California, 2021Cold in California, May 9 to 14, 2021
May 9 to 14, 2021 · NWS STO · 2 events in 2 counties and zones
Warm weather combined with cold and fast moving area waterways lead to 5 deaths across the region in the month of May.
- Deaths
- 3
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 2
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.
Warm weather combined with cold and fast moving area waterways lead to 5 deaths across the region in the month of May.
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 9, 1:58 PM PST, 2 hours 47 minutes earlier.
Area forecast discussion, May 9, 1:58 PM PST, 2 hours 47 minutes before
Area Forecast Discussion
National Weather Service Sacramento CA
258 PM PDT Sun May 9 2021
.SYNOPSIS...
Dry weather with gusty north winds and critical fire weather
conditions through the early part of this week. Warming trend
develops through mid-week.
&&
.DISCUSSION...
We continue to sit between troughing to our east and building high
pressure off the coast. This is keeping the surface pressure
gradient up and right now we are seeing a +8-9 mb gradient from
MFR-SAC. That is resulting in 20-35 mph gusts with the strongest
gusts on the west side of the Valley. A short wave trough passing
just to the east of the Sierra crest is bringing a few high
clouds the area, otherwise most sunny skies. Highs are on track to
be similar to yesterday.
The amplified upper air pattern will continue into early this
week. Northwest flow aloft will continue to support the strong
surface gradient resulting in breezy north to east winds across
the area through Monday. Combined with the low RH, red flag
conditions will persist. Winds will decrease later Monday, but
breeziness will linger into Tuesday keeping critical fire weather
conditions in place.
Highs will be on a warming trend starting tomorrow as the upper
level ridge slowly pushes east. We should see most Valley
locations reach the lower 90s tomorrow with widespread mid 90s for
the Valley Tuesday and Wednesday as we sit under the apex of the
ridge. We should see a Delta breeze develop on Wednesday and that
will bring some relief to the Delta and eventually the Sacramento
area from the hot temperatures during the late afternoon and
evening.
-CJM
&&
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)...
EPAC upper ridge remains dominant synoptic feature over interior
NorCal Thursday into Friday continuing above normal temperatures.
Highs expected to be 10 to 20 degrees above normal. Short wave
trough approaches over the weekend with forecast uncertainties due
to varying model solutions on the depth and progression.
Ensembles forecast trending towards a deeper trough, with onshore
flow and cooling temperatures. The NBM POP forecast over the
Sierra has trended a little higher over the Sierra, but currently
continues to look dry.
&&
.AVIATION...
VFR conditions over interior NorCal next 24 hrs with N-E surface
wind gusts 25 to 35 kts, locally stronger in the
foothills/mountains. Winds will diminish some after 02Z Mon and
become more widespread after 14z Mon. Areas of LLWS after 04Z Mon.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 6 PM PDT Tuesday for Carquinez Strait and
Delta-Central Sacramento Valley in Glenn, Colusa, Yuba, Northern
Sutter, and Butte County Below 1000 Ft-Eastern Mendocino NF-
Northern Sacramento Valley to Southern Tehama County Line Below
1000 Ft-Northern San Joaquin Valley in San Joaquin and
Stanislaus Counties Below 1000 ft-Southeast Edge Shasta-Trinity
NF and Western Portions of Tehama-Glenn Unit-Southern Sacramento
Valley in Yolo-Sacramento Far Western Placer, southern Sutter
and Solano County Below 1000 Ft.
Red Flag Warning until 6 PM PDT Monday for Eastern Portion of
Shasta/Trinity NF-Northern Motherlode From 1000 to 3000 Ft.
Includes portions of Nevada-Yuba-Placer-Amador and ElDorado
Units-Northern Sierra Foothills from 1000 to 3000 Ft. Includes
portions of Shasta-Trinity and Butte Units-Southern Motherlode
From 1000 to 3000 Ft. Includes portions of Calaveras-Tuolumne
Unit.
&&
Cold/Wind Chill, Northern San Joaquin Valley
- When
- May 9, 4:45 PM PST
- Where
- Northern San Joaquin Valley forecast zone
- Deaths
- 1 direct, 0 indirect
- Reported by
- Newspaper
A four year male child drowned at Lake Lodi. Life saving efforts were made but the child died at the hospital. Cause of death has yet to be determined, eg cold water, lack of life jacket, etc. Warm weather was occurring over northern California on May 9th with highs in the region in the upper 80s. Water temperatures at the Mukolumne River Bridge CNRFC Site (near Lake Lodi) reported a water temperature of 65 degrees on 5/11.
Cold/Wind Chill, West Slope Northern Sierra Nevada
- When
- May 14, 12:00 AM PST
- Where
- West Slope Northern Sierra Nevada forecast zone
- Deaths
- 2 direct, 0 indirect
- Reported by
- Newspaper
Tuolumne County Sheriff has confirmed two deaths at Gods Bath Swimming Hole along the Clavey River in Stanislaus National Forest. Originally reported as 3 victims in the search and rescue, 2 were then confirmed deceased and one is recovering. Appears to be cold-water / swift-water related, as water temperatures are in the 50s/60s, according to near-by gages on the California-Nevada River Forecast Center water temp map.
- 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.
- Flash Flooding and Hail in Texas, May 9 to 10, 20211 death · 61 kt wind · 31 events
- Tornado and Damaging Wind in Tennessee, May 9, 20211 injured · $200,000 · EF1 · 3 events
- Wildfire in Florida, May 9, 2021$810,000 · 1 event
- Hail and Damaging Winds in New Mexico, May 9, 2021$135,000 · 1 in hail · 5 events
- Flooding and Hail in Missouri, May 9, 2021$52,000 · 1.75 in hail · 23 events
- Damaging Winds in Mississippi, May 9, 2021$108,000 · 55 kt wind · 6 events
- Hail and Damaging Winds in Texas, May 9, 2021$65,000 · 1.75 in hail · 13 events
- Flooding in Ohio, May 9 to 15, 2021$47,000 · 19 events
- Strong Wind in West Virginia, May 9, 2021$35,000 · 3 events
- Tornado and Hail in Arkansas, May 9, 2021$25,000 · EF0 · 2 events
- Hail in Texas, May 9 to 10, 20212.75 in hail · 20 events
- Hail and Damaging Winds in Mississippi, May 9, 2021$4,000 · 50 kt wind · 19 events
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: 962402, 962404.