textproduct: El Paso

KEY MESSAGES

Updated at 1249 PM MDT Sun Sep 20 2026

- Quiet and warm weather will continue today, with just a very slight chance of a thunderstorm this afternoon.

- A cool front will interact with a late season monsoon moisture surge and bring widespread showers and thunderstorms to the area Tuesday afternoon through Wednesday afternoon. Localized flash flooding will be a risk over a large portion of the area.

- Periods of heavy rain and a risk of flash flooding will continue Wednesday and Thursday, before easing up some Friday into the weekend.

DISCUSSION

Issued at 1249 PM MDT Mon Sep 21 2026

Current WV imagery shows mid-latitude low moving in over SoCal with narrow band of moisture streaming into it over Arizona. Further south, plentiful sub-tropical moisture is present, both due to old cut off low just southwest of the southern Baja, and from newly formed TS Polo. At the surface, a weak back door cool front has moved into NE New Mexico.

For today/tonight...should remain relatively quiet. Plenty of CU development next 3 hours. HRRR showing a few random showers or thunderstorms possible this afternoon. By late tonight, toward midnight, the back door front reaches the eastern CWA and into the central CWA after midnight. HRRR showing isolated shower/storm activity RG Valley late night.

Tuesday through Thursday...Pacific upper low/trough has now moved in over the Great Basin and rapidly draws in the sub-tropical moisture with the help of a developing rather strong sub-tropical jet and a possible short wave/vort max moving up from northern Mexico. PWs by Tuesday night approach 1.5 or 1.6 inches in the central and eastern CWA, which is near record highs for this time of the year. Expect scattered showers and thunderstorms early Tuesday afternoon and just continuing through the night into Wednesday morning. A Flood Watch is in effect for much of the CWA Tuesday into Wednesday. The far southwest is not included at this time but I may put in with the next issuance. Wednesday/Wednesday night is still a bit uncertain as a lot depends on how much cloud cover persists Wednesday morning. But still expect numerous showers/thunderstorms. Widespread showers/thunderstorms to continue Thursday into early Friday morning.

Friday through Sunday...sub-tropical high well established over southern Texas and begins ridging west across northern Mexico. This will tend to reduce the moist southerly flow. PWs drop significantly, ranging from around .6 inches north to 1.1 inch far southeast. Thus expect showers/storms to become more isolated, with the risk of flooding lowered significantly (antecedent moisture issues could continue some flood risk). Cut off low from the original Pacific trough then moves across the area Friday night. Lower PWs and dewpoints suggest limited activity Saturday, though PWs begin rebounding again Sunday. Also moderate moisture gradient with higher values in northern Mexico could increase activity if it moves further north than planned. One significant change in the models; neither GFS/ECMWF are now bringing any tropical storm remains to our area through the 10 day forecast period.

AVIATION

(18Z TAFS) Issued at 1249 PM MDT Mon Sep 21 2026

VFR conditions through the period expected with SCT100 SCT250. Slight chance of a BKN070CB -TSRA through late afternoon. After midnight, a few showers/thunderstorms possible around the Rio Grande Valley. Variable winds AOB 8 knots this afternoon and evening. Winds briefly east 10-13 knots late tonight east of the RG Valley.

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 89 65 77 / 10 30 80 80 Sierra Blanca 65 86 61 78 / 10 30 80 80 Las Cruces 66 84 61 73 / 10 40 90 90 Alamogordo 65 86 61 75 / 10 40 90 90 Cloudcroft 49 62 47 55 / 10 60 90 90 Truth or Consequences 63 80 60 70 / 0 60 100 100 Silver City 61 77 57 70 / 0 70 100 90 Deming 66 85 61 75 / 0 50 100 80 Lordsburg 67 82 63 76 / 0 70 80 70 West El Paso Metro 71 88 65 77 / 10 30 80 80 Dell City 66 88 64 80 / 10 30 70 80 Fort Hancock 71 94 67 85 / 10 30 80 80 Loma Linda 64 82 60 72 / 10 30 80 80 Fabens 70 91 66 81 / 10 30 90 90 Santa Teresa 68 87 63 75 / 10 40 80 80 White Sands HQ 70 86 64 75 / 10 30 90 100 Jornada Range 66 85 62 73 / 10 40 90 90 Hatch 66 86 62 75 / 0 50 100 100 Columbus 69 87 64 78 / 0 50 80 70 Orogrande 66 85 62 74 / 10 30 90 100 Mayhill 54 74 53 66 / 20 70 90 90 Mescalero 53 73 52 66 / 10 60 90 90 Timberon 53 73 50 64 / 10 50 90 90 Winston 57 73 54 64 / 10 70 100 100 Hillsboro 65 80 59 71 / 10 60 100 100 Spaceport 64 82 60 71 / 0 50 90 90 Lake Roberts 48 75 54 68 / 0 70 100 100 Hurley 62 79 58 71 / 10 60 100 90 Cliff 50 83 58 76 / 0 70 90 90 Mule Creek 47 79 55 73 / 0 50 90 80 Faywood 64 79 59 70 / 10 50 100 100 Animas 67 83 63 78 / 10 70 80 60 Hachita 66 83 62 76 / 10 60 70 60 Antelope Wells 66 84 61 79 / 10 50 60 60 Cloverdale 63 79 59 77 / 10 60 70 70

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-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.