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Weeks 2-3 Global Tropics Hazards Outlook (GTH)
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ATTENTION:
The Climate Prediction Center is soliciting comments from September 13 through December 31, 2022 on the implementation of the experimental Weeks 2 and 3 Global Tropics Hazards Outlook.
Here is the Survey.
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Outlook Map and Data
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Last Updated -
09/27/22
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Outlook Discussion
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Last Updated -
09/27/22
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Valid -
10/05/22 - 10/18/22
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Madden-Julian Oscillation (MJO) activity is increasing after a recent period of incoherent tropical convective activity. Tropical convection is coalescing into a wave 1-like pattern with enhanced(suppressed) convection over the Maritime Continent(Eastern Pacific) and modest eastward propagation of these features, especially the suppressed phase. Looking ahead, there is widespread agreement among dynamical model RMM-based forecasts for the high probability of an upcoming significant MJO event. The general consensus is that the RMM signal will emerge from the unit circle during the week-1 timeframe in phase 4 or 5 and amplify significantly while propagating slowly eastward during weeks 2-3.
Tropical cyclone (TC) activity has been high over the last week. A pair of TCs formed south of Japan (Noru, 9/22; Kulap, 9/25). Noru became a strong typhoon and is currently moving toward the Vietnam coast, while Kulap has stayed out to sea and is set to become an extratropical system in the coming days. TC Newton formed in the East Pacific on 9/21 and dissipated quickly without affecting land. TC Ashley formed in the southern Indian Ocean 9/26 but is not expected to have any impacts to land. In the Atlantic Basin, TC Hermine formed near the Cape Verde Islands on 9/23 and quickly dissipated. Later on 9/23, TC Ian formed in the Caribbean Sea, and is currently near Cuba as an intensifying hurricane. Ian is anticipated to come ashore along the eastern Gulf Coast in the coming days with the potential for heavy rain and high winds during the next few days. Please refer to the National Hurricane Center (NHC) for more information and the latest forecasts.
Looking ahead to week 2, heightened MJO activity and the La Niña base state when coupled with a westerly wind burst over the equatorial Indian Ocean depicted in multiple dynamical models provide favorable conditions for TC formation on either side of the equator for the Eastern Indian Ocean. Model guidance from the ECMWF and GEFS also indicate heightened probabilities of TC formation during the week-2 time period covering a broad area in Philippine Sea, the Eastern Pacific Basin and the Main Development Region (MDR) of the Atlantic Basin.
The precipitation outlook for the next two weeks is based on anticipated TC tracks, ongoing La Nina conditions, and consensus of GEFS, CFS, and ECMWF ensemble mean solutions. Suppressed (enhanced) rainfall continues near and to the west of the Date Line (over the Maritime Continent) due to ongoing La Nina conditions and anticipated MJO phase. Below-normal precipitation is anticipated for the western tropical Indian Ocean for both weeks 2 and 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. Forecasts made over Africa are made in coordination with the International Desk at CPC.
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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 webinar) open to all interested parties in which the latest conditions in the Tropics
and the just released outlook and associated impacts are discussed. There is an opportunity to ask
questions after the briefing and the briefings are available at the Live Briefing
Archive.
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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
