Interpreting ECMWF…U.S. & Europe 6-Month Climate Pattern

Fig. 1: ECMWF upper air forecast for North America and Europe with annotated sensible weather highlights for September 2022.

Discussion: The tropics are off and running in September and the Gulf of Mexico looks busy with Texas/Louisiana land-falling storms likely according to ECMWF. The active tropics splits the continental high-pressure ridge with one center over the Northwest U.S. and a second over Southeast Canada. The NAWH is a problem for Europe. Over the cool waters of the NAWH, an upper trough is present and compensated for by an upper ridge maintaining drought in Europe.

Fig. 2: ECMWF upper air forecast for North America and Europe with annotated sensible weather highlights for October 2022.

Discussion: An unusually busy month of October in the tropics. Gulf threats will continue. North of the busy late season tropics is a lengthy broad warm ridge pattern across the U.S.  The Europe ridge continues to hang-on.

Fig. 3: ECMWF upper air forecast for North America and Europe with annotated sensible weather highlights for November 2022.

Discussion: Once again, a couple significant storms in the deep tropics maintain warm high-pressure ridging across eastern North America and Western Europe.

Fig. 4: ECMWF upper air forecast for North America and Europe with annotated sensible weather highlights for December 2022.

Discussion: The North America ridge shifts into the West and leaves the East susceptible to cold risk. Northwest Russia turns cold while Europe remains mild beneath high-pressure ridging.

Fig. 5: ECMWF upper air forecast for North America and Europe with annotated sensible weather highlights for January 2023.

Discussion: There is a subtle cold risk in East-central U.S. and Southwest/Central Europe due to occasional presence of an upper trough. An evolving polar vortex is likely in Canada where cold air masses begin to be semi-permanent and strengthen. A cold arctic air source region in Russia to expand westward into Europe does not appear likely.

Fig. 6: ECMWF upper air forecast for North America and Europe with annotated sensible weather highlights for February 2023.

Discussion: The polar vortex is well-formed in February. However, ability to force the attendant cold into the U.S. is limited. In Europe, mild high-pressure continues to finish meteorological winter.