000
FXUS63 KABR 261726 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1226 PM CDT MON SEP 26 2016

.UPDATE...
Issued at 1224 PM CDT MON SEP 26 2016

Aviation discussion updated below for 18Z TAFs.

UPDATE Issued at 1008 AM CDT MON SEP 26 2016

No major changes planned to the current forecast. Main concern
remains the potential for frost tonight and Tuesday night.

&&

.SHORT TERM...(Today through Wednesday Afternoon)
Issued at 231 AM CDT MON SEP 26 2016

With the last couple of bands exiting far northeastern Traverse
County, our focus goes away from precipitation and back to winds,
fire weather, and frost.

Will start off this period with the 500MB low spinning from western
Ontario through western Upper Michigan, with strong northwesterly
flow across the Dakotas. The low will sink across Lower Michigan and
into the Ohio valley Tuesday night and Wednesday, as a ridge slowly
builds across our region. At the surface, the low over western
Ontario will push across Lake Superior on Tuesday, slowly loosening
it`s grip on our weather. The pressure gradient will remain strong
enough over eastern SD to keep 20 to near 25kt northwest winds
with gusts of 30 to near 35kts in the fcst. This will also be the
driest area with PW values around 0.25in and dewpoints in the low
30s. RH values will bottom around 25-30 percent, even with temps in
the mid 60s to low 70s.

The dry air will remain entrenched across our east, mainly east
of the James River Valley. This will make the overnight low temp fcst
difficult tonight into Tuesday morning, especially as the sfc ridge
centers across western and central SD. Winds may stay at or above
5kts east thanks to the pesky sfc low over the Great Lakes.

A few 80 degree readings may return to central SD Tuesday afternoon,
or 3-7 degrees above those expected today. The sfc ridge should
reside over the entire fcst area from early Tuesday evening through
the entire day Wednesday. A few upper 30 readings for lows Tuesday
night/Wednesday morning will not be out of the question over the
James River Valley and east. Patchy frost has been included for a
couple of small areas tonight and Tuesday night. Some clouds may
slide into the eastern counties Wednesday, but confidence is very
low.

.LONG TERM...(Wednesday Evening through Sunday)
Issued at 231 AM CDT MON SEP 26 2016

At the start of the period high pressure at the surface and aloft
has dry and stable weather conditions in place over the cwa. At the
close of the period falling pressure at the surface and aloft has
precipitation chances increasing heading into the beginning of
October. Developing return flow pattern in the low levels will
result in a multi-day period of southerly breezy/windy conditions.
Still looks like neutral advection to weak low level warm air
advection will have daytime high temps warming generally into the
70s for most of the period...with perhaps some lower 80s creeping
into the picture in the out periods across portions of central South
Dakota.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1224 PM CDT MON SEP 26 2016

VFR conditions will prevail through the TAF forecast period.

&&

.ABR Watches/Warnings/Advisories...
SD...NONE.
MN...NONE.
&&

$$

UPDATE...TMT/Wise
SHORT TERM...KF
LONG TERM...Dorn
AVIATION...TMT