CALIFORNIA · ORANGE COUNTY SEAT

The City That Named the Wind: Santa Ana Wind Load Requirements

A modest base map speed hides the real story here — the canyon-driven downslope gusts that the whole continent borrowed a name from. Designed to CBC Title 24 and ASCE 7-22.

90–105MPH 3-SEC GUST · RISK CAT II
OrangeCOUNTY · CITY SEAT
ASCE 7-22VIA CBC TITLE 24

WHERE THE GUSTS COME FROM

A Coastal Plain Fed by Mountain Passes

Santa Ana sits on the Orange County floor where Santiago and Santa Ana Canyons funnel Great-Basin air toward the sea — the namesake of the entire Santa Ana wind regime.

The base ASCE 7-22 map speed is low for inland Southern California — but downslope channeling near canyon mouths produces intense, short-lived gust events that drive how exposure and topography get assigned.

WIND & EXPOSURE PROFILE

Low on the Map, Fierce in the Canyons

Two readings of the same site: the mapped Risk Cat II speed, and the real downslope behavior engineers must respect near canyon and river-channel openings.

Base Map Speed

90–105 mph 3-second gust for Risk Category II per the ASCE 7-22 maps.

RISK CAT II

Downslope Gust Events

Canyon channeling can briefly drive local gusts far above the calm-day average humidity-dry offshore flow.

CANYON FLOW

Exposure B, Urban Default

Dense city fabric downtown and across the residential grid supports Exposure B for most parcels.

EXPOSURE B

Exposure C Near Channels

Sites near Santiago Creek, the Santa Ana River channel, or canyon mouths may warrant Exposure C and Kzt > 1.0.

EXPOSURE C

PERMIT-READY CHECKLIST

What a Santa Ana Submittal Has to Prove

Everything an Orange County plan reviewer expects in a California-sealed wind package — before seismic, which usually governs here, even enters the conversation.

ASCE 7-22 Methodology

Velocity pressure built from the current standard, not retired 7-10 or 7-16 values.

STANDARD

Address-Based Speed

Mapped 3-second gust pulled for the exact parcel; speed varies by site within the 90–105 mph band.

VARIES BY SITE

Exposure Justification

Documented B-vs-C call with surface-roughness reasoning per ASCE 7 Section 26.7.

SECTION 26.7

Topographic Factor

Kzt assessed for hillside and canyon-mouth sites where downslope speed-up is plausible.

Kzt CHECK

MWFRS & C&C

Whole-frame pressures plus component and cladding values for every wall and roof zone.

PRESSURES

California PE Seal

Calculations prepared under a California-licensed PE, coordinated with governing seismic demands.

PE SEALED

THE OTHER HAZARD THE WIND BRINGS

When the Offshore Flow Turns Tinder-Dry

Santa Ana events don't just push on structures — they collapse humidity and carry embers, so foothill and channel-edge parcels carry a second code layer.

Parcels near Santiago Creek, foothill approaches, and regional-park edges can fall inside California's Wildland-Urban Interface. Those sites add WUI Code Chapter 7A ignition-resistant construction — roof covering, vents, exterior walls, and glazing — on top of the ASCE 7-22 wind package.

FROM CANYON GUST TO SEALED REPORT

Let the Calculator Read the Santa Ana Map

Drop in an Orange County address and get the site speed, exposure prompts, topographic check, and PE-ready MWFRS and C&C pressures — no manual map interpolation.