Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 262341

Area Forecast Discussion
National Weather Service Duluth MN
641 PM CDT Wed Jun 26 2019

.SHORT TERM...(This evening through Thursday night)
Issued at 337 PM CDT Wed Jun 26 2019

High pressure overhead has kept afternoon Cu development to a
minimum this afternoon over much of the Northland. A ribbon of
low-level convergence located over far northern Minnesota has
provided enough vertical motion to trigger a band of showers this
afternoon. Some of the cloud tops have glaciated and a few
thunderstorms are not out of the question.

An area of low pressure over western Wyoming this afternoon is
forecast to move eastward along a serpentine stationary front
which undulates from southeast Wyoming to central South Dakota and
the south to eastern Iowa. A complex of thunderstorms will
develop this evening and advance eastward across the Dakotas and
into western Minnesota by 7 AM Thursday morning. The storms should
be weakening as they move into central Minnesota by late morning.
The risk of severe weather is Marginal and limited to a narrow
stripe south of a line from Motley, MN to Pine City to Phillips,
WI. Large hail and damaging wind gusts are the greatest threat.
There is also a risk of excessive rainfall from the storms during
the afternoon and evening as they move into northwest Wisconsin.
PWAT over 1.5 inches is forecast to advect into northwest
Wisconsin and adjacent areas of east-central Minnesota. With
moisture transport vectors normal to the frontal boundary by this
time, the stage will be set for heavy rainfall and training
storms. Highs on Thursday will be in the low to upper 80s, but
cooler along the north shore and north of larger inland lakes.
Shower and thunderstorms move out of the area Thursday night.

.LONG TERM...(Friday through Wednesday)
Issued at 337 PM CDT Wed Jun 26 2019

The long term is fairly active despite a large ridge building.
The weather starts off fairly quiet as the ridge inches closer
into Saturday. Saturday night a warm front will lift north into
the area bringing rich moisture-laden air with PWATs in excess of
2" per the GFS. With this comes exceptional amounts of CAPE 4000
J/Kg and bulk shear of 40 knots too. All great ingredients to
maintain strong to severe storms. The big question is whether
model depictions of the strong cap will verify under a large
ridge. This may be hard to break unless this occurs upstream and
propagates an MCS/derecho feature through the area during the
overnight hours of Saturday into Sunday. If this did happen, there
would be plenty of energy available for these strong storms to
feed off of. I think all severe threats are on the table for this
event: flash flooding, strong winds, large hail, and tornadoes.
Hodographs are nicely curved with helicity values in excess of 400
m2/s2 around midnight Sunday morning. I would not be surprised to
see a derecho evolve from this pattern - though deciphering the
location of that is still too uncertain.

A cold front crosses the area Sunday into Monday brining more
convection though intensities should be more typical of
thunderstorms of the ordinary type, i.e. small chance for any
severe for this feature. Instability lingers through the middle of
next week for on/off chances for thunderstorms.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 641 PM CDT Wed Jun 26 2019

VFR through the forecast with high pressure nearby through 12Z.
After 12Z, a thunderstorms complex will be moving through central
Minnesota and my bring a glancing blow of showers. However, latest
model trends are suggesting this activity will stay south of the
terminals through the forecast. Low confidence with the mention of
thunder and have left out. Have a VCSH mention for the possibility
of some rain near DLH/BRD/HYR by mid morning.


Issued at 337 PM CDT Wed Jun 26 2019

Southwest winds of 10 to 15 knots though generally wave heights
should remain below two feet for the nearshore waters. A chance
for an isolated storm on Thursday, mainly west of a line from Two
Harbors to Port Wing, then a more widespread threat for storms
over the weekend, especially Saturday into Sunday where the severe
threat is fairly high.


DLH  58  81  58  80 /  10  30  30  10
INL  55  84  56  85 /   0   0  10  10
BRD  60  83  62  87 /  10  40  20  10
HYR  58  84  60  88 /  10  60  40  20
ASX  58  82  56  80 /  10  40  40  20




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