NORTH CAROLINA · MECKLENBURG COUNTY
Charlotte sits in the Piedmont, where spent hurricanes still arrive with teeth
Two-hundred miles from the Atlantic, the Queen City designs for inland gusts, not surf — 110-120 mph under North Carolina's ASCE 7-10 code.
GEOGRAPHY · INLAND PIEDMONT
How the coast hands its storms to the rolling Piedmont
A landfalling system weakens crossing the coastal plain, then spends its last fury over Mecklenburg's low ridges.
DESIGN WIND · EXPOSURE B
What a 115 mph Mecklenburg gust does to a low-rise wall
Charlotte's dense, tree-and-rooftop terrain reads as Exposure B almost everywhere — far gentler than open coastal sand.
Basic Speed V
110-120 mph 3-second gust for Risk Category II across Mecklenburg.
RISK IIWhy Exposure B Holds
Uptown towers, South End rooftops and tree canopy shelter nearly every site.
URBAN ROUGHNESSPiedmont Kzt Watch
Rolling ridges and bluffs can push the topographic factor above 1.0 on exposed crests.
KZT > 1.0Velocity Pressure
At V=115, Kz=0.70 (Exp B, 15 ft), the result is a moderate ~24 psf — well below coastal demand.
~24 PSFSTORM RECORD · INLAND IMPACTS
When Hugo proved a hurricane can still bite 200 miles ashore
Charlotte's hazard is not surge or debris — it is the weakened-but-violent core of tropical systems and Piedmont convective wind.
Hugo's 1989 Inland Blow
Sustained 60-70 mph and gusts past 85 mph flattened canopy across the metro overnight.
SEPT 22, 1989The Remnant Parade
Florence, Irma, Michael and Ian each tracked tropical-storm-force wind through the Piedmont.
RECENT DECADESpring Derecho Lines
Organized thunderstorm complexes drive straight-line gusts and the odd tornado across Mecklenburg.
CONVECTIVERISK CATEGORY · MAP SELECTION
How occupancy lifts the speed map a Charlotte project must read
Higher risk classes pull from longer-return-period maps, so the design speed climbs with consequence — not by any fixed multiplier.
| Risk Category | Charlotte Design Speed | Typical Buildings |
|---|---|---|
| I | ~105-110 mph | Ag facilities, temporary & minor storage |
| II | 110-120 mph | Homes, retail, most standard occupancy |
| III | ~125-135 mph | Schools, assembly >300, hazardous materials |
| IV | ~135-145 mph | Hospitals, fire stations, shelters, EOCs |
PERMITTING · QUEEN CITY WORKFLOW
The path from calc to a stamped Mecklenburg permit
North Carolina runs code through NCDOI and ASCE 7-10; the city and county split the counter work.
Set V to 110-120
Pull the site speed for the Mecklenburg address before sizing anything.
STEP 1Confirm Exposure B
Document built-up roughness; reserve C for cleared sites near the airport.
STEP 2Check Ridge Kzt
Run topographic factor where a lot crowns a Piedmont bluff or escarpment.
STEP 3Seal If Required
Commercial work needs an NC-licensed PE seal through NCBELS.
STEP 4File With Charlotte
City of Charlotte Code Enforcement handles permits inside city limits.
STEP 5Or County LUESA
Mecklenburg Land Use & Environmental Services covers unincorporated areas.
STEP 6CONTRAST · PIEDMONT VS SHORE
Why a Charlotte detail would be under-built on the Outer Banks
Same state, two worlds: inland Mecklenburg skips the debris and impact rules that define coastal NC.
| Requirement | Charlotte (Inland) | Coastal North Carolina |
|---|---|---|
| Design Wind Speed | 110-120 mph | 140-170 mph |
| Exposure Category | Primarily B (urban) | C or D required |
| Wind-Borne Debris | Not required | Impact protection required |
| Hurricane Impact Zone | Not applicable | Required compliance |
| Primary Risk | Severe thunderstorms, tropical remnants | Direct hurricane impacts |
REGION · CHARLOTTE METRO & BEYOND
The counties that share Mecklenburg's wind picture
The surrounding Piedmont rings hold near-identical 110-120 mph, Exposure B conditions.
North Carolina Statewide
How the coast, Piedmont and mountains split across NC's ASCE 7-10 maps.
STATE GUIDEEvery State's Rules
Jump to the wind code, speed and exposure basis for any U.S. jurisdiction.
ALL STATESLook Up Any Address
Find the 3-second-gust speed for a precise Mecklenburg or metro site.
SPEED MAPCabarrus, Gaston, Union, Iredell and York County (SC) ring Charlotte with consistent 110-120 mph, Exposure B design — verify each site, but the regional picture holds.
START · CHARLOTTE CALCULATION
Turn 110-120 mph into a PE-ready Charlotte report
Enter a Mecklenburg address and get the velocity, Exposure B basis and component pressures in minutes.