Area Forecast Discussion
Issued by NWS Twin Cities, MN

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489
FXUS63 KMPX 302000
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
300 PM CDT SAT JUL 30 2016

.SHORT TERM...(This evening through Sunday)
Issued at 253 PM CDT Sat Jul 30 2016

While high pressure is still generally prevailing across the area
before departing to the east tonight, a weak surface trough over
far SE MN into NE IA combined with modest convergence evident over
the same region in WV satellite imagery is allowing for isolated
showers/thunderstorms over SE portions of the coverage area.
Focused mainly along and east of I-35 and along and south of I-94,
in east-central and southeast MN into west-central WI, showers and
storms that have formed are slow-movers with little duration so
aside from some brief heavy downpours, will not look for much
development or coverage through the rest of the daylight hours.
Partial clearing tonight will linger into tomorrow though a
lingering mid-level trough and weak disturbance passing through
the region looks to be enough to spark off additional isolated
showers/storms over southwestern MN during the day tomorrow.
Again, not looking for anything strong/severe but some may well be
slow-movers which could produce brief heavy downpours.
Temperatures will run fairly similar tomorrow as today, possibly
1-3 degrees warmer tomorrow with high pressure exiting and a
stronger backside southerly flow bringing in slightly warmer and
slightly more moist air from the Deep South.

.LONG TERM...(Sunday night through Saturday)
Issued at 253 PM CDT Sat Jul 30 2016

Things look to be somewhat unsettled across the area for much of
the week, with chances for showers and thunderstorms, although
the most significant precipitation looks like it north and south
of the area. We`ll initially see the upper ridge build over the
area into Monday, before a piece of the shortwave trough currently
over British Columbia moves across southern Canada and pushes a
weak front through the region on Tuesday, with northwest upper
flow returning for a time. A more significant upper trough will
track farther south during the Wednesday/Thursday time frame, with
a sub-1000 mb low moving across southern Canada in association
with it. Although the guidance is similar in the overall evolution
of things, there are timing differences in the deterministic and
ensemble solutions. The GFS remains quicker with the front in
comparison to the ECMWF and Canadian. The GFS would bring the
front across Wednesday night, while the other solutions wait until
Thursday afternoon. The timing could certainly play a role in any
severe weather potential, as we should have decent instability
back in place across the area. However, the better large scale
forcing and deep layer shear looks to be to our north during that
time frame. For now, given the spread in ensemble solutions, can`t
go all-in on any particular solution, and keep some PoPs over the
area into Thursday night.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1229 PM CDT Sat Jul 30 2016

Mainly VFR conditions expected throughout this TAF set. However,
am concerned of having isolated SHRA/TSRA along and E of the I-35
corridor and along and S of the I-94 corridor, so mainly E-central
and SE MN into W-central WI (affecting KMSP-KRNH). Chances are
relatively low but VCTS looks warranted as development has already
commenced. Storms would have little motion and produce localized
rain and with some lightning. Storms look to hang around until
about 00z then mid-to-high SCT-BKN clouds will prevail.

KMSP...Have added a VCTS for the 20z-00z time period this
afternoon and evening since short-term models are generally in
agreement on the development of isolated TSRA around the area
though not so much directly over MSP. Could even see a few more
hours beyond that but confidence not high enough to put actual
precipitation into the terminal at this point.

/OUTLOOK FOR KMSP/
Mon...Mainly VFR. Chance MVFR/TSRA. Winds SE 5-10 kt.
Tue...Mainly VFR. Chance MVFR/TSRA early. Wind light/variable.
Wed...Mainly VFR. Chance MVFR/TSRA late. Wind SE 5-10 kt.

&&

.MPX Watches/Warnings/Advisories...
WI...None.
MN...None.
&&

$$

SHORT TERM...JPC
LONG TERM...
AVIATION...JPC



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