Alert archive / California / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 6, NWS San Diego, CA

May 20, 1997San Bernardino County, California

NWS San Diego, CA issued this severe thunderstorm warning at May 20, 1997, 4:45 PM PDT for San Bernardino County, California. It was in force for 60 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 20, 1997, 4:45 PM PDT (23:45 UTC)
Expired: May 20, 1997, 5:45 PM PDT
In force: 60 min
Issued by: NWS San Diego, CA
Area: Whole counties

County San Bernardino County, CA

The radar

The Edwards AFB radar (KEYX), 129 km from the middle of the area, began a volume at 23:46 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 text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS San Diego, CA wrote its last area forecast discussion before this severe thunderstorm warning went out at May 20, 2:30 PM PDT, 2 hours 15 minutes earlier.

Area forecast discussion, May 20, 2:30 PM PDT, 2 hours 15 minutes before

SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 PM PDT TUE MAY 20 1997

                         ...SYNOPSIS...

RESIDUAL MOISTURE WILL CAUSE SCATTERED SHOWERS OR THUNDERSTORMS IN
THE MOUNTAINS AND DESERTS INTO THIS EVENING AND AGAIN WEDNESDAY.
DRIER FLOW ALOFT THURSDAY. THE MARINE LAYER AND ONSHORE FLOW WILL
CONTINUE NIGHT AND MORNING LOW CLOUDS AND FOG WEST OF THE
MOUNTAINS...OTHERWISE FAIR.

                        ...DISCUSSION...

RAMSDIS/OBS SHOWING THUNDERSTORMS DEVELOPING IN THE MOUNTAINS AND
DESERTS IN THE N PART OF OUR FORECAST AREA WITH CU/TCU IN SAN
MOUNTAINS...BUT INCREASING THERE AS WELL. 12Z NKX RAOB JUST ABOUT AS
UNSTABLE AS YESTERDAY WITH LI OF 0 BUT MODIFIED SOUNDING MUCH MORE
UNSTABLE. MARINE LAYER WAS STILL QUITE DEEP WITH INVERSION BASED NEAR
3 KFT BUT INVERSION WAS WEAKER WITH BETTER CLEARING TODAY THAN
YESTERDAY. PRETTY GOOD ONSHORE GRADIENTS WITH OVER 5 MB SAN-IPL.

12Z MODELS IN A LITTLE BETTER AGREEMENT THAN PREVIOUS RUNS BUT STILL
SOME DIFFERENCES IN DETAILS. WEAK TROF ALOFT WITH ONLY SLIGHT
DECREASE IN HEIGHT/THICKNESS WED THEN SOME RECOVER THU. VERY WEAK
FLOW ALOFT WED AND NO GOOD MECHANISM TO DRY OUT ATMOSPHERE SO WILL
PROBABLY STILL HAVE SOME AFTERNOON/EVE THUNDERSTORMS IN MOUNTAINS/
DESERTS. STRONGER WLY FLOW ALOFT THU FOR BETTER DRYING AND WILL TAKE
OUT MENTION OF THUNDERSTORMS. OTHERWISE...PLENTY OF AM/PM LOW
CLOUDS/FOG INTO COASTAL MOUNTAIN SLOPES WITH SOME DECREASE WED PM/THU
AM. NOT MUCH TEMP CHANGE.

SAN BU 063/071 063/071 063 040000

ATKIN

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 4:45 PM PDT	Flash Flood Warning	SGX	San Bernardino	60 min

Nearby

Severe Thunderstorm Warnings in California, 1997 Every severe thunderstorm warning in 1997

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.