Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: J. W. Zeitler x
  • All content x
Clear All Modify Search
Full access
Matthew J. Bunkers, Brian A. Klimowski, Jon W. Zeitler, Richard L. Thompson, and Morris L. Weisman

Abstract

A physically based, shear-relative, and Galilean invariant method for predicting supercell motion using a hodograph is presented. It is founded on numerous observational and modeling studies since the 1940s, which suggest a consistent pattern to supercell motion exists. Two components are assumed to be largely responsible for supercell motion: (i) advection of the storm by a representative mean wind, and (ii) propagation away from the mean wind either toward the right or toward the left of the vertical wind shear—due to internal supercell dynamics. Using 290 supercell hodographs, this new method is shown to be statistically superior to existing methods in predicting supercell motion for both right- and left-moving storms. Other external factors such as interaction with atmospheric boundaries and orography can have a pronounced effect on supercell motion, but these are difficult to quantify prior to storm development using only a hodograph.

Full access
Peirong Lin, Larry J. Hopper Jr., Zong-Liang Yang, Mark Lenz, and Jon W. Zeitler

Abstract

This study evaluates the May and October 2015 flood prediction skill of a physically based model resembling the U.S. National Water Model (NWM) over the Texas Hill Country. It also investigates hydrometeorological factors that contributed to a record flood along the Blanco River at Wimberley (WMBT2) in May 2015. Using two radar-based quantitative precipitation estimation (QPE) products—Stage IV and Multi-Radar Multi-Sensor (MRMS)—it is shown that the event precipitation accuracy dominates the prediction skill, where the finer-resolution MRMS QPE mainly benefits basins with small drainage areas. Overall, the model exhibits good performance at gauges with fast flood response from causative rainfall and gauges that are not forecast points in the National Weather Service’s Advanced Hydrometeorological Prediction System, showing great promise for forecasts, warnings, and emergency response. However, the model suffers from poor prediction skill over regions without rapid flood response and regions with human-altered flows, suggesting the need to revisit the channel routing algorithm and incorporate modules to represent human alterations. Two contrasting flood events at WMBT2 with similar meteorological characteristics are examined in greater detail, revealing that the location of intense rainfall combined with land physiographic features are key to the flood response differences. Model sensitivity tests further show the record flood peak could be better obtained by tuning the deep-layer soil wetness and the flow velocity field in the river network, which offers hydrometeorological insights into the causes and the complex nature of such a flood and why the model struggles to predict the record flood peak.

Full access
L. M. Bastiaans, D. R. Smith, R. A. McPherson, P. A. Phoebus, J. M. Moran, P. J. Croft, M. J. Ceritelli, G. V. Rao, J. T. Schaefer, F. J. Gadomski, K. A. Kloesel, R. G. Quayle, and J. W. Zeitler

The American Meteorological Society held its Sixth Symposium on Education in conjunction with the 77th Annual Meeting in Long Beach, California. The theme of the symposium was “Atmospheric and Oceanographic Education: Teaching about the Global Environment.” Thirty-eight oral presentations and 37 poster presentations summarized a variety of educational programs or examined educational issues for both the precollege and university levels. There was also a joint session with the Eighth Symposium on Global Change Studies and a special session on “home pages” to promote popular meteorological education. Over 200 people representing a wide spectrum of the Society attended one or more of the sessions in this two-day conference where they increased their awareness of teaching about the global environment.

Full access
P. A. Phoebus, D. R. Smith, R. A. McPherson, M. J. Hayes, J. M. Moran, P. J. Croft, J. T. Snow, E. S. Takle, R. L. Fauquet, L. M. Bastiaans, and J. W. Zeitler

The American Meteorological Society (AMS) held its Seventh Symposium on Education in conjunction with the 78th AMS Annual Meeting. The theme of the symposium was “Atmospheric and Oceanographic Education: Advancing Our Awareness.” Thirty-six oral presentations and 47 poster presentations summarized a variety of educational programs or examined educational issues relevant for both the precollege and university levels.

There were also joint sessions held with the Second Conference on Coastal Atmospheric and Oceanic Prediction and Processes and the Ninth Conference on Interaction of the Sea and Atmosphere, as well as the 10th Symposium on Meteorological Observations and Instruments. Over 200 people representing a wide spectrum of the Society attended one or more of the sessions during this two-day event.

Full access