FXUS63 KDLH 250829

Area Forecast Discussion
National Weather Service Duluth MN
329 AM CDT Sun Aug 25 2019

.SHORT TERM...(Today through Monday)
Issued at 329 AM CDT Sun Aug 25 2019

A positively tilted upper level trof will lift slowly northeast into
the Dakotas/Minnesota border area through the morning. A southerly
flow of moisture is occurring ahead of the trof and has resulted in
the cloud cover over most of the forecast area at 07Z. There will be
some breaks in the cloud cover this morning, but will be relatively
short lived as the moisture increases and so does the cloud cover,
filling in those holes. Lack of forcing ahead of the trof precludes
a mention of rain, as does the dry high pressure that has been
affecting the region continuing to hold a grip over the eastern half
of the area.

The trof moves into western Minnesota this afternoon. Moisture
continues to increase over the western third of the area just ahead
of the trof. Forcing increases with embedded impulses lifting into
this portion of the area to generate some rain. Farther east, the
dry air hangs tough with the high pressure still influencing this
area. Thermodynamics are weak to near zero from all models and will
leave out a mention of thunder today.

The aforementioned upper trof lifts through the eastern third of the
forecast area tonight. With plenty of moisture advecting into the
region, and embedded impulses with the trof, have pops increasing
through the night. Have a mention of thunder over the western edge
of the region with enough instability/thermodynamics to support the
mention. The rain will be moving steadily, which will result in
lower QPF amounts for tonight and limit any excessive rainfall.

On Monday, a closed upper low that was responsible for ejecting the
previously mentioned trof, will reach central Manitoba in the
afternoon. Another trof ahead of the upper low, with more embedded
impulses, will affect the area through the day and have pops
increasing from west to east in the morning. A delay in the rain
over the eastern edge of the area due to any lingering dry air
having to be overcome and is indicated by some of the models, and
have lower pops as a result. Rainfall amounts on Monday will
approach, or exceed, one inch for the day. Not expecting any
flooding as the region has been extremely dry for the last week and
much of the rain will just be absorbed into the ground.

.LONG TERM...(Monday night through Saturday)
Issued at 329 AM CDT Sun Aug 25 2019

An upper low centered over the Manitoba Lakes Monday evening will
move into northwest Ontario Tuesday. A chance for showers and a few
thunderstorms will continue Monday night, mainly over northern
Minnesota and expand in coverage over much of the Northland Tuesday.
Cool temperatures aloft, 850MB temperatures from 5-9C, will combine
with the upper low to produce widespread showers Tuesday. Chances
Tuesday will be highest over northern Minnesota but much of the
Northland will see periodic showers. A thunderstorm will be possible
as well, although instability will be limited. Highs Tuesday will
only be in the lower sixties over far northern Minnesota to 65 to 70
over northwest Wisconsin. In addition to the showers and cool
temperatures, gusty westerly winds will occur from 25 to 35 mph.

The upper trough will move east of the region by Wednesday evening
but until then, showers will continue to be possible through
Wednesday with chances highest over far northern Minnesota. It will
again be cool with highs from the lower to mid sixties.

The ECMWF is now faster than the GFS moving a cold front through the
Northland Thursday with the GFS moving it through Thursday night.
There will be a chance for showers with this front and for now we
have some low POPs Thursday over northern Minnesota but these will
likely need to be expanded and perhaps adding some thunder once
the models come into better agreement.

High pressure will then lead to dry conditions for most areas late
in the week into the weekend. Highs will be below normal and be in
the mid sixties to around seventy.


.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1211 AM CDT Sun Aug 24 2019

A low pressure system approaching from the west will produce
deteriorating conditions through the TAF period. Initial VFR
conditions to deteriorate into MVFR stratus and fog for most of
the sites for at least a few hours in the 08Z-13Z time range,
then return to VFR. The low pressure system will push lowering
ceilings and chances for showers into the area after 21Z, with
MVFR ceilings and visibilities in showers. Thunderstorms are
possible, but timing and location are uncertain so have left out
of terminals for now.


Issued at 329 AM CDT Sun Aug 25 2019

A trough of low pressure will extend through the Northern Plains
today and a low will deepen and move into northwest Ontario Monday
evening. Winds today will be or become east to southeast for most
areas with speeds less than 15 knots. The wind should veer slightly
tonight to more southerly at 15 knots or less tonight. Winds will be
more variable across the lake Monday and we followed the higher
resolution models which depict winds more southerly along the South
Shore, east to southeast along the North Shore and easterly in the
Twin Ports area. Winds will turn westerly Monday night and increase
quite a bit into Tuesday. Westerly winds from 15 to 22 knots will
occur Tuesday into Wednesday with gusts 25 to 35 knots.


DLH 73 57 68 55 / 10 90 100 20
INL 75 62 70 53 / 40 100 100 40
BRD 72 60 72 55 / 60 100 80 10
HYR 74 60 73 54 / 10 50 90 40
ASX 77 56 76 55 / 0 50 90 50




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