019
FXUS63 KABR 272325 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
525 PM CST Thu Nov 27 2025

.KEY MESSAGES...

- A band of snow develops Friday morning in central and north
  central South Dakota, moving northeast before broadening into
  light snow Friday night and Saturday. Winter weather headlines
  are in place for this system.

- Below normal temperatures continue through at least the middle
  of next week. Coldest timeframe is Sunday/Monday with temps 15
  to 25 degrees below normal. Wind chills as cold as 5 to 15
  degrees below zero forecast for Sunday and Monday mornings.&&

.SHORT TERM /THIS EVENING THROUGH FRIDAY NIGHT/...
Issued at 301 PM CST Thu Nov 27 2025

Stratus layer continues to migrate slowly southwest having cleared
Aberdeen and not quite to Watertown, will likely linger across
central South Dakota with light flow at 850mb under a ridge. Where
it has cleared, models suggest the potential for fog re-develoment,
up along the ND/SD state line in particular. Will wait and see where
the clouds clear before updating fog mention.

Focus is on the system for Friday. There is a narrow axis of mid
level warm advection providing the impetus for a band of snow along
a corridor across central South Dakota, that weakens as it shifts
east, with a lull in advection before another broader area of weak
warm advection kicks in resulting in additional light snowfall
amounts. So how intense will these snowfall rates get? NAM BUFKIT
profiles suggest at times a very deep dendritic growth zone with
these cold temperatures aloft, and low wind speeds limiting breakup,
which is confirmed by NBM snow ratios of 16-18 to 1. HREF
probabilities of snow rates in excess of 1 inch per hour are zero
however. Average for ensembles for Mobridge/Miller/Huron run about
0.4" liquid, translating to about 6 for snowfall where this band
sets up. As such, posted a winter storm warning along and to the
northwest of the original watch to cover CAM placement.

This will be very blowable snow given snow ratios, however in
regards to the blowing snow model, the mean NBM highest winds
(sustained) will require inch per hour snowfall rates to approach
blizzard criteria, and as mentioned earlier, HREF doesn`t support
such high snowfall rates.

As for temperatures next several days, we remain under an arctic
airmass. NBM temperatures bottom out Sunday/Monday, aided by the
newest addition of snow. Northwest low level flow will keep
temperatures from cratering Sunday morning. The same can not be said
for Sunday night/Monday morning with a shift to southerlies, however
NBM does bring in some cloud cover, a thick layer of cirrus according
to GFS 300mb analysis and BUFKIT profiles, in line with an
approaching shortwave. Lower level moisture appears limited to
Nebraska at this time and the atmosphere is too dry in the subcloud
layer to support precipitation reaching the surface.

&&

.UPDATE...
Issued at 518 PM CST Thu Nov 27 2025

Forecast remains on track. No major changes planned, but will
likely need tweaks to hourly sky cover and temps.

&&

.SHORT TERM /THIS EVENING THROUGH FRIDAY NIGHT/...
Issued at 301 PM CST Thu Nov 27 2025

Stratus layer continues to migrate slowly southwest having cleared
Aberdeen and not quite to Watertown, will likely linger across
central South Dakota with light flow at 850mb under a ridge. Where
it has cleared, models suggest the potential for fog re-develoment,
up along the ND/SD state line in particular. Will wait and see where
the clouds clear before updating fog mention.

Focus is on the system for Friday. There is a narrow axis of mid
level warm advection providing the impetus for a band of snow along
a corridor across central South Dakota, that weakens as it shifts
east, with a lull in advection before another broader area of weak
warm advection kicks in resulting in additional light snowfall
amounts. So how intense will these snowfall rates get? NAM BUFKIT
profiles suggest at times a very deep dendritic growth zone with
these cold temperatures aloft, and low wind speeds limiting breakup,
which is confirmed by NBM snow ratios of 16-18 to 1. HREF
probabilities of snow rates in excess of 1 inch per hour are zero
however. Average for ensembles for Mobridge/Miller/Huron run about
0.4" liquid, translating to about 6 for snowfall where this band
sets up. As such, posted a winter storm warning along and to the
northwest of the original watch to cover CAM placement.

This will be very blowable snow given snow ratios, however in
regards to the blowing snow model, the mean NBM highest winds
(sustained) will require inch per hour snowfall rates to approach
blizzard criteria, and as mentioned earlier, HREF doesn`t support
such high snowfall rates.

As for temperatures next several days, we remain under an arctic
airmass. NBM temperatures bottom out Sunday/Monday, aided by the
newest addition of snow. Northwest low level flow will keep
temperatures from cratering Sunday morning. The same can not be said
for Sunday night/Monday morning with a shift to southerlies, however
NBM does bring in some cloud cover, a thick layer of cirrus according
to GFS 300mb analysis and BUFKIT profiles, in line with an
approaching shortwave. Lower level moisture appears limited to
Nebraska at this time and the atmosphere is too dry in the subcloud
layer to support precipitation reaching the surface.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 518 PM CST Thu Nov 27 2025

Terminals KABR,KATY,KPIR,KMBG

IFR stratus will continue to move through the region. IFR/MVFR
conditions will become more widespread early Friday morning ahead
of some moderate snow.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Storm Warning from 9 AM CST /8 AM MST/ Friday to noon CST
     /11 AM MST/ Saturday for SDZ003-009-010-015>017-034-036-037.

     Winter Weather Advisory from 9 AM Friday to noon CST Saturday
     for SDZ004.

     Winter Weather Advisory from noon Friday to noon CST Saturday
     for SDZ005-006-018-019.

     Winter Weather Advisory from 3 PM Friday to noon CST Saturday
     for SDZ007-008-011-020>023.

     Winter Storm Watch Saturday afternoon for SDZ010-017>019-036-037.

     Winter Weather Advisory from 6 AM CST /5 AM MST/ Friday to noon
     CST /11 AM MST/ Saturday for SDZ033-035-048-051.

MN...None.
&&

$$

UPDATE...20
SHORT TERM...07
AVIATION...20