May 3.2007West Gulf River Forecast Center

Rio Grande Hydrologic Services Rio Grande Hydrologic Services Expansion MeetingExpansion Meeting

Presentation OutlinePresentation Outline

Introduction to WGRFC

River Forecast Process

Rio Grande Forecast System

Challenges and Complications

The Function of WGRFCThe Function of WGRFC

To provide the most accurate and timely river stage forecasts… through a combination of our knowledge/skill of both meteorology and hydrology

This is accomplished through 2 main functions:– HAS (Hydrometeorological Analysis and Support)

Operations• 3 Forecasters

– Hydrologic Operations• 9 Forecasters

WGRFC StaffWGRFC Staff

WGRFC Hours of OperationWGRFC Hours of Operation

Normal Hours – 6:00 a.m. – 10:00 p.m.

Extension of hours– Event driven and/or in coordination with WFOs– “Close the Gap”

Overnight Shifts– 10:00 p.m. – 6:00 a.m.– Scheduled when prolonged rainfall/flooding event is expected

The WGRFC AreaThe WGRFC Area

WGRFC is one of 13 River Forecast Centers that provide

precipitation and river forecasts for the Continental U.S. and Alaska. WGRFC’s area of responsibility extends into

Mexico in order to cover tributary rivers that flow into the Rio

Grande.

Weather Forecast Offices (WFOs) Serving Weather Forecast Offices (WFOs) Serving the Rio Grande Drainagethe Rio Grande Drainage

River Forecast Center issues stage forecasts to area Weather Forecast

Office.

Weather Forecast Office adds location

specific impact statements and

disseminates

to the public.

Forecast ProcessForecast Process

Big Bend Region - 07/28/04Big Bend Region - 07/28/04

Gauge Only FieldRaw Radar Field

Satellite Derived Precipitation

Best Estimate QPE (Multi-sensor Field)

Precipitation EstimatesPrecipitation Estimates

Averaged PrecipitationAveraged Precipitation

AHPS Web PageAHPS Web Page

WGRFC Forecast TypesWGRFC Forecast Types

Daily Forecasts – Issued every morning regardless of flow El Paso Laredo

Flood Only Forecasts - Begin issuance when location is forecast to rise above a “criteria” level. Forecasts are updated until level drops below criteria. This includes the majority of WGRFC forecast points

Recreation Forecasts – Issued weekly on Wednesday afternoon for upcoming weekend flows. Presidio Boquillas (Rio Grande Village)

River Recreation ForecastRiver Recreation Forecast

Rio Grande Forecast SystemRio Grande Forecast System

Rio Grande DrainageRio Grande Drainage

Non-contributing Area

Upper Watershed

(above Elephant Butte)

Upper Rio Grande DrainageUpper Rio Grande Drainage

Water Supply Forecast

Runoff contained in lake

Pecos Basin

Pecos River DrainagePecos River Drainage

Rio Conchos Basin

(above Luis Leon)

Rio Conchos DrainageRio Conchos Drainage

Rio Grande at El PasoRio Grande at El PasoRio Grande nr CandelariaRio Grande nr Candelaria

EPRT2

CDET2

3 Day travel Time from EPRT2-CDET2

Rarely Happens

Satellite Telemetered Observations

Rio Grande above Rio ConchosRio Grande above Rio Conchos Presidio Presidio

PIOT2

18 Hr travel Time from CDET2-PIOT2

Satellite Telemetered Observations

Luis Leon ReservoirLuis Leon Reservoir

La Boquilla2.3 M Acre Feet Storage

Luis Leon273,000 Acre Feet Storage

20,600 sq mi Drainage Area1 Day Travel Time to Presidio

Rio Grande below Rio ConchosRio Grande below Rio ConchosPresidio (International Bridge)Presidio (International Bridge)

Rio Conchos belowLuis Leon3414 sq mi12 hr CrestSatellite Telemetered Data

from Mexican Gage

PRST2

Cibilo Creek269 sq mi6 hr CrestSatellite Telemetered Data

Rio Grande nr Presidio (Weir)Rio Grande nr Presidio (Weir)

PRDT2

Alamito Creek860 sq mi6 hr CrestSatellite Telemetered Data

Rio Grande nr LajitasRio Grande nr Lajitas

6-12 Hr travel Time from PRDT2

Daily Observations

TGAT2

Terlingua Creek nr TerlinguaTerlingua Creek nr Terlingua

TNGT2

Terlingua Creek784 sq mi12 hr CrestSatellite Telemetered Data

Rio Grande nr CastolonRio Grande nr Castolon

CSTT2

Observed Data on Request

Forecasts based on TELT2 hydrologic

parameters (high uncertainty)

Rio Grande at Johnson RanchRio Grande at Johnson Ranch

TELT2

6-12 Hour Travel Time from TGAT2

Satellite Telemetered Data

Rio Grande nr Boquillas Ranger Rio Grande nr Boquillas Ranger Station (Rio Grande Village)Station (Rio Grande Village)

BOQT2

6-12 Hr travel Time from CSTT2

Daily Observed Data

Rio Grande nr Heath CanyonRio Grande nr Heath Canyon

HECT2

6-12 Hr travel Time from BOQT2

No Observed Data

Rio Grande nr DrydenRio Grande nr Dryden

DYNT2

6-12 Hr travel Time from HECT2

Satellite Telemetered Data

Rio Grande at Foster RanchRio Grande at Foster Ranch

LNYT2

6-12 Hr travel Time from DYNT2

Satellite Telemetered Data

Challenges & ComplicationsChallenges & Complications

CHALLENGES & COMPLICATIONSCHALLENGES & COMPLICATIONSHydrologic Forecasting along the Big Bend of the Rio GrandeHydrologic Forecasting along the Big Bend of the Rio Grande

No Radar Coverage Few Rain Gages Limited Streamflow Observations Mountainous, Rugged Landscape:

– Fast Stream Response– Difficulty in Getting Around

International Boundary:– Data and Forecast Exchange– Communication Complexities

Radar Coverage MapRadar Coverage Map

http://www.srh.noaa.gov/wgrfc

Limited Radar & Precip. GagesLimited Radar & Precip. Gages

Gauge Only FieldRaw Radar Field

Satellite Derived Precipitation

Best Estimate QPE (Multi-sensor Field)

Availability of International DataAvailability of International Data

Please visit our website at:www.srh.weather.gov/wgrfc

For Additional Questions or Comments, Please contact us:817-831-3289 Frank.Bell@noaa.govRobert.Corby@noaa.gov

Thank You for Your Time!Thank You for Your Time!