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GTH Outlook Map and Data
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Last Updated -
02/11/25
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GTH Outlook Discussion
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Last Updated -
02/11/25
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Valid -
02/19/25 - 03/04/25
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A robust MJO event continues during early February, with both the RMM-based and CPC upper-level velocity potential based MJO indices depicting a high amplitude signal with consistent eastward propagation. The enhanced convective phase of this intraseasonal signal is currently crossing the West Pacific, where it is beginning to destructively interfere with the La Niña base state. This interference is becoming increasingly apparent as a less coherent presentation on spatial maps of upper-level velocity potential anomalies. While dynamical model forecasts show suppressed convection continuing to reign along the Equator near the Date Line, the MJO may contribute to a temporary weakening of the enhanced trade wind regime across the Pacific, and the teleconnections between the MJO activity and the extratropical base state appear to be significantly more robust than the ENSO response. Dynamical model forecasts of the MJO index consistently show an amplified MJO signal crossing the Western Hemisphere during Week-2. The signal becomes more diffuse among the ensemble systems during Week-3, with differences in the phase speed and amplitude of the MJO signal, but the majority of the guidance continues to depict an eastward propagating signal. Therefore, the MJO is favored to continue playing a substantive role in the evolution of the global tropical convective pattern. As the signal potentially returns to the Indian Ocean, constructive interference with the cold ENSO base state may result in a trade wind surge across the Pacific basin.
Although only one tropical cyclone formed since February 5, TS-16P just south of New Caledonia, the southern hemisphere tropics remains extremely active, with four ongoing systems. Three tropical cyclones are ongoing in the Indian Ocean basin: TC Talia over the south-central Indian Ocean, Vince over the southwestern Indian Ocean, and TS-17S just north of Australia’s Kimberley Coast. Both TCs Talia and Vince are forecast to recurve over open waters, with minimal threat to land. TS-17S, however, is forecast to gradually intensify prior to landfall over Western Australia, bringing significant rainfall, wind, and storm surge impacts to the Kimberley Coast. During Week-2, dynamical model guidance and composites of historical tropical cyclone activity during MJO events show an area of enhanced favorability for tropical cyclogenesis over the South Pacific, extending from the Gulf of Carpentaria and Coral Sea across Fiji and American Samoa and extending well east of the Date Line. This region may remain favorable into early Week-3, but dynamical model guidance becomes increasingly diffuse, and anticipated MJO activity would increase unfavorability for additional development. Tropical cyclone formations are also possible through the forecast period in the vicinity of Madagascar, either over the southwestern Indian Ocean or the Mozambique Channel. MJO composites show increased favorability during the Week-3 period.
Forecasts for above- and below-average precipitation are based on a continued La Niña response - particularly the high confidence region of suppressed rainfall along the Equator near the Date Line - and anticipated MJO activity crossing the Western Hemisphere during Week-2, and potentially the Indian Ocean during Week-3. A skill weighted consensus of operational dynamical model guidance was used to enhance the details and probabilities of above- and below-average precipitation. Below-average precipitation in the vicinity of Hawaii may be due in part to MJO activity, and persistent ridging in the vicinity of the US West Coast favors below-average precipitation across the Southwest. Dynamical models depict an area of suppressed rainfall and hot temperatures across central and southern Brazil. Forecasts over Africa were made in conjunction with the CPC International Desk.
For hazardous weather conditions in your area during the coming two-week period, please refer to your local NWS office, the Medium Range Hazards Forecast produced by the Weather Prediction Center, and the CPC Week-2 Hazards Outlook.
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Product Release Information
The Global Tropics Hazards Outlook (GTH) is released once per week every Tuesday at 1730 UTC (1830 UTC when on standard time) including U.S. federal holidays.
At the time of product release, there is a live briefing (available via Google Meet) open to all stakeholders where the latest conditions and the newly
released outlook are shared with the opportunity to ask questions. Folks that are interested in learning more or attending these briefings should contact
Jon.Gottschalck@noaa.gov, Scott.Handel@noaa.gov, Adam.Allgood@noaa.gov and Nicholas.Novella@noaa.gov for the required information. Each weekly outlook and GTH release briefing is
Archived and available on the website.
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Product Description
The Global Tropics Hazards Outlook is a probabilistic forecast for areas with elevated probabilities for above- or below-median rainfall, above- or below-normal
temperatures and regions where tropical cyclogenesis is favored for the upcoming Week-2 and Week-3 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 brown respectively. Above (below) normal temperature forecast areas are depicted in orange and blue respectively. Favored areas for tropical
development are shown in red. Three probability intervals are indicated for precipitation and temperature which are set at 50, 65, and 80%, while the probability
intervals for tropical cyclone development are set at 20, 40, and 60%. 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.
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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.).
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Product Forecast Tools
The outlook maps are currently based on a number of forecast tools, many of which are objective and serve as an objective first guess. The final depiction is an
assessment of these objective forecast tools augmented by the forecaster when based on additional forecast information when appropriate to create the final product.
Forecast tools include MJO composites, empirical and dynamical based MJO, ERW and KW forecasts, and bias-corrected dynamical model guidance from a number of modeling systems.
Tropical cyclone areas are based on MJO composites and statistical and dynamical tropical cyclone forecast guidance products as well as raw model forecast guidance.
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Product Purpose
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.
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Product Partners
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.
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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.
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Product Resources
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Feedback and Questions
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www.nws.noaa.gov
