Flash Flood Warning 24, NWS San Diego, CA

225 
WGUS56 KSGX 190053
FFWSGX
CAC065-073-190130-
/O.EXT.KSGX.FF.W.0024.000000T0000Z-250919T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
553 PM PDT Thu Sep 18 2025

The National Weather Service in San Diego has extended the

* Flash Flood Warning for...
  Riverside County in southern California...
  Northeastern San Diego County in southwestern California...

* Until 630 PM PDT.

* At 553 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. Additional rainfall amounts up to 0.25 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Borrego Springs, Hwy 78 Between S2 And Borrego Springs Rd, Hwy 78 
  Between Banner And S2, Borrego Palm Canyon, Hwy S22 Between 
  Ranchita And Borrego Springs, Ranchita, Hwy S2 Between Hwy 79 And 
  Hwy 78, Hwy 74 Between Anza And Palm Desert, Hwy S2 Between 
  Shelter Valley And Agua Caliente and Los Coyotes Indian 
  Reservation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3363 11638 3353 11630 3306 11631 3305 11652
      3348 11657

FLASH FLOOD...RADAR INDICATED

$$

CSP

197 
WGUS76 KSGX 190128
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
628 PM PDT Thu Sep 18 2025

CAC065-073-190138-
/O.EXP.KSGX.FF.W.0024.000000T0000Z-250919T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Riverside CA-San Diego CA-
628 PM PDT Thu Sep 18 2025

...FLASH FLOOD WARNING WILL EXPIRE AT 630 PM PDT THIS EVENING FOR 
RIVERSIDE AND NORTHEASTERN SAN DIEGO COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flood Watch remains in effect until 200 AM PDT Friday for a 
portion of Southwest California.

&&

LAT...LON 3363 11638 3353 11630 3306 11631 3305 11652
      3348 11657

$$

CSP

Area Forecast Discussion
National Weather Service San Diego CA
150 PM PDT Thu Sep 18 2025

.SYNOPSIS...
Tropical remnants will continue to move through the area this
evening with scattered showers and thunderstorms across inland
areas. There will be gradual drying and warming for Friday and
Saturday. An area of low pressure will form off the coast by early
next week. This may help funnel more tropical moisture into the
area, but timing and placement of any showers is uncertain. The
latter half of next week will be drier as an area of high pressure
moves over the region.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

Convection is beginning to occur across portions of the mountains
and deserts this afternoon, heaviest occurring in the San Diego
and Riverside County mountains. Hi-res models continue to show
scattered areas of storms across the mountains and deserts through
this evening, where rain rates over one inch are possible. Under
any heavier cells, some low water crossings in the deserts and
other areas may see localized flooding. Most areas west of the
mountains may see a rogue shower, but most places will remain dry
through tonight. Storms over the mountains and deserts will begin
to subside before midnight. Tropical moisture may be leftover on
Friday for a couple of remnant showers to remain across the LA
Basin and points north, though most hi-res models are not
depicting very much in the way of precipitation. The area of
tropical moisture will push further inland across the western part
of the country, leaving the area completely dry by Saturday.

An area of low pressure will develop off of the coast by Sunday,
lingering around that area into early next week. The placement of
this system will be crucial in if we see anymore tropical
moisture. Some models suggest that this low combined with an area
of high pressure to the southwest will help funnel in tropical
moisture into the area, which may warrant some light showers
across the region by Sunday and Monday. The best chance of showers
look to be across western San Diego County. Otherwise, dry weather
will prevail for most this weekend into early next week with high
temperatures near average and slightly more humid than normal.
Models begin to diverge by the latter half of next week. By
Tuesday and Wednesday, high pressure may expand over the region,
bringing further warming. The area of high pressure may stick
around into the end of the week but a trough may move through the
Pac NW, providing a cooler weather pattern. The marine layer will
return to our region by this weekend into next week with
night/morning low clouds within 20 miles of the coastline.

&&

.AVIATION...
182000Z....Coast/Valleys...-SHRA with isolated TSRA will continue to
be possible through tonight, although chances are lower than this
morning. Cloud bases will remain between 8000-10000ft MSL for much
of the day. Any precipitation should come to an end by 06z Friday.
Patchy lower clouds around 900-1500ft MSL possible late tonight into
Friday morning generally after 10z and clearing by 16-17z.

.Mountains/Deserts...Higher terrain intermittently obscured with
SHRA/TSRA chances through the evening. Bases generally above 10000ft
MSL but in areas of heavier RA, bases could briefly lower to around
3000ft MSL with VIS 1-5SM. TSRA could produce strong up/downdrafts,
frequent lightning, and CB tops to 35 kft along with gusty and
erratic winds at the surface. The widespread precip moves out to the
north tonight into Friday morning, with additional SHRA/TSRA chances
again over the mountains for Friday afternoon.

&&

.MARINE...There is a low chance of thunderstorms (5-10%) through
this evening. Any storm could briefly produce lightning, gusty
erratic winds, and choppy seas. Otherwise, no additional hazardous
marine conditions are expected through Monday.

&&

.BEACHES...There is a low chance of lightning (5%) through tonight.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Flood Watch through late tonight for Apple and Lucerne Valleys-
     Coachella Valley-Riverside County Mountains-San Bernardino
     County Mountains-San Diego County Deserts-San Diego County
     Mountains-San Gorgonio Pass near Banning.

PZ...None.

&&

PUBLIC...APR
AVIATION/MARINE...Zuber

Preliminary Local Storm Report
National Weather Service San Diego CA
426 PM PDT Thu Sep 18 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0335 PM     Landslide        6 NNW Forest Falls      34.16N 116.95W
09/18/2025                   San Bernardino     CA   Dept of Highways

            San Bernardino County reported mudslides
            blocking SR-38 from Valley of the Falls to
            the bottom of South Fork.

&&

LEV

Preliminary Local Storm Report
National Weather Service San Diego CA
435 PM PDT Thu Sep 18 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0432 PM     Tstm Wnd Gst     4 SW Palm Desert        33.69N 116.41W
09/18/2025  M62 MPH          Riverside          CA   Mesonet

            SCE Painted Canyon Rd observation station
            reported wind gust of 62 mph.

&&

LEV

Preliminary Local Storm Report
National Weather Service San Diego CA
437 PM PDT Thu Sep 18 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0429 PM     Tstm Wnd Gst     1 SW Palm Desert        33.72N 116.39W
09/18/2025  E56 MPH          Riverside          CA   Mesonet

            GW2765 Palm Desert obs reported wind gust of
            56 mph.

&&

LEV

Preliminary Local Storm Report
National Weather Service San Diego CA
441 PM PDT Thu Sep 18 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0140 PM     Tstm Wnd Gst     2 W Borrego Springs     33.26N 116.40W
09/18/2025  E64 MPH          San Diego          CA   Mesonet

            Anza Borrego Desert State Part Observation
            Station reported wind gust of 64 mph.

&&

LEV

Preliminary Local Storm Report
National Weather Service San Diego CA
445 PM PDT Thu Sep 18 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0415 PM     Landslide        4 WSW Forest Falls      34.06N 116.97W
09/18/2025                   San Bernardino     CA   Public

            Mudslide reported near the Oak Glen
            Steakhouse.

&&

LEV

Preliminary Local Storm Report
National Weather Service San Diego CA
450 PM PDT Thu Sep 18 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0348 PM     Landslide        4 ENE Yucaipa           34.05N 116.98W
09/18/2025                   San Bernardino     CA   Fire Dept/Rescue

            Report of mudslide and debris flow with
            powerlines compromised. This has caused Oak
            Glenn Rd to be closed from Chagall to Potato
            Canyon.

&&

LEV