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PROBABILISTIC HYDROLOGIC OUTLOOK

NATIONAL WEATHER SERVICE HOUSTON/GALVESTON, TX

1018 AM CDT Thu Apr 18 2024



...Advanced Hydrologic Prediction Service (AHPS) long range

probabilistic outlook for the San Jacinto River Basin in Southeast Texas...





The Houston/Galveston National Weather Service Office has

implemented Advanced Hydrologic Prediction Service (AHPS) for the

San Jacinto River Basin in Southeast 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 San Jacinto river near Conroe has a flood

stage of 115.8 feet. There is a 50 percent chance the Conroe

forecast point will rise above 101.7 feet during the next 90 days.





           Chance of exceeding stages at specific locations

                  Valid 04/17/2024 - 07/16/2024





Location    fs(ft)     90%  80%  70%  60%  50%  40%  30%  20%  10%

------------------------------------------------------------------

East Fork San Jacinto River

 Cleveland   19.0      6.4  8.7 10.5 10.9 11.6 13.2 13.9 15.6 16.6

 New Caney   58.0     48.5 49.7 51.6 52.0 53.2 54.8 58.0 60.2 63.0

Caney Creek

 Splendora   17.0      5.1  8.0  8.7  9.3 11.0 11.6 12.7 14.7 17.4

Peach Creek

 Splendora   14.0      5.4  7.5  8.0  9.0  9.7 10.9 11.7 12.4 15.0

West Fork San Jacinto River

 Conroe     115.8     96.3 97.6 99.8 100.8 101.7 103.0 104.6 106.2 113.2

 Porter      81.0     58.7 60.3 61.6 62.5 63.7 64.7 67.4 67.8 75.6

 Humble      49.3     43.7 44.1 44.4 44.9 45.3 45.8 46.6 47.9 51.5

Spring Creek

 Spring      91.5     75.9 77.0 77.9 78.5 79.5 80.7 82.8 85.9 91.6

Cypress Creek

 Westfield   85.5     67.7 68.8 69.6 70.2 71.2 72.4 72.9 75.4 81.8

San Jacinto River below Lake Houston

 Sheldon     10.0      1.9  2.4  3.6  3.9  4.1  4.3  6.6  7.6 11.2





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 long-range planning decisions can

be determined.





Additional supportive data and explanation are available on the

internet at: https://water.weather.gov/ahps2/long_range.php?wfo=hgx

(internet address is all lower case).





Long-range probabilistic outlooks are issued around the third

Thursday of every month.





$$