← Previous March 28, 2024 10:10 AM

FXUS63 KABR 281510 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1010 AM CDT Thu Mar 28 2024

.KEY MESSAGES...

- A disturbance moving through the region late tonight into 
  Friday will deliver a 30-50% chance for rain and/or freezing 
  rain. Up to a few hundredths of ice accumulation will be 
  possible.

- Precipitation chances increase this weekend, perhaps in two
  waves, late Saturday/Saturday night, then again late Sunday 
  through Monday. Early indications suggest a "less than 6 inch 
  type outcome" for the time being.

- Warming temperatures moving in by mid-week next week, with 40s,
  50s, and perhaps even 60s (central SD on Wed) moving into the 
  region.

&&

.UPDATE...
Issued at 1010 AM CDT Thu Mar 28 2024

The forecast remains on track this morning. No major changes are
planned. 

&&

.SHORT TERM /TODAY THROUGH FRIDAY AFTERNOON/...
Issued at 445 AM CDT Thu Mar 28 2024

We'll be able to squeak out another relatively quiet day weather-
wise today before a disturbance moves into our region toward the 
latter half of the period and generate some precip chances for parts 
of the forecast area. High pressure will gradually shift east and 
southeast of our area today while a low pressure trough continues to 
organize across the Rockies and Northern High Plains. With a ridge 
of high pressure aloft, we can expect a fair amount of sunshine 
during the day, perhaps high clouds filter out some of that sunshine 
this afternoon. Warmer daytime highs are expected today, with 
eastern zones the coolest thanks to thicker snow cover. A tighter 
pressure gradient develops this afternoon across the western and 
central Dakotas between the high to the east and the trough to the 
west. Increasing southeast breezes gusting up around 30 mph will be 
possible across the Missouri Valley.

Clouds will increase tonight as a sfc trough shifts eastward across 
the Dakotas. The upper ridge will give way to an upper trough 
lifting northeast out of the Rockies and Northern High Plains. We 
anticipate light precipitation to develop and shift east-
northeastward across our forecast area tonight into Friday. Models 
seem to be in agreement on the core of this disturbance to pivot out 
of Montana and into North Dakota keeping the focus for steadier QPF 
to our north. BUFKIT soundings do show a warm nose(above freezing) 
aloft, just off the surface with temperatures at or colder than 
freezing at the surface. That warm nose will take some time to 
saturate, but eventually it looks to and we should see a period of 
freezing rain spread across the forecast area late tonight into 
Friday morning. WPC QPF and NBM generally are in the same camp 
indicating up to a few hundredths of ice accumulation will be 
possible across the northern tier of our CWA.

&&

.LONG TERM /FRIDAY EVENING THROUGH WEDNESDAY/...
Issued at 445 AM CDT Thu Mar 28 2024

Surface high pressure will be moving over the region Friday night 
through much of the day Saturday, before pushing east Saturday night 
as the first wave of precipitation chances approach. In regards to 
the precipitation over the weekend into Monday, latest deterministic 
solutions are starting to show this in two waves now, the first 
being Saturday night, with the more meaningful onset of precip late 
Sunday through Monday. Inherited NBM PoPs, as well as ensemble probs 
for measurable still fail to adequately portray this given their 
more blended/averaged feel. Will have to watch to see if this a 
trend that holds. 

By 00Z Tuesday, probability of exceedance for accumulated snowfall 
greater than 3 inches (assuming 10:1 ratios) are running from around 
40-60% across central SD, with lesser amounts around 40% or below 
further east. Snowfall means amongst the GEFS/ENS/GEPS are running 
around 2 to 4 inches by 00Z Tuesday, with some higher end scenarios 
(75th percentiles) on the order of 4 to 6 inches (mainly over 
central SD).

Looking ahead to mid-week next week, we see signs in the cluster 
output of overall ridging trying to build across the Northern 
Plains. There still area some glaring differences in the upper level 
patterns amongst the four clusters in the 00Z Thurs - 00Z Fri 
period. Clusters 2 and 3 (with 20% and 19% membership respectively) 
hold on to a much deeper and slower moving trough over the Great 
Lakes, which in turn show a large ridge amplification over the 
High/Northern Plains. Cluster 1, which has the largest membership at 
43%, shows a more flattened upper level pattern over the region, but 
still mild nonetheless. The differences can be seen in 850mb temps 
as well, with the more amplified ridge scenario running between +7C 
to +12C across the CWA. Grand Ensemble of the clusters are generally 
between +3C and +7C from east to west across the CWA. All that said, 
the overall ridging moving in will mean a warm up into the 40s and 
50s likely, perhaps even 60s on Wednesday across central SD 
according to the inherited NBM temperatures.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 626 AM CDT Thu Mar 28 2024

Terminals KABR,KATY,KPIR,KMBG

Potential exists this morning for BR across the KATY region, so
inserted a TEMPO mention of this. Otherwise, VFR conditions can be
expected through much of the TAF period, although MVFR CIGs are
forecast to begin moving into KMBG towards the end of the period.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

UPDATE...Wise
SHORT TERM...Vipond
LONG TERM...TMT
AVIATION...TMT