Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 180549 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1249 AM CDT Tue Jul 18 2017

.UPDATE...
Issued at 1249 AM CDT Tue Jul 18 2017

06z aviation discussion updated below.

UPDATE Issued at 637 PM CDT Mon Jul 17 2017

No changes planned to the current forecast. POPs are well
represented this evening. Continuing to monitor strong to severe
storms across the region.

&&

.SHORT TERM...(This Evening through Tuesday Afternoon)
Issued at 333 PM CDT Mon Jul 17 2017

The threat for severe storms this afternoon and again late tonight
through Tuesday morning are the forecast concerns.

As of 20Z, a frontal boundary is currently located over northern
Marshall CO, southwestward to Pierre. This boundary will be the
focus for convection through this evening. With high values of
DCAPE, damaging winds will be the main threat. Steep lapse rates,
along with some shear could produce an isolated hail threat as
well. This convection should progress eastward through this
evening with a period of dry conditions expected tonight.

An upper level shortwave, currently over WY and MT will cross the
region late tonight and through the morning hours on Tuesday. While
instability is lacking, isolated severe storms will be possible due
to good 0-6 km bulk shear and upper level jet support. There have
been two events this year when the best MU-cape was south of this
cwa, but we still received severe weather with overnight
convection. The setup tonight looks similar to those two events.

The second around of convection should progress into MN by 21Z
Tuesday. With mostly cloudy skies, highs on Tuesday will be much
cooler than today.

.LONG TERM...(Tuesday Evening through Monday)
Issued at 333 PM CDT Mon Jul 17 2017

Sprawling mid level high pressure over the Southern Plains will
continue through much of the period. Meanwhile, sporadic s/w
activity within the flow aloft over the Northern Plains will
continue to promote periodic mcs activity. The focus Tuesday night
looks to be mainly south of the cwa. However, on Wednesday there is
some consistency with a system moving southeast out of ND and across
the eastern cwa. This could end up being a half way decent severe
weather day given progged moderate mlcapes/strong deep layer shear
leading to some fairly stout supercell composite values by
afternoon. The remainder of the work week looks somewhat active too
given continued moderate to high amounts of deep layer shear and
mlcape values. Plus a mean sfc frontal boundary will exist over the
region until late in the weekend when it will drift south of the
area. Temperatures overall should average out near to perhaps
slightly above normal for most of the period.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1249 AM CDT Tue Jul 18 2017

Another shortwave will bring more showers and thunderstorms to the
region overnight into Tuesday. They are expected to affect all of
the locations at or in the vicinity. VFR conditions are expected
through the period except for possibly in thunderstorms.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

UPDATE...Mohr
SHORT TERM...SD
LONG TERM...TDK
AVIATION...Mohr



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