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FGUS74 KHGX 211702
ESFHGX
220501-
PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON, TX
1102 AM CST Thu Nov 21 2024

...Advanced Hydrologic Prediction Service (AHPS) long range
probabilistic outlook for Harris County Watersheds in Southeast Texas...


The Houston/Galveston National Weather Service Office has
implemented Advanced Hydrologic Prediction Service (AHPS) for Harris
County Watersheds 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: Greens Bayou at U.S.Hwy 59 in Houston has a flood
stage of 55 feet. There is a 50 percent chance the U.S. Hwy 59 forecast
point will rise above 47.0 feet during the next 90 days.


           Chance of exceeding stages at specific locations
                  Valid 11/20/2024 - 02/18/2025


Location       fs(ft)   90%  80%  70%  60%  50%  40%  30%  20%  10%
-------------------------------------------------------------------
Spring Creek
 Tomball       155.0    141.3 143.3 144.2 145.3 145.6 146.8 146.9 147.4 147.9
Cypress Creek
 Katy-Hockley  157.3    146.3 148.3 149.8 150.2 151.0 152.1 153.0 153.9 155.3
 Grant Road    122.0    104.8 105.1 105.9 106.5 107.3 107.3 108.2 109.4 113.2
Greens Bayou
 Knobcrest St   84.8    69.5 69.9 70.4 70.8 71.4 71.7 72.3 72.5 73.8
 U.S. Hwy 59    55.0    43.4 44.3 45.2 45.7 47.0 47.6 48.1 49.4 50.8
 Ley Road       30.0     5.5  7.8  9.4 10.8 11.9 12.8 15.2 17.2 18.7
White Oak Bayou
 Heights Blvd   32.0    12.7 13.6 14.7 16.3 16.9 17.9 18.2 20.1 23.1
Brays Bayou
 Main Street    41.0    23.4 24.9 25.9 26.9 27.6 28.6 29.2 30.5 37.2
Buffalo Bayou
 West Belt      62.2    38.9 39.3 40.1 40.5 40.7 41.1 41.4 42.1 43.6
 Piney Point    52.0    32.1 32.6 33.4 33.9 34.4 34.7 35.6 36.4 37.5
 Shepherd Dr    28.0     5.8  6.8  8.1  8.6  9.2  9.7 10.6 11.1 13.6


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.


$$