FXUS63 KABR 040526 AAC AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 1126 PM CST Tue Dec 3 2024 .KEY MESSAGES... - Potent cold front moves through Wednesday morning, bringing strong northwest winds with gusts 40 to 55 mph, potential snow showers, and falling temperatures through the day. Drifting snow may cause icy roads. Patchy blowing snow could cause some reductions in visibility. - Milder temperatures for late in the week and into the weekend with highs/lows forecast to be some 10 to 20 degrees above normal. && .UPDATE... Issued at 1122 PM CST Tue Dec 3 2024 See below for an aviation forecast discussion for the 06Z TAFs. UPDATE Issued at 941 PM CST Tue Dec 3 2024 The latest available guidance supports adding central/south central South Dakota to the wind advisory. Starting it 3 hours later than the rest of the forecast area. Also, starting to see evidence in the latest guidance that during the time of fropa, stratus (super-cooled liquid droplet) clouds will be rapidly shifting southward with the fropa and rapidly cooling to the DGZ. Until it reaches the DGZ, BUFKIT soundings suggest 1KM or nearly 1KM saturation may happen (with some omega within the stratus) with drizzle/freezing drizzle for an hour or two depending on surface temperature could happen. Snow chances briefly chase that southward out of the CWA when the stratus clouds reach DGZ temperature and the droplets activate ice (snowflakes). Forecast has been updated to reflect all this. Plus, that blowing snow potential still exists (temperatures did not reach freezing or warmer up on the Coteau earlier today) up on the Coteau over into west central Minnesota from late Wednesday morning through early Wednesday evening when temperatures tumble into the upper single digits to upper teens and sustained winds, post-frontal, ramp up to 25 to 30 knots. Updates are out. UPDATE Issued at 528 PM CST Tue Dec 3 2024 See below for an aviation forecast discussion for the 00Z TAFs. && .SHORT TERM /THIS EVENING THROUGH WEDNESDAY NIGHT/... Issued at 321 PM CST Tue Dec 3 2024 Warmer temperatures have briefly returned this afternoon with readings ranging from the upper 20s along the Coteau to the lower 50s along and west of the Missouri River. However, an arctic front barrels in late tonight into Wednesday morning with H85 temps falling from +8C into the negative teens Celsius by late afternoon. Temperatures at the sfc will fall through the day, accordingly. The pressure gradient tightens ahead of the approaching high with a 10 to 12 mb spread across the state. This gradient plus the thermal packing in the strong caa will cause northwest winds to gust to 45 mph. One thing to watch will be the very strong winds aloft with 80 kts at 700 mb by afternoon and even 50 kts at 850 mb on a few model iterations. Wind gusts could easily overachieve from current probs and forecasts. Forcing outside of the caa is minimal with only some weak shortwave energy sliding through northeast SD and west central MN in the upper trough. That's where chances for some light snow accumulations of up to half an inch are focused Wed morning. Moisture in the DGZ will be the real question, but arctic fronts tend to squeeze out some snow showers even with limited moisture availability. The winds, combined with falling snow or even the snow on the ground across the Coteau, will produce some drifting or blowing snow. The question is how much the snow on the ground will blow around. Will need to watch the Coteau and possibly the Leola Hills for a winter weather advisory if snow lofts more than expected. For now, issued a wind advisory for most of the cwa. Would not be surprised if the advisory is expanded during the overnight depending on how wind observations pan out upstream. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 321 PM CST Tue Dec 3 2024 Thursday morning starts the long term with upper level flow from the northwest. This is the back (upwind) side of the trough that will be moving out of the area through the day. However, we will remain in northwesterly flow as an upper level ridge remains in place to our west. At the surface, we are under high pressure Thursday and a warm front moves through from west to east on Friday. Sunday morning, this upper level ridge moves into the region and by Sunday afternoon, the axis is over the forecast area. Monday, an upper level low starts to move southeast out of Canada into the Dakotas. The surface level low will move through the area, along with a cold front, during the day Sunday. There is potential for a second cold front to move north to south across the region Monday afternoon into Tuesday. Behind the Sunday cold front, there is a 15 to 25% chance for some light snow along the ND/SD border. Accumulations have about a 30% chance of exceeding a tenth of an inch. Some light snow with about the same accumulation chances will be possible with that potential second cold front. As for temperatures, we will be on a bit of a ride. Thursday is expected to be the coldest of the period as some pretty strong CAA moves in overnight Wednesday. The weekend is looking to be rather nice with highs just above freezing in eastern SD to as warm as low 50s west river. The cold front Sunday into Monday will bring some colder air back to the forecast area and cool temperatures back to around normal. Winds don't look to be anything out of the ordinary until potentially Monday afternoon when west river counties have a 50-70% chance of gusts higher than 35 mph as the cold front moves through. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 1122 PM CST Tue Dec 3 2024 Terminals KABR,KATY,KPIR,KMBG VFR conditions right now, but not for much longer. Between 06Z and 18Z, sub-VFR cigs approaching from the north overspread all four terminals. An arctic frontal passage could yield some scattered snow showers or patchy, short-lived, very light freezing drizzle. Strong winds coincide with the fropa and persist behind it well into the day on Wednesday. There's lower confidence in any reduced vsby in snow showers and blowing snow so haven't introduced a notably reduced visby in falling/blowing snow yet. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory from 3 AM CST /2 AM MST/ to 6 PM CST /5 PM MST/ Wednesday for SDZ003>011-015>023. Wind Advisory from 6 AM CST /5 AM MST/ to 6 PM CST /5 PM MST/ Wednesday for SDZ033>037-045-048-051. MN...Wind Advisory from 3 AM to 6 PM CST Wednesday for MNZ039-046. && $$ UPDATE...Dorn SHORT TERM...Wise LONG TERM...KK AVIATION...Dorn