NWS Hydrometeorological Prediction Center
25 Oct 2012
Despite a modest cluster of outlying deterministic solutions and ensemble members from the various modeling centers, the lion’s share of guidance indicates that the circulation associated with Hurricane Sandy will pass close enough to the amplifying polar trough over the eastern united states to become incorporated into a hybrid vortex over the mid atlantic and northeast next Tuesday.
The high degree of blocking from eastern north America across the entire Atlantic basin is expected to allow this unusual merger to take place, and once the combined gyre materializes, it should settle back toward the interior northeast through Halloween, inviting perhaps a ghoulish nickname for the cyclone along the lines of “Frankenstorm”, an allusion to Mary Shelly’s Gothic creature of synthesized elements.
As is often the case, when one part of the nation is experiencing a very energetic atmosphere disturbance, the remainder is relatively calm. This event should not prove the exception, with a fairly benign feed of Pacific air into most of the Western and Central states. The far west, particular north of California, will have enough sustained onshore flow to keep the period wet and unsettled.