Area Forecast Discussion
Issued by NWS Rapid City, SD
Issued by NWS Rapid City, SD
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
039 FXUS63 KUNR 282336 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 536 PM MDT Tue May 28 2024 .KEY MESSAGES... -Thunderstorms return Wednesday afternoon and evening with potential for hail and damaging wind -Chance of showers/thunderstorms continue through the weekend -Cooler Thur-Fri, warming back up this weekend && .DISCUSSION...(This Evening Through Tuesday) Issued at 109 PM MDT Tue May 28 2024 Active flow over the northern Pac will continue to offer progressive mean westerly flow through most of the forecast period. Mainly quiet weather ongoing across the fa today. Sfc ridge currently over the eastern Dakotas with light easterly winds, clear skies, and seasonal temps today. Upper trough is progressing into the Pac NW and will shift east with sfc pressure falls ensuing tonight. Cannot rule out an isolated shower toward central SD tonight, per high level pos theta-e adv. However, very low probs do not warrant pop mention. Thermal ridge will pass over the region Wed with gusty SE winds per ongoing pressure falls. Winds may reach adv levels across NW SD. Will defer wind headlines to the night shift. Temps will climb into the 80s most places Wed, but may struggle a bit at first given SE winds under a strong inversion. Decent ridge of ll moisture will nose into the region along the high plains, with dewpoints expected into the upper 50s and lower 60s. Lee side trough will kick out in the afternoon, timing with the upper trough, supporting increasing chances for showers and storms, first over NE WY (given sfc trough location and weak cin) and the northern BH (per eddy convergence). Expecting storms to organize into a broken line with embedded strong to severe cells, esp over NW SD where the strongest upper level forcing will be. Bulk shear is not that great, but ML CAPE in the 1.5-2 kJ/kg will be more than ample to support a few severe storms as the line shifts east in the evening, with pulse severe storms. Cold front will progress through Wed night with shower chances shifting east. Much cooler Thurs, with lingering showers possible, shifting east through the day. Large upper trough will slowly progress through southern Canada through the end of the week offering seasonal temps into the weekend locally, with continued near daily chances for showers/storms as impulse ladden flow (stemming from the parked NE PAC upper trough) continues to traverse the region. Warmer temps are expected by Sunday into the following week, as flow amplifies and WSW flow becomes established in mean model solutions. && .AVIATION...(For the 00Z TAFS Through 00Z Wednesday Evening) Issued At 535 PM MDT Tue May 28 2024 VFR conditions will continue through the forecast period. Southeasterly winds will increase late tonight into Wednesday morning, sustained 15 to 25 kts with gusts up to 35 kts. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...JC AVIATION...Dye