Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 141824

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
124 PM CDT Sat Oct 14 2017

.SHORT TERM...(Today and tonight)
Issued at 352 AM CDT Sat Oct 14 2017

Today`s forecast is associated with two different lifting mechanisms
as precipitation begins to develop across far southern Minnesota
this morning, and western Minnesota this afternoon.

Initial shower activity across eastern Nebraska is related to strong
forcing along an elevated frontal boundary over the central plains.
This area of showers will spread northeast and begin to affect far
southern Minnesota between 9 am and noon. Model CAMS indicate that
this activity will be more scattered through the morning/early
afternoon as it lifts northward across southern Minnesota.

An area of stratus across central Iowa has already begun to
develop/spread northward over northern Iowa during the pre dawn
hours. This area of lower clouds will spread rapidly northward as
winds in the boundary layer begin to increase from the southeast.

The second lifting mechanism is associated with a strong short wave
over western Wyoming. This system will move eastward and enhance the
overall lift across South Dakota by noon. As it begins to interact
with the deeper moisture surging northward across southern
Minnesota, a larger area of precipitation should develop across
western Minnesota during the afternoon. As the storm system begins
to intensify by the late afternoon, bands of showers will develop,
especially along and north of the elevated frontal boundary. This
frontal boundary will be key as to where the heaviest and steadier
precipitation develops this evening. Currently, the main area will
be across west central/central Minnesota during the evening, then
this translates eastward during the overnight hours across eastern
Minnesota and western Wisconsin. Any slight deviation from this
elevated frontal boundary and jet core moving overhead, will
determine where these bands of showers develop. Another aspect to
this system is the rapid intensification this evening which will
lead to increasing wind speeds overnight. Wind gusts of 30 to 40 mph
will likely occur in western/southern Minnesota after midnight as
the storm moves eastward over the western Great Lakes. Much colder
air will wrap into this system which could lead to some light snow
in western/central Minnesota before the precipitation ends. But no
accumulations are expected.

.LONG TERM...(Sunday through Friday)
Issued at 352 AM CDT Sat Oct 14 2017

Showers will quickly end across WI Sunday morning as the system
races across the Great Lakes. Clearing will also take place,
marking the beginning of a dry period for all of next week. Sunday
will be the coolest day of the week with highs in the upper 40s to
mid 50s.

An expansive ridge encompassing much of the central CONUS will
build in Sunday night and remain in place into next weekend. A few
impulses will ridge along the northern periphery of the ridge
across Canada, which may drop cold fronts into the Upper Midwest.
These will do little other than to delay the arrival of the most
aggressive warming. That will take place late week as the ridge
builds eastward and centers itself over the southeastern U.S. 925
mb temps of +14 to +16C Tuesday-Thursday will become +17 to +20C
by Friday and Saturday, when high temperatures could rise well
into the 70s and possibly the low 80s. Records Friday and Saturday
are in the mid to upper 80s, which would be a little tough to get
but record warm minimums in the upper 50s/low 60s are within
reach. PoPs remain near zero Sunday night through Friday.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at |108 PM CDT Sat Oct 14 2017

The main aviation concern is the arrival of precipitation, the
predominance of that precipitation and the arrival of IFR cigs
later today along with the persistence of those ceilings through
the night. Moisture and elevated instability from Iowa surged
northward across southern mn during the mid morning hours and
extended along a narrow line from Redwood Falls to Eau Claire
around 1 PM. That line of showers will continue moving northward
affecting Kmsp by 20Z. Nothing significant expected other than
-SHRA and a rapid deterioration of the the ceilings leading to IFR
 conditions. A storm system located in the Southern Plains will
 move to central Iowa by evening and northeast to northern
 Michigan by daybreak Sunday. Moisture will continue surging into
 MN the rest of the day into the evening hours. The worst
 conditions will occur between 00-06z as both cigs/vsbys will
 remain in the MVFR/IFR range along with very gusty winds from the
 north/northwest. Between 06-10z conditions will slowly improve
 in western Minnesota, with VFR/MVFR in the east. By 12Z
 conditions should be VFR across MN and MVFR in western WI. Skies
 will be mostly clear after 15z across the entire area.


Timing of precipitation/lower cigs is the main concern. Expect the
first batch of precipitation to affect the air field around 20z.
After that it is somewhat questionable as to the extent of
widespread precipitation until the low moves into Wi and wrap
around precipitation affects the air field. The most significant
precipitation will remain well south of KMSP. Early Sunday
morning, conditions will improve with VFR cigs likely.


Mon-Thu...VFR. Wind SW 5-10 kts.



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