Grants, NM 87020 Weather

Key Messages

Issued at 550 AM MDT Thu Oct 22 2026

- Flash flood risk continues in western New Mexico today, spreading eastward into central New Mexico tonight through Friday.

- Additional heavy rainfall looks increasingly likely over eastern New Mexico this weekend with a risk of flash flooding.

- There will be a risk of severe storms producing large hail and damaging winds over western New Mexico today, then over central areas Friday.

- Rainfall over northwest New Mexico this week will create rises on tributaries as well as main stem rivers such as the San Juan and Animas. No river flooding is currently forecast, but trends will be monitored closely over the next few days.

Short Term

(Today through Friday) Issued at 1241 AM MDT Thu Oct 22 2026

Scattered to numerous showers and storms will continue from the central mountain chain westward today and tonight, then storms will spread to eastern areas as well on Friday while decreasing in coverage from the west. An upper level low pressure system will pass northeastward over the Great Basin from the CA coast, drawing extremely rich subtropical moisture northward over NM today and tonight with PWATS around 0.95-1.10" over central and western areas. The GEFS Ensemble places these PWATS over 300% of normal for this time of year with record values likely. Fortunately, storms will move swiftly toward the northeast around 35-50 mph, which should mitigate the flash flood risk some. However, many locations will receive repeated rounds of storms, increasing the flood risk. The most likely rain amount forecast for today through Friday varies around 0.25 - 1.75" over north central and western areas, with lower amounts farther south and east. The NBM's 90th percentile QPF (high-end scenario) indicates a 10 percent chance that some locations along and west of the continental divide will receive 2" to potentially over 4" of rain. This is in addition to 0.25" to over 1" of rain that already fell in some areas along and west of the continental divide Tuesday night through Wednesday evening. Locations where the ground is already saturated from recent heavy rain will be especially susceptible to rapid runoff and flash flooding today through Friday.

There will also be a risk of severe storms producing damaging wind and large hail over western areas today and tonight, then from the continental divide to the central mountain chain Friday. Bulk shear over western areas today will begin around 25-40 KT, except around 50 KT over the Four Corners. Bulk shear will then climb over central and western areas tonight, and remain strong into Friday, reaching around 30-65 KT with the greatest values again over the Four Corners. Most unstable CAPE will be less impressive, varying around 1000-1400 J/KG over western areas, then trending weaker while remaining elevated and shifting eastward over central areas tonight. Friday's CAPE looks to peak around 600-1400 J/KG over central areas, with the greatest values south of the northern mountains. SPC's Tornado outlook indicates a 2% tornado threat mainly south of the Jemez Mountains and Mount Taylor on Friday, which suggests an isolated tornado or two may be possible from a few of the stronger cells.

With all the cloud cover and precipitation, temperatures will trend cooler today and Friday, with readings reaching near to around 5 degrees below 1991-2020 averages over central and western areas Friday afternoon; and as much as 3 degrees above average farther east.

Long Term

(Friday night through Wednesday) Issued at 1241 AM MDT Thu Oct 22 2026

In the wake of the exiting aformentioned upper low, a second upper level low pressure system will form over southern CA Friday, then open into a trough as it ejects northeastward over the Four Corners and CO Sunday night. This slow moving system will again draw extremely rich subtropical moisture northward over the forecast area with PWATs reaching around 0.80" along the central mountain chain, and as much as 1.20" farther east. The GEFS Ensemble shows PWATs peaking around 160-260% of normal across the east Saturday morning. Thus, after a period of less rain in between systems Friday afternoon, rain coverage and precipitation intensity will increase again Friday night through Saturday, mainly over central and eastern areas. Rainfall then looks to persist over eastern areas through Sunday night. Rain amounts Friday night through Sunday night are currently progged to reach around 1-3" across much of the eastern plains with locally higher amounts. There may also be some snow on the highest peaks of the central mountain chain Friday night through Sunday night, where 700 mb temperatures look to bottom out around +2 to +4 C. High temperatures at the surface will continue to trend cooler through the weekend, when readings should vary from a few to around 8 degrees below 30-year averages.

Drier and warmer weather is forecast early in the coming work week as a low amplitude ridge of high pressure crosses from the west.

Aviation

(12Z TAFS) Issued at 550 AM MDT Thu Oct 22 2026

Scattered to numerous showers and thunderstorms will continue along and west of the central mountain chain today and tonight. Storms will move toward the northeast around 30-45 KT. A few storms may turn severe over western areas today and tonight with erratic wind gusts around 60 mph and large hail. There will also be periods of mountain obscuration today and tonight.