Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 292351 AAA

Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
651 PM CDT MON AUG 29 2016

.SHORT TERM...(This evening through Tuesday)
Issued at 305 PM CDT Mon Aug 29 2016

Surface analysis shows a cold front extending from northwestern MN
across eastern SD early this afternoon, along with an outflow
boundary over south central MN from earlier convection. Surface
dewpoints locally in the warm sector ahead of the main front are in
the upper 60s to lower 70s, with plenty of sunshine breaking out to
aid destabilization. Mid level lapse rates around 7-7.5C will
combine with the increasing MLCAPES to spark thunderstorm
development in the vicinity of the front. The only limiting factor
is shear, which is not impressive. Therefore the threat for severe
weather remains limited but not out of the question. Given the slow
storm motion heavy rainfall will be a concern as well, and will have
to monitor the threat for a Non-supercell tornado or two over south
central MN in the vicinity of the outflow boundary.

In the wake of the convection late tonight winds are fairly weak and
we may see enough clearing to result in fog development with the
moist ground conditions.

Tuesday should bring continual clearing, with mostly sunny skies by
mid to late afternoon. Highs will still be a bit above normal, and
range in the upper 70s to around 80.

.LONG TERM...(Tuesday night through Monday)
Issued at 305 PM CDT Mon Aug 29 2016

The longer term concern remains the dry trend through the rest of
the work week...and timing of next trough and surface front into
next weekend.

Cool and dry high pressure will move across the region during the
week. The coolest day appears to be Thursday...with slow moderation
thereafter as upper heights rise/ridging and southerly surface
flow develops. The GFS and ECMWF have similar timing in passage of
the front on Labor Day. The GFS ensemble mean is a little slower
but the trough associated with this system appears to be quite
strong. Forcing will be directed favorably along the front for at
least the possibility of heavy rain. Filtered CWASP is pointing
toward a severe weather threat as several of those
parameters are looking favorable for Monday.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 650 PM CDT Mon Aug 29 2016

A cold front sagging south into central MN early this evening
has scattered convection occurring along it. Winds will ease this
evening which will weaken the convergence along the front - a main
driver of this activity. Another main driver is the very unstable
airmass which will stabilize after sunset. All model guidance
shows a diminishing trend in activity by late this evening, so
it`s possible little will impact the TAF sites. Low clouds and fog
will likely develop again overnight across WI, before drier air
arrives Tuesday with the fropa.

KMSP...Confidence is low of showers or storms impacting the metro.
The cluster to the north should slide mainly east and weaken
during the next several hours, with only isolated-sct convection
further west into far western MN and SD. Reduced mention of precip
to VCSH, but may be able to take it out altogether by the 03z
update depending on trends.

WED...VFR. Wind NNE 5 kts.
THU...VFR. Wind E 5 kts.
FRI...VFR. Wind SSE 7-10 kts.


.MPX Watches/Warnings/Advisories...


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