“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.
Please see links below for global SST details. Partially linked to the seasonal cycle, the warmest SSTs globally are across the equatorial
http://www.cdc.noaa.gov/forecast1/IndoPacific.frcst.html (note the initial projection)
Per WH (2004) measure and other tools, the moist convective signal with the ongoing strong MJO is propagating through the
Moist tropical convective forcing has already propagated poleward off the equator across the west central Pacific, increasing the tropical cyclone hazard in the region of the
There continues to be the lack of a significant projection in phase space of the WB (2009) measure of the GWO (since ~1 April). Recall (again) that the GWO is a global dynamical measure of the atmosphere, whereas the WH (2004) empirical MJO measure only considers lower and upper tropospheric winds with OLR anomalies within 15 degrees of the equator. From the global perspective, there has been a weakening La-Nina allowing relative AAM to return to about normal per R1 data climatology. In fact, through 30 April relative tropospheric AAM is slightly above normal. Additionally, AAM tendencies have not been large (for reasons), all combining to give the appearance of a weak GWO signal.
However, zonal mean and regional scale GWO components, as well as individual terms of the earth-atmosphere AAM budget have been anything but weak. These include Eastern Hemisphere subtropical wave trains that excited the 2 (stochastically forced "cheap") MJOs in the region of
Regardless of details, a superposition of phase 7 for both the GWO and MJO snr 250mb psi composite anomaly plots best depicts the current global circulation. For example, there has been subtropical transition of
It is relatively clear to me that a GWO/MJO 7-8-1-2 transition is in progress (a.k.a. a low to high zonal eddy wave number transition response across the Northern Hemisphere extratropics). The corresponding snr 250mb psi composite anomaly plots should depict the expected synoptic behavior of the atmospheric circulation over the next few weeks. The probable response for other variables such as anomalous 2m air temperature across
Enhanced moist tropical convective forcing is likely to return to the
All presentations from the 24 February 2009 GWO workshop are available via anonymous ftp. If you have not received information on how to retrieve these, let me know. There was excellent attendance at this day-long event, and feedback was strongly positive. We are working to mainstream this effort. The support is very much appreciated!
Links to CPC and PSD ENSO discussions, and a new experimental forecast technique involving a coupled LIM (3rd link below):
The following are links to information about the stratosphere and other nice monitoring tools:
http://code916.gsfc.nasa.gov/Data_services/met/ann_data.html (new stratosphere link!)
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. The first of a two-part paper, where WB formally introduce the GWO (WB (2009)), is (still) awaiting publication in MWR. An early on-line release can be downloaded from the following link:
In addition to the subseasonal snr composite anomaly plots, we would like near real-time discussions with “weather maps” to become a routine part of the ESRL/PSD GSDM web site sometime soon. Part-2 of our GWO paper will discuss the latter. 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 complete 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, extremely unscientific, and makes Rex the Rottweiler VERY angry! I am planning on posting a discussion next weekend, 8-10 May.