textproduct: Aberdeen

KEY MESSAGES

- Highs today and again Tuesday and Wednesday of next week will be around 10 degrees below normal.

- Winds Monday afternoon will gust near 30-40 mph, strongest over northern SD.

UPDATE

Issued at 615 AM CDT Fri May 1 2026

The aviation discussion has been updated for the 12Z TAFS.

DISCUSSION

Issued at 126 AM CDT Fri May 1 2026

The Northern Plains continues in north/northwest flow aloft on the western side of a large mid level low spinning over Ontario/Quebec and east of a ridge over the western CONUS. Within this flow, another 500mb weak embedded shortwave will track north to south over the CWA midday and exiting this evening, mainly bringing some lower to mid level clouds with it. At the surface, high pressure will reside over the CWA with this high shifting a bit more southeast this evening keeping conditions dry and quiet.

Continuing in this north to northwest flow aloft, a positive tilted shortwave will track southeastward out of western Canada Saturday morning and over the region through early Sunday along with its weak surface low. GEFS is a bit stronger and more westward with the track of the low than ENS at this time. For example by 00Z Sunday, the center of the low is forecast to be over southeastern ND (GEFS) or over northwestern MN (ENS), so quite the difference. Several of the CAMs do indicate scattered convective showers tracking southeast out of ND and potentially through northeastern SD into MN late afternoon Saturday through the evening, with better coverage closer to the low over ND/MN. RAP/HRRR really only indicate our far northeastern CWA being clipped whereas NamNest/HiRESW track this chance a further west to the Mo River. However, the NBM has decreased the pops to under 15% now, keeping any light pops well east of the CWA. This is most likely due to the fact as there lots of low level dry air to overcome, below 800mb, with PWAT less than 0.8", and overall weak forcing. ECAM has pops up to 35% over far NESD/MN. So low confidence on this precip occurring so kept with the NBM for now. NBM/HREF prob of QPF>0.01" is only 25% over far northeastern SD/western MN.

Behind the exiting cold front and surface trough, high pressure will track out of Alberta and over MT by early Sunday, keeping the CWA dry. Looking ahead into early next week, this mid low that was over the eastern CONUS will track north and northwest, phasing with another low that will then circle over and south of the Hudson Bay. This keeps the Northern Plains and eastward in this ongoing longwave trough pattern. Another shortwave will track more across ND/MN (and its surface low) Monday with slight pops of 15-20% east of the James River. Winds will also increase out of the northwest, per CAA/steeper low level lapse rates, with gusts up to 40 mph. Embedded shortwave activity Tuesday/Wednesday could bring additional slight pops (15-25%) but low confidence on track and timing/location of any precip. Aloft, this persistent +PNA pattern will continue through the end of next week with the ridge broadening bit by the end of the week.

With mainly north to northwest surface winds (colder air aloft), highs for today will still be about 5-15 degrees below average, ranging in the 50s to around 60 (over north central SD, closer to the warmer air ahead of next low) and lows in the lower to mid 30s. WAA per southwesterly flow (and 850mb temps warming to the 70-85th percentile), surface highs for Saturday will be warmer ranging in the mid 60s (Coteau) to the mid 70s, warmest along and west of the Mo (5-10 degrees above climo over central SD). Highs for Sunday will drop back down, ranging in the 60s per cooler air behind the front. Additional shots of cooler air is expected to plunge southward early next week on the backside of this persistent cutoff 850mb low as the NBM 25-75th spread in MaxT is on the order of 10-12 degrees Monday (timing of next cold front) and 5-10 degrees Tues/Wed, with highs by this time ranging in the 50s. Temps are forecast to increase end of next week with the broad ridge back into the 60s to possibly the 70s, however, the NBM 25-75th spread is over 10 degrees for the entire CWA.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 615 AM CDT Fri May 1 2026

Terminals KABR,KATY,KPIR,KMBG

The forecast for all terminals will remain VFR through this forecast cycle. A FEW to SCT low to mid level cloud deck is expected to advect in from the north this morning along with additional daytime development. These clouds are expected to clear out this evening. Generally light northerly winds are expected today before switching around the south and southeast this evening into early Saturday.

ABR WATCHES/WARNINGS/ADVISORIES

SD...None. MN...None.