WEST GULF RIVER FORECAST CENTER

A Little Bit of Everything…

Introduction We want to welcome you to Fort

Worth. “All work and no play makes Jack a

dull boy” We hope that after this week’s

conference, Fort Worth isn’t “dull” Try to brief you on what makes West

Gulf RFC…West Gulf…

The WGRFC Area

The WGRFC Area402,000 mi2 total area 87,000 mi2 in MX (Rio Grande headwaters)320 forecast points, 15 major river systems

Snowpack Water supply

Rocky terrainFlash flood threatsRapid river responses

Tropical threatsStorm surges Coastal flooding

Prolonged river floodingComplex reservoir operations

Are we the biggest? APRFC – 571,000 sq. mi. * MBRFC – 509,000 sq. mi. WGRFC – 402,000 sq. mi. (87000 sq. mi. in MX) NCRFC – 325,000 sq. mi. CBRFC – 303,000 sq. mi. NWRFC – 285,000 sq. mi. SERFC – 258,000 sq. mi. CNRFC – 239,000 sq. mi. LMRFC – 209,000 sq. mi. ABRFC – 208,000 sq. mi. OHRFC – 178,000 sq. mi. NERFC – 106,000 sq. mi. MARFC – 87,000 sq. mi.* APRFC would be the 16th largest country in the world

“Autonomous?”

Every river starts in the WGRFC area, and ends in the ocean…

All but NCRFC, OHRFC, ABRFC, MBRFC, and LMRFC also meet this criteria

Tropical Impacts?

We have a lot, but we are not alone

WGRFC Facts…

3 top 10 Metro areas in the U.S. (DFW Metro, Houston Metro, Austin/San Antonio Metro)

8 Fastest Growing Counties (in the national top 100*) Rockwall, Williamson, Collin, Hays,

Montgomery, Comal, Kendall, Denton Texas has one natural lake (Cadd0

Lake) All others man-made It is not in our area

* U.S. Census Bureau change from 2000 to 2006

World/U.S.Record Rains

Alvin, 1979 Tropical Storm Claudette Estimated 43.00 inches 24 hour U.S. Record

World/U.S. Record Rains

Thrall (1921) – 38.20 inches storm total 36.40 inches in 18 hours (World Record)

World/U.S. Records

D’Hanis 17NW (05/31/1935) 22.00 inches in 2 hours 45 minutes

(World Record)

World/U.S. Record

Kerr/Bandera Counties Tropical Storm Amelia August 1-4, 1978 42.00 inches (48 inches near Medina 3

day total) 72 hour U.S. Record

Texas Record

New Braunfels (05/11/1972) 10.00 inches in 1 hour

Other Storms of Note

T.S. Allison 2001 38.99 inches NE Harris County (5 day

total) Marble Falls 2007

18.00+ inches in approx. 4 hours July 2002

45+ inches in a week over Hill Country Ingram 07/1932

19.6” in 6 hrs; 32.4” in 18 hrs; 35.6” in 36 hrs.

WGRFC – More on Rainfall

We see big rains…often

May 2008

May 2007 June 2007

June 2008

WGRFC

WGRFC is primarily a “Flood” RFC 14 daily stage forecasts 4 daily flow forecasts

From Texas History – settlers were very disappointed with our rivers. They were useless for commerce/transportation (thus our city centers are not necessarily located near them).

It is not uncommon to see a Texas river go from baseflow, to major flooding, to baseflow in 24 to 36 hours.

WGRFC HAS Unit

Frontrunner of the RFCs on the Q2 project Q2 in MPE on hourly basis (11/07) 24 hour comparison of gauge, Q2, raw

radar, best QPE Paper on results for Oct 2008 NWA

conference Instructions/guidance for OHRFC and

CBRFC Future Possibilities

Q2 in the FieldGen Process (bias correction)

Local WFO level for SSHP

Why Q2?

24 Hours -Raw Radar (DPA)

24 Hours - Q2 24 Hours - Best Estimate

WGRFC HAS Unit

Hydrologic Decision Support tools (Chiclets) SR RFC Team

Create “river flood” threat for WFO pages Greg Shelton (Sr. HAS) is “the” RFC

representative on the National Team

WGRFC HAS Trendsetter Graphical Hydrometeorlogical

Discussion (HMD) One Stop Shopping

WGRFC Hydrology

Variational Assimilation (D.J. Seo and Lee Cajina)

Uses real-time streamflows to “back” calculate initial state conditions Assimilates real-time streamflow, real-time MAP and

climatological MAPE into lumped SAC-UHG Adjusts SAC states, MAP and MAPE

Available at headwaters Ran at WGRFC

Since 2003 Hourly time step Model forecast 72 hours out

Like Others

Work with DHMS SSHP and VAR Flood Inundation Mapping AHPS

The End

Questions/comments?