Flood in California, May 14 to 21, 2006

Name: Flood in California, May 14 to 21, 2006
Start: 2006-05-14T22:15
End: 2006-05-21T11:30
Location: California

May 14 to 21, 2006 · NWS HNX · 1 event in 1 county or zone

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
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 HNX wrote it up.

Encouraged by a dramatic warming to much above normal temperatures in mid-May, snowmelt resulted in the Merced River rising to and above Flood Stage diurnally from late in the evening of the 14th to the morning of the 21st. Generally the river rose above Flood Stage at Pohono Bridge Gaging Station in the very late evening hours and dropped below Flood Stage at dawn with an average change in the peak-to-lull of close to a foot per day. Other Southern Sierra Nevada and Tulare County Mountain rivers also ran high during this period from the much above normal winter snowpack (169% in the S.Sierra Nevada and 175% in the Tulare County Mountains). The runoff into the Kings River placed Pine Flat Reservoir at the 95% storage capacity at one point as the river below the dam handled releases at river capacity while inflow was still exceeding that river capacity.

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 Hanford, CA wrote its last area forecast discussion before the first event at May 14, 8:38 PM PST, 1 hour 37 minutes earlier.

Area forecast discussion, May 14, 8:38 PM PST, 1 hour 37 minutes before

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
938 PM PDT SUN MAY 14 2006

.UPDATE...
UPPER LEVEL MOISTURE CONTINUES TO STREAM IN ACROSS THE AREA.
MOISTURE IS NOT REAL DEEP AND PRECIP CHANCES ARE SLIM TO NONE.
HOWEVER WITH STRONG UPPER LEVEL LIFT ASSOCIATED WITH UPPER VORT
MAX MOVING THROUGH THE AREA. WILL KEEP IN SLIGHT CHANCE OF SHOWERS
AND POSSIBLY A THUNDERSTORM. MODELS ARE MOVING THIS FEATURE
NORTH AND THE RIDGE IS BUILDING IN OVER THE AREA ON TUESDAY AND
WEDNESDAY. THIS WILL ALLOW THINGS TO WARM UP AND WOULD EXPECT SOME
ISOLATED THUNDER ALONG THE SIERRA CREST EACH DAY. CROSS SECTIONS
INDICATE MOISTURE WILL BE DEEPER IN THE NW PORTION OR THE CWA. HAVE
BUMPED UP POPS ALONG THE MOUNTAINS TO BE IN BETTER AGREEMENT WITH
SURROUNDING FORECAST OFFICES.

WE ARE EXPECTING POHONO BRIDGE TO FLOOD OVERNIGHT TONIGHT. IT IS
RUNNING ABOUT .2 FEET HIGHER THAN THIS TIME LAST NIGHT. LAST
NIGHT IT CAME VERY CLOSE TO FLOOD STAGE...SO FLOODING LOOK VERY
PROBABLE TONIGHT.

&&

.PREV DISCUSSION... (ISSUED 235 PM PDT SUN MAY 14 2006)

SHORT TERM...HIGH CLOUDS ARE BEGINNING TO MOVE ONSHORE AS THE
TROPICAL MOISTURE ARRIVES. THUS FAR, SKIES HAVE BEEN SUNNY AND
TEMPERATURES ARE RUNNING WARMER OVER THE MOUNTAINS, HOWEVER OVER
THE SAN JOAQUIN VALLEY AND KERN DESERT AREAS, LINGERING EFFECTS OF
MARINE AIR IS KEEPING TRENDS DOWN FROM 2-3 DEGREES OVER SATURDAY.
AS STATED THIS MORNING, THE MAIN FORECAST CHALLENGE IN THE SHORT
TERM IS WHETHER THUNDERSTORMS WILL DEVELOP OR NOT FROM THE
INCOMING TROPICAL MOISTURE FETCH AND SHORTWAVE TROUGH. THUS FAR
THE SYSTEM IS HOLDING TOGETHER PRETTY WELL AND LATEST VISIBLE
IMAGERY SHOWS A CONTINUED CELLULAR APPEARANCE NEAR THE VORTICITY
CENTER WHICH IS NOW AROUND 350 MILES SOUTHWEST OF POINT
CONCEPTION. ALTHOUGH NOT TOO GREAT, I FEEL THERE IS A REAL THREAT
OF ISOLATED THUNDERSTORMS BEGINNING AFTER MIDNIGHT TONIGHT FROM
KERN COUNTY NORTHWARD AS THE SHORTWAVE, VORTICITY CENTER AND
DEEPEST MOISTURE ARRIVE OVERNIGHT AND MONDAY MORNING. LATEST RUN
OF THE NAM12 MODEL SHOWS LOTS OF INSTABILITY MONDAY OVER THE AREA
AND AT THE MINIMUM, SKIES WILL BE PARTLY CLOUDY. MODELS PUSH THE
SHORTWAVE AND DEEPEST MOISTURE OFF TO THE NORTHEAST ON MONDAY
NIGHT AND THEN BUILD IN A STRONG ANTICYCLONE (HIGH PRESSURE
CENTER) OVER THE GREAT BASIN AND NORTHERN MEXICO FOR TUESDAY AND
WEDNESDAY. SHOULD SEE THE WARMEST TEMPERATURES OF THE YEAR BY
WEDNESDAY WITH A FEW LOCATIONS SEEING THE FIRST 100 DEGREE
READINGS OF THE YEAR.

CONCERNING MELTING SNOW PACK AND THE FLOODING ALONG THE MERCED
RIVER IN YOSEMITE, TONIGHTS CLOUDS SHOULD KEEP MINIMUM
TEMPERATURES IN THE SNOW COVERED REGIONS HIGHER THAN THE PAST FEW
NIGHTS. THIS COMBINED WITH THE WARMING FROM THE BUILDING RIDGE
WILL LIKELY INCREASE SNOW MELT RATES FOR THE NEXT FEW DAYS. HAVE
ISSUED A RIVER FLOOD WARNING FOR THE MERCED AT POHONO BRIDGE IN
YOSEMITE BASED ON LAST NIGHTS FLOW AND THE EXPECTED INCREASE IN
SNOW MELT. WILL NEED TO KEEP A WATCH ON ANY THUNDERSTORM
DEVELOPMENT OVER THE WATERSHED AS THIS WOULD EXACERBATE THE
SITUATION WITH INCREASED FLOW.

LONG TERM...FOR WEDNESDAY NIGHT THROUGH SUNDAY...MEDIUM RANGE
MODELS IN GOOD AGREEMENT INDICATING WARM AND DRY CONDITIONS
CONTINUING EARLY IN THE PERIOD THEN A GRADUAL COOLING OFF FOR THE
WEEKEND. A STRONG RIDGE OVER THE WESTERN U.S WILL PROVIDE DRY
CONDITIONS AND ABOVE NORMAL TEMPERATURES INTO THURSDAY.
EXCEPT FOR THE CANADIAN GEM, MOST MODELS PROG FOR THE RIDGE TO
WEAKEN AND FLATTEN AS SHORT WAVE ENERGY MOVES THROUGH BRITISH
COLOMBIA, WHILE AN UPPER TROF MEANDERING OVER THE EASTERN
PACIFIC EDGES CLOSER TO THE WEST COAST. THIS WILL LEAD TO AN
INCREASING SOUTHWEST FLOW ALOFT WHICH WILL BRING COOLER MARITIME
AIRMASS INTO NORTH AND CENTRAL CALIFORNIA FOR THE WEEKEND.
THE WARM TEMPERATURES WILL KEEP THE CONCERN OF HIGH...FAST AND
COLD RUNNING RIVERS AND STREAMS DUE TO MELTING SNOW AT A HEIGHTEN
STATE OF CAUTION.

AVIATION...LIGHTNING ACTIVITY WILL BE POSSIBLE AFTER 07Z MONDAY AS
AN UPPER LEVEL DISTURBANCE AND SUB TROPICAL MOISTURE MOVES ONSHORE
TONIGHT. ANY THUNDERSTORMS THAT DEVELOP ARE EXPECTED TO BE DRY OR
PROVIDE LITTLE RAINFALL AS AVAILABLE MOISTURE WILL BE LIMITED TO THE
MID AND UPPER LEVELS OF THE ATMOSPHERE. OTHERWISE VFR CONDITIONS
ARE EXPECTED THROUGH 00Z TUESDAY. FOR SPECIFIC DETAILS...PLEASE
REFER TO TAFS FOR KMCE...KFAT
AND KBFL.

.HNX WATCHES/WARNINGS/ADVISORIES...
FLOOD WARNING FOR POHONO BRIDGE CAC043 (SEE SFOFLWUSJ).

&&

PUBLIC...JDB
AVIATION...DS

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 flood. Local standard time, as filed.

Flood, Mariposa

When: May 14, 10:15 PM PST to May 21, 11:30 AM PST
Where: Mariposa County, 1 mi ESE of Yosemite Vlg
Reported by: OFFICIAL NWS OBS.
Coordinates: 37.582, -119.905 (the zone’s center; the record gives no point)

What these are

Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

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

The same day elsewhere

Every storm in California in 2006 Every state in 2006 This day in weather history Warnings in California, May 2006

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: 5509837.