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HOME > Climate & Weather Linkage > Global Tropics Outlook


Weeks 2-3 Global Tropics Hazards Outlook (GTH)

For week-1 tropical cylone information and forecasts, please visit the National Hurricane Center and the Joint Typhoon Warning Center. For week-1 precipitation and temperature related products, please visit the Weather Prediction Center or refer to your local NWS office.

ATTENTION:

The Climate Prediction Center is soliciting comments from August 1, 2023 through December 31, 2024 on the implementation of the Week 2 and experimental Week 3 Global Tropics Hazards Outlook.

Here is the Survey.


GTH Outlook Map and Data
Last Updated - 06/18/24
GIS Ready Formats
Hazard
Tropical Cyclone Formation Probability KMZ KML SHP KMZ KML SHP
Enhanced Precipitation Probability KMZ KML SHP KMZ KML SHP
Suppressed Precipitation Probability KMZ KML SHP KMZ KML SHP
Above Average Temperatures Probability KMZ KML SHP KMZ KML SHP
Below Average Temperatures Probability KMZ KML SHP KMZ KML SHP

Tropical Cyclone Only GTH Map
Precipitation Only GTH Map
Temperature Only GTH Map
Lines Only GTH Map

Latest Product (PDF Format)
Latest Briefing (PDF Format)
GTH Archive
 
GTH Outlook Discussion
Last Updated - 06/18/24
Valid - 06/26/24 - 07/09/24
The Madden Julian Oscillation (MJO) has been inactive during the first half of June, with the RMM-based index residing in the unit circle. The ECMWF and GEFS ensembles depict some reorganization of the MJO across the Western Hemisphere and propagating to the Indian Ocean by the end of week-2, although the phase speed may be more indicative of a Convectively Coupled Kelvin Wave (CCKW). This feature is forecast to result in anomalous divergence aloft across the Atlantic in the near-term, and shifting into the Eastern Hemisphere by week-2, with anomalous convergence aloft beginning to move across the Americas and the Atlantic in its wake. Constructive interference with a low frequency convective signal across the far western Pacific is possible during early July, resulting in an increasingly favorable environment for tropical cyclone (TC) development.

No new TCs have formed during the past week, although an uptick in global TC activity is likely over the next few weeks. According to the National Hurricane Center (NHC), Potential Tropical Cyclone One, currently over the southwestern Gulf of Mexico, has an 80 percent chance of developing into a TC in the next 2 days with heavy rainfall impacts likely over parts of eastern Mexico and the western U.S. Gulf Coast. The continued active Central American Gyre (CAG) favors additional development around the same location this weekend, with NHC designating a 20 percent chance of TC formation in the next 7-days. Beyond that and into the week-2 period, several 6z and 12z GEFS ensemble members develop a third disturbance, with potentially a more northerly track. However, the ECMWF ensemble is not as robust with this third wave, and the convective environment aloft is forecast to become less favorable as more suppressed convection moves over the Americas and the CAG weakens. Therefore, only a 20-40 percent chance of TC development is highlighted across portions of the western Caribbean and Gulf of Mexico for week-2.

Given the enhanced convective envelope beginning to move over the Eastern Hemisphere, the GEFS and ECMWF indicate an uptick in TC development probabilities across the Bay of Bengal. The arrival of the Indian Monsoon may limit TC development across this area, but a 20-40 percent chance of TC formation is highlighted in the forecast for week-2 given the higher probabilities depicted in the dynamical models. TC development chances are forecast to shift more toward the Western Pacific and South China Sea later in week-2 and especially into week-3 due to the convergence of several modes of tropical variability, with a 20-40 percent chance of TC development highlighted in week-2, increasing to 40-60 percent in week-3. This is also consistent with the increasing seasonal climatology.

The precipitation outlook for weeks 2 and 3 is based on potential TC activity, MJO composites, and the dynamical models. During week-2 ,above-normal rainfall is favored across portions of the north Atlantic and Central America, with decreasing chances by week-3. Enhanced chances for above-normal (below-normal) rainfall are forecast across much of the Arabian Sea, Bay of Bengal, and the Western Pacific (Eastern Pacific and northern South America) for both weeks 2 and 3. For week-2, above-normal temperatures are likely for northern India and the eastern two-thirds of the U.S.

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. Forecasts made over Africa are made in coordination with the International Desk at CPC.


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.

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.


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 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.

Product Purpose
The product supports the NOAA mission in three primary ways:
  1. 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
  2. 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)
  3. Support various sectors of the U.S. economy (finance, energy, agriculture, water resource management) that have foreign interests.
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.

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.

Product Resources

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Page last modified: 6-Mar-2024 12:53 PM EST
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