Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 230832

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
331 AM CDT Fri Jun 23 2017

.SHORT TERM...(Today and tonight)
Issued at 331 AM CDT Fri Jun 23 2017

A busy northwest flow pattern will continue today with one main
ribbon of vorticity rotating through this morning. It is in advance
of a subtle short wave trough that isn`t doing much early this
morning, but should be influential with daytime heating to build
clouds and a few showers as it passes over southern MN and western
WI later this morning. NAM forecast soundings exhibit a very
modestly unstable profile, so cannot rule out a lightning strike or
two either with the most vigorous cells.

IR satellite shows clear skies over much of the Upper Midwest at 3
AM, with lower cloud cover confined to North Dakota and portions of
northern MN behind a surface cold front. Winds behind that boundary
are gusting into the 30s and forecast soundings support similar
conditions today across the region following its passage.

The loss of daytime heating and a stabilizing boundary layer should
allow stratocu to diminish quickly this evening, leaving a mostly
clear and quiet night tonight.

.LONG TERM...(Saturday through Thursday)
Issued at 331 AM CDT Fri Jun 23 2017

In the longer term, we`ll remain in cool northwest flow into
Monday, before we finally see the eastern upper lift north and
east. The upper flow then looks to become somewhat zonal over our
area by midweek, then things get more muddled by the end of the
week with a fair amount of spread in the guidance. However, the
main signal looks to be for ridging to build out west once again,
with northwest flow potentially re-developing over our area. The
main upper cold pool looks to descend into our area on Saturday,
so we`ll have scattered showers and a few thunderstorms around,
particularly in the afternoon into early evening, with the central
and eastern portions of the area looking to have the best
potential to see some activity. Although the surface ridge will
slowly start to work in from the west Sunday and Monday, we will
still maintain sufficient cyclonic flow and cold air aloft for
shower activity once again Sunday. By Monday, this potential
appears to be limited to the far eastern portion of the area.

High pressure looks to keep things dry Tuesday, but strong warm
advection and returning low-level moisture look to quickly bring
chances for showers/thunderstorms back in from west to east
Tuesday night into Wednesday. There are some differences in the
position of the surface low moving through the area on Wednesday,
with the GFS much faster and well north of the ECMWF and Canadian
solutions. This leads to the GFS lingering the baroclinic zone
over the southern portion of the area on Thursday, while the other
solutions shove it farther south. It`s a bit soon to try and latch
onto any specific solution, particularly with a significant amount
of spread noted in the ensembles. So, will have PoPs for most of
the area from late Tuesday night through Thursday, although the
best potential looks to be late Tuesday night through Wednesday


.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 1000 PM CDT Thu Jun 22 2017

Skies become most clear overnight but it will be short-lived with
cyclonic flow bringing in a dense deck of stratocu clouds Friday
morning. Ceilings will lower to around 5000 feet, and potentially
even lower to around 2500ft (mainly at northern sites-KAXN/KSTC).
Northwest winds will also become gusty on Thursday morning,
generally around 15-17kts with gusts to between 22-25kts.

VFR conditions overnight and then bkn-ovc low-end VFR deck (5KFT)
moves in for Thursday, with sct MVFR clouds around 2500 ft. Gusts
to around 25 knots develop by late morning.

Sat...VFR. Chc MVFR with p.m. -TSRA. Winds NW 15g25kts.
Sun...VFR. Chc MVFR with p.m. -TSRA. Winds NW 10kts.
Mon...VFR. Winds NW 5-10 kts.




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