Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 46 47 48 49 50

FXUS63 KDLH 140221

Area Forecast Discussion
National Weather Service Duluth MN
921 PM CDT Wed Sep 13 2017

Issued at 921 PM CDT Wed Sep 13 2017

Showers and storms have yet to form this evening and the latest
guidance suggests they will take a bit longer to form so we
delayed them by a couple hours.

Fog was also forming already and we expanded the mention,
especially across northern Minnesota.


.SHORT TERM...(This evening through Thursday)
Issued at 332 PM CDT Wed Sep 13 2017

The unseasonably warm and humid weather will continue into
Thursday as a stationary front over far northern Minnesota does
not make much movement during the time. The subtle front extends
from Ontario, north of Lake Superior, across north-central
Minnesota into southern Red River Valley. The front and passing
weak shortwaves overnight might trigger some showers and storms
near the Canadian border this evening and overnight. This
evening`s storms would likely develop over parts of Koochiching
County, and the environment could favor brief strong storms
capable of small hail and heavy rain.

The relatively humid dew point temperatures will prop up
temperatures tonight, despite light wind flow and mostly clear
skies for much of the night for most areas. Overnight low will be
in the upper 50s to lower 60s. Fog is possible later tonight.

The quasi-stationary front will make a little southward and
eastward movement into northeastern Minnesota Thursday. Additional
shortwaves will likely lift into the Northland in the afternoon,
and the shortwave`s forcing will likely trigger more showers and
thunderstorms, especially across much of northeastern Minnesota
near the front. There might be up to 2500 J/kg of MUCAPE and 25 to
35 knots of 0-6 km deep layer wind shear, as well as 1.5 inches
of precipitable water. Some of the storms could be strong to
borderline severe, capable of hail and heavy rain.

Cloud cover will limit heating across the north Thursday, whereas
there will be more plentiful sunshine across northwest Wisconsin
into central Minnesota. Highs should range from the upper 60s to
middle 70s across northern Minnesota, to the lower 80s across
northwest Wisconsin into central Minnesota.

.LONG TERM...(Thursday night through Wednesday)
Issued at 332 PM CDT Wed Sep 13 2017

Thursday night through early Saturday the warm front that will
have been draped across the area from eastern South Dakota
northeast across the forecast area will serve as a focus for
waves of showers and thunderstorms that will move across the area.
For now the most likely periods to see showers and thunderstorms
is Thursday night, and again Friday afternoon and evening as
shortwaves move across the area. Of note, there will be enough
instability and shear for a marginal risk of severe storms, though
this is likely to be very limited. Temperatures through the
period will be on the warm side, but the cloud cover will keep us
from getting as warm as we have today.

The surface low and a fairly strong upper level shortwave will
move out of the plains and across the forecast area on Saturday,
bringing yet another round of showers and thunderstorms during the
afternoon and evening. Considering the synoptics of the situation
severe storms seem possible somewhere along the cold front as it
trails behind the surface low, but this is likely to be south of
the forecast area.

Sunday and Monday it will be cooler across the area as the
surface low and upper level trough axis shifts east of the
forecast area, with some cooler air moving into the area from the
northwest. In fact, would not be very surprised if we need to
lower the minimum temperatures, and we may need a frost advisory
for one of those nights.

Precipitation chances return for the early part of next week, but
there is considerable disagreement on this for Tuesday and
Wednesday, and do not have good confidence for this period. Have
carried low chance pops for now, but we may be able to dry out
some of these periods.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 638 PM CDT Wed Sep 13 2017

A frontal boundary extended from western South Dakota east then
north into northern Minnesota this evening. VFR conditions were
occurring with no showers or storms yet. There will be a chance
for showers/storms along the frontal boundary tonight with chances
ramping up Thursday afternoon and night. Fog will be possible
tonight leading to IFR or LIFR conditions in spots. The fog will
lift Thursday morning with MVFR ceilings continuing over parts of
far northern Minnesota. More IFR or MVFR conditions will occur
under stronger storms, especially later Thursday afternoon into
Thursday night.


DLH  60  76  59  67 /  10  30  60  30
INL  59  68  53  59 /  40  40  50  60
BRD  62  82  61  75 /  10  30  40  40
HYR  61  82  61  80 /   0  10  40  10
ASX  60  82  58  74 /  10  10  50  20




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