Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 281202 AAA

Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
702 AM CDT Wed Jun 28 2017

.SHORT TERM...(Today and tonight)
Issued at 400 AM CDT Wed Jun 28 2017

Fairly widespread showers and thunderstorms are ongoing early this
morning across southern and portions of central Minnesota along a
tight 850 mb moisture gradient. One nearly stationary band
stretching from Long Prairie and Alexandria southward to Redwood
Falls and New Ulm is evidence the LLJ has strengthened to at least
the mean wind. Some building of convection to the east is expected
with the jet veering around sunrise, before the best moisture
convergence shifts to the east of the CWA and support for the rain
and thunder diminishes for the rest of the morning.

Infrared satellite imagery shows cloud tops warming across eastern
South Dakota with cigs greater than 12kft per observing stations.
This is a good sign we`re going to clear out later this morning with
atmospheric recovery expected by afternoon. Increased high
temperatures into the lower 80s across southern MN. Dew points will
also be climbing in the warm sector to the upper 60s, beneath a
pocket of mid level lapse rates as steep as 7.5-8.0 C/km. This will
contribute to 2500-3000 J/kg SBCAPE by mid afternoon across eastern
MN and west central WI while a mid level vort passes overhead.
Scattered to numerous thunderstorms should develop in this area,
shifting southeast by evening. As previously discussed, wind shear
is a major limiting factor for severe thunderstorms with the mid
level jet down to the south across Iowa into southern Wisconsin. A
few could still become severe given the moderate to strongly
unstable airmass, however.

.LONG TERM...(Thursday through Tuesday)
Issued at 400 AM CDT Wed Jun 28 2017

Cool yet unstable weather persists through the weekend, and then a
pattern transition occurs at the end of the long-term forecast
period which brings a return to warm and humid air late next week.

The daytime period on Thursday looks to be dry as brief ridging
sets in over the area. This break in precipitation is short-lived,
as the next shortwave trough arrives Thursday evening and
amplifies over the area on Friday, bringing another round of
showers and thunderstorms. Cyclonic flow looks to persist over the
area on Saturday, and bring scattered showers and thunderstorms
primarily along/east of I-35.

It will be another cool weekend as high temps on Saturday and
Sunday top out in the 70s.

Monday and Tuesday bring mid level ridging into the central CONUS
which is expected to translate to dry weather and moderating
temperatures. Highs for Fourth of July holiday look to be right
around normal in the 80-85 degree range.


.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 702 AM CDT Wed Jun 28 2017

Highly variable cigs out there early this morning ranging from VFR
to IFR. Expect MVFR or lower with the rain. There has been a
diminishing trend with the heavier showers, but light showers are
redeveloping across western MN with the presence of an upper low.
After it heads east, skies should begin clearing and allow the
atmosphere to become unstable again for the next round of storms
later this afternoon along and east of I-35. VFR conditions
expected from this afternoon and beyond outside of thunderstorms.

KMSP...Showers are expected to continue for the next few hours.
VFR/MVFR cigs are in place, but IFR are nearby and cannot rule
out some of those moving in for short instances this morning. Most
of the thunderstorm activity today should be south and east, but a
few could be nearby.

Fri...VFR. Chance MVFR with TSRA. Winds variable 5 kts.
Sat...VFR. Chance MVFR with TSRA. Winds WNW 5-10 kts.
Sun...VFR. Chance of TSRA/SHRA. Winds light and variable.




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