textproduct: Raleigh

WHAT HAS CHANGED

* SWODY1 now has areas east of the Triangle in a slight risk along with marginal risk extending as far west and the eastern Triad region.

KEY MESSAGES

As of 244 AM Tuesday...

1) Marginal to slight risk for severe storms today...with marginal east of the Triad and slight east of the Triangle.

2) Excessively hot weather is possible again on Friday-Saturday and especially by Sunday-Monday.

DISCUSSION

As of 244 AM Tuesday...

KEY MESSAGE 1... Marginal to slight risk for severe storms today...with marginal east of the Triad and slight east of the Triangle.

A weakening MCS currently moving across eastern TN will continue moving eastward and across the southern Appalachians today as a cold front advances southeastward toward and into the Carolinas. While weakening of the activity to our west is expected as it crosses the mountains, a remnant convective line or outflow boundary should survive crossing the mountains and enter the western Piedmont later this morning before moving across the rest of central NC this afternoon. More specifically regarding timing of thunderstorms today: the Triad region should see showers/tstms roughly late this morning... early afternoon for the Triangle region and eastern Piedmont...and mid to late afternoon for the Coastal Plain.

Ahead of the approaching cold front, temperatures will climb into the lower 90s with dewpoints remaining in the lower 70s. This should yield mixed-layer CAPE values of 1500-2500 J/kg despite some cloud cover. That CAPE, along with 40kt of mostly unidirectional shear should result in multicell thunderstorm development initially which may organize into a squall line later this afternoon, with the potential for strong to severe storms with damaging straight-line winds the main hazard.

Otherwise, the cold front itself should move across central North Carolina during the afternoon and evening hours. By late evening and overnight, the front should settle toward eastern NC and the coastal plain. Thunderstorm coverage should gradually diminish from west to east after sunset as instability decreases.

KEY MESSAGE 2... Excessively hot weather is possible again on Friday- Saturday and especially by Sunday-Monday.

A strong ridge will build and strengthen across the Deep South and Carolinas from Friday into Monday. This will bring hot conditions to central NC with gradually increasing temperatures. Forecast highs on Friday are in the mid-to-upper-90s and by Saturday and Sunday, we are expecting highs in the mid-90s to around 100. Lows will mainly be in the lower-to-mid-70s. This is resulting in 50-85% probabilities of at least Major HeatRisk from the Triangle south and east on Friday and Saturday and everywhere by Sunday and Monday. Confidence decreases slightly by Monday as a backdoor front may try to approach from the NE, but otherwise the heat will continue. The one saving grace is humidity doesn't look overly oppressive during the period, with dew points in the mid-to-upper-60s. Still, heat indices approaching 105 will be possible from the Triangle south and east especially by Sunday, and Heat Advisories may be needed.

CLIMATE

Record High Temperatures:

June 22: KRDU: 100/2022 KFAY: 101/2022

June 25: KRDU: 100/1952

June 26: KFAY: 101/1951

June 27: KFAY: 102/1998

Record High Minimum Temperatures:

June 23: KGSO: 74/2024 KRDU: 78/2024 KFAY: 77/2024

June 25: KFAY: 75/1952

June 26: KGSO: 74/2010 KRDU: 77/2024 KFAY: 76/1997

June 27: KRDU: 76/1952 KFAY: 77/1998

RAH WATCHES/WARNINGS/ADVISORIES

None.