Public Information Statement
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
NOUS45 KBOU 151149
PNSBOU

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
548 AM MDT WED APR 15 2015

...FLASH FLOOD SAFETY...

ONLY TWO YEARS AGO MAJOR FLOODING IN SEPTEMBER RESULTED FROM OVER EIGHT
INCHES OF RAIN THAT FELL OVER A LARGE AREA FROM NORTHERN JEFFERSON COUNTY
TO THE WYOMING BORDER. THIS RAIN CAUSED FLASH FLOODING IN A NUMBER OF
CREEKS AND RIVERS...CAUSING CONSIDERABLE FLASH FLOODING. RUNOFF FROM
AREA STREAMS COMBINED TO CAUSE MAJOR FLOODING ALONG THE SOUTH PLATTE
RIVER. MITIGATION IS STILL ONGOING REPAIR FLOOD DAMAGE ALONG THE STREAMS
AND RIVERS IN AND NEAR THE FOOTHILLS FROM LARIMER COUNTY TO EL PASO
COUNTY AND ALONG THE TRIBUTARIES TO THE SOUTH PLATTE RIVER.

FLASH FLOODING REFERS TO A DANGEROUS SUDDEN RISE IN WATER ALONG A CREEK
...RIVER...OR A NORMAL DRY LAND AREA. FLASH FLOODS RESULT FROM HEAVY
RAINFALL...SUDDEN BREAKS IN RIVER ICE JAMS...AND DAM OR LEVEE FAILURES.
FLASH FLOODS CAN OCCUR WITHIN A FEW MINUTES OR HOURS...AND CAN MOVE AT
SURPRISINGLY HIGH SPEEDS...STRIKING WITH LITTLE WARNING. FLASH FLOODS
ARE QUITE DESTRUCTIVE BECAUSE OF THE FORCE OF THE MOVING WATER...AND THE
DEBRIS THAT ACCUMULATES IN FLOOD WATERS...SUCH AS TREES AND BOULDERS...
WHICH CAN DESTROY ROADWAYS...BRIDGES...AND BUILDINGS.

OTHER COMPLICATIONS IN COLORADO ARE RECENT FIRES WHICH RAISE THE FLOOD
THREAT WHEN LOCALLY HEAVY RAIN FALLS ON RECENTLY BURN SCARS. RESIDENTS
IN AND NEAR BURNED AREAS NEAR MANCOS...DEBEQUE OR IN THE FRONT RANGE
FOOTHILLS FROM LARIMER TO EL PASO COUNTIES SHOULD PLAN AHEAD ON RESPONSE
ACTIONS FOR FLOODING.

THE NATIONAL WEATHER SERVICE WILL DISCUSS FLOOD AND FLASH FLOOD POTENTIAL
IN DAILY HAZARDOUS WEATHER OUTLOOKS AND IN THE WEATHER STORY ON NATIONAL
WEATHER SERVICE WEBSITES. ON DAYS WITH A HIGH THREAT OF FLOODING YOU MAY
HEAR...

A FLASH FLOOD OR FLOOD WATCH...WHICH MEANS THAT FLASH FLOODING OR
FLOODING IS POSSIBLE WITHIN THE WATCH AREA.

A FLOOD WARNING...WHICH MEANS THAT FLOODING IS IMMINENT OR HAS BEEN
REPORTED ALONG A RIVER.

A FLASH FLOOD WARNING...WHICH MEANS THAT FLASH FLOODING HAS BEEN REPORTED
OR IS IMMINENT.

WHEN A FLASH FLOOD WARNING IS ISSUED FOR YOUR AREA...ACT QUICKLY. IF
ADVISED TO EVACUATE...DO SO IMMEDIATELY. GO TO HIGHER GROUND OR
CLIMB TO SAFETY BEFORE ACCESS IS CUT OFF BY FLOOD WATERS. AN URBAN
FLOOD ADVISORY WILL BE ISSUED FOR IMPACT FLOODING THAT IS NOT IN
ITSELF LIFE THREATENING.

IN AN URBAN AREA IF YOU WERE COMMUTING
DURING RUSH HOUR DURING A FLOOD ADVISORY YOU COULD EXPECT SOME
INTERSECTIONS TO BE UNDER WATER AND A MUCH LONGER COMMUTE. A SMALL
STEAM FLOOD ADVISORY MIGHT BE ISSUED WHEN FLOW IS BANKFULL WITH
MINOR FLOODING ALONG THE STREAM.

NEARLY HALF OF ALL FLASH FLOOD FATALITIES ARE VEHICLE RELATED. DO
NOT ENTER A FLOODED ROADWAY...INSTEAD TURN AROUND DO NOT DROWN. IN
RAPIDLY RISING WATERS...BACKING UP AWAY FROM WATER MAY BE SAFER. ONE
OR TWO FEET OF WATER WILL CARRY AWAY MOST VEHICLES AND YOU ALSO
CANNOT TELL IF THE ROAD IS DAMAGED BENEATH MOVING WATER.

COLORADO SEVERE WEATHER PREPAREDNESS WEEK CONTINUES THROUGH THIS
SATURDAY.


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.