Climate Prediction Center - Global Tropical Hazards Outlook

Climate Prediction Center - Global Tropical Hazards Outlook
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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.
GTH Outlook Map and Data
04/21/26
GIS Ready Formats
Hazard
Week-2
Week-3
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
04/21/26
Valid -
04/29/26 - 05/12/26
Earlier this month, constructive interference between the enhanced phase of the Madden-Julian Oscillation (MJO) and equatorial Rossby Wave (RW) activity over the western Pacific produced an exceptionally strong lower-level Westerly Wind Burst (WWB) event, and contributed to the development and intensification of Super Typhoon Sinlaku. Westerly wind episodes have been repetitious over the western Pacific this year, resulting in the development of very warm subsurface waters over the central and eastern Pacific via oceanic downwelling Kelvin wave activity. Thus, the latest WWB event is likely to reinforce and possibly strengthen much of the anomalously warm water volume in place over the equatorial Pacific, and aid in the favored transition from ENSO-neutral to El Nino conditions later this year.
In the wake of this tropical wave interaction over the Pacific, MJO activity has become increasingly organized. There is good consistency between both RMM and upper-level velocity potential observations featuring the enhanced (suppressed) phase of the MJO propagating eastward into the Western Hemisphere (Maritime Continent) while gaining amplitude during the past week. Dynamical models agree in continued eastward propagation of the MJO signal over the western Hemisphere, but vary in regards to its eventual strength and phasing during the next several weeks. The ECMWF remains the most robust and progressive with the MJO, with its bias-corrected RMM solutions favoring potentially strong MJO activity over the Indian Ocean and possibly reaching the Maritime Continent in May. In contrast, RMM forecasts from the GEFSv12 and CFSv2 favor a weaker and slower mean RMM solution while gravitating the signal more to the west. The struggle to gain RMM1 and propagate the signal eastward in these models may be explained by weaker convective responses over the Indian Ocean, as well as a greater potential for competing interference with an emerging low frequency lower-level westerly wind signal favored in the western Pacific. However, upper-level velocity potential forecasts from the GEFSv12 and CFSv2 reveal a healthier subseasonal outlook, as both maintain eastward propagating MJO activity in the objective wave filtering well into May. Therefore, the updated GTH outlook relies on subseasonal forcing, with added consideration of an emerging low frequency circulation favored over the western Pacific. Continued eastward propagation of the MJO would favor increased (decreased) chances for Tropical Cyclone (TC) development over the Indian Ocean (western Pacific) in the coming weeks. However, odds of formation in these areas look to be countered by a less active TC climatology in the southern Hemisphere, as well as the low frequency signal supportive of genesis in the western Pacific through early May.
Since forming on 4/9, TC Sinlaku dissipated over the northern Pacific, with no new TC development during the past week. Looking ahead, chances for tropical cyclogenesis remain low during the week-1 period (consistent with a quiet April climatology), though probabilistic TC genesis tools continue to highlight a few areas for potential development towards the end of April. Tied to the lower-level westerly phase of the MJO shifting into the Indian Ocean, 20% chances for development are posted for week-2 from approximately 50E to 75E where ensemble solutions favor an area of mean low pressure with decreasing shear conditions. TC formation is also possible over the southeastern Indian Ocean during week-2 based on the tools, though higher shearing over this part of the basin looks to inhibit development and no corresponding areas are issued. In the western Pacific, guidance has been consistent in featuring elevated formation chances east of the Marianas tied to the aforementioned low frequency circulation consisting of a region of anomalous low-level westerlies, decreased shear, and enhanced divergence aloft. With additional support from AI tools favoring potential genesis in the wake of Sinlaku, 40% chances for TC development are also issued for week-2 near 160E where genesis signals are strongest, with a broader 20% area from approximately 140E to 170E. With these favorable environmental conditions expected to persist later in May based on CFSv2, GEFS ,and ECMWF extended range guidance, 20% chances of TC development for this part of the basin for week-3.
The precipitation outlooks for weeks 2 and 3 is based on a skill weighted blend of CFSv2, GEFSv12, and ECMWF ensemble forecasts, historical composites of Western Hemisphere and Indian Ocean MJO events, and the low frequency signal favored in the equatorial Pacific. For temperatures, above-normal, but non hazardous conditions are favored for portions of the southern tier of the contiguous U.S. (CONUS), Mexico, Hawaii, and portions of southeastern Brazil. Potential excessive heat conditions, with increased chances for daytime temperature exceeding 100 deg F are predicted for portions of northern India, and Pakistan, and portions of southeastern Asia during week-2. For hazardous weather concerns in your area during the next two weeks, please refer to your local NWS office, the Medium Range Hazards Forecast from the Weather Prediction Center (WPC), and the CPC Week-2 Hazards Outlook. Forecasts issued 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:
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.
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
ENSO weekly update:
MJO weekly update:
Earth System Research Laboratory
National Hurricane Center:
Central Pacific Hurricane Center:
Joint Typhoon Warning Center:
CPC African Desk:
USAID/FEWS:
Australian Government Bureau of Meteorology:
Feedback and Questions
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Page Author:
CPC Web Team
Page last modified: 30-Nov-2025 1:45 PM UTC
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