Area Forecast Discussion
Issued by NWS Aberdeen, SD

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725
FXUS63 KABR 260528 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1228 AM CDT Wed Jul 26 2017

.UPDATE...
Issued at 930 PM CDT Tue Jul 25 2017

Severe weather threat looks to have ended this evening. Thus,
cancelled the watch. Also, trimmed pops back for the night and may
be able to trim them back even more.

UPDATE Issued at 703 PM CDT Tue Jul 25 2017

00z aviation discussion updated below.

&&

.SHORT TERM...(This Evening through Wednesday Afternoon)
Issued at 248 PM CDT Tue Jul 25 2017

The threat for severe storms this evening will be the main forecast
concern.

A surface low pressure system located in south central SD with a
warm front extending into western MN. Decent moisture convergence,
combined with hot temperatures will create an unstably environment
along the front. While 700 mb temps exceed 13C, cin is beginning to
erode, mainly in northern NE and south central SD. Overall upper
level support is lacking, there appears to be the presence of a weak
upper level shortwave which should aide in convective development
within the next few hours in south central SD. There is consensus
among models for a rapid expansion of convective development along
the front. Large hail and damaging wind gusts will be the main
threats. However with high PWATS, a slow storm portions, and surface
front parallel to the upper level flow, heavy rainfall will also be
possible. East central SD, from Watertown to Brookings, will have
the best potential of seeing locally heavy rainfall. Timing of the
severe storms is best between 4 pm to 10 pm.

High pressure building into the area from the north will bring dry
conditions for most locations on Wednesday. Areas along and south of
Highway 14 will have a chance for pcpn Wednesday morning.

.LONG TERM...(Wednesday Evening through Tuesday)
Issued at 248 PM CDT Tue Jul 25 2017

Zonal flow continues Thursday before starting to shift to a more
meridional flow throughout the rest of the forecast period. Models
are fairly consistent in that an upper-level ridge and associated
high pressure build into the region Friday.  This will result in a
few shortwaves and the potential for sporadic convection over the
weekend and into early next week.

Models are inconsistent on temperature output, with the GFS being
much warmer Friday and Sunday, while the Euro is significantly
cooler Saturday. Overall, blended temperature highs appear to be at
or slightly below average across the CWA.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1227 AM CDT Wed Jul 26 2017

VFR conditions are expected at all locations through tonight and
Wednesday. Showers and thunderstorms are expected to affect ATY
tonight at or in the vicinity with possible MVFR conditions.

&&

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

$$

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



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