Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 171737

Area Forecast Discussion
National Weather Service Duluth MN
1237 PM CDT Thu Aug 17 2017

Issued at 1218 PM CDT Thu Aug 17 2017

Updated for the 18z Aviation Discussion below.

UPDATE Issued at 1037 AM CDT Thu Aug 17 2017

Updated the forecast through tonight, mainly to reflect the latest
consensus of the higher resolution short term models` timing on
the rain. Also, think once it clears up later tonight and light
wind speeds develop, a good setup for fog will develop considering
residual soil moisture from the rain. Added patchy/areas of fog to
parts of the Northland. The best chances of fog will be across
northeast Minnesota because of better clearing, and because those
areas received the greatest rainfall.

UPDATE Issued at 640 AM CDT Thu Aug 17 2017

Updated aviation section below for 12Z TAF TAF issuance.


.SHORT TERM...(Today through Friday)
Issued at 415 AM CDT Thu Aug 17 2017

Rain comes to an end today as the low pressure system centered over
the Twin Cities early this morning lifts northeast towards eastern
Lake Superior tonight. Rain showers will gradually come to an end
from west to east today, with winds becoming out of the north in the
wake of the low. Clearing skies tonight as drier air briefly moves
in, then a chance for diurnally-driven showers and storms for parts
of central/north central Minnesota on Friday afternoon as a mid-
level shortwave trough races across the eastern Dakotas southeast
towards southern Minnesota. Limited instability and weak winds
through the column will lead to just some isolated/scattered short-
lived showers and storms, but certainly not a washout. Cooler today
in the 60s for highs, then lows in the 50s tonight as skies clear
out. Warmer with highs in the mid 70s to near 80 Friday.

.LONG TERM...(Friday night through Wednesday)
Issued at 415 AM CDT Thu Aug 17 2017

Friday night and Saturday a ridge of high pressure should keep the
weather relatively quiet for the area, with temperatures slightly
above normal.

Saturday night and Sunday a weak cold front is progged to drop
through the area from the northwest, accompanied by a weak shortwave
aloft.  Do not expect much out of this boundary either period, but
am carrying some slight to low end chance pops with above normal

Sunday night through Monday night the cold front sags to just south
of the area, and serves as the focus for shower and thunderstorm
development as a shortwave ripples across the area through the broad
troughing aloft.  At this time range am not terribly confident in
the timing of this wave, but models have been rather consistent over
the last few runs and have gone with chance to low end likely pops
for some areas during this time range.  Unless this trend changes,
it is likely to be too cloudy for eclipse watching in the local area.

Tuesday through Thursday appear to be dry for the area with the
upper level trough to our east and northwest flow aloft with a
strong surface ridge building into the area.  Temperatures cool off
to near to below normal values.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1237 PM CDT Thu Aug 17 2017

MVFR to LIFR conditions will gradually improve through the
afternoon as an area of low pressure, currently located over
west-central Wisconsin, will continue to move northeast. Winds
will continue to turn more north to northwesterly as the low
pressure advances northeastward. A tightening sfc pressure
gradient on the backside of the low will support gusty conditions
over KDLH, KHIB, KBRD, and KHYR TAF terminals, with gusts between
15 to 25 kts possible. Ceiling heights will remain in the
MVFR/IFR range this evening, with some improvement overnight.

An area of high pressure will then move into the region for early
Friday, which will cause the winds to go light. This, coupled with
saturated soil conditions, will lead to the development of fog
in some locations. Some of the model guidance is indicating fog
to drop to IFR categories, but confidence isn`t high enough at
this point to go with this solution. Instead, went with more MVFR
vsby reductions.


DLH  65  55  76  56 /  80  10  20  10
INL  67  50  77  53 /  90  10  20  10
BRD  68  54  76  54 /  80   0  30  20
HYR  69  56  75  54 /  80  20  20  10
ASX  67  59  76  57 /  70  40  10  10


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 10 PM CDT this evening for LSZ141>143-

     Small Craft Advisory until 4 PM CDT this afternoon for LSZ144-

     Small Craft Advisory until 4 AM CDT Friday for LSZ121-140-148.



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