WFO Denver/Boulder


PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BOULDER CO
ISSUED BY NATIONAL WEATHER SERVICE PUEBLO CO
600 AM MDT WED OCT 26 2011

HIGH WINDS ARE A MAJOR THREAT IN COLORADO DURING THE WINTER.

GOVERNOR JOHN HICKENLOOPER HAS PROCLAIMED THIS WEEK THROUGH OCTOBER 29TH
AS WINTER WEATHER PREPAREDNESS WEEK IN COLORADO.  THIS IS THE
TIME TO REVIEW WINTER WEATHER PREPAREDNESS PLANS.

THE TWO MAIN CAUSES OF HIGH WINDS IN COLORADO DURING THE COLD SEASON
ARE THE AIR PRESSURE DIFFERENCE BETWEEN STRONG LOW PRESSURE AND
COLD HIGH PRESSURE SYSTEMS...AND CHINOOK WINDS DEVELOPING ALONG THE
FRONT RANGE AND MOUNTAINS ACROSS THE EASTERN HALF OF THE STATE.

A STRONG LOW PRESSURE SYSTEM IN COLORADO...COUPLED WITH A HIGH
PRESSURE SYSTEM TO THE WEST...CAN SEND A COLD WIND...KNOWN AS A BORA...
THROUGH THE WESTERN PART OF THE STATE AND DOWN THE SLOPES OF THE  
EASTERN MOUNTAINS.  THE RESULT CAN BE WIDESPREAD HIGH WINDS FROM 
THE WEST OR NORTHWEST INTO THE ADJACENT PLAINS AT SPEEDS WHICH CAN
OCCASIONALLY EXCEED 100 MPH. THE DAMAGE CAUSED BY THIS EVENT CAN 
POTENTIALLY BE MUCH MORE WIDESPREAD THAN DAMAGE CAUSED BY A LOCALIZED
SEVERE THUNDERSTORM IN THE WARM SEASON.

MID AND UPPER LEVEL WINDS OVER COLORADO ARE MUCH STRONGER IN THE WINTER 
THAN IN THE WARM SEASON...BECAUSE OF THE HUGE DIFFERENCE IN
TEMPERATURE FROM NORTH TO SOUTH ACROSS NORTH AMERICA.  WEST WINDS...
UNDER CERTAIN CONDITIONS...CAN BRING WARM...DRY CHINOOK WINDS PLOWING 
DOWN THE SLOPES OF THE EASTERN MOUNTAINS. THESE WINDS CAN EXCEED 
100 MPH IN EXTREME CASES...BRINGING THE POTENTIAL FOR WIDESPREAD 
DAMAGE.  WINDS OF 60 TO NEAR 100 MPH ARE POSSIBLE IN AND NEAR THE FOOTHILLS 
IN THE FORT COLLINS...BOULDER...DENVER...COLORADO SPRINGS...CANON CITY...
WESTCLIFFE...WALSENBURG AND TRINIDAD AREAS. THE AREAS AROUND BOULDER AND 
WESTCLIFFE ARE ESPECIALLY PRONE TO THESE EXTREME WIND EVENTS. 

DANGERS FROM HIGH WINDS INCLUDE FLYING DEBRIS...COLLAPSED
STRUCTURES...AND OVERTURNED VEHICLES.  THE NATIONAL WEATHER
SERVICE WILL ISSUE A HIGH WIND WATCH WHEN THERE IS A 50 PERCENT OR 
GREATER CHANCE FOR HIGH WINDS TO DEVELOP DURING THE NEXT DAY OR TWO.  
WHEN THE THREAT BECOMES MORE CERTAIN IN A SPECIFIC AREA...A HIGH WIND 
WARNING WILL BE ISSUED.  COLD STRONG WINDS CAN ALSO BRING DANGEROUSLY 
LOW WIND CHILL VALUES...PROMPTING A WIND CHILL ADVISORY OR WIND CHILL 
WARNING.

IF HIGH WINDS ARE FORECAST FOR YOUR AREA...IT IS A GOOD IDEA TO
BRING LIGHTWEIGHT OBJECTS INDOORS...OR TIE THEM DOWN OR MOVE THEM
SO THEY DO NOT BECOME DANGEROUS MISSILES.  ANY DOWNED POWER LINES 
SHOULD NOT BE APPROACHED...INSTEAD CALL THE UTILITY COMPANY.  
STAY CLEAR FROM BUILDINGS UNDER CONSTRUCTION DURING HIGH WINDS.  
THEY CAN EASILY COLLAPSE.  TRAVELING ON NORTH SOUTH ROADS NEAR THE 
MOUNTAINS ALONG THE FRONT RANGE DURING A HIGH WIND EVENT CAN ALSO BE 
DANGEROUS.  IF YOU DRIVE A LIGHTWEIGHT OR HIGH PROFILE VEHICLE...YOU 
MAY WANT TO WAIT UNTIL THE HIGH WINDS DIE DOWN.


TOM MAGNUSON
WARNING COORDINATION METEOROLOGIST
NATIONAL wEATHER SERVICE  PUEBLO COLORADO

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