The RMM-based MJO and CPC velocity potential indices depicted a weak signal during the past week. Other modes of tropical convective anomalies are apparent in the low-level wind anomalies and OLR field, including an atmospheric Kelvin Wave and an Equatorial Rossby Wave constructively interfering over the west-central Pacific. Enhanced convection is currently observed over this region.
Dynamical model MJO index forecasts indicate an increase in the amplitude of the MJO signal during the next week with an eastward propagation of the enhanced convective phase across the West Pacific during Week-2. The statistical tools indicate a much weaker MJO signal during the next two weeks. Based on recent observations and dynamical model forecasts, the MJO is anticipated to contribute to enhanced convection across parts of the west-central Pacific during the next two weeks with a drying trend forecasted across the Maritime Continent during Week-2. The longevity of any coherent MJO signal is uncertain as it advances into the Western Hemisphere later in March.
Tropical Storm Glenda developed over the south-central Indian Ocean, south of Diego Garcia, on February 24. Glenda remained relatively weak as it tracked southwestward over open water. During Week-1, tropical cyclogenesis is favored for the Mozambique Channel, between Java and the Kimberley Coast of Australia, and across the South Pacific. These favored areas are supported by current satellite imagery and model guidance. Above-normal SSTs also exist offshore of the Kimberley Coast of Australia and South Pacific, from 150E to the Date Line. During Week-2, large-scale environmental conditions are expected to remain favorable for tropical cyclone development over the South Pacific.
Anomalous rainfall during the next two weeks is based on model consensus and MJO precipitation composites. During Week-1, above-average rainfall is favored from Mozambique east to Madagascar and adjacent water of the southwest Indian Ocean, parts of the Maritime Continent and West Pacific, and the Central Pacific including Hawaii. Below-average rainfall is favored for parts of the South Indian Ocean and southern areas of Africa although forecast confidence is lower than the above-average rainfall shapes.
During Week-2, above-average rainfall is forecasted to persist for parts of the West and Central Pacific, while below-average rainfall is favored from parts of the Maritime Continent through the West Pacific southeast of Philippines, where model guidance indicates the largest negative precipitation anomalies. These wet and dry areas are generally consistent with MJO precipitation composites. Hawaii is also expected to remain relatively wet with an enhanced plume of moisture extending northeast from near the Date Line.
Product Release Information
The Global Tropics Hazards and Benefits Outlook is released once per week every Tuesday at 1530 UTC (1630 UTC when on standard time) including U.S. federal holidays. At the time of product release, there is a live briefing (available via webinar) open to all interested parties in which the latest conditions in the Tropics and the just released outlook and associated impacts are discussed. There is an opportunity to ask questions after the briefing and the briefings are available at the Live Briefing Archive.
The Global Tropics Hazards and Benefits Outlook is a forecast for areas with elevated odds for above- or below-median rainfall and regions where tropical cyclogenesis is favorable or unfavorable for the upcoming Week-1 and Week-2 time periods. The rainfall outlook is for precipitation integrated over a week and targets broad-scale patterns, not local conditions as they will be highly variable. Above(below) median rainfall forecast areas are depicted in green and yellow respectively. Favored areas for tropical development are shown in red. Two measures of confidence are indicated, high (solid) and moderate (hatched) and are currently subjective in nature and not based on an objective system. Work towards a probabilistic format of the product and so an objective measure of confidence is ongoing. The weekly verification period ranges from 00 UTC Wednesday to 00 UTC the following Wednesday.
Along with the product graphic, a written text outlook discussion is also included at release time. The narrative provides a review of the past week across the global Tropics, a description of the current climate-weather situation, the factors and reasoning behind the depicted outlook and notes on any other issues the user should be aware of. The discussion discusses the impacts in the Tropics as well as potential impacts in the Extratropics when relevant.
Product Physical Basis
The product synthesizes information and expert analysis related to climate variability across multiple time scales and from various sources, including operational climate monitoring products. The physical basis for the outlooks include
El Nino-Southern Oscillation (ENSO) , the
Madden-Julian Oscillation (MJO), strength and variations of the monsoon systems, other coherent subseasonal tropical variability such as atmospheric Kelvin waves (KW), Equatorial Rossby waves (ERW), African easterly waves, as well as interactions with the extratropical circulation (i.e. high latitude blocking, low-latitude frontal activity, etc.).
Product Forecast Tools
The outlook maps are currently created subjectively based on a number of forecast tools, many of which are objective. The final depiction is an assessment of these forecast tools based on a number of factors to create the final product. Work is ongoing to create an objective consolidation of some of the available forecast tools to serve as a first guess for the forecaster. Forecast tools include MJO composites, empirical and dynamical based MJO, ERW and KW forecasts, and raw dynamical model guidance from a number of modeling systems. Tropical cyclone areas are based on MJO composites and statistical and dynamical tropical cyclone forecasts as well as raw model forecast guidance.
The product supports the NOAA mission in three primary ways:
- Assess and forecast important changes in the distribution of tropical convection (i.e., potential circulation changes across the Pacific and North America sectors) and communicate this information to NWS forecasters
- Provide advance notice of potential hazards related to climate, weather and hydrological events across the global tropics (including tropical cyclone risks for several NWS regions)
- Support various sectors of the U.S. economy (finance, energy, agriculture, water resource management) that have foreign interests.
The product is created through collaboration with other NOAA centers, [the National Hurricane Center (NHC) and the Central Pacific Hurricane Center (CPHC)], the Department of Defense [The Joint Typhoon Warning Center (JTWC) and the Naval Postgraduate School (NPS)], the Australian Bureau of Meteorology, Taiwan Central Weather Bureau, the State University of New York at Albany (SUNY) and the Center for Climate and Satellites (CICS), among other collaborators.
Product Users and Applications
Known users include U.S. government agencies such as NOAA [National Weather Service (NWS), River Forecast Centers (RFCs), the National Marine Fisheries Service (NMFS), the Department of the Interior (U.S. Forest Service), aid organizations (U.S. and international Red Cross, USAID), domestic and global private sector interests (financial, energy, water resource management and agricultural sectors), international weather services and various media meteorologists.
Some special applications of the product in the past include extended range predictions to support Haiti earthquake and Deepwater Horizon oil spill relief efforts as well as support for the Dynamics of the MJO (DYNAMO) scientific field campaign held from October 2011 through March 2012.