UPDATED INFORMATION ON*

USA’s

ANTARCTIC and sub-ANTARCTIC

“WEATHER-FORECASTING” INTERESTS

for

The International Antarctic Weather Forecasting Handbook:

IPY 2007-08 Supplement

by

Jordan Powers

Mesoscale and Microscale Meteorology Division

National Center for Atmospheric Research

Boulder, Colorado, USA

powers@ucar.edu

Submitted February 2008

The weather forecasting of the United States for nonmilitary purposes in these regions is done under the auspices of the U.S. National Science Foundation (NSF).  It is NSF which is ultimately charged with providing for the forecasting for American scientific activities occurring in the Antarctic.  NSF funds and manages the United States Antarctic Program (USAP), which in turn provides for the weather forecasting effort.  At present, forecasting services for the USAP in the Antarctic and sub-Antarctic are provided by the Space and Naval Warfare (SPAWAR) Systems Center Charleston, which is based in Charleston, South Carolina, USA.  As described below, however, the Antarctic forecasting centers are at two sites.  SPAWAR subcontracts to the Scientific Research Corporation (SRC) for forecasters and weather observers that work with SPAWAR’s own meteorologists, meteorological managers, information technology personnel, and engineers in carrying out the mission.

The weather forecasting is done at two facilities: the SPAWAR Remote Operations Facility in Charleston, South Carolina, and at McMurdo Station.  The larger contingent of forecasters operates out of the Remote Operations Facility (ROF).  The ROF issues Terminal Aerodrome Forecasts (TAFs) for Amundsen-Scott Station and other U.S. deep-field camps on the Ice.  It provides flight weather briefings via web-based video conference for pilots conducting the airborne missions originating in Christchurch, New Zealand destined for McMurdo, with these briefings addressing weather conditions along flight routes and at destinations.  The Remote Operations Facility issues enroute forecasts for the annual mission of an icebreaker and resupply ships to McMurdo in the austral summer, enroute forecasts for two NSF-operated Antarctic Research Vessels that operate year-round in the Antarctic, and daily forecasts for Palmer Station.  It also responds to needs for special weather information or forecast requests for on-Ice locations exclusive of the McMurdo area.

A second group of forecasters operates from McMurdo.  This unit is responsible for issuing TAFs for the McMurdo area airfields— Ice Runway, Pegasus Field, and Williams Field.  They issue forecasts supporting helicopter operations normally within 200 miles of McMurdo, provide over-the-counter flight weather briefs for pilots conducting continental missions as well as those destined for Christchurch, issue daily forecasts for McMurdo Station, and declare the (Severe) Weather Condition for McMurdo Station and selected locations within the McMurdo complex. The setting of a (Severe) Weather Condition is intended to invoke awareness of potential risk situations affecting personnel safety.  Standard procedures have been established to minimize risk associated with each category of (Severe) Weather Condition.  Weather Condition 3 is least restrictive regarding travel and is the normal condition in effect.  Conditions are augmented as weather deteriorates to the next category.  Severe Weather Condition 2 attends poorer weather defined by sufficiently low visibility, strong winds, or cold air or wind chill temperatures, and in this regime certain travel restrictions are imposed.  Severe Weather Condition 1 is defined by visibility less than 31 m, winds exceeding 55 kts, or wind chill temperatures colder than -73C, and requires all personnel to remain at their location when the condition is set.

Weather observers are used in support of the USAP forecasting effort.  They function at the main U.S. facilities and airfields near them.  Designated personnel are also tasked with making observations at field sites.  The observations provide crucial information on site conditions, and are used in weather briefings, forecast preparation, and forecast review and verification.

The meteorologists enlist a number of data sources and tools in making the forecasts.  Fundamental to the process are the observations from across the Ice, providing basic information on the various site conditions.  The second key tool, relied on heavily, is satellite imagery.  Image loops are pored over to determine synoptic and mesoscale conditions, developments, and trends.  Polar orbiting satellite imagery is scrutinized along with information from the surface and upper-air observations and NWP model output.  The latter is the third tool, and the main NWP capability relied on is AMPS, the Antarctic Mesoscale Prediction System (Powers et al. 2003) (AMPS described in Sec. x.y).  This is a high-resolution, mesoscale atmospheric modeling system developed specifically for the USAP forecasters.  It provides numerical model forecast guidance over all of the Antarctic and sub-Antarctic.  A set of model forecast domains provides varying resolution across the continent, with the pivotal (for the USAP) McMurdo region currently covered by a grid of 2.2-km horizontal spacing.  AMPS runs at the National Center for Atmospheric Research in the U.S., and the products are disseminated via both a web page and the Antarctic Internet Data Distribution (Antarctic IDD) collaboration (Lazzara et al. 2006).  The model forecast products include surface and upper-air charts, soundings, surface meteograms, and animated meteorological fields.  The broad range of products has been developed and tuned in collaboration with SPAWAR to meet its needs.

The SPAWAR Antarctic meteorological effort includes Antarctic forecaster training and seasonal forecast performance review.  These activities are conducted in Charleston.  Forecast effort personnel share their experiences and knowledge with the broader Antarctic meteorological community through participation in the annual Antarctic meteorological workshops (e.g, the Antarctic Meteorological Observation, Modeling, and Forecasting Workshop).

References cited by Powers

Lazzara, M.A., G. Langbauer, K.W. Manning, R. Redinger, M.W. Seefeldt, R. Vehorn, and T. Yoksas, 2006: The Antarctic internet data distribution (Antarctic-IDD) system.  22^nd Int’l. Conf. on Interactive Information Processing Systems for Meteorology, Oceanography, and Hydrology.  Amer. Metor. Soc., Atlanta, GA.

Powers, J.G., K.W. Manning, Y.-H. Kuo, and D.H. Bromwich, 2003: Mesoscale modeling over Antarctica: The Antarctic Mesoscale Prediction System (AMPS).  Bull. Amer. Meteor. Soc., 84, 1533–1546.