Alert archive / California / Flash Flood Watches in 2021
Flash Flood Watch 1, NWS San Diego, CA
NWS San Diego, CA issued this flash flood watch at Jan 19, 2021, 10:07 AM PST for Riverside County, San Diego County, California. It took effect at Jan 20, 2021, 12:00 AM PST. It was in force for 24 hr.
The area
The counties it named.
The facts
- Issued
- Jan 19, 2021, 10:07 AM PST (18:07 UTC)
- In effect from
- Jan 20, 2021, 12:00 AM PST
- Expired
- Jan 21, 2021, 12:00 AM PST
- In force
- 24 hr
- Issued by
- NWS San Diego, CA
- Flood severity
- None
Counties Riverside County, CA, San Diego County, CA
The radar
The San Diego radar (KNKX), 80 km from the middle of the area, began a volume at 18:10 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
San Diego, CA (KNKX), launched 12:00Z, 6.1 hours before the alert went out and 100 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1193 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -13 m²/s²
- 0-3 km storm-relative helicity
- 27 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
412 WGUS66 KSGX 191807 FFASGX URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service San Diego CA 1007 AM PST Tue Jan 19 2021 CAZ056-058-061-062-200215- /O.NEW.KSGX.FF.A.0001.210120T0800Z-210121T0800Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Riverside County Mountains-San Diego County Mountains-Coachella Valley-San Diego County Deserts- Including the cities of Palm Desert, Indio, La Quinta, Idyllwild-Pine Cove, Julian, Palm Desert Country, Pine Valley, Palm Springs, Coachella, Borrego Springs, and Cathedral City 1007 AM PST Tue Jan 19 2021 ...FLASH FLOOD WATCH IN EFFECT FROM LATE TONIGHT THROUGH WEDNESDAY EVENING... The National Weather Service in San Diego has issued a * Flash Flood Watch for a portion of southwest California, including the following areas, Coachella Valley, San Diego County Deserts, and the desert mountain slopes of the Riverside and San Diego County Mountains. * From late tonight through Wednesday evening * Moderate to locally heavy showers will impact the deserts and the desert mountain slopes. The showers will develop this afternoon and become most widespread and heaviest Wednesday afternoon through Wednesday evening. The heaviest rainfall is expected to occur over the San Diego County deserts and adjacent mountain areas, where 1 to 3 inches of rain is forecast. While the rain will not be as heavy across the Coachella Valley, scattered heavy showers are possible there with total rainfall amounts of around a half an inch, but locally up to one inch is possible. There is even a slight chance of thunderstorms. * Heavy rainfall could lead to flash flooding. Normally dry river beds and culverts could see sudden water rises. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Gregoria
5 follow-up statements
419 WGUS66 KSGX 192258 FFASGX Flood Watch National Weather Service San Diego CA 258 PM PST Tue Jan 19 2021 CAZ056-058-061-062-200700- /O.CON.KSGX.FF.A.0001.210120T0800Z-210121T0800Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Riverside County Mountains-San Diego County Mountains-Coachella Valley-San Diego County Deserts- Including the cities of Palm Desert, Indio, La Quinta, Idyllwild-Pine Cove, Julian, Palm Desert Country, Pine Valley, Palm Springs, Coachella, Borrego Springs, and Cathedral City 258 PM PST Tue Jan 19 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT FROM MIDNIGHT PST TONIGHT THROUGH WEDNESDAY EVENING... The Flash Flood Watch continues for * A portion of southwest California, including the following areas, Coachella Valley, San Diego County Deserts, and the desert mountain slopes of the Riverside and San Diego County Mountains. * From Midnight PST tonight through Wednesday evening * Moderate to locally heavy showers will impact the deserts and the desert mountain slopes. The showers will develop this afternoon and become most widespread and heaviest Wednesday afternoon through Wednesday evening. The heaviest rainfall is expected to occur over the San Diego County deserts and adjacent mountain areas, where 1 to 3 inches of rain is forecast. While the rain will not be as heavy across the Coachella Valley, scattered heavy showers are possible there with total rainfall amounts of around a half an inch, but locally up to one inch is possible. There is even a slight chance of thunderstorms. * Heavy rainfall could lead to flash flooding. Normally dry river beds and culverts could see sudden water rises. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Gregoria
457 WGUS66 KSGX 200511 FFASGX Flood Watch National Weather Service San Diego CA 911 PM PST Tue Jan 19 2021 CAZ056-058-061-062-201315- /O.CON.KSGX.FF.A.0001.210120T0800Z-210121T0800Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Riverside County Mountains-San Diego County Mountains-Coachella Valley-San Diego County Deserts- Including the cities of Palm Desert, Indio, La Quinta, Idyllwild-Pine Cove, Julian, Palm Desert Country, Pine Valley, Palm Springs, Coachella, Borrego Springs, and Cathedral City 911 PM PST Tue Jan 19 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH WEDNESDAY EVENING... The Flash Flood Watch continues for * A portion of southwest California, including the following areas, Coachella Valley, Riverside County Mountains, San Diego County Deserts and San Diego County Mountains. * Through Wednesday evening * Moderate to locally heavy showers may impact the deserts and the desert mountain slopes. The showers will develop overnight and become most widespread and heaviest Wednesday afternoon through Wednesday evening. The heaviest rainfall is expected to occur over the San Diego County deserts and adjacent mountain areas, where 1 to 3 inches of rain is possible. While the rain will not be as heavy across the Coachella Valley, scattered heavy showers are possible there with total rainfall amounts of one-half to locally one inch. There is even a slight chance of thunderstorms. * Heavy rainfall could lead to flash flooding. Normally dry washes could see sudden water rises. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ 10
841 WGUS66 KSGX 201156 FFASGX Flood Watch National Weather Service San Diego CA 356 AM PST Wed Jan 20 2021 CAZ056-058-061-062-202000- /O.CON.KSGX.FF.A.0001.000000T0000Z-210121T0800Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Riverside County Mountains-San Diego County Mountains-Coachella Valley-San Diego County Deserts- Including the cities of Palm Desert, Indio, La Quinta, Idyllwild-Pine Cove, Julian, Palm Desert Country, Pine Valley, Palm Springs, Coachella, Borrego Springs, and Cathedral City 356 AM PST Wed Jan 20 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS EVENING... The Flash Flood Watch continues for * A portion of southwest California, including the following areas, Coachella Valley, Riverside County Mountains, San Diego County Deserts and San Diego County Mountains. * Through this evening * Scattered mostly light showers will continue this morning. More widespread showers with moderate to locally heavy rainfall are possible for this afternoon and evening. The heaviest rainfall is expected to occur over the San Diego County deserts and adjacent mountain areas, where 1 to 2 inches of rainfall is possible with isolated rainfall to 3 inches. * Heavy rainfall could lead to flash flooding. Normally dry washes could see sudden water rises. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ 17
049 WGUS66 KSGX 202223 FFASGX Flood Watch National Weather Service San Diego CA 223 PM PST Wed Jan 20 2021 CAZ056-058-061-062-210630- /O.CON.KSGX.FF.A.0001.000000T0000Z-210121T0800Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Riverside County Mountains-San Diego County Mountains-Coachella Valley-San Diego County Deserts- Including the cities of Palm Desert, Indio, La Quinta, Idyllwild-Pine Cove, Julian, Palm Desert Country, Pine Valley, Palm Springs, Coachella, Borrego Springs, and Cathedral City 223 PM PST Wed Jan 20 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL MIDNIGHT PST TONIGHT... The Flash Flood Watch continues for * A portion of southwest California, including the following areas, Coachella Valley, Riverside County Mountains, San Diego County Deserts and San Diego County Mountains. * Until Midnight PST tonight * Although most of the showers will be light, there still is the potential of locally heavier showers which could produce flash flooding. * Heavy rainfall could lead to flash flooding. Normally dry washes could see sudden water rises. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Gregoria
035 WGUS66 KSGX 210550 FFASGX FLOOD WATCH NATIONAL WEATHER SERVICE San Diego CA 950 PM PST Wed Jan 20 2021 CAZ056-058-061-062-210800- /O.CON.KSGX.FF.A.0001.000000T0000Z-210121T0800Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Riverside County Mountains-San Diego County Mountains- Coachella Valley-San Diego County Deserts- Including the cities of Idyllwild-Pine Cove, Julian, Pine Valley, Indio, Palm Springs, Cathedral City, Palm Desert, Palm Desert Country, La Quinta, Coachella, and Borrego Springs 950 PM PST Wed Jan 20 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL MIDNIGHT PST TONIGHT... The Flash Flood Watch continues for * A portion of southwest California...including the following... Coachella Valley...Riverside ...County Mountains...San Diego County Deserts and San Diego County Mountains. * until midnight PST tonight * Although most of the showers will be light, there still is a slight risk for an isolated heavy rain shower, which could produce some localized flooding problems. Any remaining showers will taper off by late tonight. * Brief heavy downpours could lead to flash flooding. Normally dry washes could see sudden water rises. * Outlook: storm systems arriving late Friday night and a second storm late Sunday night could bring another round of precipitation and potential flooding problems. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ jmb
The office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 19, 4:53 AM PST | Winter Weather Advisory | SGX | Riverside, San Bernardino | 16 hr |
Nearby
Flash Flood Watches in California, 2021Every flash flood watch in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.