Alert archive / California / Flash Flood Warnings in 2018

Flash Flood Warning 2, NWS San Diego, CA

July 7, 2018San Bernardino County, California

NWS San Diego, CA issued this flash flood warning at Jul 7, 2018, 12:43 PM PDT for San Bernardino County, California. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 7, 2018, 12:43 PM PDT (19:43 UTC)
Expired
Jul 7, 2018, 3:45 PM PDT
In force
3 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County San Bernardino County, CA

The radar

The Santa Ana Mts radar (KSOX), 61 km from the middle of the area, began a volume at 19:46 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, 7.7 hours before the alert went out and 178 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.

Skew-T log-pSkew-T log-p diagram, San Diego, CA at 12:00Z on 2018-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 12:00Z on 2018-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3366 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

648 
WGUS56 KSGX 071943
FFWSGX
CAC071-072245-
/O.NEW.KSGX.FF.W.0002.180707T1943Z-180707T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service San Diego CA
1243 PM PDT SAT JUL 7 2018

The National Weather Service in San Diego has issued a

* Flash Flood Warning for...
  San Bernardino County in southern California...

* Until 345 PM PDT

* At 1240 PM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding will likely begin
  shortly.

* Some locations that will likely experience flooding include...
  Wrightwood, Hwy 2 Between Phelan And Wrightwood, Hwy 138 Between
  I-15 And Hwy 2, Pinon Hills and Phelan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3426 11751 3426 11765 3431 11765 3443 11766
      3451 11766 3451 11754

$$

Small
2 follow-up statements
804 
WGUS76 KSGX 072129
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
229 PM PDT SAT JUL 7 2018

CAC071-072245-
/O.CON.KSGX.FF.W.0002.000000T0000Z-180707T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
229 PM PDT SAT JUL 7 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM PDT FOR SAN
BERNARDINO COUNTY...

At 220 PM PDT, Doppler radar mostly light rain over the warned areas 
around Phelan, Pinon Hills and Wrightwood with heavier rain farther 
south between Mount Baldy, Upland and Rancho Cucamonga. More 
thunderstorms with heavy rain could affect the warned area at times 
through 345 PM and could produce flash flooding.

Some locations that could experience flooding include... 
Wrightwood, Hwy 2 Between Phelan And Wrightwood, Hwy 138 Between I-
15 And Hwy 2, Pinon Hills and Phelan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3426 11751 3426 11765 3431 11765 3443 11766
      3451 11766 3451 11754

$$

Maxwell
640 
WGUS76 KSGX 072239
FFSSGX

Flash Flood Statement
National Weather Service San Diego CA
339 PM PDT SAT JUL 7 2018

CAC071-072248-
/O.EXP.KSGX.FF.W.0002.000000T0000Z-180707T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
339 PM PDT SAT JUL 7 2018

...THE FLASH FLOOD WARNING FOR SAN BERNARDINO COUNTY WILL EXPIRE AT
345 PM PDT...

At 330 PM PDT, only light rain was occurring over Wrightwood, Phelan 
and Pinon Hills. Flooding is no longer expected to pose a threat.

LAT...LON 3426 11751 3426 11765 3431 11765 3443 11766
      3451 11766 3451 11754

$$

Maxwell

The office that day

Everything else NWS San Diego, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 7, 12:56 PM PDTFlash Flood WarningSGXSan Bernardino3 hr
Jul 7, 2:07 PM PDTFlash Flood WarningSGXRiverside, San Diego3 hr

Nearby

Flash Flood Warnings in California, 2018Every flash flood warning in 2018

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.