Storm Updates: Four Corners Flood — Oct 22

As of this Thursday afternoon desk, October 22, 2026 (approximately 8:14 PM PDT / 11:14 PM EDT / 0314Z October 23), the national picture centers on the Southwest. The Weather Prediction Center maintains a Moderate Risk of excessive rainfall over portions of southwest Colorado, southern Utah and northwestern New Mexico. The Storm Prediction Center holds a Slight Risk of severe thunderstorms from eastern Arizona into western New Mexico, with scattered severe storms remaining possible across the Southwest and Great Basin into the evening. Post-Tropical Cyclone Josephine is accelerating northeastward away with no U.S. coastal watches or warnings.

Tropical: None · Severe: Slight · Flood: Moderate

What Changed

• Compared with the prior version of this afternoon desk and the October 21 afternoon desk (quiet-pulse-2026-10-21-afternoon): SPC Day 1 Convective Outlook (latest 0100 UTC / 8:01 PM CDT Thursday, October 22, 2026, valid 230100Z–231200Z) continues a SLIGHT RISK of severe thunderstorms from eastern Arizona into western New Mexico. Scattered severe storms remain possible across the Southwest and Great Basin tonight, with the most intense cells expected across western New Mexico through the remainder of this evening. Large hail, damaging winds, and a tornado or two are possible. No upgrade beyond Slight.
• WPC Day 1 Excessive Rainfall Outlook (updated 0042 UTC Friday October 23 / discussion 844 PM EDT Thursday, valid 01Z–12Z October 23) holds a MODERATE RISK over portions of southwest Colorado, southern Utah and northwestern New Mexico. Additional 1–2 inches (locally higher) possible in the Moderate area amid training convection and upslope; flash flooding likely in terrain, burn scars and slot canyons. Slight Risk surrounds it. Category unchanged from the earlier expansion.
• NHC last advisory confirms Josephine has become a powerful extratropical low. No tropical storm or hurricane watch or warning remains in effect on the U.S. coast or Gulf of America. The system is accelerating northeastward away from the United States. Eastern Pacific Tropical Storm Vance continues well south of Mexico with no U.S. threat.
• Severe Thunderstorm Watch 694 is in effect for central and southwest New Mexico until 9 PM MDT (isolated large hail to 1.5 inches, damaging winds to 70 mph). Earlier Tornado Watch 693 covered northern/eastern Arizona and western New Mexico. Tornado Warnings were issued this afternoon for portions of Apache and Navajo Counties, Arizona, and parts of New Mexico. Local storm reports document hail to 1.5–3 inches in Yavapai, Navajo, Apache, Graham and Santa Cruz counties, Arizona, plus 1-inch hail and wind gusts to 70–73 mph in New Mexico and Arizona. Flash Flood Warnings (including considerable threat in Apache County / Canyon de Chelly) remain active.
• Nothing material closed either the severe or flood lane. The Moderate flood risk remains the highest open categorical level on Day 1. Quiet Pulse remains closed. Previous morning desk for October 22 not located under the standard slug; this afternoon desk links the October 21 afternoon under Sources.

Live Status

SPC Day 1 (0100Z October 23) lists a Slight Risk (Level 2 of 5) from eastern Arizona into western New Mexico. Mid-level southerly flow remains strong on the eastern periphery of the upper trough. Ongoing convection is a mix of supercells and linear clusters shifting into western New Mexico and southern Colorado. Buoyancy around 1000 J/kg supports robust storms into the evening, with favorable deep-layer shear (50–60 kt) for hail and severe gusts. A tornado or two remains possible, particularly from northwestern New Mexico northward toward southern Colorado where low-level flow is backed. Farther north into the Great Basin, isolated strong to severe storms remain possible under more limited buoyancy, with damaging gusts the primary hazard.

WPC Day 1 maintains the Moderate Risk (Level 3 of 4) over southwest Colorado (San Juan Mountains), southern Utah and northwestern New Mexico. Anomalous moisture, diffluent flow, and training convection continue to support flash flooding. The San Juans see the heaviest accumulations, with model consensus for 3–4 inches and localized higher. Broader Slight Risk covers additional Southwest and Four Corners areas. Marginal Risk remains for parts of the interior Northwest and southeast Florida.

Hotspots

Four Corners (southwest Colorado, southern Utah, northwest New Mexico): Moderate excessive rainfall risk. Heavy rain cores on the San Juans and surrounding high terrain, plus southern Utah canyons and burn scars. Flash Flood Warnings already verified in parts of Arizona that feed into the region. Life-threatening flooding possible in slot canyons, dry washes and urban areas.

Eastern Arizona into western New Mexico: Slight severe risk with active convection. Supercells and clusters producing large hail (reports to 1.5–3 inches) and damaging winds (gusts to 70+ mph); tornado potential elevated where low-level shear and terrain align. Tornado Warnings verified rotation this afternoon in Apache/Navajo Counties and into New Mexico. Phoenix metro and Mogollon Rim remain influenced. Flash flooding accompanies the convection.

Residual California and Great Basin: Isolated severe hail/wind and brief tornado potential under limited instability ahead of the upper low. Marginal excessive rainfall risk in places; main threat is terrain-driven runoff rather than widespread flooding. Earlier activity produced flooding and snow reports in California and Nevada.

Just-Hit

National Weather Service offices issued multiple Severe Thunderstorm Warnings across Arizona (Flagstaff and Phoenix CWAs) for 60 mph winds and quarter-size hail. Tornado Warnings were issued this afternoon for portions of Apache and Navajo Counties, Arizona (including areas near Whiteriver, McNary, and Show Low) and parts of New Mexico. Flash Flood Warnings remain active for Apache County (Canyon de Chelly / Chinle Creek) with considerable damage threat noted and for portions of McKinley and Cibola Counties, New Mexico. SPC local storm reports include 1.5-inch hail near Camp Verde and Rio Rico, Arizona, 3-inch hail near Page Springs, and 70–73 mph wind gusts near Quemado, New Mexico and Safford, Arizona. No confirmed tornado damage reports received so far today. No widespread major river flooding reported, but rapid runoff is occurring in sensitive basins.

Pulse Table

Rising Queries

Rising queries tied to the Southwest hotspot include “flagstaff tornado,” “Arizona severe weather,” and “Four Corners flooding.”

Restoration Read

Primary restoration drivers are large hail and damaging wind impacts to roofs, vehicles, windows and vegetation across eastern and central Arizona, plus flash-flood damage to roads, low-water crossings, homes in washes and infrastructure in the Four Corners Moderate area. Burn scars and slot canyons remain highly sensitive. Isolated tornado potential adds tree and structure damage risk where rotation was indicated. No tropical wind or surge component on U.S. land. Water and hail remain the dominant ticket generators for the next 12–24 hours.

What This Is Not

This is not a tropical cyclone landfall, a High Risk excessive rainfall event, or an Enhanced or Moderate severe outlook. No hurricane or tropical storm warning is in effect for any U.S. coastline or the Gulf of America. The Moderate flood risk is geographically focused on the Four Corners high terrain rather than a broad river flood. Isolated to scattered severe reports are occurring, but coverage remains limited.

Looking Ahead One Day

Friday: The upper low continues northeastward. SPC Day 2 maintains residual severe potential shifting eastward. WPC Day 2 carries the excessive rainfall threat into the southern and central High Plains. Josephine remains post-tropical and moves farther away. California and the Southwest see gradual drying behind the system, though residual runoff continues in saturated basins. No new tropical threat indicated for U.S. land.

Sources

• SPC Day 1 Convective Outlook (0100 UTC October 23, 2026): spc.noaa.gov
• WPC Day 1 Excessive Rainfall Outlook: wpc.ncep.noaa.gov/qpf/ero.php
• NWS watches/warnings and LSRs: weather.gov and spc.noaa.gov/climo/reports
• NHC Josephine post-tropical: nhc.noaa.gov
• Previous desk: Storm Updates: Arizona Slight — Oct 21

Informational only — not an official warning. Always confirm with the latest official forecasts from weather.gov, spc.noaa.gov, wpc.ncep.noaa.gov, and nhc.noaa.gov. Turn around, don’t drown.