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Office: FSD

FXUS63 KFSD 191119

Area Forecast Discussion
National Weather Service Sioux Falls SD
619 AM CDT Fri Oct 19 2018

.SHORT TERM...(Today and Tonight)
Issued at 311 AM CDT Fri Oct 19 2018

The southern branch of the upper level jet will shift east this
morning as a strong northern branch drops south this afternoon. This
will swing a cool front through the area with the brunt of the
colder air settling in on Saturday morning.

Southwest winds this morning will transition to the west and then
northwest with gusts around 35 mph expected this afternoon. Some
stronger winds not to far above the top of the mixed layer so if we
can mix a touch higher the winds could be another 5 to 10 mph
stronger, so that will be something to watch out for. Highs are
still expected to be in the 60s.

Some marginally stronger northwest winds will continue through the
night so low temperatures will be mild in the upper 30s to lower
40s. Clouds may increase a bit over southwest MN but the latest
soundings are not as aggressive with the small moist layer at the
top of the mixed layer when the cold advection dives in.

.LONG TERM...(Saturday through Thursday)
Issued at 311 AM CDT Fri Oct 19 2018

Windy conditions will again be likely on Saturday with a reinforcing
shot of colder air. The strongest winds should be in Southwest MN
and northwest IA where gusts around 35 mph will be likely in the
morning. The winds will slacken a bit into the afternoon as the
pressure gradient and cold air advection weaken.

By Sunday upper level winds will become more westerly which will in
turn set up a well mixed lower level environment supportive of very
mild temperatures. Will see highs in the 60s with a few 70s likely
in central SD. While winds will be a bit breezy in northwest IA, the
remainder of the area should see moderately breezy conditions with
winds likely decreasing through the afternoon.

As the upper level jet to the north moves through cooler air near
the surface will shift south. This will bring highs back into the
50s on both Monday and Tuesday. Both days are expected to be dry.

Broad somewhat unfocused flow is expected Wednesday and Thursday
with a few minor chances for rainfall. Decreased the chances a bit
from what was loaded as confidence in this type of pattern not real
high. Overall still mild with highs likely in the 50s and morning
temperatures in the 30s to lower 40s.


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 606 AM CDT Fri Oct 19 2018

Light rain showers, mainly east of I-29, will gradually taper off
early this morning. The main impact will be winds. Gusty winds
from 30 to 40 mph are expected through late afternoon. LLWS
around 40 knots at 1800-2000 ft will be possible Friday night,
impacting mainly KFSD.





Office: UNR FXUS63 KUNR 190946 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 346 AM MDT Fri Oct 19 2018 .DISCUSSION...(Today Through Thursday) Issued at 345 AM MDT Fri Oct 19 2018 Strong upper ridging is persisting across the western CONUS, with a weak shortwave trough now crossing the Dakotas into the Colorado plains. At the surface...a cold front is pushing into North Dakota, sliding SSE. The front will push through the area this morning, bringing cooler, but near average temperatures to the area. Gusty northwest winds are also expected today. Aside from some morning clouds across northwest SD, sunny skies are again expected. Another cooler day is expected Saturday, but return flow will set up as a storng surface high slides east of the CWA late in the day. Warmer temps will advect in for Sunday with highs reaching the 60s to low 70s again. Quiet weather will persist through the first half of the work week as the upper level blocking pattern remains nearly stationary. Temperatures will be generally in the 60s. An upper trough is progged to push into the Pac NW Tuesday which will break down the blocking pattern. This more active pattern may then bring chances for precip Wednesday. && .AVIATION...(For the 12Z TAFS Through 12Z Saturday Morning) Issued At 345 AM MDT Fri Oct 19 2018 VFR conditions will continue through the period. Gusty NW winds can be expected today mainly across the western SD plains. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION...13 AVIATION...Pojorlie
Office: ABR FXUS63 KABR 191114 AAA AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 614 AM CDT Fri Oct 19 2018 .SHORT TERM...(Today and Tonight) Issued at 321 AM CDT Fri Oct 19 2018 Sisseton Hills downslope event continues, with 40kt winds peak gusts being reported at 8D3. The initial sfc trough stretched from McPherson to Jones Counties at 07Z, with more steady north- northwesterly winds behind the cold front set up across northwestern ND and southeastern MT. This feature shows up well on satellite imagery, and will sink across the forecast area around 15Z-19Z. Raised temperatures slightly for today, given the good mixing. However, given the timing of the cold front, temperatures will likely become pretty steady after 18Z. Gusts of 25 to near 35kts are expected this afternoon, strongest from 18-21Z. The grassland fire danger index will reach the very high category today as breezy northwest winds combine with ongoing dry conditions and relative humidity values of 25 to 35 percent. Have highlighted the very high grassland fire danger index in the HWO. While we should remain precipitation free, it's not completely out of the realm of possibility that light rain/snow falls east of the Sisseton Hills after 06z tonight as a secondary cold front sinks in from the north. Will keep the dry forecast going due to the uncertainty, and the idea that the best chance of any precipitation will stay to our northeast. Will continue to revisit the precipitation chances for tonight. .LONG TERM...(Saturday through Thursday) Issued at 321 AM CDT Fri Oct 19 2018 The latest model runs remain pretty consistent with each other and their previous runs. Stable rex block over the western CONUS remains in place until the latter part of next week. At that time, some energy breaks through the ridge and lifts out of the southwest CONUS, and into the plains. The ECMWF/CMC are a bit more aggressive and quicker to bring moisture/pcpn into the region vs the GFS. The model blend will suffice for now given the model differences noted, and no clear preference that far out in the forecast. As for temperatures, did bump up Sunday temps given progged LL thermal progs, and some LL mixing per soundings. The rest of the period should feature temperatures right around normal as a cooler airmass works into the region. && .AVIATION...(For the 12Z TAFS through 12Z Saturday Morning) Issued at 613 AM CDT Fri Oct 19 2018 VFR skies/vsbys are expected through the entire taf valid period at all terminals. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ SHORT TERM...KF LONG TERM...TDK AVIATION...TDK