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GTH Outlook Map and Data
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Last Updated -
06/24/25
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GTH Outlook Discussion
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Last Updated -
06/24/25
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Valid -
07/02/25 - 07/15/25
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The Madden-Julian Oscillation (MJO) remains weak as Equatorial Rossby and Kelvin Waves continue to drive anomalous rainfall across the global tropics. In addition, a low-frequency pattern with enhanced (suppressed) rainfall has developed over the West Pacific (western Indian Ocean). According to the 200-hPa velocity potential anomaly forecasts from the GEFS and ECMWF ensemble means, anomalous upper-level divergence with enhanced rainfall is forecast to persist over the West Pacific while anomalous upper-level convergence and associated suppressed rainfall expands west from the tropical Atlantic to Central America and the East Pacific by mid-July. There is little to no apparent signal for a strengthening MJO in the RMM index forecasts from the dynamical models during the next two to three weeks.
On June 19, Category 3 Hurricane Erick made landfall in the Oaxaca state of southern Mexico. Since the end of May, five tropical cyclones (TCs) have developed across the East Pacific and a sixth TC is likely to form by July 1st. The National Hurricane Center is monitoring a broad area of low pressure located a few hundred miles offshore of Central America and there is a 70 percent chance of TC genesis during the next seven days. The GEFS and ECMWF ensemble members are in good agreement that this potential TC tracks northwest towards the southern Baja Peninsula which would spread enhanced low to mid-level moisture northward into the southwestern United States. This is expected to increase the chance of above-average precipitation and flash flooding across the Southwest during early July. From July 2-8, the GEFS depicts another Kelvin Wave crossing the East Pacific and there is enough ensemble member support to designate at least a 20 percent chance of TC development. By week-3 (July 9-15), model guidance indicates less favorable conditions, including higher wind shear, across the East Pacific and no TC development is expected.
The first Tropical Storm of the 2025 Atlantic season, Andrea, developed across the central subtropical Atlantic on June 24. It is forecast to dissipate within the next 36 hours. During weeks 2 and 3 (July 2-15), no TC development is expected for the tropical Atlantic. However, the deterministic 0Z ECMWF model and a few of its ensemble members are showing a low pressure system, potentially with tropical characteristics, forming along a stalled front offshore of the southeastern United States from July 2 to 4.
Tropical Storm Sepat formed in the West Pacific on June 23 and the Joint Typhoon Warning Center is currently monitoring a potential area for TC development west of the Philippines. Based on predicted constructive interference between the low-frequency state and an Equatorial Rossby Wave, a 40 to 60 percent chance of TC development is forecast for the West Pacific from July 2-8. This region is expected to remain active through mid-July, but TC formation probabilities decrease to 20-40 percent from July 9-15 due to uncertainty on where any TC would form.
The precipitation outlook for weeks 2 (July 2-8) and 3 (July 9-15) is based largely on the historical skill weighted blend of the GEFS, CFS, and ECMWF since the MJO is expected to remain weak through mid-July. The West Pacific and eastern Maritime Continent are likely to remain wetter-than-normal, while the Indian Monsoon overall is forecast to be suppressed. Below-average rainfall is forecast to expand west from the Caribbean Sea to Central America and the East Pacific from week 2 to 3.
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
