NORTH CAROLINA · GUILFORD COUNTY
Greensboro anchors the Piedmont Triad, where mill-town terrain tames the wind
North Carolina's third-largest city designs for inland gusts and spent tropical systems — 100-110 mph under the state's ASCE 7-10 code.
GEOGRAPHY · THE TRIAD
One wind picture shared by three Piedmont cities
Greensboro, Winston-Salem and High Point sit on the same gently rolling plateau, roughly 850-900 ft up and 200 miles from salt water.
DESIGN WIND · EXPOSURE B
What a 105 mph Guilford gust means for a low-rise wall
Greensboro's dense neighborhoods, mill blocks and heavy tree canopy read as Exposure B almost everywhere — far gentler than open coastal sand.
Basic Speed V
100-110 mph 3-second gust for Risk Category II across Guilford County.
RISK IIWhy Exposure B Holds
Downtown blocks, repurposed mills and broad tree cover shelter nearly every site.
TRIAD ROUGHNESSMostly Flat Kzt
The rolling plateau stays gentle, so the topographic factor sits near 1.0 except on rare crowned lots.
KZT ≈ 1.0Velocity Pressure
At V=105, Kz=0.70 (Exp B, 15 ft), qz lands near a moderate ~17 psf — well under coastal demand.
~17 PSFSTORM RECORD · INLAND IMPACTS
The Triad's hazard is remnant wind and a stray tornado
Greensboro never takes a direct landfall, but spent tropical cores and Piedmont convective lines still reach Guilford County.
Hugo & Fran Remnants
Both storms pushed inland gusts past 50-60 mph, stripping canopy and cutting power across the Piedmont.
1989 · 1996The 2018 Greensboro Tornado
An EF2 tore through east Greensboro, a sharp reminder the Triad does spawn tornadoes.
APRIL 15, 2018Severe Thunderstorm Lines
Spring and summer squall lines drive straight-line gusts that govern more Triad damage than tropical systems.
CONVECTIVERISK CATEGORY · MAP SELECTION
How occupancy lifts the speed map a Greensboro project must read
Higher risk classes draw from longer-return-period maps, so the design speed climbs with consequence — there is no fixed multiplier between categories.
| Risk Category | Greensboro Design Speed | Typical Buildings |
|---|---|---|
| I | ~95-100 mph | Ag facilities, temporary & minor storage |
| II | 100-110 mph | Homes, retail, most standard occupancy |
| III | ~110-120 mph | UNCG & NC A&T halls, schools, assembly >300 |
| IV | ~120-130 mph | Hospitals, fire stations, shelters, EOCs |
PERMITTING · GATE CITY WORKFLOW
The path from calc to a stamped Guilford permit
North Carolina runs code through NCDOI on the ASCE 7-10 basis; the city and county split the counter work.
Set V to 100-110
Pull the site speed for the Guilford address before sizing anything.
STEP 1Confirm Exposure B
Document the built-up Triad roughness; reserve C for cleared, open parcels.
STEP 2Verify Flat Kzt
Keep Kzt at 1.0 on the plateau; run it only where a lot crowns a Piedmont rise.
STEP 3Seal If Required
Commercial work needs an NC-licensed PE seal through NCBELS.
STEP 4File With Greensboro
City of Greensboro Building Inspections handles permits inside city limits.
STEP 5Or Guilford County
County inspections cover sites outside the Greensboro and High Point city limits.
STEP 6CONTRAST · TRIAD VS SHORE
Why a Greensboro detail would be under-built on the Outer Banks
Same state, two worlds: inland Guilford skips the debris and impact rules that define coastal North Carolina.
| Requirement | Greensboro (Inland Triad) | Coastal North Carolina |
|---|---|---|
| Design Wind Speed | 100-110 mph | 140-170 mph |
| Exposure Category | Primarily B (built-up) | 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 · TRIAD & BEYOND
The cities that share Greensboro's wind picture
Across the Triad and the wider Piedmont, conditions hold near-identical 100-110 mph, Exposure B.
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 Guilford or Triad site.
SPEED MAPWinston-Salem (Forsyth), High Point and the surrounding Piedmont counties ring Greensboro with consistent 100-110 mph, Exposure B design — verify each site, but the regional picture holds.
START · GREENSBORO CALCULATION
Turn 100-110 mph into a PE-ready Greensboro report
Enter a Guilford County address and get the velocity, Exposure B basis and component pressures in minutes.