Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 251730 AAC

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1230 PM CDT SUN SEP 25 2016

Issued at 1033 AM CDT SUN SEP 25 2016

Continue to see strong and gusty winds across central SD this
morning, with some obs within advisory criteria. A few obs just
east of the advisory have also been hit and miss in low end
criteria, so have expanded wind advisory another tier of counties
east. Think it will be difficult to see widespread advisory level
winds much farther east, although it will still be windy
nonetheless. Hi-res models showing the core of strongest winds
across central SD today, then shifting into ND. Will continue to
monitor wind speeds for any possible changes. Otherwise, some weak
radar returns showing up across the northeast CWA, with either
light rain or drizzle visible on the Summit web cam. Also received
report of drizzle north of Bristol. Have added mention of drizzle
for the northeast CWA for the remainder of the morning. Current
forecast highs seem in the ballpark so no changes there. Will
continue to see cloud deck advance eastward through the day.
Clearing is noted over central SD, with clearing expected into the
James Valley this afternoon.


.SHORT TERM...(Today through Tuesday Afternoon)
Issued at 241 AM CDT SUN SEP 25 2016

Windy and cool, with diminishing clouds west to east during the
afternoon hours can be expected today behind the sfc low exiting
across Manitoba. Light showers are rotating in from the northwest.
Will keep these in the fcst, with some enhancement over the late
morning/early afternoon hours mainly to the east of ABR. The
strong northwesterly winds will continue to be the main weather
story for today. Winds have already been gusting in the 35 to near
45kt range has been reported at Faith and the Grand River RAWS
sites prior to 07Z. Will keep the Wind Advisory in tact for today,
but wouldn`t be surprised if it can be dropped after 21Z. The area
of strongest winds will also be where the lowest humidity values
will be this afternoon. PW values will bottom out around 0.25in
over our western tier of counties, where RH values will drop to
20-30 percent /lowest over Jones County/. This will be in contrast
to the 50-60 percent min RH values over the eastern counties. The
grassland fire danger index will jump to Very High today over our
western tier counties from Corson to Jones.

The drier air will be more fully entrenched across the forecast area
on Monday morning, where PW values of 0.25in will be more common.
While northwesterly winds linger into Monday as the Canadian low
sinks across Lake Superior. This will keep the strongest winds over
the eastern half of the CWA. RH values area-wide will bottom out
between 20 and 30 percent. Given the lighter winds than Sunday,
grassland fire danger will max out more in the high category west.

Dry high pressure will remain across the Plains States through at
least Tuesday. Kept near the low end of guidance for low temps
Monday night/Tuesday morning, with upper 30s across the James River
Valley. Look for temperatures to moderate back into the low 80s
southwest to upper 60s northeast /closer to the lingering low
spinning across the Upper Great Lakes/ Tuesday afternoon.

.LONG TERM...(Tuesday Evening through Saturday)
Issued at 241 AM CDT SUN SEP 25 2016

As advertised, a portion of longwave trof upper level low pressure
is currently being separated from the rest of the longwave trof and
in all likelihood will meander over the far southwestern CONUS over
the next few days until it is picked up by strengthening upper level
southwesterly flow aloft later in the week. This upper level energy
is still forecast by tonight`s 00z gsm solutions to lift newd
through the northern plains by Friday, setting the stage in
southwest flow aloft for one or more mid-level shortwave trof
passages over the weekend and heading into the first full week of
October. Precipitation chances slowly ramp up at the end of the week
and over the weekend. Prior to Friday, the extended forecast is dry,
dominated by northwest flow and a building upper level ridge of high

It does not appear, right now, that wild fluctuations in
temperatures will be experienced in the out periods, with neutral
air to weak warm air advection in the low levels through Thursday.
Low level winds really start to pick up in return flow pressure
gradient pattern on Friday, persisting into the weekend which could
produce some slightly warmer temps due to better mixing.


.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1228 PM CDT SUN SEP 25 2016

An area of mvfr stratus associated with an exiting cold front
continues to impact KATY. This cloud deck will continue to move
east and should clear KATY by 21z leaving all sites VFR for the
remainder of the period. Gusty northwest winds of 20 to 40 kts
will slowly diminish this evening before increasing back to 15 to
25 kts on Monday.


.ABR Watches/Warnings/Advisories...
SD...Wind Advisory until 7 PM CDT /6 PM MDT/ this evening for SDZ003>005-



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