October 18–22, 2026

Provisional
Network median 2.24 in (range 1.18–3.62 in)
Published

October 18, 2026

Summary

Across 39 gauges the event total ranged from 1.18 to 3.62 in (median 2.24 in). The central 80% of the network-mean rain fell between Oct 21 05:00 MST and Oct 22 10:00 MST (29 h). ERA5 does not yet cover this event, so the atmospheric setting is not yet described.

Rain across the network

Event rain total at each city and county gauge (circle area proportional to total, labels in inches) over shaded relief (USGS 3DEP), 200-m elevation contours, streams (USGS NHD) and highways (Census TIGER). Orange triangles: SNOTEL sites with event precipitation (in). Square: Flagstaff airport.

Hourly and cumulative rain across the gauge network (median and 10th–90th percentile; cumulative from the start of the event window). When ERA5 is available: IVT, 250-hPa wind speed and 500-hPa height at the ERA5 grid point nearest Flagstaff. Times UTC.
  • Network rain (39 gauges): median 2.24 in; 10th–90th percentile 1.26–3.21 in; lowest 1.18 in (Spruce Wash at Route 66), highest 3.62 in (Waterline Rd #1 (Lenox-Wupatki Trails)).
  • Peak hour: network median 0.35 in (hour beginning Oct 21 06:00 MST); highest single-gauge hour 0.63 in.
  • SNOTEL event precipitation: Fort Valley 0.7 in; Snowslide Canyon 2.8 in; Fry 1.6 in.
  • Provisional: ERA5 does not yet cover this event; maps will be added when it does.

Climate context

  • Airport precipitation: 0.83 in over 5 local days (1 day not yet reported), against a 1991–2020 normal of 0.24 in for those days (3× normal).
  • Rank: the 78th largest 5-day airport total in October among 129 years with data since 1898 (each year’s largest 5-day total ending in October).
  • Airport temperature: highs averaged -1.5 °F and lows +9.0 °F relative to normal.
  • Water year to date (Oct 1, 2026 – Oct 22, 2026): airport 4.38 in (normal 1.08 in); SNOTEL Fort Valley 5.20 in (median 0.50 in); Snowslide Canyon 10.70 in (median 1.60 in); Fry 7.30 in (median 0.80 in).

Station data

Flagstaff airport (local days; normals 1991–2020; M = not yet reported)

Precip (in) Normal (in) Snow (in) High (°F) High vs normal Low (°F) Low vs normal
Oct 18 0.09 0.05 0.0 56 -7 41 +10
Oct 19 0.00 0.05 M 62 +0 35 +5
Oct 20 0.00 0.05 0.0 65 +3 33 +3
Oct 21 0.74 0.04 0.0 60 -2 48 +18
Oct 22 M 0.05 M M M M M
Total 0.83 0.24 0.0

SNOTEL (water-year precipitation from Oct 1; medians 1991–2020)

site Event precip (in) Water-year precip (in) Median to date (in) % of median SWE at end (in) Max snow depth (in)
Fort Valley 0.7 5.2 0.5 — 0 0
Snowslide Canyon 2.8 10.7 1.6 — 0 1
Fry 1.6 7.3 0.8 — 0 0