NWS Western Region Science Webinar on Object Analysis of Atmospheric Rivers
At the request of the National Weather Service (NWS) Western
Region, a webinar was held March 7, 2012, at 10 AM MST. The webinar was
hosted by Brian Garcia with Wallace Clark and Tara Jensen presenting,
with a focus on object analysis relevant to Western Region coastal
forecasting.
Topics Covered
Delineating significant meteorological entities and events (e.g., ARs and AR landfalls) via object analysis.
Measuring biases and uncertainties in event size, location, and intensity using metrics based on object attributes.
Strategic use of multiple domains.
Real-time postprocessing with the Developmental Testbed Center's MODE object analysis package.
Highlights
Because IWV and IVT objects are synoptic scale or larger, the full Northeast Pacific (NEP) domain is needed for
Meaningful comparison of SSMIS and model IWV data.
Addressing longer lead-time forecasting by development of indexes of the wetness and amount of flux over the NEP domain.
A narrow coastal-strip domain, when applied to frequent (~hourly) observational and/or model output, provides:
Landfall detection
Measures of latitudinal location and track
Measures of event intensity
Times of arrival and duration.
A broader (~1000 km longitudinally) coastal strip domain:
Allows visual comparison of forecast to observational objects as they come ashore.
Aids physical interpretation of events detected as narrow coastal-strip objects.
Causes difficulties in interpreting the built in MODE object attributes due to object truncation by the seaward domain boundary.
New special-purpose attributes need to be developed for this domain.
Contributors: Wallace Clark*, Tara Jensen, Brian Garcia*, Ed Tollerud, Ellen Sukovich