LYLE STRATUS STUDY FOR FORECASTING GULF STRATUS AT RANDOLPH AFB, TEXAS
WEATHER SQUADRON (24TH) RANDOLPH AFB TX DETACHMENT 10
Pagination or Media Count:
Gulf stratus in Texas is defined as a stratus cloud layer formed by a nocturnally cooled gulf air flow. Warm moist air from the Texas Gulf coastal area is cooled to saturation by nocturnal radiation and by adiabatic cooling as it moves upslope from the coast to the five to nine hundred foot elevation of central Texas. Forecasting methods have concentrated primarily on the forecasting of low level moisture and wind flow. Pressure gradient is used rather than wind flow for this study because pressures were thought to be more representative and timely than wind parameters. The 00Z pressure data gave 89 accuracy for occurrence and nonoccurrence of a stratus ceiling at Randolph AFB. Formation of stratus ceilings occurred within one hour and fifteen minutes in 63 of the cases and formed within 300 ft of forecast height in 62 of the cases. Minimum ceilings within 300 ft of forecast occurred in about 65 of the cases.