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000
FXUS63 KABR 191514 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1014 AM CDT Fri Apr 19 2024

.KEY MESSAGES...

- Windy again today, with gusts ranging from 35 to 45 mph across the
forecast area. A few light snow showers (15-30%) possible as well,
mainly over northern to northeastern SD into western central MN.
Any accumulations, if any, will be minor.

- Below normal temperatures through Saturday before warming back to
near to above normal for early to mid week next week.

- The next chance of rain (35-65%) will be Monday/Monday night.

&&

.UPDATE...
Issued at 1010 AM CDT Fri Apr 19 2024

Made some minor tweaks to sky cover and winds. Overall, the
forecast remains on track, though, with no major changes planned.

&&

.SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/...
Issued at 255 AM CDT Fri Apr 19 2024

Short term models agree on a fairly stacked closed low intensifying
as it pushes east and will be centered over western to central
Ontario by 12Z this morning. This leaves the CWA on the southern
side of this cyclone/troughing pattern with westerly flow (50-70kts
at 500mb over the CWA) this morning and turning more northwesterly
this evening on the backside of the low. At 850mb, gusty winds of 30-
40kts, out of the northwest, will also be over the area today and
over the eastern CWA tonight through the overnight. An elongated
high pressure system will start to swing down, with the high
centered over southern Alberta/Saskatchewan by 00Z Sat. For
Saturday, this high will be the dominant pressure system at the
surface with a very positive tilted trough over the CWA aloft.

With this setup, a steeper pressure gradient continues over the
Northern Plains as 850mb temperature advection indicates
-4 to -11C/12hrs this morning and rising to -2 to -5/12hrs this
afternoon. Pressure rises won`t be anything spectacular, around 1-
2mb/6hrs, so the gusty winds will come from the CAA as several Rap
soundings this morning indicate the classic "inverted v" look with
mixing heights up to 850-700mb, tapping into these gustier winds.
With daytime heating, soundings indicate sustained winds around 18-
20kts at the surface, which is around what the HREF is showing
through the afternoon/early evening with Rap indicating gusts 25-
35kts across the CWA. NBM seems to be a little higher with sustained
winds more 20-30kts with gusts up to 35-40kts. As this high gets
closer and the low moves more east, winds will diminish west to
east, but still could see wind gusts around 25-30kts over the Coteau
through the overnight, as winds at 850mb stay stronger in this area.
We are not expecting widespread wind advisory criteria gusts,
however, some areas could be close so will need to keep a watch.

Lastly, a few of the CAMs continues to spit out some northwest to
southeast moving showers, in the form of snow, from late morning
through this afternoon (15-30%). Soundings back this up, indicating
saturation in the DGZ zone, however, omega really is not there as
this is more a weakly forced environment. Lapse rates should be
steep enough to help form these showers. This will mainly be over
northern and northeastern SD into west central MN. Wet bulb temps
will be below 0C during this time even as surface temps warm up
above 0C which is why precip will stay as snow. Any accumulations
will be minor. These showers will diminish towards the evening. With
the cooler airmass overhead, temps will continue to be below average
through the short term with highs ranging in the upper 30s to the
mid 40s today and lows dipping into the 20s again tonight. Little
bit of a rebound for Saturday with highs ranging in the upper 40s to
the lower 50s.

&&

.LONG TERM /SATURDAY EVENING THROUGH THURSDAY/...
Issued at 255 AM CDT Fri Apr 19 2024

An active long term is possible, where it appears a couple of areas
of low pressure could work over the region. When the period opens,
high pressure at the surface and aloft is happening over the
northern plains. Eventually, the high pressure influence is expected
to give way to an area of low pressure bringing mid-level WAA-forced
shower (35-65%) chances to the CWA heading into daytime hours on
Monday. After spending some time in the (15 to 30 mph northwest
wind) warm sector of this system Monday afternoon/evening, models
are progging its cold front to sweep southward through the CWA by
Tuesday morning. More high pressure at the surface and aloft for
Tuesday/Wednesday (northwest flow aloft) until the upper ridge axis
clears the region on Thursday. Timing differences are creeping
during days 6 and 7, but "modest confidence" in steering flow
features exists, at this point, with guidance depicting a
large/broad western CONUS longwave trof establishing during the
second half of next week, placing this CWA underneath southerly or
southwesterly flow aloft by the end of the week. 15-35% PoPs start
creeping into the forecast Wednesday night/Thursday, presumably as
low level jet winds take shape and more moisture/instability is
added to the column. Ensemble guidance PoPs continue to slowly rise
right on through the end of the period, as the ensemble signal for
precipitation potential increases.

Looks like the "wind machine" will take a break Saturday night and
Sunday, and Tuesday evening through Wednesday (the two instances
when surface high pressure will be directly influencing the CWA). It
also still appears that the warming trend being described for the
early to middle portion of next week is in tact.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 636 AM CDT Fri Apr 19 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast to continue at all TAF sites today
through Saturday. Winds will be out of the west/northwest, with
sustained winds increasing to 15-25kts. Gusts could reach up to
30 to 35kts. Winds will be diminishing west to east late tonight
through early Saturday morning. Isolated to widely scattered
showers (some rain, but some snow) are expected to develop
throughout the region this afternoon in daytime heating.


&&

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

$$

UPDATE...Wise
SHORT TERM...MMM
LONG TERM...Dorn
AVIATION...Dorn