Area Forecast Discussion
Issued by NWS Aberdeen, SD

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 181117 AAA

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
617 AM CDT Wed Oct 18 2017

Issued at 613 AM CDT Wed Oct 18 2017

See below for an aviation forecast discussion for the 12Z TAFs.


.SHORT TERM...(Today through Friday Afternoon)
Issued at 313 AM CDT Wed Oct 18 2017

The main story today will be the result of the sfc low moving
east into central and northern Manitoba, and the cold front just
to our northwest early this morning that will quickly push across
the Dakotas by late morning. Although temperatures will still be
above normal, they will be over 10F cooler than yesterday as
breezy northwest winds push cooler air into the region. Expect
winds of 15-20kts 15-19Z west, and 17-21Z east. Gusts of 20 to
near 30kts are also expected behind the cold front. While relative
humidity does bottom out around 20 percent near and west of the
Missouri River from around 18-22Z, the peak winds should be before
this period. Will continue to highlight the breezy winds and
relative humidity values less than 25 percent along and west of
the James River Valley in the fire weather products.

High pressure over western SD at 18Z will shift over central NE by
00Z Thursday, with a ridge extending across the entire forecast
area. The sfc high will continue to sink southeast, and across IA
Thursday morning. The pressure gradient will increase in between
this exiting high and low pressure over southwestern Canada. General
zonal flow aloft will be replaced by a ridge Thursday afternoon,
that will stretch southeast through the Gulf of Mexico. Temperatures
will rebound back into the 70s, with breezy afternoon winds from
south central SD through our eastern counties. This will again be
offset from the area of lowest relative humidity values, west of the
Missouri River.

The 500mb ridge will move to the eastern U.S. Thursday night and
Friday, with southwesterly flow setting up late Thursday afternoon
through Friday. Eastern SD and western MN will again be the focus
for breezy southerly winds Friday afternoon, as high pressure
remains at the sfc over the eastern U.S., and low pressure crosses
into south central Canada (with a trough extending south over
eastern MT and the western Dakotas late in the day. Did increase
winds Friday from a general model blend, with some gusts of 30 to
near 35kts not out of the question near the Sisseton Hills.

.LONG TERM...(Friday Evening through Tuesday)
Issued at 313 AM CDT Wed Oct 18 2017

It`s not looking all that great for precipitation chances Friday
night into Saturday, even though the cwa will be under southwesterly
flow aloft. Model consensus remains that shortwave energy will work
through the region during that time. But, currently, precipitation
amounts being forecast are not all that much and not widespread in
coverage. What seems like a higher confidence forecast element, at
this time, is breezy to windy south-southwesterly winds Friday
night. By the start of next week, when the pattern over this cwa has
transitioned to northwest flow influence, there is a little bit of
"cold air instability" precipitation potential mainly across the far
northeastern portion of the cwa and mainly Monday into Monday
evening. As far as temperatures go, the cooler conditions that set
up over the region on Saturday are briefly usurped by a little bit
of low level warm air advection on Sunday before low level cold air
advection sets back up early next week.


.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 613 AM CDT Wed Oct 18 2017

Other than some breezy/windy northwest winds today, VFR
conditions are forecast to prevail across the area over the next
24 hours.




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