Evaluation of the Atmospheric Water Budget Following an Intense Cold-Air Outbreak over the Gulf of MexicoApplication of a Regional Forecast Model and SSM/I Observations

Abstract The atmospheric water budget is examined for a 12-day period following an intense cold-air outbreak over the Gulf of Mexico. Budget terms are compared using analyses from the U.S. National Meteorological Center's operational Nested Grid Model (NGM) and using precipitable water and surface wind speed estimated from the Special Sensor Microwave/Imager (SSM/I) instrument aboard the defense meteorological satellite F8. The atmospheric-storage term, determined from the areal-averaged total precipitable water, does not differ significantly between that obtained from the NGM and that obtained from SSM/I data. The storage increases by a factor of more than 3 during the initial five days following the passage of the surface high over the Gulf. Horizontal flux divergence of water vapor computed from the full vertical structure in the NGM output is well approximated by the substitution of the surface-700-mb mean wind and the total precipitable water for the vertical profiles along the boundaries of the atmo...