Heat, Severe Storms and Heavy Rain Lead Into a Cooler Weekend Across North Carolina
Thursday will bring several weather concerns across North Carolina, with dangerous heat across portions of central and eastern North Carolina and a risk of strong to severe thunderstorms developing later in the day. The good news is that a cold front will eventually bring relief from the heat, with noticeably cooler and more comfortable conditions arriving this weekend.
For Rowan County Weather's regional coverage area, today will be a day to keep an eye on both the thermometer and the sky, followed by an increasing heavy-rain concern heading into Friday.
Severe Thunderstorms Possible Thursday Afternoon and Evening
A broad Level 1 of 5 Marginal Risk for severe thunderstorms covers much of the western Carolinas, including the North Carolina mountains and Piedmont.
Scattered thunderstorms are expected to develop later this afternoon and continue into the evening. While most storms will remain below severe limits, a few could become strong to severe.
The primary severe-weather threat will be damaging straight-line wind gusts.
Across central North Carolina, the severe threat increases farther north and northeast. A Level 2 of 5 Slight Risk extends across portions of north-central and northeastern North Carolina, including areas near and northeast of the Triangle toward Rocky Mount and Roanoke Rapids.
The remainder of much of central North Carolina is under a Level 1 Marginal Risk.
For central North Carolina, the most likely period for severe thunderstorms is approximately 5 PM to 9 PM Thursday. Damaging winds are the primary concern, while the tornado and hail threats are considerably lower.
Residents across the region should have multiple ways to receive weather warnings as storms develop later today.
Dangerous Heat Continues Thursday
Before storms arrive, heat and humidity will once again be significant.
Across the western Carolinas and Piedmont, afternoon heat index values are expected to climb into the upper 90s and lower 100s in many locations. Around the Charlotte area and portions of the Interstate 77 corridor, heat index values near 100 to 104 degrees are possible.
Friday could remain hot and humid before the front completes its passage. Depending on exactly where the front and thunderstorms set up, portions of the southern Piedmont could again experience heat index values above 100 degrees.
Heat Advisory for Central and Eastern North Carolina
The most dangerous heat Thursday will be farther east.
A Heat Advisory is in effect from 11 AM until 8 PM Thursday for a large portion of the eastern Piedmont, Sandhills and Coastal Plain.
The advisory includes areas around Durham, Raleigh, Cary, Chapel Hill, Pittsboro, Sanford, Southern Pines, Fayetteville, Smithfield, Wilson, Rocky Mount and surrounding communities.
Heat index values could reach 105 to 109 degrees within the advisory area.
Prolonged exposure to this combination of heat and humidity can increase the risk of heat-related illnesses. Anyone spending significant time outdoors should drink plenty of fluids, take frequent breaks, limit exposure to direct sunlight when possible and check on relatives and neighbors who may be particularly vulnerable to the heat.
Friday Brings an Increasing Heavy-Rain Threat
Once Thursday's severe-weather threat passes, attention quickly shifts toward another concern.
Friday into Friday night could become a very wet period across portions of North Carolina.
A cold front settling into the region will provide a focus for repeated showers and thunderstorms. With a very moist atmosphere and potentially slow-moving or merging storms, rainfall could become locally excessive.
The greatest concern currently appears to extend from portions of the eastern Piedmont through the Triangle and toward the Interstate 95 corridor.
Some areas could receive 2 to 4 inches or more of rain, particularly where thunderstorms repeatedly move across the same locations.
That creates the possibility of localized flash flooding Friday into Friday evening, especially in urban and poor-drainage areas.
The exact location of the heaviest rainfall remains uncertain. A shift of the frontal boundary by even 50 miles could significantly change which communities receive the greatest rainfall totals.
Triad and Western Piedmont Still Need to Watch Friday
While the greatest flash-flood potential currently appears east of the Triad, that does not mean areas farther west will miss the rain.
Parts of the Triad could receive an inch or more of rainfall during the event.
Across the western Piedmont, including the Rowan County area, guidance also supports the potential for repeated thunderstorms and locally heavy rainfall Friday into Friday night. Some guidance has indicated localized totals of 2 to 3 inches over relatively short periods where storms repeatedly track over the same locations.
Friday may also bring another severe-weather concern. Strong instability ahead of the front could allow thunderstorms to produce wet microbursts and damaging wind gusts.
The combination of strong storms, slow storm movement and heavy rainfall means Friday's setup will need to be monitored closely across the region.
Relief From the Heat Is Finally Coming
There is some very welcome news behind the cold front.
Relief from the heat is in sight.
The front will usher cooler air into the Carolinas beginning Saturday. Temperatures and humidity levels should become increasingly comfortable through the weekend.
Saturday will begin the transition, although some lingering showers and thunderstorms may remain possible depending on how quickly the front moves through.
By Sunday, much of the western Piedmont and western Carolinas should experience considerably more comfortable conditions.
High temperatures across much of the Piedmont should settle into the mid to upper 80s, while nighttime temperatures fall into the 60s.
That cooler and more seasonable air is expected to continue into the beginning of next week.
What I'm Watching
There are several pieces of this forecast I'll be following closely over the next 48 hours:
Thursday afternoon and evening: The development of thunderstorms and the potential for damaging straight-line winds.
Central and eastern North Carolina Thursday: Dangerous heat, including heat index values potentially reaching 105 to 109 degrees within the Heat Advisory.
Friday and Friday night: The location of the cold front and where repeated thunderstorms develop.
Heavy rainfall: The potential for localized 2-to-4-inch-plus totals and flash flooding, particularly from the eastern Piedmont and Triangle toward the Coastal Plain.
Western Piedmont and Triad: How far west the corridor of heavier rainfall ultimately develops.
The weekend: The arrival of cooler and less humid air behind the front.
Thursday and Friday will be the two most active weather days of this stretch. The severe-weather threat comes first, followed by an increasing heavy-rain and flooding concern Friday.
After that, the payoff should be a much more comfortable weekend and start to next week.
I'll continue monitoring the latest data and provide updates through Rowan County Weather Regional Forecasts as the storms and cold front move across North Carolina.