Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 231748
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1248 PM CDT SAT JUL 23 2016

.UPDATE...
Issued at 1248 PM CDT Sat Jul 23 2016

Updated for the new 18Z Aviation Discussion below.


&&

.SHORT TERM...(Today through Sunday)
Issued at 408 AM CDT Sat Jul 23 2016

We have quiet conditions across the forecast area this morning, with
a weak surface ridge over Ontario.  A surface low over southeast
Montana with a stationary front draped east across South Dakota and
northern Iowa.  This surface low is expected to move east across
South Dakota, and drag the warm front north into southern Minnesota
and the North/South Dakota border.  Convection is expected to form
this afternoon ahead of the surface low in the vicinity of this warm
front, then slide southeast tonight.   The main question driving the
location of the convection will be the position of the warm front.
It may surge as far north as the southern portions of the forecast
area, which would produce significant afternoon convection over the
southern half of the forecast area.  However, some models are
keeping it farther south closer to the I-94 corridor, which would
keep the strongest convection across southern Minnesota this
afternoon and evening.  We would still get thunderstorms, but
without the juice for much severe weather or heavy rain.  Folks up
here involved in clean-up activities from the last two rounds of
severe weather would probably appreciate it if we could make that
latter solution work out.  However, at this time I cannot rule out
either one, and we will have to wait and see how things develop over
the next several hours before making that call. Thus...have kept the
Flash Flood watch going for about the southern two rows of zones of
the forecast area for this afternoon and tonight.  The extra cloud
cover over the area today along with the warm front to our south
will keep temperatures cooler today, with highs expected to get into
the lower 80s north to the mid 80s south. Sunday to be much quieter
with westerly flow behind the cold front with a surface low up in
Ontario.  Expect fairly breezy conditions with steep low level lapse
rates and reasonable mixing heights. Highs to cool farther, ranging
from the upper 70s to low 80s.

.LONG TERM...(Sunday night through Friday)
Issued at 408 AM CDT Sat Jul 23 2016

A shortwave trof will be departing Sunday night, while at the
surface, high pressure will be building into the area. Weak upper
level and surface ridging will cover the area on Monday. Monday
evening will be dry as well with some ridging nearby. However, a
transition to a fast quasi-zonal flow aloft occurs late Monday
night. This pattern remains in place through Thursday night. A
series of embedded pieces of short waves will travel across the area
and bring round after round of precipitation to the region.
Thermodynamic profiles suggest a mention of thunderstorms is
warranted through Wednesday. By Wednesday night, the best
instability will remain to the south of the region and have a
mention of showers through Thursday night. A more vigorous trof
begins to carve its way through the forecast area by Friday.
Meanwhile, high pressure over Hudson Bay tries to influence the
sensible weather. Have used a consensus of models which results in a
mention of showers as the best thermodynamics remain south of the
region. Max temps will be in the 80s on Tuesday, but only in the 70s
for the rest of the week with the cloud cover and rain chances each
day.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1248 PM CDT Sat Jul 23 2016

There will be increasing chances of showers and storms this
afternoon into the evening across the Northland, and some storms
could be strong to severe. Heavy rain is possible because of the
abundant moisture in the overall atmosphere, and damaging winds
are another concern. It will be difficult to time storms beyond a
few hours because of the nature of the environment, with many
factors at play and lack of model agreement. The greatest risk for
heavy rain and flash flooding is for the KBRD/KDLH/KHYR areas.

The showers and storms will spread east overnight as a cold front
works its way into the Northland from the west. There will likely
be lowering conditions to IFR/MVFR ceilings and/or visibility in
the wake of the passing showers. Once stronger westerly winds kick
in around or shortly after sunrise, there should be a return to
mostly clear skies and VFR.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  79  61  80  60 /  70  80   0   0
INL  83  61  77  57 /  50  60  20   0
BRD  83  64  81  61 /  90  70   0   0
HYR  86  65  83  59 /  80  90   0   0
ASX  82  64  83  62 /  60  80  10   0

&&

.DLH Watches/Warnings/Advisories...
WI...Flash Flood Watch through Sunday morning for WIZ001>004-006>009.

     Beach Hazards Statement until 11 PM CDT this evening for WIZ001.

MN...Flash Flood Watch through Sunday morning for MNZ025-026-033>038.

     Beach Hazards Statement until 11 PM CDT this evening for MNZ037.

LS...Small Craft Advisory until 11 PM CDT this evening for LSZ144-145.

&&

$$

UPDATE...Grochocinski
SHORT TERM...LE
LONG TERM...GSF
AVIATION...Grochocinski


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