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David M. Schultz: Research Interests
- FRONTS: My M.S. thesis was on occluded fronts. With the
honor of speaking at the Fred Sanders Symposium in January 2004, I was
given the opportunity to revisit many issues of frontal structure and
dynamics that have always interested me. A few of these topics are
- SCALE INTERACTIONS: My Ph.D. thesis
explored the interaction between the synoptic scale and the mesoscale
in forming different cyclone/frontal conceptual models. (I've since
collaborated with Heini Wernli and Fuqing Zhang on modeling these
structures in baroclinic channel models.) Since coming to NSSL in
1996, I have tried to apply my knowledge of synoptic and mesoscale
processes to understanding the convective scale.
- THE INTERMOUNTAIN
PRECIPITATION EXPERIMENT (IPEX): An investigation of the
structure, evolution, dynamics, microphysics, and precipitation
associated with orographic precipitation and lake-effect snowbands in
the Wasatch Mountains and Salt Lake Valley, Utah. My research has
been focused on IPEX IOP 4 on 14 February 2000. The cold front
associated with this storm produced a tornadic bow echo in southern
Idaho, as well as strong winds in northern Utah. We found that
evaporation/sublimation of the falling precipitation in the dry
subcloud layer (characteristic of the Great Basin) was important in
controlling the distribution of precipitation in the lowlands versus
the mountains (Schultz
and Trapp 2003). The evaporation of precipitation in the subcloud
layer was also responsible for giving the cold front an unusual
forward-tilting structure. Future research will investigate the
evolution of this weather system from landfall from over the Pacific
Ocean, through the complex terrain of the Sierra Nevada and Great
Basin, to northern Utah.
- IMPROVEMENTS TO OPERATIONAL FORECASTING: One
of the goals of synoptic-dynamic meteorology is to perform research
that leads to better weather forecasts. NSSL is co-located with the
National Weather Service/Storm Prediction Center, which forecasts
severe winter and convective weather across the United States. Some
of my research projects have involved collaborations with forecasters
in the National Weather Service.
Future of Operational Numerical Weather Prediction: This essay
examines the role of both high-resolution and ensemble modeling
systems in operational forecasting. Written with Paul Roebber, Brian
Colle, and David Stensrud.
- Conditional Symmetric
Instability: Not all forecasting diagnostics are necessarily
useful. This is my article on this abused and misunderstood concept
for understanding and forecasting heavy precipitation. Written with
Phil Schumacher of the NWS Sioux Falls Forecast Office.
Flux Convergence: Like conditional symmetric instability, I
believe that moisture flux convergence has been misused as a
diagnostic. This misuse is especially relevant when applied to
forecasting convective initiation. Pete Banacos of the Storm
Prediction Center and I explored the history of moisture flux
convergence and why it is not appropriate for forecasting convective
- Spatial Bias Errors in Operational Forecast Models:
Forecasters talk about model bias errors all the time in their
forecast discussions. Do they know what the spatial bias errors
really look like? This work is a collaboration with Kim Elmore and
Mike Baldwin. [PDF]
- Snow Forecasting: There are many difficulties with trying
to forecast snow depth accurately. One is snow
density. The other is snow microphysics. This work is
collaboration with Paul Roebber, Sara Bruening, John Cortinas, Eric
Ware, and Harold Brooks.
PREVIOUS RESEARCH INTERESTS
- Cyclone/Frontal Conceptual Models: My
Ph.D. thesis research. How to use the large-scale flow
(confluence/diffluence) as an indicator of what type of cyclone/frontal
structure (Shapiro--Keyser/Norwegian) might result.
- Superstorm of March 1993: Diagnosing the
failure of numerical model forecasts of a spectacular cyclogenesis
over the Gulf of Mexico.
- A climatology of
drizzle in the United States and Canada: with Addison
Sears-Collins of the University of Virginia.
- Reexamining the cold conveyor belt:
The circulation through extratropical cyclones is not what you might
have thought it was.
- Cold Surges: Observational and
numerical modeling research on North and Central American cold surges
and tehuantepecers (wind storms in the Gulf of Tehuantepec,
- Weekend Precipitation: Does it really
rain more on weekends? Check out the map
to see if your location experiences more than its share of rainy
weekends! (Published in the Annals of
- Western US Fronts and Cyclones: How do
fronts and cyclones pass over the Rocky Mountains and reform in their
- Upper-Level Frontal Conceptual
Models: Examination of the Shapiro (1982) conceptual model of
upper-level frontogenesis for different flow regimes.
Instability: Russ Schumacher and I have performed a climatology of
inertial instability and examined the possible relationship between
inertial instability and severe storms.
- Henry's Rule: What
processes are occurring when a mobile shortwave trough displaces a
stationary cutoff cyclone over the Southwest U.S.? Follow this work
Trough Genesis: Fred Sanders and I consider the synoptic
environments and thermal-advection patterns associated with a
climatology of 186 mobile trough births. Can features that are
inherently baroclinic be generated by barotropic processes?
- Lightning in Winter Storms: Under what
conditions do lightning and snow occur simultaneously?
- January Thaw: What is the nature of a
climatological warm period during late January across the Northeast
- Flash Floods and Potential Vorticity:
Do mid- and upper-tropospheric potential vorticity anomalies precede
flash floods? Our research suggests, "Yes, in some cases." But this
work poses many more unanswered questions.
Comments or Questions
Last updated 23 November 2004. DMS.
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