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000
FXUS63 KMPX 241720
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1220 PM CDT Sat Jun 24 2017

.SHORT TERM...(Today and tonight)
Issued at 319 AM CDT Sat Jun 24 2017

Things will be somewhat similar today as they were yesterday,
except there is a stronger shortwave trough working through the
area, so expect to see more widespread showers and some
thunderstorms. The shortwave trough is quite evident in water
vapor imagery, currently dropping southeast through North Dakota,
and has a PV anomaly associated with it that the RAP indicates
down to around 500 mb. There is a band of mid-level clouds already
with this feature, and expect to see some SHRA develop with it
over the next several hours. It should work into the western
portion of the area this morning, then dive southeast through the
afternoon. Scattered showers and a few thunderstorms can be
expected given the large scale forcing and MLCAPE values of
200-500 J/Kg. A quick look at forecast NST parameter values from
the NAM suggest some potential for at least a few funnel clouds
from central/west central into south central Minnesota during the
afternoon hours, which isn`t surprising given the upper low,
associated cold pool, good low-level lapse rates, and pools of
cyclonic surface vorticity with an enhanced surface trough progged
to accompany the upper wave. We should see activity quickly wane
in the evening hours.

.LONG TERM...(Sunday through Friday)
Issued at 319 AM CDT Sat Jun 24 2017

On Sunday, we`ll still have some cyclonic flow in the boundary
layer along with cold air aloft, so some shower and thunderstorm
activity is expected once again, although with ridging starting to
work in from the west, would expect things to mainly be near and
east of I-35 on Sunday. Otherwise, the latter portion of the
forecast period still appears to be most interesting around
midweek when we`ll see the eastern trough shoved east while a
shortwave ridge and pronounced warm advection work into our area.
This looks to be followed by a brief period of westerly upper flow
before the western ridge re-asserts itself and we get back into
northwest upper flow by the weekend. Any lingering showers in
association with the upper low should be confined to the far
eastern portion of the area on Monday.

After that we should have sufficient ridging for dry weather
through the day on Tuesday. However, strong warm advection will
begin to setup Tuesday night as low pressure develops over the
Northern Plains. Expect to see elevated convection develop to our
west Tuesday night and work into the area overnight, perhaps
reaching the Twin Cities metro by Wednesday morning. The ECMWF has
come around more to the GFS and MPAS idea of tracking the main
surface low near the Canada/Minnesota border on Wednesday, with
the cold front moving through during the late afternoon/evening
hours. Given the amount of forcing and elevated instability
expected with the warm advection and moisture surge Tuesday night
and early Wednesday, it currently doesn`t look like we`d recover
too much from that round of showers/thunderstorms to have anything
significant in the way of instability when the cold front moves
through, but it`s a number of days away so certainly should be
monitored.

A secondary and weaker shortwave trough will push east through the
region on Thursday, but it appears the main baroclinic zone should
be mostly south of our area by then, so PoPs will be confined
primarily across the south. However, a slightly stronger upper
wave looks to work into the area on Friday, which should lead to
more widespread chances of precipitation as the upper flow
transitions back to northwesterly by Saturday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1215 PM CDT Sat Jun 24 2017

No major changes to the first 6 hours of the taf period as
SHRA/TSRA will develop along and southeast of a circulation near
Alexandria, Mn. Although the best concentration of the SHRA/TSRA
will occur near the circulation, anywhere in southern Minnesota,
and west central Wisconsin will have a good shot of lower
vsbys/cigs associated with the heavier SHRA. After 00z, most of
the SHRA/TSRA will end, with a developing area of MVFR cigs in
northwest Minnesota, diving south/southeast during the overnight
hours. I did introduce MVFR cigs 1-2k for a wide area of
central/southern Minnesota, and into west central Wisconsin. These
lower cigs will likely hold on until mid/late Sunday morning.

KMSP...

Confidence remains high for SHRA development this afternoon, lower
confidence on TSRA. Will continue with the same scenario with a
period of 5SM SHRA this afternoon. Overnight remains questionable
as MVFR cigs develop in central Minnesota and dive southeast
across east central Minnesota. I did introduce these lower cigs
1.5k by 9z, but cigs could be lower or higher depending upon
upstream conditions. No other major changes past 16z, with cigs
rising to VFR.

/OUTLOOK FOR KMSP/

Mon...VFR. Winds NW 5-10 kts.
Tue...VFR. SHRA/TSRA late, with MVFR cigs. Winds S 5-10 kts.
Wed...VFR/MVFR. Periods of SHRA/TSRA early. Winds SSW 10-15 bcmg W.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&

$$

SHORT TERM...
LONG TERM...
AVIATION...JLT