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fxus63 kmpx 252204 

Area forecast discussion
National Weather Service Twin Cities/Chanhassen Minnesota
504 PM CDT Tue Jun 25 2019

Update...for 00z aviation discussion below


Short term...(this evening through Wednesday night)
issued at 355 PM CDT Tue Jun 25 2019

Isolated showers will continue to spread across northern portions of
central Minnesota and west-central Wisconsin this afternoon as a
shortwave skirts to our north along the international border. MUCAPE
values of a few hundred j/kg. A few instances of thunder are
possible as well with MUCAPE values approaching 1000 j/kg. This
diurnally-driven precipitation will dissipate after sunset, and then
our precipitation chances tonight turn a a thunderstorm complex
expected to develop across the Dakotas this evening. With the low level jet
weakening towards sunrise and moisture flow from the Gulf being
blocked off by a stationary to our front to our south, believe this
complex should diminishing as it enters western Minnesota this
morning. The best chance for precipitation looks to be across
southwest Minnesota where amounts should be light given the
weakening complex. Central and eastern Minnesota should remain dry
as the system completely dissipates by late morning.

The well-advertised heat and humidity begins to move into the region
beginning Wednesday as a warm front begins moving into the region
and brings plenty of Gulf moisture along with it. Strong instability
will move into the area behind the front with thunderstorm chances
increasing Wednesday evening, and especially overnight into
Thursday, when a shortwave rounds over the top of the amplifying
ridge nosing into the upper Midwest. Effective bulk shear looks to
be around 30 kts which would be supportive of organized convection,
and sure enough cams are hinting at a mesoscale convective system developing Wednesday
evening and tracking it somewhere into our vicinity overnight. The
Storm Prediction Center currently has a marginal risk of severe weather out for much of
our area, with the severe threat conditional accounting for the
uncertainty in the track of this complex. Will have to monitor
mesoscale trends closely as we get into tomorrow evening.

One last "windows open" sleeping night tonight as lows drop to
around 60. Heat and humidity build into the region beginning
tomorrow afternoon, with highs in the low-mid 80s and lows Thursday
morning generally in the mid to upper 60s.

Long term...(thursday through tuesday)
issued at 355 PM CDT Tue Jun 25 2019

Main concerns in the long term are the expected heat and humidity
for Thursday through the weekend, and periodic chances for

Little has changed with the forecast for the long term period. A
deepening longwave trough over the West Coast will lead to a
building ridge over central North America. With southerly flow
developing, temperatures and dew points will be the highest we've
seen locally this year. High temperatures will be near 90 Friday,
and in the low to mid 90s Saturday and Sunday. Dew points will
likely reach the lower 70s, and heat indices should surpass 100

In terms of thunderstorm chances, there is a marginal risk of severe
weather Thursday. There is some spread in the models in terms of how
far north or south a shortwave overtopping the upper level ridge
will go. Overall the expectation is for a shortwave will move west
to east across Minnesota into WI during the day Thursday, but the
differences are simply either southern Minnesota or northern Minnesota. Confidence
is higher that southern Minnesota will be impacted by this wave, with the
possibility of a remnant mesoscale convective vortex emerging from the Dakotas and moving
east-southeast through southern Minnesota and western WI Thursday. An eml will precede
this wave, and MLCAPE values of 2,000 j/kg certainly present the
opportunity for a marginal threat for severe weather with large hail
and gust winds possible.

Into the weekend, the ridge builds across the upper Midwest, and
while the guidance suggests the possibility of subtle shortwave
energy to ride the ridge and impact our local area, timing and
coverage of such chances are rather inconsistent so quite a bit of
uncertainty exists. The best chance for widespread thunderstorms
this weekend currently looks to be Sunday night when the ridge
actually begins to break down as the western trough moves over
central Canada.


Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 505 PM CDT Tue Jun 25 2019

Cumulus clouds will dissipate by sunset. Isolated
showers/thunderstorms will move across North/East central Minnesota and
northwest WI, but are expected to stay north of taf sites and
will also diminish with sunset. After that, expect clear skies
overnight with increasing mid-level clouds on Wednesday. Wind
gusts will subside between 00z and 02z, then speeds will be at or below 10
knots through the remainder of the period. Direction will shift
from west/northwest to south/southwest for Wednesday. additional concerns.

/Outlook for kmsp/
Thu...VFR. Chc MVFR/tsra. Winds south-southeast 5-10 kts.
Fri...VFR. Winds south-southeast 5-10 kts.
Sat...VFR. Winds S 5-10g15 kts.


Mpx watches/warnings/advisories...

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