Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 221147
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
647 AM CDT SUN MAY 22 2016

.SHORT TERM...(Today through Monday)
Issued at 401 AM CDT Sun May 22 2016

The warm and dry weather pattern, which has affected the Northland
since early this past week, will culminate today. Above normal
temperatures and gusty southerly flow will also contribute to an
elevated fire weather risk this afternoon. The weather pattern is
about to change though, with much more humid air pumping north
into the region tonight and Monday ahead of an approaching trough
boundary from the west. Showers and storms are possible late
tonight and early Monday, and will become more likely and
widespread Monday afternoon.

The axis of an upper level ridge over the Northern Plains, as of
early this morning, will shift to over the Northland by later this
morning. Plentiful sunshine and dry humidity will allow
temperatures to quickly climb into the upper 70s and low 80s by
early this afternoon, and good mixing will drawn down winds of 20
to 25 mph from aloft. Much of the Northland will see critical or
near critical fire weather conditions this afternoon and early
evening, through combinations of the dryness of the vegetation,
wind speeds, and humidity of 20% to 25%.

As for the temperature and humidity forecasts for today, leaned on
the models seeming to perform the best the past few days, namely
the bias corrected outputs of the Canadian-regional, consensus
mos, and SREF models.

A lake breeze from Lake Superior is expected today, but will not
likely move far inland because of the strong southerly flow and
heating/mixing overland. The lake breeze will keep areas near Lake
Superior a little cooler and more humid than areas more inland.

The winds will subside after sunset. However, it will be different
story aloft as low pressure approaches from the west in the Great
Plains. A ssw low level jet of about 40 to 45 knots will develop
by later in the evening and pump moisture into the Northland. The
NAM12, SREF, and GFS20 models and model soundings indicate there
will be building elevated instability from the west overnight. The
jet, slightly falling heights from the west, and late night
shortwaves in the sw flow could help develop showers and
thunderstorms, mainly over the western forecast area. Severe
weather is not likely, but the storms could be capable of
producing small hail.

Monday will be another warm, but much more humid day. Dew points
will climb to the upper 50s and lower 60s, and precipitable water
values will increase to around 1.5 inches. Cloud cover and
increasing chances of showers and storms from the west will mean a
bit cooler temperatures in the lower 70s across the western
forecast area, but northwest Wisconsin could still reach 80
degrees due to tapping into more sunshine and drier conditions.
The heights will continue to fall as low pressure approaches from
the west, providing the synoptic lift to help develop showers and
storms. More shortwaves could lift through the region, too, and a
trough boundary will move into the western forecast area later in
the afternoon or early evening. The models are not in good
agreement concerning pcpn and severe weather parameters, but the
nam12/sref is indicating mixed layer cape could reach around 1500
J/kg amidst 25 to 35 knots of deep layer (0 to 6 km) wind shear.
There is a slight risk of severe weather due to the potential
storm environment. Much of northeast Minnesota can expect
widespread rainfall of 0.25" to 0.50" by Monday evening.

.LONG TERM...(Monday night through Saturday)
Issued at 401 AM CDT Sun May 22 2016

The extended period will be unsettled with periods of showers and
storms possible.

A large upper level trough will be over the western CONUS through
the entire period with several shortwaves moving through the
Northland bringing chances for showers/storms. A trough/frontal
boundary will continue to move east through the Northland Monday
night into Tuesday. Showers/storms will be likely ahead of these
features Monday evening over the eastern half of the area,
diminishing overnight into Tuesday from west to east. Some of the
storms could be severe but there are questions on the amount of
instability that will be present due to expected convection that
should be occurring over western areas that will spread east
during the day.

A weak upper ridge will move over the Northland briefly on
Tuesday into Tuesday night which will lead to weaker forcing and
lower chances for any additional showers/storms for most areas.
The exception will be far eastern areas Tuesday morning which will
have a better chance for precipitation.

Both the GFS and ECMWF bring another shortwave into the area on
Wednesday with a surface low also lifting north. Shower/storm
coverage should ramp up as these features approach on Wednesday
into at least Wednesday evening then they will diminish as the
wave lifts into Ontario later Wednesday night.

Shower/storm chances will continue into Thursday, although at
this time there does not appear to be any strong features for
forcing so coverage should be lower than what is expected
Wednesday.

The GFS/ECMWF show an area of low pressure and another stronger
shortwave impacting the area Friday/Friday evening. There are some
timing differences, but both do indicate stronger forcing and
shower/storm coverage should increase once again.

Tuesday will be the warmest day of the period with highs in the
mid seventies to lower eighties, cooler around the lake. Wednesday
through Saturday will feature highs from the mid sixties to mid
seventies but it will be cooler around Lake Superior with a
persistent onshore wind expected.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 647 AM CDT Sun May 22 2016

The Northland will be between high pressure to the east and an
area of low pressure and cold front to the west. The low and front will
be moving east through the period toward the Northland. The wind
will be stronger today as a result of the gradient between the
high/low. VFR conditions are expected through much of the period.
However, a LLJ will develop tonight as the low pressure system
moves toward the Red River Valley. Increasing moisture and lift
will lead to increasing clouds later tonight and the threat for
some showers/storms. We added a mention of TSRA to KHIB/KINL/KBRD
late tonight where we have the most confidence at this time. MVFR
and even brief IFR conditions will be possible with the stronger storms.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  78  55  73  55 /   0  20  70  60
INL  82  59  74  51 /   0  40  70  30
BRD  81  62  74  56 /   0  50  70  40
HYR  82  57  80  58 /   0   0  50  70
ASX  80  54  80  56 /   0   0  50  70

&&

.DLH Watches/Warnings/Advisories...
WI...None.
MN...Red Flag Warning from noon today to 7 PM CDT this evening for
     MNZ010>012-018-019-025-026-035-037.

LS...None.
&&

$$

SHORT TERM...Grochocinski
LONG TERM...Melde
AVIATION...Melde


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