ALABAMA · MOBILE
Where Mobile Bay Meets the Gulf Coast Wind Line
A working port at the mouth of the bay, squarely inside the Atlantic-Gulf hurricane track. Mobile County design wind speeds run 140-150 mph (3-second gust) under ASCE 7-22.
GULF EXPOSURE · MOBILE COUNTY
Why Bay-Mouth Sites Carry a Higher Wind Number
Mobile sits at the head of Mobile Bay with an open fetch straight to the Gulf of Mexico, so its 140-150 mph design speed sits well above inland Alabama.
Open Gulf Fetch
Unobstructed wind run across open water at the bay mouth drives Exposure C, and Exposure D where fetch over water governs.
EXPOSURE C / DHurricane Track
Mobile County lies in the recurring landfall corridor for Atlantic and Gulf systems crossing the north-central coast.
LANDFALL CORRIDORDebris Region
Coastal Mobile is a wind-borne debris region: openings need impact glazing or shutters, though not Florida HVHZ TAS protocols.
WIND-BORNE DEBRISSTORM RECORD · GULF COAST
Three Storms That Rewrote Mobile's Building Practice
Frederic, Ivan, Katrina, and Sally each tightened how the Gulf Coast frames, fastens, and seals against wind.
Hurricane Ivan — 2004
Category 3 landfall near Gulf Shores, ~120 mph and a ~15-ft surge; widespread roof and cladding loss drove major Alabama code updates.
CAT 3 · ~120 MPHHurricane Katrina — 2005
Category 3 to the west still delivered serious wind and surge to Mobile, confirming the need for elevated loads coast-wide.
CAT 3 · ~125 MPHHurricane Sally — 2020
Slow Category 2 (~105 mph) near Gulf Shores; historic rain and surge, yet code-current buildings outperformed older stock.
CAT 2 · ~105 MPHMobile / Mobile County at a Glance
Design wind speed (Risk Cat II): 140-150 mph 3-sec gust · Risk Cat III ~155-165 mph · Risk Cat IV ~165-175 mph. Exposure: C coastal / Mobile Bay, B possible well inland. County: Mobile County, Alabama. Standard: ASCE 7-22 via the Alabama Building Code (IBC + state amendments). HVHZ: no — that is a Florida-only designation.
ASCE 7-22 · RISK CATEGORY
How Occupancy Lifts the Coastal Wind Speed
Higher risk categories read from a longer-return-period map, so the design speed climbs with what the building must protect.
| Risk Category | Mobile Design Wind Speed | Typical Building Types |
|---|---|---|
| Risk Cat I | ~130-135 mph | Agricultural buildings, temporary structures, minor storage |
| Risk Cat II | 140-150 mph | Residential, commercial, most standard occupancies |
| Risk Cat III | ~155-165 mph | Schools, assembly over 300, substantial hazardous materials |
| Risk Cat IV | ~165-175 mph | Hospitals, fire stations, emergency shelters, EOCs |
PERMIT PATH · ALABAMA
What a Mobile Permit Set Has to Show
Every Mobile County submittal carries PE-sealed ASCE 7-22 wind loads tied to the actual bay-side address.
Design Wind Speed
140-150 mph (Risk Cat II) pulled from ASCE 7-22 maps at the project address.
140-150 MPHExposure Category
Document C for shoreline and bay-front sites; B only where dense terrain inland justifies it.
EXPOSURE CRisk Category
Assign per ASCE 7-22 Table 1.5-1; III and IV read from higher-speed maps.
TABLE 1.5-1MWFRS + C&C
Both whole-frame and component pressures for windows, doors, roof panels, and wall cladding.
FULL PRESSURESDebris Glazing
Impact-rated glazing or shutters to ASTM E1996 / E1886 where the debris region applies.
ASTM E1996Alabama PE Seal
Calculations sealed by a Professional Engineer licensed in Alabama for the building permit.
PE SEALEDNEARBY COAST · STATEWIDE
Compare Mobile Across the North-Central Gulf
Neighboring port cities and the Alabama statewide picture, side by side.
Pensacola, FL
Panhandle neighbor just east, sharing the same Gulf landfall corridor.
GULF CITYNew Orleans, LA
Major delta port to the west, hit by many of the same storms.
GULF CITYState Requirements
Alabama code adoption and wind rules across every state.
ALL STATESWind Speed by Location
Look up the ASCE design speed for any address or zip.
LOOKUPRUN THE NUMBERS
Calculate Mobile Bay Wind Loads in Minutes, Not Map Reading
Enter a Mobile County address and get the 140-150 mph design velocity, exposure guidance, risk-category adjustments, and PE-ready ASCE 7-22 reports.