Expires:No;;048968
FXUS63 KABR 092009
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
309 PM CDT Wed Apr 9 2025

.KEY MESSAGES...

- A Red Flag Warning is in effect through 8PM CDT, due to the 
  combination of humidity from 15 to 20 percent, and northwest 
  winds gusting from 30 to 45 mph.

- Elevated fire weather conditions, including high/very high 
  Grassland Fire Danger Index values, will develop again over 
  portions of central SD Thursday and Friday, mainly west of the 
  Missouri River, and across much of the area Sunday and Monday. 

- High temperatures in the upper 60s and 70s this weekend will be 15 
  to 20 degrees above normal for this time of year.

&&

.SHORT TERM /THIS EVENING THROUGH THURSDAY NIGHT/...
Issued at 309 PM CDT Wed Apr 9 2025

Several locations have seen their RH values drop below 20 percent 
already, mainly from the James River valley westward into central 
SD. We're also seeing red flag criteria being reached a tad further 
east than current headline shows, mainly from ABR down to ATY. Have 
therefore expanded the Red Flag Warning a bit further east, still in 
effect through 01Z. 

Cold front drops south over the region tonight, with low-level cold 
air advection taking place. 925mb temps around +12C to +15C at 00Z 
this evening cool to about +3C to +6C by 12Z Thursday. This cooler 
air overspreads the CWA on Thursday, so looking at highs being cooler 
than today, with 50s east to the 60s across central SD. The cooler 
air will be felt more over the eastern CWA. Elevated fire weather 
conditions mainly west of the Missouri River Thursday afternoon as 
humidity drops down to around 20 percent, with wind gusts around or 
above 25 mph. So, may need to evaluate for a headline.

As for precipitation, have expanded mention of 20-30% chance showers 
this evening with the passage of the cold front and associated mid 
level wave that's evident on water vapor imagery. Radar this 
afternoon is already lighting up with shower activity across ND and 
over western SD. May need to make some changes to PoPs for the late 
afternoon and early evening hours yet in the next hour or two.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 309 PM CDT Wed Apr 9 2025

Warm and dry conditions this weekend, and temperatures will continue 
to increase into the weekend. Highs will reach the 70s by Saturday, 
and areas with full insolation may break 80. This broad ridge also 
supports drier air out of the desert southwest to occupy the region, 
leading to the persistence of fire weather concerns through the 
weekend and beyond. High to Very High Grassland Fire Danger is 
expected Friday through Monday, and Red Flag Warnings may be needed. 
The days of highest concern will be Sunday and Monday due to strong 
northwesterly gusts upwards of 30 knots over much of the forecast 
area. Minimum afternoon humidity will be a key factor in determining 
whether or not a Red Flag Warning is needed, as currently minimum 
humidity is borderline or just above criteria for the remainder of 
the forecast period.  

There is increasing model confidence on the arrival of a low 
pressure center tracking over the northern Plains on Sunday due to 
the incoming upper level trough. While there is still some 
variability in the track, models have consistently resolved the 
swath of heaviest precipitation remaining to the north over the past 
few forecast cycles. Assuming that the track remains consistent, 
frontal passage may be a concern Sunday afternoon. While there is 
lift available with the presence of the front and good shear, an 
early look at model sounding lapse rates along the front do not look 
very favorable for any deep convection or severe storm development. 
As it stands now ensembles are giving only ~30-50% chance for 
measurable precipitation out of the whole event, and 10-30% chance 
for 0.1" of liquid. A few select ensemble members bring snow into 
the equation in the early morning hours Monday, but for the most 
part the expectation is that any precipitation will fall as rain.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1236 PM CDT Wed Apr 9 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast to start off the TAF period. MVFR CIGs
are forecast to move southward into the region by Thursday
morning, with greatest potential to see these at KABR/KATY. There
may also be isolated -SHRA moving southeast across the region this
evening, although confidence is low on placement and areal
coverage. 


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Red Flag Warning until 8 PM CDT /7 PM MDT/ this evening for 
     SDZ003>006-009-010-015>020-022-023-033>037-045-048-051.

MN...None.
&&

$$

SHORT TERM...TMT
LONG TERM...BC
AVIATION...TMT