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 222015

Area Forecast Discussion
National Weather Service Aberdeen SD
315 PM CDT Sat Oct 22 2016

.SHORT TERM...(This Evening through Monday Night)
Issued at 314 PM CDT SAT OCT 22 2016

Temperatures have risen well above forecast for many areas as a dry
air mass and breezy winds help boost temperatures under plenty of
sunshine. And, as usual, MBG has risen several degrees above
forecast and maintains their warm bias that we will have to continue
applying to the forecast. Winds/RH area flirting with Red Flag
across the southwest CWA, but as expected, we are seeing winds begin
to subside from west to east with obs across Stanley/Jones counties
beginning to see a drop in winds.

Overnight, a cold front will move east across the area and bring
breezy northwest winds and cooler temperatures. Highs on Sunday will
only be in the 50s to low 60s across the CWA. Surface high pressure
then settles into the area Sunday night, bringing lighter winds and
chilly temperatures. SuperBlend temps looked a bit too warm given
the setup, so have decreased temperatures more to towards MET
guidance which was on the colder end of guidance. This was a
collaborative effort and something that should be carried on to
future forecasts. Applied this mainly to the eastern CWA where winds
will be the lightest the longest.

Low pressure begins to organize over the Rockies on Monday, with a
tightening pressure gradient throughout the day. Again, SuperBlend
seemed to be too light with the winds and increased them some,
especially over central SD. This low pressure will pull out into the
central Plains Tuesday into Tuesday night, with continued chances
for showers across the eastern CWA. 12Z EC run has come it a bit
further north and west with shower potential late Monday night, so
have nudged slight chances further west into the James Valley
compared to SuperBlend. Will have to see if this is a trend other
models pick up on.

.LONG TERM...(Tuesday through Saturday)
Issued at 314 PM CDT SAT OCT 22 2016

As the period opens, high pressure is in place over the region.
However, an area of low pressure will quickly move through the
northern plains Tuesday and Tuesday night bringing the best chances
for measurable precipitation across northeast South Dakota and west
central MN. Beyond that, there really aren`t any noteworthy
precipitation chances to mention in the out periods, while the upper
level steering flow flip-flops between northwest flow and nearly
zonal flow.

Not much confidence in the temperature forecast this go around.
Beyond Wednesday, the GFS and ECMWF become increasingly out of sync.
For example, at peak heating on Saturday, the GFS maintains 925hpa
thermal progs over KABR of 0.5C, while the ECMWF 925hpa thermal
progs are appx 15C. Maintained superblend output for now.


.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1156 AM CDT SAT OCT 22 2016

VFR conditions will prevail across the area this afternoon through
Sunday morning. Look for breezy southeasterly winds today to
switch around to northwest winds overnight...becoming breezy
northwest on Sunday, especially over KABR/KATY.




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