Marine Weather and Tides
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen
|Sunrise 7:40AM||Sunset 4:54PM||Sunday December 8, 2019 4:01 PM CST (22:01 UTC)||Moonrise 3:09PM||Moonset 3:50AM||Illumination 91%|
7 Day Forecast for Marine Location Near Vermillion, SDHourly EDIT Help
Area Discussion for - Sioux Falls, SD  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS63 KFSD 082058 AFDFSD
AREA FORECAST DISCUSSION National Weather Service Sioux Falls SD 258 PM CST Sun Dec 8 2019
SHORT TERM. (This Evening through Monday) Issued at 258 PM CST Sun Dec 8 2019
Upcoming forecast concerns will be fog today and tonight, then the band of snow overnight and early Monday morning and then an extended period of cold weather.
Fog and stratus lower and far more aggressive at pushing south than the models have anticipated. Even the latest high resolution data struggling with this push of cold and saturated air. Have opted to issue a dense fog advisory through midnight. While some locations that go down to near zero will improve this afternoon, all hints are that many locations will either continue to trend downward or head back in that direction once the sun goes down. With surface winds remaining from the east and northeast through the early overnight and no source of drier air from that direction the fog should remain in place until north to northwest winds increase later tonight and light snow moves through.
As for the incoming snow chances, the combination of good saturation and falling temperatures through the column of air, light snow can be expected for most locations north of roughly a Gregory SD to Storm Lake IA line. The farther north the better the chance. Along and south of I-90 late tonight and early Monday morning the snow will likely fall for about 2 to 4 hours while closer to highway 14 it may fall for about 3 to 5 hours. This will bring higher snow amounts to those areas. Will aim for about a half an inch to an inch and a half along Interstate 90 and and inch and a half to 3 inches closer to highway 14. Northwest IA, far southern SD and northeast NE should just catch a glancing blow. Temperatures will crash through the night with a stronger surge of cold air coming in late tonight.
This cold surge will keep temperatures falling through Monday morning and they may only steady out in the afternoon before falling more at night. Most locations will see temperatures of about 5 to 15 degrees by 9 am with a fairly stout north wind at 20 to 30 mph. This will drop wind chill values to about 5 below to 15 below zero.
LONG TERM. (Monday Night through Sunday) Issued at 258 PM CST Sun Dec 8 2019
Monday night into early Tuesday morning will see a small chance for some additional light snowfall. The dendritic layer is from near the surface to about 800 mb and hints are that it will be saturated. Forcing weak but should be enough to at least get a few flurries. Will not add any threat for accumulation but watch trends to see if the threat increases.
Another weak warm advective shot moves through on Tuesday night and will usher in additional cold air. Not out of the question for a little more light snow but will likely remain flurries.
Not much change in temperatures Tuesday night into Wednesday as the reinforcing shot of cold air keeps temperatures trapped in the single digits and teens most locations.
Temperatures begin to modify going into Thursday. Broad warm advection develops but thermally we start to lose touch with the dendritic layer and saturation so not a real strong threat for light snow. Will continue to monitor Wednesday night for potential but appears that the higher threat will be north of the area.
The models diverge a bit Friday into next weekend on timing of next shot of cold air. The good news is for now looking like a short term shot of cold air and will not be in place for more than a couple of days. So the basic trend is back to normal or a touch above Thursday and Friday then back below normal Saturday and Sunday, but not as cold as this early week arctic outbreak.
AVIATION. (For the 18Z TAFS through 18Z Monday afternoon) Issued at 1110 AM CST Sun Dec 8 2019
IFR and LIFR conditions spreading south more rapidly than most models have anticipated. Seeing dense fog become much more widepsread as well. Hints that we may have trouble shaking these conditions until the snow and the wind shift come in later tonight. KSUX will likely miss the brunt of the lower conditions but KHON already in them and KFSD should fall into them between 18z and 19z.
FSD WATCHES/WARNINGS/ADVISORIES. SD . Dense Fog Advisory until midnight CST tonight for SDZ053>056- 059>062-065>067.
MN . Dense Fog Advisory until midnight CST tonight for MNZ080-081-089- 090-097-098.
IA . Dense Fog Advisory until midnight CST tonight for IAZ001>003.
NE . NONE.
SHORT TERM . 08 LONG TERM . 08 AVIATION . 08
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports. Follow links for more data.
|Yankton, Chan Gurney Municipal Airport, SD||20 mi||65 min||E 7||10.00 mi||Fair||40°F||34°F||79%||1007.5 hPa|
Link to 5 minute data for KYKN
Wind History from YKN (wind in knots)
|1 day ago||S||SE||SE||SE||S||S||S||S||SE||SE||S||S||S||S||SE||E||SE||SE||S||S||S||S||S||S|
|2 days ago||NW|
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GEOS Local Image of EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
Link to Loop
Other links: Northern Pacific Contential US Full GOES-East
Wind Forecast for Sioux Falls, SD (17,4,5,8)(on/off)  Help
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