“The views expressed are those of the author and do not necessarily represent those of the National Weather Service.”
Please keep in mind the ESRL/PSD GSDM web link, below, while reading this discussion.
The 91-day signal to noise ratio anomaly composites are now updated daily, centered on the date shown (see product descriptions). Stay tuned as our work slowly moves forward. Again, this effort is a work in progress with extremely limited resources.
There is little significant change to the global pattern of SSTs discussed a week ago. The warmest ocean waters are from the west central into the tropical northwest Pacific (totals ~29-30C), and anomalous warmth persists across the equatorial
http://www.cdc.noaa.gov/forecast1/IndoPacific.frcst.html (note the initial projection)
The weather-climate situation is extremely complicated having mixed signals. Many different interpretations can be offered. Regardless, this is another example where “cookbook prediction techniques (including relying on the models alone)” and blanket statements like “ENSO neutral” are not scientifically complete efforts. I want to do my best to cut to the chase what rigorous daily monitoring within the WB (2008) GWO and WB (2007) GSDM frameworks are telling me.
Enhanced tropical convective forcing is concentrated in the region of
Even though the WH (2004) plots show a projection in ~octant 2 in phase space, in reality some of the recent
The bottom line is I think extratropical Rossby wave energy dispersions (RWDs) involved with the fast GWO orbits contributed to both the Western Hemisphere signal (in addition to the MJO) and the west central Pacific Ocean tropical convection. AAM transports tied to the mountain torques have “helped” to shift zonal mean westerly wind flow anomalies off the equator to well into the subtropical atmospheres (~30N/20S). An extratropical PNA response has been an anomalous extension of the polar jet stream across the North Pacific Ocean (~45N/250mb wind speed anomalies roughly 30m/s) leading to west coast ridge amplification and a trough in the central USA. The latter is consistent with phase 4 of the GWO composite, and that was the location in phase space of the GWO ~7-9 August.
Zonal mean easterly wind flow anomalies are increasing across the global tropics, and phase 2 of the WH (2004) MJO composite streamfunction anomaly represents the tropics very well. During approximately next week, temperature composites on phases 8-1 of the WB (2008) GWO are reasonable, suggesting a western
Finally, a serious subseasonal monitoring issue will be to see not only far east the above mentioned coupled forcing shifts, but also for subsequent events. Should strong tropical convective forcing initiate equatorial westerly wind bursts across the anomalously warm west central
The solutions being served up by most models are reasonable through days 7-10. Among other impacts (should be understood), intense/severe MCS activity may return to the Northern Plains and
Intense to severe tropical thunderstorm activity is probable to persist and even intensify across the Eastern Hemisphere monsoon systems of
Please see the latest official tropical cyclone forecasts for all basins. I trust the expertise of the appropriate meteorological centers to alert the public of additional weather hazards worldwide (there has been a recent increase).
Links to CPC and PSD ENSO discussions:
The following is a link to information about the stratosphere and other nice monitoring tools:
The following is a link to NCEP model verifications (surf around for lots more)
The following is a link discussing recent global weather and related events.
These are probabilistic statements. We hope that an opportunity will arise for us (soon) to allow our dedicated web page effort to mature, expediting objectively and accountability. This web page effort will hopefully include an objective predictive scheme for the GWO with hindcasts.
The WB (2007) paper on the GSDM has been published in the February issue of MWR. In addition, the first of a two-part paper has been submitted to MWR where WB formally introduce the GWO. A pdf version can be downloaded from the following link:
Overlapping seasonally varying subseasonal composites for variables such as surface temperature, precipitation, geopotential height and streamfunction anomalies are planned on being posted on the web site mentioned above and presented in part-2 of our paper. We want to emphasize notions such as global-zonal mean-regional scale linkages as well as forcing-response-feedback (with subsequent interactions) relationships. An important purpose is to provide a dynamical weather-climate linkage framework to evaluate the numerical models in a sophisticated manner as part of a subseasonal (and any time scale) forecast process, in addition to a climate service for all users. Relying on the numerical models alone is a cookbook!
Given shift work and travel, updates are extremely difficult. I hope to do another discussion next weekend, ~23-24 August.