Operational Use and Development of a High-Resolution Mesoscale Model in the Colorado Mountain Region for Wintertime and Other Forecast Applications

The overall objective is to enhance operational forecasting procedures and techniques, through the use of a high-resolution mesoscale forecast model, for weather that significantly impacts public activities in the Intermountain West. The emphasis is on improved forecasting of phenomena related to winter storms, including quantitative precipitation forecasting (QPF), snow depth, blizzards, blowing snow, and icing conditions.

Funded by: University Corp. for Atmospheric Research/Cooperative Prog. For Operational Meteorology, Education and Training.
For more information contact Israel Jirak

Sensitivity of the North American Monsoon to Soil Moisture and Vegetation, and its Telecommunication Mechanisms into the U.S.: A Modeling Study

This research focuses on the following goals:
1) Examine positive potential vorticity anomalies generated by monsoon convection as a telecommunication mechanism between convection over Northern Mexico during monsoon surges and convection/mesoscale convective systems over the central U.S.
2) Examine the relative influence and dynamics of LLJs and the monsoon boundary later on the evolution of precipitating systems associated with the North American Monsoon (NAM)
3) Examine the sensitivity of the NAM to soil moisture, SSTs and vegetation. Plans are to continue regional simulations of the evolution of the NAM for selected years using RAMS and to perform sensitivity studies with the model.

Funded by: National Oceanic and Atmospheric Adm.
For more information contact Steve Saleeby

Retrieval of Cloud Nucleating Aerosol Concentrations using an Ensemble Kalman Filter - A Feasibility Study

It is proposed to implement an ensemble Kalman filter to examine the feasibility of retrieving cloud condensation nuclei (CCN), giant CCN (GCCN), and ice forming nuclei (IFN) concentrations in regions where boundary layer clouds are prevalent. Two models will be used as part of this process. One is a two-dimensional cloud-resolving model (CRM) which contains mixed phase microphysics. The second model is a probability density function (PDF)-based single-column model of the cloudy boundary.

Funded by: National Aeronautics and Space Adm.
For more information contact Gustavo Carrio

Numerical Simulation and Analysis of Severe Storms and Mesoscale Convective Systems

This research focuses on the following:
1) Performed a detailed observational analysis of the environment in which MCSs initiate and develop with a focus on their predictability
2) Examination of the impacts of forward flank downdraft (FFD) and rear flank downdraft (RFD) cold-pool variability on mesocyclones and near-surface tornado-like vorticity in simulated supercell tornado-producing stroms
3) Performed airborne Doppler radar analysis of derecho cases observed in the Bow Echo and MCV Experiment (BAMEX)
4) Examined microphysical influences on supercell storms.
The broader impacts of this research will be on the short range prediction of severe storms amd MCSs, including tornadoes, rainfall and severe winds.

Funded by: National Science Foundation
For more information contact Dr. William Cotton

Urban Influences on Clouds, Precipitation and Lightning

The proposed research focuses on the following topics:
1) Modeling the affects of enhanced cloud condensation nuclei and giant cloud condensation nuclei concentrations on afternoon Convection over St. Louis, MO
2) Case study modeling of urban impacts on organized mesoscale convective systems (MCSs) passing over St. Louis, MO
3) Idealized modeling of urban impacts on organized MCSs; Participation in the HEAT field campaign
4) Modeling urban impacts on convection and cloud structures favorable for lightning over Houston, Texas

Funded by: National Science Foundation
For more information contact Sue Van Den Heever

Aerosol/Boundary Layer Cloud Interactions-Simulations and Parameterization Testing

Our Research Focuses on:
1) Large-eddy simulation (LES) of RICO cases for testing the microphysics model and testing the PDF single-column model and furthering our fundamental understanding of aerosol cloud interactions in the trade wind regime
2) Further development, calibration and testing fo the CCN, GCCN and IN aerosol source and transport model
3) Further development of the PDF single-column model interfaced to the Regional Atmospheric Modeling System (RAMS) microphysics
4) Participation in GEWEX Cloud System Study (GCSS) Working Group #1

Funded by: National Science Foundation
For more information contact Dr. William Cotton

DoD Center for Geosciences/Atmospheric Research Modeling and Assimilation in Very Cloudy Conditions

This CG/AR research project has the following goals:
1) Improve boundary layer cloud simulations and aerosol direct and indirect effects in climate models
2) Improve air quality prediction
3) Commerce and Transportation - Should improve forecasts of hazardous aviation weather associated with clouds, fog and dust

Funded by: Department of Defense
For more information contact Dr. William Cotton

Collaborative Research: Inhibition of Snofall by Pollution Aerosols

This NSF project seeks to examine the impact of cloud condensation nuclei (CCN), giant-CCN (GCCN), and ice forming nuclei (IFN) upon the snowpack over Colorado during the winter season. The Regional Atmospheric Modeling System (RAMS) is being utilized to perform high resolution mesoscale simulations (750m grid spacing) focused over the Storm Peak Lab (SPL) observatory at Steamboat Springs, Colorado. Several significant snowfall events during the winter of 2004-2005 are being targeted as cases during which SPL recorded data on aerosol, cloud and ice spectra, as well as snowfall rate and meteorological conditions. Sensitivity studies with varying aerosol concentrations, as well as the verification data from SPL, will help provide a solid understanding of potential pollution impacts on Colorado snowfall.

Funded by: National Science Foundation
For more information contact Steve Saleeby