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Area forecast discussion
National Weather Service Twin Cities/Chanhassen Minnesota
604 am CDT Tue Jul 23 2019

Update...for 12z aviation discussion below


Short term...(today through wednesday)
issued at 211 am CDT Tue Jul 23 2019

Another picture-perfect weather day is on tap for much of the area,
as surface high pressure dominates the region. A tad more fair-
weather cumulus cloud cover is anticipated, along with slightly
warmer high temperatures in the upper 70s to lower 80s. Winds will
be relatively light at speeds around or under 10 mph. The only
potential setback to dry weather is faint shortwave energy
funneling between the western upper ridge and eastern trough, which
could generate a few (isolated) showers or thunderstorms over west
central Wisconsin this afternoon and evening. Most areas will remain
dry however.

Mostly clear skies prevail Tuesday night and Wednesday with highs
moderating another couple of degrees as southerly flow returns.

Long term...(wednesday night through monday)
issued at 211 am CDT Tue Jul 23 2019

The long term period becomes potentially more active with a few
shortwaves near our region bringing chances of showers and
thunderstorms. Otherwise, temperatures near normal for late-July are

By Wednesday night, a shortwave trough will be moving nearly due
east over the Canadian rockies of Alberta. This wave will over-top
the western North America ridge, flattening it somewhat as it moves
through. A surface low will emerge across Saskatchewan and continue
east with the parent upper level low on Thursday. For US in
Minnesota and western Wisconsin, our concern with this system will be
a frontal boundary draped south of the low, which will likely lead
to some scattered showers and thunderstorms along the front. Theta-E
advection ahead of the front looks decent, and marginal instability
given the moisture pooling will be present. There are still some
slight timing differences in the model guidance with handling this
system, but at this point late Thursday night looks to be our best
chance for precipitation across the area. The low itself will stay
north of the Canadian border as it moves east through Friday, and
will be weakening (filling) Thursday-Friday, which limits some of
our potential for widespread precip development.

The upstream ridge over western North America will still be in place
Friday, but not as amplified as it was earlier in the week. The next
shortwave to watch will be coming onshore in the Pacific northwest
Friday night, and move quickly east through the weekend, potentially
taking a somewhat similar track to the Thursday system. This wave
however, looks to eject strong lead energy out ahead and southeast
of the main low, which would bring a better chance of widespread
precipitation to our area Saturday night. This system will be
followed by cooler and less humid Canadian high pressure for early
next week.


Aviation...(for the 12z tafs through 12z Wednesday morning)
issued at 604 am CDT Tue Jul 23 2019

VFR conditions are expected through the period. Scattered cumulus
clouds develop this afternoon. A few showers are possible this
afternoon/evening over west central Wisconsin, but have not
included a mention given the low chance the activity will impact
sites. Northwest winds peak this afternoon around 10 mph. concerns.

/Outlook for kmsp/
Wed...VFR. Wind SW 5-10 kts.
Thu...VFR. Wind SW 10g20 kts.
Fri...VFR. Chc a.M. MVFR/-tsra. Wind SW 10g20 kts.


Mpx watches/warnings/advisories...

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