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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.
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GTH Outlook Map and Data
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Last Updated -
06/25/24
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GTH Outlook Discussion
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Last Updated -
06/25/24
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Valid -
07/03/24 - 07/16/24
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The MJO has remained weak since the beginning of June according to the RMM-based index along with a less coherent 200-hPa velocity potential anomaly structure. As of June 24th, the GEFS and ECMWF ensemble mean forecasts favor a strengthening MJO during early July. These dynamical models depict an increase in the amplitude of the RMM-based index with an eastward propagation to the Maritime Continent and West Pacific. Likewise, a more coherent wave-1 pattern of anomalous upper-level divergence (convergence) is forecast to develop over the eastern (western) Hemisphere. The magnitude of these anomalies are also forecast to increase with time.
Only one tropical cyclone (TC) has developed globally so far during June and that was Tropical Storm Alberto in the western Gulf of Mexico on June 19. Alberto tracked westward into northeastern Mexico and resulted in heavy rainfall across Coahuila, Nuevo Leon, and Tamaulipas. As of 8am EDT on June 25, the National Hurricane Center (NHC) is monitoring a tropical wave tracking westward across the Caribbean Sea. NHC states that there is a 20 percent chance that this system becomes a tropical cyclone during the next week. Since any development could be delayed until the beginning of week-2 (July 3) and there are likely to be additional easterly waves, a 20 to 40 percent chance of TC development is posted for the southwestern Gulf of Mexico and Caribbean Sea from July 3 to 9. This elevated chance of TC development extends east of Hispaniola and Puerto Rico since consecutive ECMWF model runs favor TC genesis in that region during the first week of July. By week-3, the large-scale environment is expected to become less favorable for TC development across the Atlantic basin and forecast confidence is too low for the East Pacific during weeks 2 and 3. A strengthening and eastward propagating MJO would provide a more favorable large-scale environment for TC development across the West Pacific during early to mid-July. Based o MJO composites and dynamical model output, TC formation probabilities increase from week 2 to 3.
Due to a major network outage, the historical skill weighted blend of the GEFS, CFS, ECCC, and ECMWF models was unavailable for the release of this week's GTH outlook. The precipitation outlook for weeks 2 and 3 was mostly based on recent GEFS model runs and MJO precipitation composites for phases 4, 5, and 6. As the MJO propagates eastward to the West Pacific, a northward shift in the enhanced above-average precipitation probabilities are forecast across Southeast Asia from week 2 to 3. MJO composites favor a drying trend across Central America and the Caribbean Sea 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.
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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
