Oceanic Convection and Nowcasting Hazards

The Research Applications Laboratory is addressing oceanic weather needs for aviation through the development of an intelligent system that generates 0-2 hour nowcasts.

Examples of the CTH and CDO polygon products
 
Examples of the CTH and CDO gridded products

Remote, oceanic regions have severely limited data availability and therefore, have few, if any, high resolution weather products that indicate current locations of convection. Convective hazards impact the safety, efficiency and economic viability of oceanic aircraft operations by producing turbulence, icing and lightning and by necessitating aircraft rerouting while in-flight, leading to higher fuel costs and delays. The Research Applications Laboratory is addressing oceanic weather needs for aviation through the development of convection diagnostic products. These products are the Cloud Top Height (CTH) and the Convection Diagnosis Oceanic (CDO). Both use geostationary satellite data as a primary input with the CDO also utilizing lightning data. These two products focus on the needs of pilots, dispatchers, air traffic managers and forecasters within the oceanic aviation community.

Prototype CTH/CDO products are now available. To request data access visit the tab above "Data Access".

cdo-info@rap.ucar.edu

 

The Remote Oceanic Meteorology Information Operational (ROMIO) Demonstration

RAL Benefits & Impacts: Avoiding Dangerous Weather Oceanic Flights:

Remote Oceanic Met Info Operational (ROMIO)

Images

CONVECTIVE WEATHER HAZARDS DISPLAY

HOURLY EXTRAPOLATION FORECASTS

CLOUD TOP HEIGHT DISPLAY

ITCZ REGIONS: ATLANTIC, SOUTH PACIFIC, CENTRAL PACIFIC

CONVECTION PRODUCT SUITE

 

CLOUD TOP HEIGHT (CTH)

Oceanic Convection Diagnosis and Nowcasting
The Cloud Top Height (CTH) product combines geostationary satellite Infrared data and numerical weather prediction output to create a detailed diagnosis of the estimated heights of convective cloud tops over the open ocean.

The Cloud Top Height (CTH) product combines geostationary satellite Infrared data and numerical weather prediction output to create a detailed diagnosis of the estimated heights of convective cloud tops over the open ocean. Provided that clouds are of sufficient optical thickness such that transmission from the lower atmosphere may be safely neglected (such as occurs within deep convection), the emitting temperature of the cloud across the ~11.0 micron window channel is assumed to be representative of the ambient environment. Soundings generated by the National Center for Environmental Prediction (NCEP) Global Forecasting System (GFS) numerical model are employed to convert the satellite brightness temperatures to flight-level altitudes (expressed in Kilo-feet). Specifically, the CTH makes a conversion from satellite brightness temperature to the equivalent GFS pressure surface. This pressure level is then used to interpolate to a standard atmosphere height. Similarly, aircraft altimeters also convert a pressure measurement to an equivalent altitude using the standard atmosphere.

The product performs for both day- and night-time hours and gives valid results for clouds with tops at and above 15,000 feet.

The Naval Research Laboratory in Monterey, CA (NRL-MRY) originally developed the CTH algorithm. The following reference applies:

Donovan, M.F., E.R. Williams, C. Kessinger, G. Blackburn, P.H. Herzegh, R.L. Bankert, S. Miller, and F.R. Mosher, 2006: The identification and verification of hazardous convective cells over oceans using visible and infrared satellite observations, Preprints-CD, 12th Conference on Aviation, Range and Aerospace Meteorology, AMS, Atlanta, GA, 30 January-2 February 2006.

REFERENCES

Bedka et al., 2010: Objective satellite-based detection of overshooting tops using infrared window channel brightness temperature gradients, J. Appl. Meteor. Clim., 49, 181-202.

Donovan et al., 2008: The identification and verification of hazardous convective cells over oceans using visible and infrared satellite observations, J. Appl. Meteor. Clim., 47, 164-184.

Donovan et al., 2009: An evaluation of a Convection Diagnosis Algorithm over the Gulf of Mexico using NASA TRMM Observations. 16th Conf. Satellite Meteor. Ocean., Amer. Meteor. Soc., Phoenix, AZ, 12-15 Jan 2009.

Frazier, E., C. Kessinger, T. Lindholm, J. Olivo, B. Barron, G. Blackburn, B. Watts, R. Stone, D. Keany, D. Tyler and T. J. Horsager, 2017: The Remote Oceanic Meteorology Information Operational (ROMIO) Demonstration. World Meteorological Organization, Proceedings of the 2017 WMO Aeronautical Meteorology Scientific Conference, Toulouse, France, 6-10 November 2017, pages P2-94:P2-102.

Kessinger, C., et al., 2015: Demonstration of a Convective Weather Product into the Flight Deck. 17th Conf. Aviation, Range and Aerospace Meteorology, Amer. Meteor. Soc., 4-8 January 2015, paper 13.4.

Kessinger, C., et al., 2017: The global weather hazards project. 18th Conf. Aviation, Range and Aerospace Meteorology, Amer. Meteor. Soc., 23-26 January 2017, paper 9.3.

Kessinger, C., D. Megenhardt, G. Blackburn, J. Olivo, L. Lin, V. Hoang, M. Nayote, K. Sievers, A. Ritter, D. Wolf, O. Matz, R. Scheinhartz and J. Cahall, 2017: Displaying convective weather products on an electronic flight bag, The Journal of Air Traffic Control, 59 (3), 52-61.

Kessinger, C., 2017: An update on the Convection Diagnosis Oceanic Algorithm, 18th Conf. on Aviation, Range, and Aerospace Meteorology, American Meteorological Society, Seattle, WA, 22-26 Jan. 2017, poster 211.

Kessinger, C., E. Frazier, T. Lindholm, B. Barron, J. Olivo, B. Watts, R. Stone, S. Abelman, A. Trani, M. DeRis and C. Gill, 2019: “The Remote Oceanic Meteorology Information Operational (ROMIO) Demonstration”, 19th AMS ARAM Conference, 7-10 Jan 2019, Phoenix, AZ.

Kessinger, C., E. Frazier, A. Izadi, A. Trani, T. Lindholm, J. Olivo, B. Watts, R. Stone, B. Norris, S. Abelman,  E. Senen, and K. Bharathan, 2020: “Remote Oceanic Meteorology Information Operational (ROMIO) Demonstration”, 20th AMS ARAM Conference, 12-16 Jan 2020, Boston, MA, paper 12.1.

Miller, S., et al., 2005: Technical Description of the Cloud Top Height (CTOP) Product, the first component of the Convective Diagnosis Oceanic (CDO) Product. Submitted to FAA AWRP, 11 March 2005, 30 pp.

Mosher, 2002: Detection of deep convection around the globe. Preprints, 10th Conf. Aviation, Range, Aerospace Meteor., Amer. Meteor. Soc., Portland, OR, 289-292.

Funding

Federal Aviation Administration (FAA)