Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 171922

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
222 PM CDT Wed May 17 2017

.Updated for 18Z Aviation discussion...
Issued at 200 PM CDT Wed May 17 2017


.SHORT TERM...(Today and tonight)
Issued at 424 AM CDT Wed May 17 2017

We are not out of the woods as far as a severe weather threat is
concerned. Early morning surface analysis shows the stationary
front stretching from the intersection of SD/MN/IA, northeast
across east central MN and west central WI to the UP of Michigan.
The main surface low will skirt the MN/IA border today, while a
strong shortwave trough ejects from the Central Plains across MN
toward WI this afternoon. Shear profiles will be enhanced ahead of
the low, with adequate diurnal destabilization anticipated to
promote thunderstorm redevelopment this afternoon/evening. Given
the low level shear profiles, in addition to large hail and
damaging winds, tornadoes will again be a threat, generally for
points south and east of a Fairmont to Red Wing to Ladysmith line.
With precipitable water values still lovering around 1.5", bursts
of heavy rainfall are also likely with the stronger
thunderstorms. Given the likelihood for today`s storms to be more
transient given the more progressive mid level flow, will not
issue another flash flood watch at this point. Surface winds will
also be brisk out of the northeast with gusts to 40 mph expected.

.LONG TERM...(Thursday through Tuesday)
Issued at 424 AM CDT Wed May 17 2017

Precipitation gradually comes to an end on Thursday as the
aforementioned wave weakens and lifts to Ontario, and we are
influenced by weak ridging ahead of the strong mid/upper low over
the Four Corners Region. This feature lifts to the area Thursday
night, and causes precipitation to spread north and east across
the area on Friday. There does not look to be much of a severe
threat with this activity, but another inch of rain looks to be

The shortwave trough pivots across the Upper Midwest into the
weekend, and then model diverge notably regarding its evolution
into early next week. For now have included 20-30 pops, which can
be refined once the fate of the low becomes more clear.

High temperatures through the period will generally range in the
50s to 60s, with lows generally in the 40s. Could see some frost
on Thursday night from central MN into west central WI where lows
will dip into the mid 30s.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 204 PM CDT Wed May 17 2017

A frontal boundary will linger across the region for most of the
afternoon and evening. Expect MVFR/IFR CIGS with -RA north of the
frontal boundary today, and -TSRA south of the boundary today. A
surface low will track across southeast MN and central WI. Winds
will become northerly as the low pressure moves through with low
clouds expected to continue overnight and into Thursday.

A few thunderstorms will develop across northern Iowa and lift
northward this afternoon. They should reach KMSP by 22Z. Expect
showers and thunderstorms to continue this evening, with MVFR
conditions developing tonight and lasting through most of

Fri...VFR with MVFR/-TSRA possible in afternoon. Wind NE at 10kt
Sat...MVFR/RA with IFR possible. Wind E at 10G20kt
Sun...VFR with MVFR possible. Wind NW at 15G25kt




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