Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 221126
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
626 AM CDT FRI JUL 22 2016

.SHORT TERM...(Today through Saturday)
Issued at 353 AM CDT Fri Jul 22 2016

Another day of above-normal temperatures today but not as humid the
past few days. Sunny skies today due to high pressure building in
across the upper Midwest, then increasing clouds late tonight into
Saturday as a warm front lifts north into the region. A chance for
showers and thunderstorms during the afternoon, with storms likely
in the evening.

High pressure building in across southern Canada, stretching
southeast across the Midwest behind the cold front that moved
through yesterday. While there will not be much in the way of heat
relief - 850mb temps in the 16-21C range today - the cold front has
cleared out the low 70s dew points that were prevalent across
northwest Wisconsin yesterday, and dew points are generally expected
to continue to lower today in the northwest flow. Upstream dew
points are in the upper 50s to low 60s, and through the afternoon
those kinds of dew points are expected across northeast Minnesota.
Highs today will be in the upper 80s to low 90s - fairly similar to
yesterday. Breezy northwest winds across the MN Arrowhead and along
the south shore of Lake Superior as sunny skies will lead to deep
mixing, perhaps as high as 700mb, resulting in gusts to 20-30mph in
the afternoon. Outside of the arrowhead weaker northwest winds can
be expected as winds aloft are not as strong.

Clear skies this evening, with increasing high-level clouds from
west to east across north-central Minnesota due to late day
convection expected across the eastern Dakotas. High pressure
centered over central Manitoba will move east into northwest Ontario
resulting in light/variable winds overnights gradually becoming
easterly by Saturday morning. Temperatures will fall to the low to
mid 60s, with some locations across northeast Minnesota and
especially northern parts of the Arrowhead may fall to the upper
50s.

On Saturday light east to southeast winds combined with some high-
level clouds will result in slightly cooler temperatures - highs
only in the low to mid 80s with low to mid 70s along the Lake
Superior shoreline and surrounding areas. However, low level
moisture will be on the increase as a warm front rapidly advances
north through Minnesota and Wisconsin, resulting in dew point values
approaching the low 70s in the Brainerd Lakes/Lake Mille Lacs area
in the afternoon. Isolated showers and storms are possible by the
early afternoon across north-central to east central MN, with higher
confidence in mid to late-afternoon scattered to widespread
thunderstorms moving into this area, with storms expanding into
northeast Minnesota and northwest Wisconsin. These storms will be
strong to severe, especially if early-day activity does not
materialize. Moderate to extreme instability will develop by late
day with 2500-4000 j/kg MUCAPE along and behind the warm front which
is expected to be along the Highway 2 corridor by 00z. Wind profiles
are favorable for sustaining organized clusters with 25-35 knots of
deep-layer shear present along and behind the warm front, with a
north-northeast storm motion of 20-30mph. With such a warm airmass
still in place (despite the cooler high temps), 0c height of 14-
15kft AGL will result in less of a hail threat with these storms.

.LONG TERM...(Saturday night through Thursday)
Issued at 353 AM CDT Fri Jul 22 2016

Saturday night looks like another active night across the forecast
area, with the surface low over southern Manitoba with a cold front
slowly advancing across Minnesota during the evening.  A very warm
and unstable airmass will have been pulled up into the region ahead
of the cold front, and will ride up over a leading warm front
extending east to northwest Wisconsin just south of Lake Superior.
Between the instability and the shear parameters, we are looking at
another round of severe weather during the afternoon and evening.
Have increased pops through the period and refined the timing
somewhat.   The front sweeps far enough east early Sunday morning to
bring the precipitation to an end.  Showers and a few thunderstorms
may affect the area in the west-northwest cold air advection on the
southwest side of the low, with precipitation chances limited to
along the Canadian border.

Sunday and Monday the heat and thunderstorm chances let up somewhat,
with highs by Sunday in the mid 70s and low 80s, warming only
slightly for Monday.

Large model differences bring more uncertainty to the forecast by
mid week, with fairly fast zonal flow with some fast moving
shortwaves within it.  Each of the models have some fairly
significant placement and timing differences, so have kept some
small precipitation chances in the forecast Tuesday through Friday.
Temperatures will be near to slightly above normal during this time
range.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 623 AM CDT Fri Jul 22 2016

VFR conditions expected through the forecast period. Lingering fog
expected to diminish by 13z this morning. Northwest winds may
become gusty this afternoon 17z-23z, with gusts in the 15-20kt
range. Fog may once again affect the terminals after 09z, and have
put MVFR visibilities into the terminals at the locations most
likely to be affected.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  88  63  79  62 /  10   0  60  80
INL  86  60  82  62 /   0   0  60  80
BRD  90  66  84  65 /  10  10  70  70
HYR  90  63  87  66 /  10   0  60  80
ASX  92  63  82  64 /  10   0  50  70

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...None.
LS...None.
&&

$$

SHORT TERM...JJM
LONG TERM...LE
AVIATION...LE



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