight low temperatures will fall into the 40s throughout
the Northland.

Will see precipitation come to an end across NW WI during the
morning hours on Tuesday as the low moves off to the northeast. Will
see a period of dry weather from Tuesday afternoon through Wednesday
evening with quasi-zonal 500 hPa flow across the region. High
temperatures on Tuesday range from the mid 50s in the International
Falls area, to the mid 60s in NW WI. Expect cooler temperatures on
Wednesday as colder 850 hPa advects into the region due to northwest
flow aloft. Readings will be in the 40s and low 50s in NE MN, and in
the low to mid 50s in NW WI.

Precipitation chances return late on Thursday to the MN arrowhead
and far eastern portions of NW WI as a longwave trough moves across
the Upper Midwest into the central Great Lakes by the evening. Model
consensus is still in decent agreement this far out, however the
ECWMF is a bit more progressive and weaker than the GFS/GEM
solutions. Regardless, will still see cold air advection bringing
the coolest temperatures of the week with readings in the 40s
throughout the Northland. Still expect precipitation to remain all
rainfall at this point.

Late in the week and heading into the weekend, there is good
agreement between the GFS/ECMWF with the longwave trough lifting
into the Mid Atlantic/Northeast. Upstream of the longwave, guidance
shows shortwave troughs moving into the area with large differences
in timing and strength. As a result kept low precipitation chances
for Saturday. Highs Friday through Sunday range from the mid 40s to
the mid 50s.


.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 120 PM CDT Sun Oct 16 2016

There was VFR conditions, scattered high clouds, and light east to
east-southeast winds across the Northland as of early this
afternoon. Expect increasing high clouds this afternoon into this
evening as low pressure approaches from the west.

Showers and scattered thunderstorms are expected tonight when an
occluded/warm front lifts into the region from the west and
southwest. Also, a strong low-level jet will develop, about 40 to
50 knots, bringing a period of substantial low-level wind shear.

There will be lowering ceilings, and probably visibility too, in
the wake of the passing front and showers. Expect a transition
from VFR to IFR/LIFR conditions early Monday morning. High clouds
Wednesday morning will delay how quickly the low ceilings can lift
or move out of the area amids the light westerly flow Monday
morning. May need to lower visibility for KDLH because fog is
possible from the east flow, with the most likely time for 1/4 or
1/2 mile visibility being some time between 7 am and 9 am.


DLH  56  48  61  47 /  10  80  40  70
INL  57  46  61  44 /  30  60  10  10
BRD  63  52  63  47 /  10  60  50  60
HYR  65  56  66  49 /  10  80  50  70
ASX  60  50  63  49 /  10  90  50  70


.DLH Watches/Warnings/Advisories...
LS...Small Craft Advisory until 10 AM CDT Monday for LSZ140>146.



AVIATION...Grochocinski is the U.S. government's official web portal to all federal, state and local government web resources and services.