California, 2020

Cold in California, May 28, 2020

May 28, 2020 · NWS STO · 1 event in 1 county or zone

Area water ways were cold and fast moving at the end of May, while daytime high temperatures were about 10 to 15 degrees above normal for the time of year.

The toll

Deaths
3
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS STO wrote it up.

Area water ways were cold and fast moving at the end of May, while daytime high temperatures were about 10 to 15 degrees above normal for the time of year.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sacramento, CA wrote its last area forecast discussion before the first event at May 28, 2:22 PM PST, 1 hour 38 minutes earlier.

Area forecast discussion, May 28, 2:22 PM PST, 1 hour 38 minutes before
Area Forecast Discussion
National Weather Service Sacramento CA
322 PM PDT Thu May 28 2020

.Synopsis...
Hot weather will come to an end due to a pattern change that begins
Friday. Low pressure will move into Norcal with cooler temperatures
and a chance of showers and thunderstorms over the weekend.

&&

.DISCUSSION...
Marine stratus has returned to the coast and with it a "Delta
trickle" to help cool things a tad in the marine/Delta influenced
areas. At 20z temps were running generally 2-7 degrees cooler than
yesterday in this area, and 6-19 degrees cooler at VCB and through
the Strait at Vallejo, respectively. Farther inland, temps were
running on par or even warmer than yesterday, especially in the
Sierra.

Looks as if RDD and RBL will hit the century mark today. For RDD it
will be the initial triple digit reading for the current heat wave,
but that site has been surpassed a few times already by DTS, SAC,
SCK and MOD during this heat wave.

This heat wave will be "blown away" by increasing onshore gradients
and the Delta Breeze later tonight and Fri. By Fri morning, both the
MAV and MET guidance for SUU have sustained wind speeds from 22-29
kts as thermal differences from land-sea and the approaching upper low
drive onshore momentum well inland. Over the Nrn Sac Vly, the flow
will turn up-Valley on Fri cooling their temps probably into the
mid, maybe upper, 90s.

When one concern is alleviated (the heat), another one emerges
(thunderstorms) with the potential for locally heavy rains. The
closed upper level low vcnty 28N/128W will tend to phase a couple
of PWAT plumes as it moves towards the MTR/SFO Bay areas early Sat
morning, and then over Norcal on Sat. The NAEFS anomaly table shows
about a +3 PW anomaly over Norcal on Sat, and about a 5 year return
interval, highlighting the potential for some heavier rainfall.

Although the NAM 3km REF prog keeps our area quiet on Fri, it
explodes an area of SE to NW oriented convection roughly from
BLU-OVE-N of Alder Springs late Fri nite and in the wee hours of
Sat morning. This is right in the area of strong PVA and upper
level diffluence in the NE quadrant of the approaching closed low.
Forecast soundings look quite wet during this time with PWs
above 1.0" at BAB, CIC, RBL, RDD. Moist SEly flow around the
closed low should favor the east side of the Trinity Alps/Coastal
Range (our western Tehama/Shasta Counties) for some heavier
rainfall. Earlier indications suggest some areas in Shasta County
could receive .60" in the 6 hr period early Sat morning, and
about 1.50" for the Sat/Sat nite time frame.

The shower and thunderstorm threat will diminish by late
Saturday afternoon and evening, with a residual chance of showers
and storms into Sun over the Nrn mtns and Sierra with the
approach of a secondary Pac trof. This will continue onshore flow
and cloud cover over our CWA, and although temps will recover some
on Sun it will still be much cooler than normal. After this big
heat wave (Max temps some 15 to 20 degrees above normal) how
about this for a cool down...6 to 20 degrees below normal on Sat,
and 5 to 12 degrees below normal on Sun?    JHM

&&

.EXTENDED DISCUSSION (Monday THROUGH Thursday)...

No major changed to the previous forecast. A highly amplified
pattern is in place to start the work week as an elongated
longwave trough sits off the California coast while a strong ridge
occupies the middle of the country. Embedded shortwaves advancing
into northern California will ignite scattered showers across the
foothills and mountains, especially on Monday and Tuesday.
Ensembles gradually cut off this trough in the vicinity of
southern California although its exact position is debatable given
the typical forecast spread at these ranges. There is a slight
chance of afternoon showers are possible over the mountains every
day. Upper ridging curling up and around the low center should
prompt a notable warm up after starting a few degrees below
climatology. High temperatures are likely to return to the upper
80s/low 90s by mid- week. ~BRO/HEC

&&

.AVIATION...

VFR SKC conditions over Interior NorCal through Fri. Delta Breeze
expected to increase to 22-29 kts with gusts around 40 kts late
tonight and Fri through the Carquinez Strait and into the Sac Delta.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning until 7 PM PDT this evening for Carquinez
Strait and Delta-Central Sacramento Valley-Motherlode-Mountains
Southwestern Shasta County to Western Colusa County-Northeast
Foothills/Sacramento Valley-Northern Sacramento Valley-Southern
Sacramento Valley.

Excessive Heat Warning until 7 PM PDT this evening for Northern
San Joaquin Valley-Shasta Lake Area / Northern Shasta County.

&&

In the hours before

Local storm report, May 28, 11:57 AM PST, 4 hours 3 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
1257 PM PDT THU MAY 28 2020

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

0700 AM     SNOW             KYBURZ                  38.78N 120.30W
03/25/2020  M4.0 INCH        EL DORADO          CA   TRAINED SPOTTER

            SPOTTER REPORTED 4 INCHES OF SNOW.

&&
Local storm report, May 28, 1:00 PM PST, 3 hours before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
200 PM PDT THU MAY 28 2020

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

0700 AM     SNOW             CHESTER                 40.30N 121.23W
03/25/2020  M4.5 INCH        PLUMAS             CA   PUBLIC

            SPOTTER REPORTED 4.5 INCHES OF SNOW
            ACCUMULATION.

&&
Local storm report, May 28, 1:02 PM PST, 2 hours 58 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
202 PM PDT THU MAY 28 2020

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

0700 AM     SNOW             LONG BARN               38.09N 120.13W
03/25/2020  M2.0 INCH        TUOLUMNE           CA   DEPT OF HIGHWAYS

            CALTRANS REPORTED 2 INCHES OF SNOW
            ACCUMULATION.

&&
Local storm report, May 28, 1:03 PM PST, 2 hours 57 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
203 PM PDT THU MAY 28 2020

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

0700 AM     SNOW             4 WSW TAMARACK          38.41N 120.13W
03/25/2020  M4.0 INCH        CALAVERAS          CA   DEPT OF HIGHWAYS

            CALTRANS REPORTED 4 INCHES OF SNOW
            ACCUMULATION AT THE CABBAGE PATCH
            MAINTENANCE YARD.

&&
Local storm report, May 28, 1:04 PM PST, 2 hours 56 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
204 PM PDT THU MAY 28 2020

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

0800 AM     SNOW             PACIFIC HOUSE           38.76N 120.50W
03/25/2020  M2.0 INCH        EL DORADO          CA   TRAINED SPOTTER

            SPOTTER REPORTED 2 INCHES OF SNOW
            ACCUMULATION.

&&
Local storm report, May 28, 1:19 PM PST, 2 hours 41 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SACRAMENTO CA
219 PM PDT THU MAY 28 2020

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

0235 PM     FUNNEL CLOUD     1 NW ROSEVILLE          38.77N 121.31W
05/18/2020                   PLACER             CA   PUBLIC

            A MEMBER OF THE PUBLIC SENT PICTURES AND
            VIDEO OF WHAT APPEARS TO BE A POSSIBLE
            FUNNEL CLOUD. THE PERSON LOOKED TO BE NEAR
            PLEASANT GROVE AND WAS LOOKING TO THE
            SOUTHEAST, ABOUT 10 MILES FROM ROSEVILLE.
            LOCATION IS NOT APPROXIMATE.

&&

Event by event

1 cold/wind chill. Local standard time, as filed.

Cold/Wind Chill, Motherlode/Camptonville to Groveland

When
May 28, 4:00 PM PST to 4:10 PM PST
Where
Motherlode/Camptonville to Groveland forecast zone
Deaths
0 direct, 3 indirect
Reported by
Law Enforcement

Three men went missing after being swept into the Cosumnes River in El |Dorado County on Thursday. The El Dorado County Sheriff’s Office said |at around 4pm a caller reported seeing the men get swept into the river and disappear. Sheriff’s deputies, a dive team, a helicopter, and multiple fire and rescue crews all assisted in the search on Thursday but were unsuccessful. The sheriff office advised the three were still missing, and that it was too dangerous now to attempt to dive for the bodies. Waterways were running cold and fast.The bodies were recovered days later.

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

EventDateAgeSexWhereKind
Cold/Wind Chill, Motherlode/Camptonville to Groveland2020-05-2824MaleIn WaterIndirect
Cold/Wind Chill, Motherlode/Camptonville to Groveland2020-05-28MaleIn WaterIndirect
Cold/Wind Chill, Motherlode/Camptonville to Groveland2020-05-28MaleIn WaterIndirect

What these are

Cold/Wind Chill
Cold or wind chill below warning criteria that caused deaths, injuries or damage.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in California in 2020Every state in 2020This day in weather historyWarnings in California, May 2020

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 898115.