|
|
GTH Outlook Map and Data
|
Last Updated -
11/19/24
|
|
|
|
|
|
GTH Outlook Discussion
|
Last Updated -
11/19/24
|
Valid -
11/27/24 - 12/10/24
|
The MJO has been quite active over the last month, completing a full circumnavigation of the globe during that period, and at a high amplitude as the enhanced convective envelope moved over the Maritime Continent and Western Pacific. The MJO has slowed and weakened somewhat as the enhanced convective envelope moved over the Indian Ocean during the last week, likely the result of interactions with the emerging La Nina footprint and other modes of tropical variability. This forecast slowing of the enhanced convective envelope is likely to promote enhanced tropical cyclone (TC) activity across the Southern Indian Ocean and Bay of Bengal during the next two weeks. TC activity is also possible in week-3 over the Western Pacific due to MJO forcing despite the basin being less climatologically active in December.
Two TCs formed over the last week. On November 14, TC Sara formed in the Western Caribbean. It reached Tropical Storm strength while tracking along the Honduran coast before making landfall over Belize on Nov 17. Also on Nov 14, TC Bheki formed southeast of Diego Garcia and began tracking southwestward. Bheki reached a Category 3 intensity on the Saffir-Simpson scale but has since weakened from this peak. Over the coming days Bheki is favored to continue tracking southwest towards Port Mathurin and Mauritius. For the latest information on TC Bheki please refer to the Joint Typhoon Warning Center (JTWC).
With the MJO forecast to be in phases 3-5 (Indian Ocean and Maritime Continent) during the forecast period, the Indian Ocean (IO) is favored to be the most active region for TC activity during weeks 2-3. Both the ECMWF and GEFS depict high probabilities of TC activity in the southern IO, although genesis is most likely to occur during week-1, precluding a corresponding TC area for week-2. However, 20% chances are posted from the Bay of Bengal to the South China Sea based on some support in the tools favoring development during the week-2 period. As these enhanced probabilities shift eastward to the northwest coast of Australia by late week-2 and into week-3, both models also indicate the potential for TC genesis in the Bay of Bengal and South China Sea for both weeks, as well as enhanced TC potential spreading into the Western Pacific during. As a result, 20% chances are issued from the Bay of Bengal to the Philippine Sea, as well as 20% chances posted over the southwestern Indian Ocean for week-3 as the MJO enhanced convective envelope propagates across the Maritime Continent.
The precipitation outlook for weeks 2 and 3 is based on potential TC activity, the anticipated state of ENSO and the MJO, and informed by GEFS, CFS, Canadian, and ECMWF ensemble mean solutions. During week-2 below-normal temperatures are indicated for western portions of the Contiguous U.S, while above-normal temperatures are favored for the Florida region. 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:
- 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
|
|
Feedback and Questions
|
|
www.nws.noaa.gov
