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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 - 03/26/24
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 - 03/26/24
Valid - 04/03/24 - 04/16/24
A robust Madden Julian Oscillation (MJO) signal has circumnavigated the globe during the past month and now resides across the Western Hemisphere (phase 1), with a well defined wave-1 asymmetry pattern in the global upper-level velocity potential field. This MJO event has led to significant upwelling across the Equatorial Pacific resulting in SSTs continuing to decrease, along with an increase of below-normal subsurface temperatures, reflective of a weakening El Nino. The MJO is forecast to return to the Indian Ocean by early April, with the CFS, GEFS, and ECMWF ensembles indicating a continued eastward propagation toward the Maritime Continent and far Western Pacific by week-3. Ensemble variability increases in the models, with some individual members weakening the MJO into the RMM-based unit circle, although others maintain a higher amplitude into mid-April. Uncertainty in the RMM-based forecast can be attributed to the 120-day mean removal which includes the +IOD event this past fall, and the uncertainty regarding the transition out of El Nino.

The only tropical cyclone (TC) formation in the past week was Gamane on 3/26 just to the northeast of Madagascar. During week-2, enhanced TC development chances (20 percent or greater) are forecast to shift toward the eastern Indian Ocean and along the northern coast of Australia. Higher probabilities were considered due to MJO composites, but uncertainty in the MJO strength along with generally weak signals for TC development in the dynamical guidance supported keeping probabilities low. By week-3, dynamical guidance depicts increased signals for TC formation near and along the northern coast of Australia, and decreasing chances over the eastern Indian Ocean as more suppressed convection builds in the wake of the MJO. However, only 20 percent or greater probabilities for TC formation are indicated across the northern Australia coast as the diminishing seasonal climatology by week-3 precludes higher probabilities.

The precipitation outlook for weeks 2 and 3 is based on potential TC activity, the anticipated state of the MJO, and a skill-weighted consensus of GEFS, CFS, Canadian, and ECMWF ensemble mean solutions. Above-normal rainfall is favored across the Equatorial Indian Ocean, extending into the Maritime Continent during week-2, consistent with the MJO propagation. A drying trend is likely across some of these areas by week-3, although the emergence of a low-frequency signal across the Indian Ocean is likely to persist above-normal rainfall chances across portions of eastern Africa and the western Indian Ocean. Above-normal precipitation chances remain elevated for the Equatorial central and eastern Pacific for both weeks due to El Nino. Above-normal temperatures are favored across parts of southern Africa, and Central and South America, with some of these areas having maximum temperatures greater than 35 deg C (95 deg F), exacerbating water supply concerns.

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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