Heat in California, July 10 to 12, 2002

Name: Heat in California, July 10 to 12, 2002
Start: 2002-07-10T12:00
End: 2002-07-12T18:00
Location: California

July 10 to 12, 2002 · NWS EKA · 3 events in 3 counties and zones

Record setting heat occurred on three consecutive days across the interior of northwest California. Ukiah set a record on the 10th of 110 degrees.

The toll

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

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 EKA wrote it up.

Record setting heat occurred on three consecutive days across the interior of northwest California. Ukiah set a record on the 10th of 110 degrees. A few other locations and peak temperatures: Weaverville 115, Laytonville 111, and Big Bar 114.

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 Eureka, CA wrote its last area forecast discussion before the first event at Jul 10, 7:45 AM PST, 4 hours 15 minutes earlier.

Area forecast discussion, Jul 10, 7:45 AM PST, 4 hours 15 minutes before

NORTHWEST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
845 AM PDT WED JUL 10 2002

STRONG UPPER RIDGE CONTINUES TO DOMINATE WEATHER PICTURE OVER MUCH
OF THE WEST...WITH RECORD HIGH TEMPERATURES EXPECTED TO EXPAND
NORTHWARD INTO THE INTERIOR VALLEYS OF CA BY THIS AFTERNOON. 500MB
HEIGHTS RISING TO AROUND 597DM AND 850MB TEMPS OVER 30C WILL HELP
THE MERCURY SOAR TO NEAR 115F IN THE HOTTEST SPOTS. HEAT ADVISORY
ISSUED OVERNIGHT WILL STAND...EVEN THOUGH CONTRIBUTION FROM RELATIVE
HUMIDITY LEVELS WILL BE MINIMAL. MORNING SOUNDINGS AND PROFILERS
SHOW CONTINUED WARMING ALOFT...YET AT A SLOWER PACE THAN 24 HOURS
AGO. SHALLOW MARINE INVERSION HAS RETURNED TO THE COAST WITH
EXTENSIVE STRATUS IN ZONE 1 AND THE NEAR SHORE COASTAL WATERS. SOME
COOLING ACROSS INTERIOR PARTS OF DEL NORTE COUNTY DUE TO THE SLIGHT
MARINE INFLUX MAY KEEP TEMPS A TAD COOLER IN A FEW SPOTS...BUT
OTHERWISE JUST AS HOT OR HOTTER AS YESTERDAY. COASTAL AREAS SHOULD
ALSO COME DOWN SLIGHTLY WITH MORNING CLOUDS...AND THEN PERHAPS AN
AFTERNOON SEA BREEZE BRINGING PATCHES OF LOW CLOUD BACK IN LATER.

THE STRONG RIDGE BEGINS TO MOVE SLOWLY EASTWARD BY THU WITH HEIGHTS
LOWERING A TAD. HOWEVER...LOW LEVEL THICKNESS AND TEMPERATURES EVEN
RISE A BIT SO AGAIN NO SIGNIFICANT COOLING THRU THU. MONSOONAL
MOISTURE ALONG WITH A VORT ROTATING AROUND THE RIDGE MAY PROMOTE
SOME ISOLATED CONVECTION (PERHAPS INITIALLY DRY) ALONG THE EASTERN
SPINE OF THE CWA BY LATE THU INTO FRI AS MID LEVEL FLOW TURNS
SOUTHEAST AHEAD OF THE INCOMING TROF. BEST SHOT AT STORMS SHOULD
HOLD OFF TIL FRI AS MORE MID LEVEL MOISTURE BECOMES ENTRAINED INTO
THE REGION AND MID LEVEL TEMPERATURES COOL INCREASING LAPSE RATES.

GALE WARNINGS POSTED FOR OUTER WATERS BEGINNING THIS AFTERNOON AS
THE THERMAL TROF INTENSIFIES. WILL MAKE ONLY COSMETIC CHANGES TO
MARINE PACKAGE AND LEAVE ALL WARNINGS/ADVISORIES IN PLACE. NO
CHANGES EXPECTED TO PUBLIC ZONES AT THIS TIME.

ALL POPS ZERO

SOROKA

.EKA...HEAT ADVISORY TODAY...CAZ003...CAZ004 AND CAZ076.
    ...SMALL CRAFT ADVISORY TIL THU NIGHT PZZ450 AND PZZ455.
    ...GALE WARNING TIL THU NIGHT PZZ470 AND PZZ475.

Event by event

3 heat. Local standard time, as filed.

Heat, Mendocino Interior

When: July 10, 12:00 PM PST
Where: Mendocino Interior forecast zone
Reported by: AWOS,ASOS,MESONET,ETC

Heat, North Coast Interior

When: July 10, 12:00 PM PST
Where: North Coast Interior forecast zone
Reported by: AWOS,ASOS,MESONET,ETC

Heat, Upper Trinity River

When: July 10, 12:00 PM PST to July 12, 6:00 PM PST
Where: Upper Trinity River forecast zone
Reported by: AWOS,ASOS,MESONET,ETC

What these are

Heat: Heat below excessive heat criteria that still caused deaths, injuries or significant impacts.

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

The same day elsewhere

Every storm in California in 2002 Every state in 2002 This day in weather history Warnings in California, July 2002

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: 5304505, 5304506, 5304507.