TEXAS · TARRANT COUNTY
Where the plains break into the Cross Timbers, Fort Worth designs for the storm
West of Dallas on the Trinity River, Cowtown sits where the rolling prairie meets the oak belt and the southern reach of Tornado Alley. Design wind speeds run 100-115 mph under ASCE 7-22.
NORTH TEXAS · WHERE PRAIRIE MEETS OAK
A flat prairie city under a storm-prone sky
No coast, no hurricanes, no mountains - just open North Texas terrain, the Trinity River corridor, and the spring convective season that drives the design wind.
Open prairie to the west, a sheltering urban core, the Trinity threading the center - and the anvil of a North Texas supercell overhead.
DESIGN BASIS · TARRANT COUNTY
What sets Fort Worth's wind and exposure
Cowtown's relatively flat ground (about 650 ft elevation) keeps topography out of the picture - exposure and risk category do the work instead.
100-115 mph basic wind
ASCE 7-22 maps for North Texas, 3-second gust, Risk Category II - driven by severe convection, not the coast.
3-SEC GUSTExposure B in the core
Downtown, the Cultural District, TCU, the Stockyards and older neighborhoods sit in closely built terrain that shelters the wind.
URBAN BExposure C out west
Alliance, far-west and north Fort Worth still transitioning from ranch land read as open terrain - higher Kz, higher pressure.
OPEN CFlat ground, Kzt ≈ 1.0
No ridges or escarpments across the prairie, so the topographic factor stays at 1.0 - verify per site, but expect no boost.
Kzt = 1.0Going from sheltered Exposure B to open Exposure C at 30 ft raises Kz from 0.70 to 0.98 - about 40% more velocity pressure on the same building. On the prairie fringe, the exposure call matters more than the map.
TORNADO ALLEY · SOUTHERN FRINGE
Spring storms are the real wind story
March through June, the DFW Metroplex runs the gauntlet of supercells, downbursts and tornadoes - including the EF3 that tore through downtown on March 28, 2000.
Tornado potential
Tarrant County sits on the southern fringe of Tornado Alley; the 2000 downtown EF3 proved dense cores are not immune.
EF-SCALEDownbursts & squall lines
Straight-line winds and microbursts can top 100 mph over a mile or two, hammering low-slope and metal roofs with uplift.
STRAIGHT-LINESevere hail
Spring hail riding the same cells loads roofs and skylights alongside wind - design impact resistance per IBC Chapter 15.
IMPACTWind code is qualitative here: ASCE 7-22 doesn't add a tornado load for typical buildings, but Risk Category III/IV facilities - schools, hospitals, shelters - read a longer-return-period map (higher V) and should weigh storm shelters per ICC 500.
ASCE 7-22 · TABLE 1.5-1
Risk category sets the speed map you read
There is no importance-factor multiplier - a higher category just points you to a map with a longer return period and a higher wind speed.
| Risk Category | Return Period (MRI) | Fort Worth Wind Speed | Typical Buildings |
|---|---|---|---|
| I | 300-year map | ~95-110 mph | Minor storage, ag and temporary structures |
| II | 700-year map | 100-115 mph | Homes, retail, hotels, most occupancies |
| III | 1,700-year map | ~110-125 mph | Schools, assembly >300, hazardous materials |
| IV | 3,000-year map | ~115-130 mph | Hospitals, fire stations, emergency shelters |
CITY OF FORT WORTH · BUILDING INSPECTIONS
What a compliant Fort Worth submittal needs
The Building Inspections Division (IBC 2021 with local amendments) reviews to ASCE 7-22; Tarrant County governs sites outside city limits.
Address & wind speed
Site coordinates with the 100-115 mph value pulled from ASCE 7-22 maps.
Exposure justified
B vs. C with upwind terrain studied for 20H or 2,600 ft, whichever is less.
Kzt verified
Typically 1.0 on the flat prairie - confirmed, not assumed, per site.
Risk category
Per Table 1.5-1, documented - it selects the speed map you read V from.
MWFRS & C&C
Main-frame and component-and-cladding pressures for every element.
Texas PE seal
Calculations sealed by a PE licensed by the Texas Board (TBPELS).
EXPLORE · TEXAS & THE METROPLEX
Neighboring cities and statewide context
Compare across the DFW Metroplex and step up to the Texas and national picture.
Arlington
Mid-cities neighbor, same Tarrant County wind basis.
TARRANT CO.Dallas
The Metroplex's east half, just across the county line.
DALLAS CO.Houston
Gulf coast contrast - hurricane-driven design speeds.
COASTAL TXTexas statewide
Code adoption and wind zones across the whole state.
STATEAll state requirements
ASCE editions and wind rules state by state.
50 STATESWind speed by location
Look up the design wind speed anywhere in the U.S.
LOOKUPSINCE 2002 · 100% PERMIT-APPROVAL TRACK RECORD
Run Fort Worth wind loads the verified way
Enter a Tarrant County address and get ASCE 7-22 wind speed, Exposure B/C guidance, MWFRS and C&C pressures, and a PE-ready report for Building Inspections. A Texas PE confirms site exposure.