DISCUSSION
(Today Through Friday)
Issued at 300 AM MDT Sat Jul 27 2024

Current surface analysis shows nearly stationary cool front from northwest MN to central SD and the NE panhandle beginning to wash out across the area. A weak area of low pressure is located across northeast WY, with another cool front developing along it from central Canada to southwest MT. Upper level analysis shows low pressure over northern SK into northwest mb, with west-southwest flow to the south of it into the northern Rockies and Plains. A couple of areas of high pressure are located over the southern Plains and the Desert Southwest. Skies are partly to mostly cloudy across much of the area, with the most clouds east of the Black Hills. Scattered showers and a few thunderstorms are lingering across mostly far eastern portions of the forecast area early this morning. Temps are fairly pleasant across much of the area compared to the last few mornings, upper 50s and 60s. However, some 70s linger over south central SD in vicinity of dissipating cool front. Winds are light in most areas, though a bit breezy toward far south central SD.

Hot conditions persist today, slightly warmer in many areas compared to yesterday, as dissipating front to the south and east allows south to southwest winds to develop across the area. Winds remain breezy across south central SD, but fairly light elsewhere. Highs will reach the 90s to around 100 degrees across the plains, warmest over the western SD plains. Heat index values will be in the upper 90s to near 100 for a while later this afternoon across portions of west central and south central SD where dew points rise to the upper 50s and lower 60s. Haze and smoke will generally increase again today and through the weekend as flow aloft brings smoke into the area from Pacific NW and northern CA wildfires. As low pressure and weak front move into the western Dakotas later this afternoon, shortwave energy aloft, noted over northern UT now, will approach the area. Chances for showers and thunderstorms should increase later this afternoon and especially into the evening. Better buoyancy is expected to be east of the Black Hills, ahead of the front and developing surface trough ahead of it, 500 to as much as 1500 j/kg into central SD. Shear looks to be relatively weak in many areas, so the threat for severe storms will be pretty low, especially for any sustained storms. However, a few strong to marginally severe storms with some hail and gusty winds are a good possibility, especially from the Black Hills area and eastward.
Activity should gradually taper off overnight into early Sunday from southwest to northeast.

Sunday could be a more favorable day for severe storms as cool front likely stalls out over the area during the day. Highs will be in the 80s and 90s, warmest to the south and east of the Black Hills.
Energy aloft will interact with the surface front to bring another round of showers and storms during the afternoon and early evening hours. MLCAPE of 500 to 1500 j/kg expected over much of the area Sunday afternoon, with some better shear expected to the east of the Black Hills. The better threat for severe storms should mostly be north and east of the Black Hills in closer vicinity to where the front is expected to be.

Southern plains upper high is expected to drift gradually north- northwest early next week, with ridge building northward across the Plains through midweek and then likely westward after that. This would allow hot conditions to persist through next week, with mainly dry conditions. Highs look to be in the 90s to near 100 degrees on the plains for much or all of next week. Tuesday looks to be the hottest day at this time, with probabilities near or above 50 percent for triple digit highs across much of the western SD plains.
Fire weather concerns would increase with drier air in place, but winds would likely be a limiting factor for critical fire wx conditions on most days.

AVIATION
(For the 12Z TAFS Through 12Z Sunday Morning)
Issued At 527 AM MDT Sat Jul 27 2024

VFR conditions are expected for most locations through the period.
Smoke/haze will increase from west to east beginning around 15z, which could lead to some minor reductions in vsbys thru the period, especially from the Black Hills westward. Isolated SHRA/TSRA are possible late this afternoon through tonight area- wide, some of which could produce strong and erratic wind gusts.

FIRE WEATHER
Issued At 300 AM MDT Sat Jul 27 2024

Elevated fire weather conditions can be expected over the weekend from at least northeast WY to far western SD. Very warm to hot weather can be expected over the weekend, with RH dropping into the teens this afternoon across northeast WY and far western SD.
However, winds look to be relatively light later today, mostly 5 to 15 mph with some higher gusts. Another round of showers and thunderstorms is expected late this afternoon into tonight, especially from the Black Hills eastward, with at least widely scattered wetting rains. Slight cooler temperatures and slightly higher humidity is expected for Sunday with isolated to scattered showers and thunderstorms expected during the afternoon and evening.

Hot and mainly dry conditions will develop for next week as an upper ridge develops over the region and then gradually slides west of the area later in the week. Elevated fire wx conditions expected for much or all of next week. Near critical fire wx conditions are likely over parts of northeast WY on Monday. At this time, Tuesday looks to be the hottest day with the lowest afternoon humidity across the forecast area. Near critical fire wx conditions look likely over northeast WY and parts of far western SD, with at least some potential for winds to be strong enough for critical fire wx conditions over some of these areas. Will continue to monitor.

UNR WATCHES/WARNINGS/ADVISORIES
SD...None.
WY...None.