Urban Drainage and Flood Control DistrictUrban Drainage and Flood Control District

Early flash flood prediction, Early flash flood prediction, detection, notification & warning detection, notification & warning for the greater Denver/Boulder for the greater Denver/Boulder metropolitan area since 1979metropolitan area since 1979

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Buffalo Creek 19962 lives lost

Big Thompson 1976145 dead or lost

Cheyenne 198512 deaths Rapid City 1972

237 dead

Basic Elements of Warning Basic Elements of Warning PlanPlan

Early Early detection and evaluationdetection and evaluation of the threat of the threat

DisseminationDissemination of the warning of the warning

ResponseResponse by those at risk to the warning by those at risk to the warning

All three elements must function properly or All three elements must function properly or

the plan will fail.the plan will fail.

Early Detection & Early Detection &

EvaluationEvaluation

For flash flood threats this process For flash flood threats this process

needs to begin needs to begin beforebefore it rains for it rains for

the warning process to be truly the warning process to be truly

effective.effective.

Flood Threat Recognition

WeatherStationin Aurora

Rain Gage Maintenance

ALERT Stream Gage housed with USGS gaging station on South Platte River in Denver

Rain & Stream Gage at Ralston Reservoir in Jefferson County

ALERT Gaging ALERT Gaging StationsStationslocal vesting in the processlocal vesting in the process

Westerly &Westerly &Toll GateToll Gate

RalstonRalston

Boulder &Boulder &S. BoulderS. Boulder

LenaLena

BearBearGoldsmith/Harvard

Basin-specific flood warning plansBasin-specific flood warning plans

Denver/Boulder Area ALERT SystemDenver/Boulder Area ALERT Systemautomated real-time gage networkautomated real-time gage network

Flood Detection NetworksFlood Detection Networks1978 Boulder Creek1980 South Boulder Creek1982 Lena Gulch1986 Ralston Creek1987 Westerly Creek1988 Toll Gate Creek1989 Goldsmith/Harvard Gulch1989 Bear Creek1997 Douglas County

ALERT Stations & SensorsALERT Stations & Sensors124 Rain Gages 69 Stream Gages 15 Weather Stations 6 Repeaters 8 Base StationsThis extensive network includes This extensive network includes more than 260 sensors andmore than 260 sensors and145 stations.145 stations.

ALERT Users in ColoradoALERT Users in Colorado

Federa l State & Local Others

NWS CWCB & SEO News Media

NOAA/FSL Universities Meteorologists

NCAR Police & Fire Engineers

USGS Public Works/Engineering Contractors

USFS Emergency Managers Attorneys

BOR & COE W&S Districts Citizens

Data Interpretation AidedData Interpretation Aidedbyby

Graphical DisplaysGraphical Displays

STORM Watch (Windows-based software by DIAD Inc.)STORM Watch (Windows-based software by DIAD Inc.)

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Meteorological Meteorological SupportSupport

Supplements NWS watches & warningsSupplements NWS watches & warnings Maintains direct contact with local Maintains direct contact with local

government emergency preparedness government emergency preparedness and response agenciesand response agencies

Tailors communications to specific Tailors communications to specific jurisdictional concernsjurisdictional concerns

Supports comprehensive multi-Supports comprehensive multi-jurisdictional basin flood warning plansjurisdictional basin flood warning plans

Meteorologists monitor weather radar and other real-time data sources to keep local officials informed concerning threatening conditions.

Standard F2P2 MessagesStandard F2P2 Messages(relayed by voice and fax to dispatchers)(relayed by voice and fax to dispatchers)

MESSAGE 1 (Internal Alert)This is an advisory message which is meant to inform key people that weather conditions are such that flood producing storms could develop later in the day. It will be issued by HMS after consultations with NWS. If HMS feels this weather advisory requires priority handling by the communications dispatcher, the message will be preceded with the statement: "THIS IS A RED FLOOD ALERT MESSAGE."

MESSAGE 2 (Flash Flood Watch)This message indicates that a Flash Flood Watch has been issued by NWS and/or HMS feels the risk is high that a life-threatening flood may occur later in the day. HMS will add any additional information which is available. If HMS feels this watch requires priority handling by the communications dispatcher, it will be identified as a RED FLOOD ALERT message.

MESSAGE 3 (Flash Flood Warning)This message indicates that a Flash Flood Warning has been issued by NWS and/or HMS feels that a life-threatening flood is imminent. Again, HMS will add any additional information which is available. This warning message requires priority handling by the communications dispatcher (i.e. an automatic RED FLOOD ALERT).

MESSAGE UPDATEThis message will be used by HMS to update any of the previous messages, particularly in the event of a disagreement between HMS and NWS. For example, this message can be used to narrow a watch or warning area as more information becomes available or to provide more site specific data and direction during an event. If HMS feels this update requires priority handling by the communications dispatcher, it will be identified as a RED FLOOD ALERT message.

MESSAGE 4 (All Clear)This message cancels the flood potential status. This message is issued by HMS after consultation with NWS and other entities involved with direct HMS communications.

Standard F2P2 Message Standard F2P2 Message FormsForms

AllAll F2P2 “Messages” are communicated F2P2 “Messages” are communicated by phone to dispatchers.by phone to dispatchers.

Standard forms are faxed to Standard forms are faxed to dispatchers prior to phone call to dispatchers prior to phone call to minimize the potential for minimize the potential for misinterpretation.misinterpretation.

Copies of forms are included with all Copies of forms are included with all District-support basin flood warning District-support basin flood warning plans.plans.

Other F2P2 ProductsOther F2P2 Productsvia Broadcast Fax & Webvia Broadcast Fax & Web

Daily Heavy Precipitation Outlook (Daily Heavy Precipitation Outlook (HPOHPO) issued ) issued by 11:00 a.m.by 11:00 a.m.

Internal Message Status Report (Internal Message Status Report (IMSIMS) replaces ) replaces HPO when a “Message” is in effect.HPO when a “Message” is in effect.

Probabilistic Quantitative Precipitation Probabilistic Quantitative Precipitation Forecast (Forecast (QPFQPF) provides more detailed basin-) provides more detailed basin-specific information.specific information.

Storm Track (Storm Track (STST) provides hour lead describing ) provides hour lead describing movement, size, QPF and expected path.movement, size, QPF and expected path.

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Dissemination Example for Jefferson County, ColoradoDissemination Example for Jefferson County, Colorado

Weather/flood messages relayed by emergency communication centers.More than 30 known point contacts for Jeffco. Subsequent relays unknown.

* Private Meteorological Service

District Flash Flood District Flash Flood Prediction ProgramPrediction Program

‘‘High Tech’ helps save lives, but it does High Tech’ helps save lives, but it does notnot replace replacethe need for the ‘High Touch’ observations andthe need for the ‘High Touch’ observations andcommunications that people provide.communications that people provide.

Used to predict flood Used to predict flood potentials and storm potentials and storm tracks, and to identify tracks, and to identify meteorological triggers meteorological triggers beforebefore if rains. if rains.

Weather Station MesonetWeather Station Mesonet

ALERT Weather StationALERT Weather Stationa forecast tool & morea forecast tool & more

Precipitation Wind Speed/Direction Wind Gusts Air Temperature Relative Humidity Dewpoint (calculated) Fuel Moisture &

Temperature (fire weather) Key pre-storm flood forecasting Key pre-storm flood forecasting

parametersparametersHiwan Golf CourseHiwan Golf Coursenear Evergreen, COnear Evergreen, CO

THE ALERTTHE ALERTMESONETMESONET

How well does all this How well does all this stuff really work?stuff really work?

August 17, 2000August 17, 2000

Rocky Mountain NewsRocky Mountain News

August 18, August 18,

20002000

August 19, August 19,

20002000

August 22, August 22,

20002000

Sept. 1, 2000Sept. 1, 2000

Building RelationshipsBuilding Relationships

38 Local Government Partners38 Local Government PartnersPrivate MeteorologistsPrivate Meteorologists

Media & OthersMedia & Others