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Now showing items 31-40 of 45
Characteristics of Tropopause Polar Vortices Based on Observations Over The Greenland Ice Sheet
(2018-12-14)
Tropopause Polar Vortices (TPVs) are long-lived, coherent vortices that are identified by closed material contours of potential temperature on the dynamic tropopause. They are characterized by PV anomalies that spend most ...
Understanding and Predicting Nocturnal Convection Initiation using an Ensemble-based Multi-scale Data Assimilation System
(2016-08-12)
A nocturnal maximum in precipitation exists over the Great Plains during the summer. The initiation of nocturnal storms is notoriously difficult to forecast in numerical models due to the storms often involving interactions ...
Inferring Bulk Microphysical Characteristics of Mesoscale Convective Systems Using Polarimetric Radar Observations
(2017)
In 2013, the network of NEXRAD WSR-88D’s were upgraded to dual-polarization. Dual-polarization allows for the identification of particle shape, size, orientation, and concentration within a radar sample volume due to the ...
SIMULTANEOUS ASSIMILATION OF RADAR AND SATELLITE DATA FOR CONVECTIVE SCALE NWP USING HYBRID ENSEMBLE VARIATIONAL DATA ASSIMILATION APPROACH
(2017)
Recently, an ensemble of the three-dimensional variational data assimilation (En3DA) system has been developed based on Advanced Regional Prediction System (ARPS) three-dimensional variational (3DVar) data assimilation ...
Boundary Layer Profiling Using Rotary-Wing Unmanned Aircraft Systems: Filling the Atmospheric Data Gap
(2018-08)
The planetary boundary layer (PBL) is comprised of energy exchanges with the Earth’s surface, and as such plays a large factor in the evolution of weather con- ditions. However, traditional methods of observing the atmosphere, ...
Assessing the Impact of Non-Conventional Observations on High-Resolution Analyses and Forecasts
(2017-05)
A key recommendation of a 2009 report by the National Research Council (NRC) was for new mesoscale networks to be integrated with existing ones to form a nationwide “network of networks”. This recommendation originated ...
Environmental Conditions Producing Thunderstorms with Anomalous Vertical Polarity of Charge Structure
(2018-05)
Electric field soundings and Lightning Mapping Arrays have confirmed the existence of thunderstorms with vertical charge structure that is inverted from the usual polarity. This inverted charge structure can be described ...
A Sub-daily Severe Weather Climatology and Its Implications for Forecasting
(2017-05)
While there has been an abundance of research dedicated to the seasonal climatology of severe weather, very little has been done to study hazardous weather probabilities on smaller scales. Using a similar process to the ...
Using Machine Learning to Predict Damaging Straight-line Convective Winds
(2016-08-12)
Thunderstorms, including straight-line (non-tornadic) winds, cause an average of over 100 deaths and $10 billion of insured damage per year in the United States. In the past decade machine learning has led to significant ...
Supercell Predictability: Exploring Ensemble Sensitivity to Initial Condition Spread
(2017-05-12)
The sensitivity of full-physics ensemble forecasts of supercells to initial condition (IC) uncertainty is investigated. The motivation for the study largely stems from the NOAA Warn-on-Forecast (WoF) program, where the ...