000 FGUS74 KEWX 191702 ESFEWX 201102- PROBABILISTIC HYDROLOGIC OUTLOOK NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 1102 AM CST THU NOV 19 2009 ...ADVANCED HYDROLOGIC PREDICTION SERVICE (AHPS) LONG RANGE PROBABILISTIC OUTLOOK FOR THE COLORADO RIVER BASIN IN SOUTH CENTRAL TEXAS... THE AUSTIN/SAN ANTONIO TEXAS NATIONAL WEATHER SERVICE OFFICE HAS IMPLEMENTED ADVANCED HYDROLOGIC PREDICTION SERVICE (AHPS) FOR THE COLORADO RIVER BASIN IN SOUTH CENTRAL TEXAS. AHPS ENABLES THE NATIONAL WEATHER SERVICE TO PROVIDE LONG-RANGE PROBABILISTIC OUTLOOKS. THIS SERVICE IS ALSO AVAILABLE ON THE INTERNET. IN THE TABLE BELOW...THE 90 THROUGH 10 PERCENT COLUMNS INDICATE THE CHANCE THE RIVER COULD RISE ABOVE THE LISTED STAGE LEVELS IN THE NEXT 90 DAYS. EXAMPLE: THE COLORADO RIVER AT SMITHVILLE HAS A FLOOD STAGE OF 20 FEET. THERE IS A 50 PERCENT CHANCE CHANCE THE SMITHVILLE FORECAST POINT WILL RISE ABOVE 7.1 FEET DURING THE NEXT 90 DAYS. CHANCE OF EXCEEDING STAGES AT SPECIFIC LOCATIONS VALID 11/17/2009 - 2/16/2010 LOCATION FS(FT) 90% 80% 70% 60% 50% 40% 30% 20% 10% -------- ------ --- --- --- --- --- --- --- --- --- COLORADO RIVER AUSTIN 24.0 5.1 5.1 5.7 6.3 6.7 7.1 7.7 8.0 10.3 BASTROP 23.0 4.4 5.0 5.8 6.8 7.9 8.9 10.8 11.8 21.0 SMITHVILLE 20.0 2.7 3.8 4.6 5.5 7.1 8.5 9.6 12.5 17.6 LA GRANGE 26.0 5.3 7.0 8.2 9.7 11.5 13.7 16.1 20.4 28.8 LLANO RIVER LLANO 10.0 1.4 1.7 1.9 2.1 2.4 2.9 3.7 4.3 5.3 SANDY CREEK NEAR KINGSLAND 12.0 5.1 5.1 6.3 6.8 7.2 7.5 7.9 8.0 8.4 PEDERNALES RIVER FREDERICKSBURG 22.0 5.3 5.4 5.4 5.5 5.6 6.0 6.4 6.9 7.9 JOHNSON CITY 14.0 10.4 10.5 10.6 10.8 11.1 11.2 11.5 11.7 12.1 BARTON CREEK LOOP 360 AUSTIN 8.0 3.3 3.4 3.8 4.3 4.5 4.7 4.8 5.1 6.1 ONION CREEK HWY 183 AUSTIN 17.0 4.2 4.4 4.7 5.1 5.7 6.2 7.1 7.6 7.9 THIS LONG-RANGE PROBABILISTIC OUTLOOK CONTAINS NUMBERS THAT ARE CALCULATED USING MULTIPLE SCENARIOS FROM 50 YEARS OF HISTORICAL CLIMATOLOGICAL AND STREAM FLOW DATA. THESE NUMBERS ALSO TAKE INTO ACCOUNT CURRENT CONDITIONS OF THE RIVER AND SOIL MOISTURE. BY PROVIDING THE COMPLETE RANGE OF PROBABILISTIC NUMBERS...THE LEVEL OF RISK ASSOCIATED WITH THE LONG-RANGE PLANNING DECISIONS CAN BE DETERMINED. ADDITIONAL SUPPORTIVE DATA AND EXPLANATION ARE AVAILABLE ON THE INTERNET AT: HTTP://AHPS.SRH.WEATHER.GOV/INDEX.PHP?WFO=EWX (INTERNET ADDRESS IS ALL LOWER CASE). LONG-RANGE PROBABILISTIC OUTLOOKS ARE ISSUED AROUND THE THIRD THURSDAY OF EVERY MONTH.