In the spring of 1994,

No abstract

The first Advanced Microwave Sounding Unit (AMSU) was launched aboard the NOAA-15 satellite on 13 May 1998. The AMSU is well suited for the observation of tropical cyclones because its measurements are not significantly affected by the ice clouds that cover tropical storms. In this paper, the following are presented: 1) upper-tropospheric thermal anomalies in tropical cyclones retrieved from AMSU data, 2) the correlation of maximum temperature anomalies with maximum wind speed and central pressure, 3) winds calculated from the temperature anomaly field, 4) comparison of AMSU data with GOES and AVHRR imagery, and 5) tropical cyclone rainfall potential. The AMSU data appear to offer substantial opportunities for improvement in tropical cyclone analysis and forecasting.

No abstract

GOES-8 visible and infrared cloud frequency composites have been created from imagery collected during June, July, and August for the years 1996-99 over northern Florida. These cloud frequency composites are unique because they offer high-resolution coverage over a small area and have been tailored to address forecast needs. Both monthly and regime cloud frequency composites are presented. Nine regimes were designated to reflect the strength and development of the sea-breeze front under various synoptic winds and the resulting effect on convective development. The regimes were designated by mean boundary layer wind speed and direction over the region of interest. Results from four of the regimes are presented.A total of 222 days (60% of all possible days) were designated for the various wind regimes. Regime 4 (W to SW flow) occurred most frequently (24%) and had the most widespread distribution of higher cloud frequency, occurring both near the coast and inland. Regime 2, with contrasting E to NE flow, was the next most frequently occurring regime (17%) and had lower cloud frequencies, particularly inland in Alabama and Georgia. Regime 5, with strong W to SW flow (15%, not presented) was third, followed by Regime 8 with N to NW flow (13%) and Regime 1 (11%) with light and variable or light SE flow.The monthly composites included the days from the various regime days as well as those with a completely disturbed or completely suppressed sea-breeze circulation. Nonetheless, the influence of the sea-breeze circulation can readily be seen in the diurnal progression of cloud frequency over a month. The variations seen in monthly cloud frequency composites for June, July, and August 1996-99 highlight periods of high and low cloud frequency and offer a different perspective on year-to-year and month-to-month variability.The regime cloud frequency results are actively being used during the summer season in aviation and public forecasting to supplement available information.