← Previous February 27, 2024 12:45 PM

FXUS63 KABR 271845 AAD

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1245 PM CST Tue Feb 27 2024


- Behind the passing of a cold front today, temperatures will
  continue to drop (into the teens by this afternoon) with strong
  northerly winds gusting 45 to 50 mph.

- New snow accumulations of an inch of less expected through early
  to mid afternoon. Snow falling on roads that cool to below 
  freezing may lead to some travel impacts, along with periods of 
  visibility reductions due to blowing snow. 

- Dry and turning warmer for Wednesday through Saturday.


Issued at 1243 PM CST Tue Feb 27 2024

Have allowed the Winter Weather Advisory for Corson county to
expire, and have cancelled the Winter Weather Advisory for
Campbell and McPherson counties. Also put all three of these
counties into the Wind Advisory. No other changes made to the
forecast at this time. 

UPDATE Issued at 1125 AM CST Tue Feb 27 2024

See updated aviation discussion below.

UPDATE Issued at 1014 AM CST Tue Feb 27 2024

Area of light snow continues to slowly drift eastward. The snow
has pretty much come to an end west of the Missouri River. Should
be able to get rid of the Winter Weather Advisory by midday as
snow should be completely over in those areas by then. No changes
made to winds or temperatures at this time. 


Issued at 313 AM CST Tue Feb 27 2024

Mid level shortwave continues to push across southern Canada/ND 
border along with the main trough sinking into the Rockies this 
morning and pushing east/southeast though the day. NAEFS indicates 
heights/SLP are 1 to 0.5% below climo with this system! As of 1AM, 
the surface front is zipping' southeastward quickly (ABR already 
behind the front) with the surface low forecasted to be over MN/WI 
border at 12Z and the cold front well out of the CWA to our east and 
southeast. Rap/HREF models continue to show the 925/850mb front 
pushing southeast right behind the surface cold front. The better 
forcing and widespread snow showers (radar imagery) appears to stay 
up in ND into MN. This is also indicated on the Snowband Prob 
Tracker. However, it indicates our northern CWA looks to be on the 
southern edge of this better forcing/moisture and overall could see 
higher snowfall amounts than the rest of the CWA. With collab from 
northern offices, I did increase the QPF slightly from northern 
Corson and eastward through northern Brown. Northern portions of the 
CWA could end up with to a little over an inch with two being on
the high end. This matches well with the HREF ensembles and WPC 

Things get a little tricky later this morning into the midday as we 
actually see a split in the precip as the better lift and moisture 
will be along parts of northern and northeastern SD/ND border and 
northeastward into eastern ND/western MN. Other area is to our 
south/southeast. In between we lose much of this moisture to produce 
much more than light snow at most as pops diminish to 15-35% around 
and east of the James River by the noon time hour. Cams vary a bit 
with RAP keeping the line intact as it pushes southeast with the 
other Cams showing this split. So I blended in a few of them along 
with the NBM to get a better picture. Overall precip should be out 
of the area by this afternoon with dry weather expected Wednesday as 
the arctic high sinks southeastward. The rest of the CWA should see 
an inch or less in accumulations with barely anything over eastern 
CWA where the line splits.

Winds will be the main concern behind the front as steep pressure 
gradients exists to due strong CAA and pressure rises. EC indicates 
CAA of -10 to -25C/12 hours over the CWA by 12Z and GFS indicates 
pressure rises of +7 to +13/6 hours! Wind gusts shortly before 
midnight were already up to 47mph in Ridgeview and 49mph in Trail 
City. Current wind gusts as of 2:30AM at the office is around 40mph. 
The pressure rises and CAA continues to overspread the CWA as the 
front pushes southeastward with gusts 45-50mph through the morning 
and up to 45mph this afternoon. As the high sinks in behind the 
system and pressure gradients becoming less steep, we will see winds 
diminishing west to east tonight through the overnight. With the 
gusty winds and falling snow, this will lead to temporary reductions 
in visibility as BLSN model indicates drifting to areas of blowing 
snow across northern and northeastern SD. Areas along the ND border 
could see more widespread coverage at times. WSSI shows this well 
with minor to moderate impacts along the border. The WWA remains in 
effect from Corson-Mcpherson but may need to be expanded further 
east if we get lower viz there. A wind advisory covers the rest of 
the CWA.

Temps continue to fall behind the cold front. By 00Z 850mb temps 
will range from -14 to -19C and 925mb temps -10 to -15C! At the 
surface, temps will be around zero to even single digits below zero 
through the overnight. Highs rebound a bit for Wednesday with cooler 
temps staying over northern/northeastern SD and warmer over central 
and south central SD.


Issued at 313 AM CST Tue Feb 27 2024

The long term begins with ridging aloft exerting itself across the 
Northern Plains. And that ridging will persist through the first 
half of the upcoming weekend. The ridge will bring with it mainly 
dry conditions, and mild temperatures through Sunday. GEFS 2m temp 
anomalies suggest as much as 15 to 20 degrees above normal for 
Friday and Saturday. Then a storm moves in for late weekend and 
early next week. Storm details concerning pcpn/snow and timing 
remain somewhat elusive given model differences. The main trend has 
been toward a more progressive system overall, and less total QPF in 
general. The high PoPs in the NBM for Sunday and Monday are 
justified given the varying model outcomes during that time period. 
Once can say the forecast confidence for early next week is not high 
at this point in regards to QPF.


Issued at 1125 AM CST Tue Feb 27 2024


An area of light snow will track across the eastern part of the
region during the early to mid afternoon hours, with periods of
MVFR vsbys possible. Northwest winds will be in the 25 to 40 knot
range this afternoon into the early evening hours before
diminishing to become light and variable overnight. Once the snow
comes to an end, VFR conditions will then prevail through the
remainder of the TAF period. 


SD...Wind Advisory until 8 PM CST this evening for SDZ006>008-011-

     Wind Advisory until 6 PM CST /5 PM MST/ this evening for 

MN...Wind Advisory until 8 PM CST this evening for MNZ039-046.