Sugar Mountain

Forecast Discussion

Summary

SYNOPSIS

... Broad high pressure will persist over the southeast through the rest of the week, limiting daily shower and thunderstorm activity and keeping temperatures well above normal. The ridge of high pressure will strengthen over the weekend, resulting in near-record high temperatures each day.

NEAR TERM /THROUGH TONIGHT/... As of 1040 am: A few light remnant showers from the overnight activity persist along the I-77 corridor in the Carolina Piedmont late this morning. A relative lull in coverage is expected into the early afternoon. The next features of interest should be weak vorticity lobes diving southeast across the Appalachians this afternoon and evening. Each of these will provide forcing over the spine of the mountains to trigger scattered convection, which may advect east across the adjacent foothills with westerly steering flow. Surface-based CAPE values are already around 2000 J/kg in and near the mountains on the latest LAPS analysis and slowly thinning mid/high clouds along with gradually dissipating lower stratus will bump this up quickly this afternoon given the limited dewpoint mixing. Will thus maintain the scattered thunderstorm coverage in and near the mountains for this afternoon/evening, and taper PoPs down quickly over the lower piedmont areas. The latest RAP profiles also exhibit some mid-level drying, which could lead to a slightly better wind and hail threat east of the Blue Ridge in western NC, where sfc-6 km shear is also a bit better. Will keep the HWO mention going for this.

Convection is forecast to diminish quickly this evening, giving way to an unseasonably warm and somewhat muggy night, with min temps expected to average around 10 degrees above climo in most areas.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 330 AM EDT Thursday: Amplified ridge aloft over much of the eastern CONUS will dominate the weather pattern through the short term forecast period, with latest guidance suggesting this feature slightly dampening as it shifts eastward into Saturday. A few weak waves of s/w energy around the ridge and a cold front to the north (progged to dip into the eastern Carolinas into Saturday) along with limited available moisture and instability may allow for isolated showers and thunderstorms both days, the higher low end PoPs expected on Saturday. Convection looks to remain confined along the escarpment and to the west, though could not entirely rule out a rogue shower or thunderstorm lingering elsewhere across the area.

Aside from convection, the heat will be the main story for Friday and the beginning of the Memorial Day holiday weekend, with temperatures expected to climb well above normal (and near-record through into early next week), into the mid 90s along and south of the I-85 corridor, into the lower 90s across the northern foothills, and slightly cooler across the mountains. Slightly cooler temperatures are expected across the NW Piedmont with the lingering frontal boundary off to the northeast, but overall, temperatures will still be above normal. Mid to upper 90s are possible across the Upstate, into the lower 90s across along the I-77 corridor and back to the west towards the Blue Ridge escarpment. Once again, slightly cooler temperatures will be in store for the mountains. Overnight lows will remain above normal, in the 60s to lower 70s.

As have mentioned over the past few days, with the expected heat and essentially the warmest temperatures thus far of 2019, people with outdoor plans for the Memorial Day holiday weekend should stay well hydrated and find shade when possible to avoid heat-related illnesses. Don't forget about persons with disabilities and the elderly, as well as outdoor pets/animals. For record max temperature information for Asheville, Charlotte, and Greenville, please see the Climate section below.

LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 355 AM EDT Thursday: As alluded to in the short term forecast discussion, the main story for Sunday and through midweek will be the near-record high temperatures across the area. Once again, persons spending time outside should take necessary precautions to stay safe from the heat.

Latest guidance continues to depict the upper ridge gradually de- amplifying as a positively tilted upper trough over the western CONUS gradually shifts eastward through early next week, extending through the central Plains and into the Upper Midwest. At the sfc, with high pressure over the Southeast, the parent sfc low off to the west will take a similar path through into the Upper Midwest, dragging it's associated cold front towards the western Carolinas towards the end of the fcst period. The driest of the days through mid week will be Sunday, with isolated showers and thunderstorms possible Monday and Tuesday across the NC mountains. Into Wednesday, anticipate coverage to expand southeastward across the FA (though remaining north of the I-85 corridor), as the aforementioned cold front approaches from the NW. Elsewhere, expect dry and hot conditions to prevail, with plenty of sunshine and passing clouds at times through the period. High temperatures will climb each day into the mid to upper 90s (higher values across the southern portions of the FA), remaining cooler yet above normal, across the mountains. Overnight lows, once again, above normal.