Area Forecast Discussion
Issued by NWS
Issued by NWS
924
FXUS64 KEPZ 220630
AFDEPZ
Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
1230 AM MDT Tue Sep 22 2026
...New DISCUSSION, AVIATION...
.KEY MESSAGES... Updated at 1220 AM MDT Tue Sep 22 2026
- The risk of heavy rainfall and medium to higher-end flooding
impacts is increasing, especially for south-central New Mexico,
especially Tuesday evening into Wednesday morning.
- This is all due to a back door cold front interacting with an
upper level trough pulling in deep subtropical moisture form
the Pacific.
- THe focus for heavy rainfall will shift east later Wednesday
into Thursday, but will become more localized. Additional
scattered showers and thunderstorms are expected through Friday
in southwestern New Mexico.
- Quieter weather will prevail for the weekend, with showers and
thunderstorms returning late Monday.
&&
.DISCUSSION...
Issued at 1141 PM MDT Mon Sep 21 2026
The threat for higher-end flooding is increasing, especially for
south-central New Mexico. The overall forecast pattern and is more
or less locked in, now it is down to specific details like which
specific arroyo and stream basins see the most rainfall.
Our upper level low over California is slowly weakening as it
drifts into Nevada, while 200 mb streamline analysis shows broad
upper level diffluence over the Sierra Madres near the junction
of Sonora, Chihuahua, and Sinaloa. Convection in this region was
fairly concentrated this evening, but water vapor imagery shows
some signs of a tight upper level low taking shape, as expected.
This system will weaken into a shortwave trough as it rolls
northwards up the Sierra Madres Tuesday, aided by broadening upper
level diffluence across Chihuahua and New Mexico and a
strengthening subtropical jet streak in SE Arizona.
Meanwhile, at the surface, the back door cold front has topped the
Sacramento and Guadalupe Mountains. Mesonet obs show steady east
winds with a few gusts around 20-25 mph in parts of Alamogordo,
and the upper range of WSMR. The Dell City West Texas Mesonet
station also has an east wind along with PX Well RAWS. Expect some
low stratus and fog to develop along the east slopes of the
Sacramentos as cooler/moisture air seeps in closer to dawn,
lagging behind the initial wind shift. A few spots could see brief
dense fog.
By Sunrise, some sparse showers may be on-going in SW New
Mexico, and the back door front tries to reach the Arizona state
line by mid-morning. Thunderstorms look to initiate tomorrow
afternoon along the higher terrain, but also near the cold front
in SW New Mexico. Outflow looks to push the front back to the east
a bit, falling in line with a surface and low level trough that
develops ahead of the approaching shortwave trough from the south.
By evening, the surface front and low level trough will become
the focus for intense moisture convergence. This is where the
heaviest rain will focus, with several waves of showers and
embedded thunderstorms training across the broader region.
Unfortunately, there is still some uncertainty into where exactly
this region sets up. Notably, a few high res models have a sharp
eastern cutoff to the significant precip Tuesday night, with some
producing 2-3 inches of rain in parts of south-central New Mexico,
and scant amounts over El Paso.
The most likely scenario broadly produces 2-3 inches of rain
from the east slopes of the Black Range to the San Andres
Mountain, and south across much of Luna and Dona Ana County,
tapering off into western El Paso County. The worst-case scenario
type model runs (e.g., the 00Z HRRR with its hopefully-outlier
cataclysmic totals east of the Black Range, appear to the result
of repeated training of the max precip rates over the same area
with very little variation. The more likely scenario would see
isolated pockets of 3 to 5 inches within the broader 2-3 inch
area.
That said, the greatest probabilities when looking at various
exceedance levels (1 inch, 2 inch, 3 inch) focus on western
Sierra County and northern Dona Ana County. All the long-run
arroyos coming off the Black Range towards the Rio Grande are at
risk of seeing higher-end flooding. This same area has broadly
seen 2-3 inches of rain over the past 7 days, including portions
of the Black Range crest, but mainly east of the Lake
Valley/Highway 27 corridor all the way into the northern end of
the Jornada del Muerto. That extra saturation will enhance runoff.
A fair amount of the heavier rain will likely fall into basins
that feed in south of Caballo Dam (everything south of Percha
Creek), which will likely bring significant rises in the Rio
Grande. Thankfully, water levels have dried back up through most
of the Rio Grande south of Caballo, but we may still come close to
bankfull in the reaches from Percha Dam south through Selden
Canyon, down to around Leasburg.
Heavy rainfall is likely to be ongoing Wednesday morning,
impacting the morning commute, especially if El Paso ends up back
in the heaviest rain axis. The shortwave trough will move north
into the Gila region by midday Wednesday, with a trailing vort
lobe curling down towards El Paso and west of the Big Bend. The
heaviest rain will lift northeast as it does so, with the
intensity moderating a bit. Much of southwestern New Mexico could
see a significant dry period Wednesday afternoon. Meanwhile, the
focus for rain will shift east.
The trough will linger over Hudspeth County heading into Wednesday
Night and Thursday, but the overall QPF amounts look to pale in
comparison to what central areas are looking to get Tue Night/Wed
AM. Kept the Flood Watch as is, though the eastern extension of it
looks questionable.
An additional upper low that develops from the lifting west coast
trough looks to move up towards the Four Corners by Friday
morning. Additional rounds of more widely scattered showers and
thunderstorms look likely Thursday night into Friday, especially
in the Gila Region, but may avoid the most hard-hit areas from
Tue/Wed.
A lull for the weekend looks to be followed by increasing showers
and thunderstorms late Monday. Tropical systems in the Eastern
Pacific will need to be monitored for the middle of next week, but
it looks like the moisture will stay at bay through Tuesday, and
there is considerable uncertainty beyond that, and enough to focus
on in the near term.
&&
.AVIATION...
(06Z TAFS)
Issued at 1141 PM MDT Mon Sep 21 2026
VFR conditions through the night, with increasing chances for
showers and thunderstorms Tuesday afternoon and evening. All
NM terminals are likely to see steady rain and lowering ceilings
after 03-06Z Wed, with embedded heavy rain, thunderstorms, and
periods of IFR to MVFR visibilities. ELP will be more on the
fringes of the steadier rainfall through 09-12Z. Any restriction
will likely be due to visibility rather than ceilings, which will
remain in the 4500-6500 foot range.
&&
.FIRE WEATHER...
Issued at 1249 PM MDT Mon Sep 21 2026
Little in the way of fire concerns for this week. Rapidly
increasing moisture Tuesday with lead to widespread showers and
thunderstorms, lasting through Thursday night. Areas of flash
flooding are likely during this period. Showers and thunderstorms
become a bit more isolated Friday through the weekend as moisture
decreases some. Temperatures will be at or below normal all week.
Min RH: Lowlands 25-35% Tuesday increasing to 45-60% Wednesday
through Saturday. Mountains 35-50% Tuesday, increasing to 60-80%
through Thursday, then back to 45-60% Friday and Saturday. Vent
rates fair-good Tuesday, becoming poor-fair Wednesday through
Saturday.
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 71 90 65 76 / 0 60 80 90
Sierra Blanca 65 86 60 79 / 0 30 40 80
Las Cruces 66 85 60 71 / 10 60 90 100
Alamogordo 65 87 60 75 / 0 50 70 90
Cloudcroft 49 63 46 55 / 0 70 70 90
Truth or Consequences 63 80 59 68 / 10 70 100 100
Silver City 61 77 55 66 / 10 70 90 90
Deming 66 86 59 72 / 20 60 90 90
Lordsburg 67 83 61 72 / 10 50 60 70
West El Paso Metro 71 89 64 75 / 0 60 80 90
Dell City 66 89 64 81 / 0 20 40 80
Fort Hancock 71 95 68 85 / 0 40 60 70
Loma Linda 64 83 59 72 / 0 50 70 80
Fabens 70 92 66 80 / 0 50 70 80
Santa Teresa 68 88 62 74 / 10 60 90 90
White Sands HQ 70 86 62 73 / 0 70 90 90
Jornada Range 66 85 60 72 / 10 70 100 100
Hatch 66 87 61 73 / 10 70 100 100
Columbus 69 88 63 75 / 20 50 90 90
Orogrande 66 86 62 74 / 0 50 80 90
Mayhill 54 74 53 66 / 10 70 80 90
Mescalero 53 74 52 66 / 10 70 70 90
Timberon 53 73 49 64 / 10 50 70 90
Winston 57 73 54 61 / 0 70 100 100
Hillsboro 65 80 57 68 / 10 80 100 100
Spaceport 64 82 59 69 / 10 70 100 100
Lake Roberts 56 75 53 64 / 10 70 100 90
Hurley 62 79 56 68 / 10 70 90 90
Cliff 63 83 61 72 / 0 70 80 80
Mule Creek 61 79 57 68 / 0 50 60 60
Faywood 64 80 58 67 / 20 70 100 90
Animas 67 83 62 74 / 20 50 60 60
Hachita 66 84 60 73 / 20 60 80 80
Antelope Wells 66 84 61 75 / 20 60 80 60
Cloverdale 63 79 58 73 / 20 60 70 50
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
TX...Flood Watch from Tuesday afternoon through Wednesday evening for
Eastern/Central El Paso County-Northern Hudspeth
Highlands/Hueco Mountains-Rio Grande Valley of Eastern El
Paso/Western Hudspeth Counties-Rio Grande Valley of Eastern
Hudspeth County-Salt Basin-Southern Hudspeth Highlands-
Western El Paso County.
NM...Flood Watch from Tuesday afternoon through Wednesday evening for
Central Grant County/Silver City Area-East Central Tularosa
Basin/Alamogordo-East Slopes Sacramento Mountains Below
7500 Feet-Eastern Black Range Foothills-Lowlands of the
Bootheel-Northern Dona Ana County-Otero Mesa-Sacramento
Mountains Above 7500 Feet-Sierra County Lakes-Southeast
Tularosa Basin-Southern Dona Ana County/Mesilla Valley-
Southern Gila Foothills/Mimbres Valley-Southern Gila Region
Highlands/Black Range-Southwest Desert/Lower Gila River
Valley-Southwest Desert/Mimbres Basin-Uplands of the
Bootheel-Upper Gila River Valley-West Central Tularosa
Basin/White Sands-West Slopes Sacramento Mountains Below
7500 Feet.
&&
$$
FORECASTER...25-Hardiman