Area Forecast Discussion
Issued by NWS Aberdeen, SD

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KABR 301729 AAB

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1229 PM CDT MON MAY 30 2016

Issued at 1225 PM CDT MON MAY 30 2016

See updated aviation discussion below.

UPDATE Issued at 1017 AM CDT MON MAY 30 2016

Made a few adjustments to pops based on current activity and
latest model forecast. Storms look to begin west river between 18z
and 20z...then will track eastward through the afternoon and
evening hours. No changes made to winds or temperatures at this


.SHORT TERM...(Today through Wednesday Afternoon)
Issued at 414 AM CDT MON MAY 30 2016

Currently watching showers and thunderstorms on the nose of the low
level jet from Sully county southeast through Hand and Buffalo
counties. Models show the low level jet shifting to the east this
morning but weakening. CAM solutions all over the place in regards
to areal coverage of any showers or storms that develop over the
next several hours further east over northeast SD. With the
weakening low level jet, will keep pops on the low end through the
remainder of the morning for the eastern CWA.

Main focus will be on this afternoon and evening as the severe storm
threat will increase with the approach of a cold front and good
upper level dynamics/forcing. Plume of moderate instability develops
this afternoon as low level moisture increases and lapse rates aloft
steepen. 0-6km bulk shear eventually reaches 40 to 50 knots over the
western CWA by late afternoon. Expecting strong to severe storms to
develop over the western CWA by mid to late afternoon ahead of the
advancing cold front. Will also be seeing a subtle warm front
lifting northward through the afternoon, with a slight backing of
the winds possible over north central SD. Sig Tor parameters of 1 to
2 showing up over this area during the late afternoon. Cannot rule
out an isolated tornado over north central SD with 0-1km shear in
the 10 to 20 knot range. As we get into the evening hours, expecting
convection to organize into more of a linear fashion ahead of the
cold front as activity marches east through the rest of the CWA.
Threat for large hail and gusty winds within supercellular
structures early on over the western CWA will eventually transition
to more of a strong wind threat into the evening hours further east
from the James Valley and points east. Storms will exit the CWA
during the nighttime hours, likely fairly early as CAM solutions are
showing a pretty quick movement eastward once the MCS/linear mode
gets going.

Tuesday and Wednesday will feature a large upper low moving across
ND and into MN. Rather chilly air aloft is associated with this low
with highs dipping down into the 60s and 70s both days. Tuesday
appears to be dry slotted for the most part which will cut off
precip chances for eastern areas. Further west, a bit more moisture
to work with so with the cool air aloft and steep lapse rates, could
see widely scattered afternoon showers and thunderstorms. Shower
threat will continue for the far northeast CWA on Wednesday as the
upper low departs.

.LONG TERM...(Wednesday Evening through Sunday)
Issued at 414 AM CDT MON MAY 30 2016

The models remain consistent in forecasting a shift to a positive
PNA pattern over the CONUS during the period. Through out the long
term mid level heights will continue to increase...with a consequent
decrease in pcpn chances. About the only chance for meaningful pcpn
is on Friday as a frontal boundary marches across the forecast area.
But even then pcpn coverage looks to be sct at best.  Temperatures
should average out about normal for most of the period.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1225 PM CDT MON MAY 30 2016

For the most part...VFR conditions will prevail across the area
through the TAF period. However...a line of storms is expected to
develop west of the Missouri River during the early to mid
afternoon hours...then will track eastward during the late
afternoon and evening. Vsbys will likely fall into the MVFR
category with the stronger storms. Gusty winds and hail are also


.ABR Watches/Warnings/Advisories...


AVIATION...Parkin is the U.S. government's official web portal to all federal, state and local government web resources and services.