Flood Potential Outlook
Issued by NWS Sacramento, CA

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HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE SACRAMENTO CA
103 PM PST THU MAR 3 2016

...LOW SNOWMELT FLOOD POTENTIAL EXPECTED FOR CALIFORNIA THIS
SPRING...

THE POTENTIAL FOR FLOODING IN CALIFORNIA DUE TO THE SPRING SNOWMELT
IS LOW AT THIS TIME AT ALL FORECAST POINTS.  LONG-RANGE HYDROLOGIC
ENSEMBLE FORECASTS CURRENTLY INDICATE A 25% OR LESS CHANCE OF
PRODUCING FLOODING.  NOTE THAT FLOODING COULD STILL RESULT FROM
HEAVY RAINFALL ALONE, OR COMBINED WITH SNOWMELT ANYTIME DURING THE
SPRING.

APART FROM THE SPRING SNOWMELT, SHORTER RANGE ATMOSPHERIC MODELS ARE
CURRENTLY INDICATING ABOVE NORMAL PRECIPITATION DURING THE FIRST
HALF OF MARCH,INCREASING THE LIKELIHOOD OF RAIN DRIVEN FLOODING AT
MANY LOCATIONS IN CALIFORNIA OVER THE NEXT COUPLE OF WEEKS.  THE
ADDITIONAL SNOWPACK THAT IS EXPECTED OVER THE NEXT COUPLE OF WEEKS
WILL INCREASE THE CHANCES OF SPRING SNOWMELT FLOODING.

CURRENT BASIN CONDITIONS

SNOWPACKS

- ABOVE AVERAGE OVER THE UPPER CA PORTIONS OF THE KLAMATH RIVER AND
  PIT RIVER IN THE UPPER SACRAMENTO BASIN
- NEAR AVERAGE OVER HIGHER ELEVATIONS OF THE NORTHERN, CENTRAL,AND
 SOUTHERN SIERRA CARSON AND WALKER RIVER DRAINAGES IN THE EAST SIERRA

SEASONAL PRECIPITATION

- NEAR TO ABOVE AVERAGE ACROSS THE CA PORTIONS OF THE KLAMATH
- NEAR AVERAGE OVER MOST OF THE SACRAMENTO AND SAN JOAQUIN BASINS
- NEAR TO ABOVE AVERAGE ACROSS THE WALKER AND CARSON BASINS ON THE
  EAST SIDE OF THE SIERRA

SEASONAL (APRIL-JULY) RUNOFF FORECASTS

- NEAR TO ABOVE AVERAGE OVER THE KLAMATH
- NEAR TO SLIGHTLY BELOW AVERAGE OVER MOST OF THE SACRAMENTO RIVER
  BASIN
- NEAR AVERAGE OVER THE SAN JOAQUIN AND TULARE BASINS
- NEAR TO SLIGHTLY ABOVE AVERAGE OVER THE CARSON AND WALKER RIVER
  BASINS

RESERVOIR STORAGE

STORAGE LEVELS IN MOST MAJOR RESERVOIRS IN CA ARE CURRENTLY BELOW TO
MUCH BELOW AVERAGE, WITH FOLSOM LAKE ON THE AMERICAN RIVER ONE OF
THE FEW PROMINENT EXCEPTIONS WITH ABOVE AVERAGE CONTENTS.

                              AVERAGE                   CAPACITY
TRINITY                         47%                       35%
SHASTA                          84%                       61%
OROVILLE                        78%                       52%
FOLSOM                          112%                      62%
NEW MELONES                     32%                       19%
NEW DON PEDRO                   63%                       46%
MILLERTON                       80%                       51%
PINE FLAT                       54%                       27%
ISABELLA                        23%                        8%

FLOOD EXCEEDANCE PROBABILITIES

CONSULT THE AHPS LONG RANGE FLOOD RISK MAP FOR THE LATEST POINT
EXCEEDANCE PROBABILITIES:
HTTP://WATER.WEATHER.GOV/AHPS/LONG_RANGE.PHP?PERCENT=10

WHILE FORECASTS ARE TRENDING HIGHER FOR SEASONAL RUNOFF VOLUMES AND
PEAKS DUE TO STORMS EXPECTED TO IMPACT THE STATE OVER THE NEXT TWO
WEEKS, LONG-RANGE HYDROLOGIC ENSEMBLE FORECASTS CURRENTLY INDICATE A
RELATIVELY LOW POTENTIAL FOR RIVER FLOWS TO EXCEED FLOOD STAGE DUE
TO THE SPRING SNOWMELT.

AT THIS TIME, SNOWMELT BASINS IN THE KLAMATH, SACRAMENTO, SAN
JOAQUIN AND TULARE RIVER BASINS ARE SHOWING A 25% OR LESS CHANCE
OF FLOODING AT THIS TIME. PROBABILITIES FOR EXCEEDING FLOOD STAGE
AT SPECIFIC FORECAST POINTS INCLUDE:

SCOTT RIVER NR FT. JONES, CA:                         <10%
FEATHER RIVER AT PORTOLA, CA:                         <10%
SUSAN RIVER AT SUSANVILLE, CA:                        <10%
MERCED RIVER AT POHONO BRIDGE, CA:                    <30%
WEST FK. CARSON RIVER AT WOODFORDS, CA:               <10%
WEST WALKER RIVER NR COLEVILLE, CA:                   <10%

MOST PROBABLE DATES FOR PEAK DAILY DISCHARGE RANGE FROM MID APRIL TO
LATE MAY OVER THE ENTIRE CA REGION.  MOST PROBABLE PEAK FLOW DATES
FOR SUB-REGIONS ARE AS FOLLOWS:

* MID TO LATE APRIL OVER THE UPPER SACRAMENTO RIVER BASIN AND NORTHERN SIERRA
* MID TO LATE MAY OVER THE SAN JOAQUIN AND TULARE BASINS IN THE SOUTHERN SIERRA
* MID TO LATE MAY OVER PORTIONS OF THE KLAMATH BASIN AND
* LATE MAY OVER THE HIGHER ELEVATIONS OF THE WALKER AND CARSON DRAINAGES OF THE EAST SIERRA

SUMMARY

THE CURRENT FORECAST CALLS FOR PROBABILITIES OF 25% OR LESS FOR
SNOWMELT FLOODING AT FORECAST POINTS IN CA. THIS FORECAST IS
CURRENTLY TRENDING HIGHER DUE TO STORMS EXPECTED ACROSS THE REGION
OVER THE NEXT TWO WEEKS. HYDROLOGIC ENSEMBLE FORECASTS ARE UPDATED
ON A DAILY BASIS AND USERS ARE ADVISED TO CHECK THE NATIONAL AHPS
AND THE LOCAL CNRFC WEB SITES FOR THE LATEST INFORMATION.

FOR LONG RANGE OUTLOOK FLOOD POTENTIAL PLEASE REFER TO THE AHPS
LONG RANGE OUTLOOK PRODUCT AT:
HTTP://WATER.WEATHER.GOV/AHPS/LONG_RANGE.PHP

FOR SHORT-TERM HYDROLOGIC FORECASTS, PLEASE SEE THE AHPS PAGES
AT: NORTHERN CALIFORNIA:
HTTP://WATER.WEATHER.GOV/AHPS2/FORECASTS.PHP?WFO=STO SOUTHERN
SIERRA: HTTP://WATER.WEATHER.GOV/AHPS2/FORECASTS.PHP?WFO=HNX

FOR GENERAL WATER RESOURCE INFORMATION PLEASE REFER TO THE CNRFC
PAGE AT: HTTP://WWW.CNRFC.NOAA.GOV/WATER_RESOURCES_UPDATE.PHP

$$
CNRFC/BW
WFO/CM



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