This study explores the updraft and downdraft properties of mature stage mesoscale convective systems (MCSs) in terms of draft core width, shape, intensity, and mass flux characteristics. The observations use extended radar wind profiler (RWP) and surveillance radar data sets from the U.S. Department of Energy Atmospheric Radiation Measurement program for midlatitude (Oklahoma, USA) and tropical (Amazon, Brazil) sites. MCS drafts behave qualitatively similar to previous aircraft and RWP cloud summaries. The Oklahoma MCSs indicate larger and more intense convective updraft and downdraft cores, and greater mass flux than Amazon MCS counterparts. However, similar size‐intensity relationships and draft vertical profile behaviors are observed for both regions. Additional similarities include weak positive correlations between core intensity and core width (correlation coefficient r ∼ 0.5) and increases in draft intensity with altitude. A model‐observational intercomparison for draft properties (core width, intensity, and mass flux) is also performed to illustrate the potential usefulness of statistical observed draft characterizations. Idealized simulations with the Weather Research and Forecasting model aligned with midlatitude MCS conditions are performed at model grid spacings (△x) that range from 4 km to 250 m. It is shown that the simulations performed at △x = 250 m at similar mature MCS lifecycle stages are those that exhibit draft intensity, width, mass flux, and shape parameter performances best matching with observed properties.

In preparation for new observations on board the next generation of the European operational meteorological satellite (EUMETSAT Polar System—Second Generation (EPS‐SG)), a parametrization of the sea‐surface emissivity is proposed from 10–700 GHz: Tool to Estimate Sea‐Surface Emissivity from Microwaves to sub‐Millimeter waves (TESSEM²). It is based on the community model FAST microwave Emissivity Model (FASTEM) at frequencies up to 200 GHz, where FASTEM has been calibrated and validated operationally. It follows a physical emissivity model at higher frequencies. A preliminary evaluation of TESSEM² has been conducted with success, by comparison with airborne International Sub‐Millimetre Airborne Radiometer (ISMAR) observations from 118–325 GHz, under low wind speed (3–5 m s⁻¹) off the coast of Scotland. TESSEM² is a fast parametrization that can easily be implemented in a community radiative transfer model. The code is available to the community and will be distributed with the next version of Radiative Transfer for the TIROS Operational Vertical Sounder (RTTOV).

The Tool to Estimate Land Surface Emissivity from Microwave to Submillimeter Waves (TELSEM²) is linked to a climatology of monthly emissivity estimates and provides a parameterization of the surface emissivity up to 700 GHz, in the framework of the preparation for the Ice Cloud Imager (ICI) on board the Meteorological Operational Satellite Second Generation (MetOp-SG). It is an updated version of the Tool to Estimate Land Surface Emissivities at Microwave Frequencies (TELSEM; Aires et al. 2011). This study presents the parameterization of continental snow and ice and sea ice emissivities in TELSEM². It relies upon satellite-derived emissivities up to 200 GHz, and it is anchored to the Special Sensor Microwave Imager (SSM/I) TELSEM monthly climatology dataset (19–85 GHz). Emissivities from Météo-France and the National Oceanic and Atmospheric Administration (NOAA) at frequencies up to 190 GHz were used, calculated from the Special Sensor Microwave Imager/Sounder (SSMIS) and the Advanced Microwave Sounding Unit-B (AMSU-B) observations. TELSEM² has been evaluated up to 325 GHz with the observations of the International Submillimeter Airborne Radiometer (ISMAR) and the Microwave Airborne Radiometer Scanning System (MARSS), which were operated on board the Facility for Airborne Atmospheric Measurements (FAAM) aircraft during the Cold-Air Outbreak and Submillimeter Ice Cloud Study (COSMICS) campaign over Greenland. Above continental snow and ice, TELSEM² is very consistent with the aircraft estimates in spatially homogeneous regions, especially at 89 and 157 GHz. Over sea ice, the aircraft estimates are very variable spatially and temporally, and the comparisons with the TELSEM² were not conclusive. TELSEM² will be distributed in the new version of the RTTOV radiative transfer community code, to be available in 2017.

Ground-based observatories use multisensor observations to characterize cloud and precipitation properties. One of the challenges is how to design strategies to best use these observations to understand these properties and evaluate weather and climate models. This paper introduces the Cloud-resolving model Radar SIMulator (CR-SIM), which uses output from high-resolution cloud-resolving models (CRMs) to emulate multiwavelength, zenith-pointing, and scanning radar observables and multisensor (radar and lidar) products. CR-SIM allows for direct comparison between an atmospheric model simulation and remote-sensing products using a forward-modeling framework consistent with the microphysical assumptions used in the atmospheric model. CR-SIM has the flexibility to easily incorporate additional microphysical modules, such as microphysical schemes and scattering calculations, and expand the applications to simulate multisensor retrieval products. In this paper, we present several applications of CR-SIM for evaluating the representativeness of cloud microphysics and dynamics in a CRM, quantifying uncertainties in radar–lidar integrated cloud products and multi-Doppler wind retrievals, and optimizing radar sampling strategy using observing system simulation experiments. These applications demonstrate CR-SIM as a virtual observatory operator on high-resolution model output for a consistent comparison between model results and observations to aid interpretation of the differences and improve understanding of the representativeness errors due to the sampling limitations of the ground-based measurements. CR-SIM is licensed under the GNU GPL package and both the software and the user guide are publicly available to the scientific community.

This study contrasts characteristics of mature squall‐line mesoscale convective systems (MCSs) observed by extended ground‐based radar wind profiler (RWP) deployments from the U.S. Department of Energy Atmospheric Radiation Measurement program. This analysis compares the dynamical structure, precipitation, and cold pool properties associated with MCS events over RWP sites in Oklahoma, USA, (midlatitude) to those observed during a 2‐year RWP deployment to Manaus, Brazil, during GoAmazon2014/5 campaign (tropical). The MCSs indicate similar convective line rainfall rates and total rainfall accumulations. However, midlatitude events suggest a larger fractional stratiform contribution to total precipitation. For both regions, convective line cold pools are associated with sharp decreases (approximately 10 K) in the surface equivalent potential temperature (θ_e) near the time of line passage. Surface θ_e properties for both regions suggest a modest relationship between rainfall rate and the probability of observing measurable surface rainfall. The probability of observing convective updrafts in both tropical and midlatitude MCS events is found to be similar as a function of low‐level radar reflectivity. However, midlatitude MCSs are associated with more intense convective updrafts, with upward air motions (mean, maximum) peaking at higher altitude. The most pronounced contrast is the propensity for deeper and more intense downdrafts in midlatitude MCSs. An analysis based on observed downdraft properties is performed using simple mixing assumptions. For these events, the vertical gradient of θ_e in the lower troposphere is relatively consistent between the Amazon and Oklahoma, suggesting similar mixing rates for downdrafts originating below 3 km (0.1 km⁻¹). However, if downdrafts originate nearer to the level of minimum θ_e at SGP, mixing may be occurring at rates comparable to 0.3 km⁻¹.

This study classifies meteorological regimes in the southeastern Texas region to identify environmental conditions that favor sea‐breeze induced convection. The classification is accomplished using a Self‐Organizing Map (SOM) approach. We applied SOM to 10 years of 700‐hPa geopotential height anomalies during the summer months from reanalysis data to distinguish three dominant synoptic regimes, with a continuum of transitional states between those. The primary regimes include: (a) a pre‐trough regime associated with a synoptic trough, (b) a post‐trough regime with upper‐level northerly flow, and (c) an anticyclonic regime within the westward extent of the Bermuda High. We project the data from the Geostationary Operational Environmental Satellite and the Next Generation Weather Radar system onto each SOM node to investigate the characteristics of cloud and precipitation properties in different regimes. When southeastern Texas is positioned to the southwest quadrant of a maritime high pressure system, an increased cloud frequency is observed over the region during the afternoon hours due to significant moisture advection. A confluence of synoptic southerly flow and sea‐breeze circulation commonly occurs in this regime. When a high pressure system is over southeastern Texas, the area is dominated by large‐scale subsidence with weak pressure gradients and moderate precipitable water vapor. This weak synoptic forcing is favorable for the formation of a sea‐breeze circulation. This is confirmed by an enhanced onshore flow and a decreased temperature at the surface in the early afternoon, as well as a sharp increase in radar echo top height.