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Abstract: Many of the meteorological phenomena occurring at meso-γ require observations sufficiently close together in time and space. The multichannel microwave radiometer (MMWR) provides continuous temperature and humidity profiles. We demonstrate a method for profile bias correction that significantly improves vertical temperature (T) and water vapor density (δwv) profile accuracy. We compared MMWR temperature (TRD) and humidity (δwvRD) profiles during winter in the Sierra of Guadarrama (Madrid) at 1150m altitude with thousands of radiosonde temperature (TRW) and humidity (δwvRW) soundings from a launch site at 610m altitude and 50km distance. In spite of relatively large horizontal and vertical separation between the two sites, sounding differences above the boundary layer are comparable to observation error typically assigned to radiosonde soundings when they are assimilated into numerical weather models. Systematic bias between the paired values of TRW and TRD and δwvRW and δwvRD ranges from 0.2 to 1.2K and 0.05 to 0.5gm−3. This bias can be removed using a corrector function that is applied at each T and δwv level. Using this method, the bias for both variables is reduced to insignificant levels and their accuracy is significantly improved. [Copyright &y& Elsevier]

Abstract: Microphysical measurements inside cumulonimbus clouds (Cb) are technically complex and imply some risks. However, data such as the characteristics of the hydrometeors in a cloud, both in liquid and solid phases, their spectrum or the liquid water content are essential to understand microphysical processes inside severe storms as well as the internal structure of the storm. These data can also be used to validate numerical models to characterize severe storms beyond the information provided by the measurements. During a campaign for gathering microphysical data, measurements were carried out through a vigorous cloud turret rising on the flank of a Cb that produced hailstones, at an altitude with temperatures around −5°C. Hydrometeor spectra and the liquid water content were determined. The droplet concentration, measured by an FSSP 100, varied a lot depending on the sampling area. The droplet concentration varied inversely when compared to the concentration of larger hydrometeors registered by an OAP 2D2-C. In addition, in some areas supercooled large drops were found to form accumulation zones. The microphysical results have been used to calculate the minimum magnitude of a sustained updraft required to produce supercooled water at an altitude of −16°C in adverse conditions for the increase in liquid water due to the presence of ice particle populations. [Copyright &y& Elsevier]