Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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071 FXUS63 KFSD 200814 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 314 AM CDT Sat Oct 20 2018 .SHORT TERM...(Today and Tonight) Issued at 314 AM CDT Sat Oct 20 2018 The latest water vapor imagery shows a strong upper level jet max diving south through the eastern Dakotas and western MN early this morning. This will bring a quick change to colder conditions today, but luckily this will be a short lived cool down as southerly flow brings warmer conditions back for Sunday. An increased pressure gradient and fairly strong cold air advection will create breezy conditions this morning, but winds will gradually diminish through the afternoon as high pressure builds south. The brunt of the coldest air will remain east of the area so expect a normal diurnal rise in temperatures. Highs will only reach the 40s in most locations while some lower 50s will be possible in central SD. Some fragmented stratocumulus and a few flurries or sprinkles will be possible before about 15z today, but any one location will likely not see these clouds for more than about 3 hours. Most of the high resolution models are dry with this frontal passage as well as the lower resolution models, with only the NMM and ARW producing some very light precipitation in southwest MN. By tonight the surface high pressure will quickly shift east, but winds will be on the light to calm side along and east of Interstate 29 through about 9z. This will allow for some radiational cooling and lows in the upper 20s. Southerly return flow will set up from west to east through the night and help modify any falling temperatures, and likely bring a small rise in temperatures to those locations that drop off the most. Lows from the upper 20s in northwest IA to near 40 in south central SD. .LONG TERM...(Sunday through Friday) Issued at 314 AM CDT Sat Oct 20 2018 Sunday night into Monday will see the right entrance region of the upper level jet shift east and drop a cool front into the area. Some winds will hang on through the night so Monday morning lows will likely be in the lower to mid 30s. Temperatures will mix fairly nicely with a very dry environment, so looking at upper 50s to lower 60s. Weak upper level ridging will provide a low amount of cloud cover and fairly light winds Monday night into Wednesday. By Wednesday afternoon into Wednesday night a weak southern stream cut off low pressure will drift into the area and bring with it a chance for showers. This chance will linger into Thursday. Friday right now looking fairly quiet and mild as upper level energy passes to the north but this of course could change quite a bit by the time next Friday becomes reality. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1032 PM CDT Fri Oct 19 2018 VFR conditions through the TAF period. Low level wind shear will develop at all TAF sites overnight. Northwesterly winds will pick up on Saturday morning, gusting 20 to 30 kts into the afternoon. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ SHORT TERM...08 LONG TERM...08 AVIATION...JM is the U.S. government's official web portal to all federal, state and local government web resources and services.