Nov 15, 2012

Thanksgiving Week Coastal Storm? Update 2

Latest long range weather data sources: the GFS, ECMWF, UK and GGEM all continue to point to the ocean storm for Thanksgiving week to be basically a "fish" storm, that is out to sea (OTS) with little if any impacts on interior Eastern NY State's weather for the holiday travel period.

The strong blocking high pressure system over Canada is expected to remain (and this is important) to the north and even a little northwest of the developing storm. Thus the forecast OTS track.

Below is the forecast from HPC for Sunday morning 7AM EST 18 November. Let me point out some important features on this forecast map:  1) the position of the high with respect to the developing low off of the Southeast U.S. Coast. 2) Also the red dot to the south of Cape Cod. This dot is over the "Benchmark"  (40° North latitude and 70° West longitude). This point is used as a gauge for whether or not coastal storms will have an impact on the Northeast States' weather. Storms that pass over or to the west of it will produce a greater (more) impact(s) than those that pass off to the south and east of it; if the later occurs then the storm's impacts are minimal to none on our weather.


The more significant impacts from this expected system will be along the immediate coastal areas from South Carolina north to the Southern New England Coastal regions where strong onshore NE-E winds, perhaps to gale force will occur during the Monday through Wednesday period.

In addition to the winds some minor coastal flooding is also possible along with rough surf and swells leading to beach erosion. The next forecast map is for Monday morning 7 AM EST for 19 November. The storm is located to the southeast of Cape Hatteras, NC. Also note the number of isobars or pressure lines between the low and Long Island (6). The spacing between the lines would support winds of  near 35-45 mph from the NC coast to the Delmarva and winds of 20-35 mph north to Southern New England. Also note the high remains to the north of the storm and there is also a strong ridge or extension of the high pressure area that extends south-southwestward to Louisiana.


In our next forecast map for 7 AM EST Wednesday 20 November note the position of the high remaining to the north and northwest of the storm AND note the storm's position relative the red dot or benchmark it's far to the southeast of it.


Precipitation from the storm will likely skirt the immediate coast of North Carolina and perhaps Southeastern New England, mainly due to the moist onshore flow of air; as for our area we will  remain dry but cool probably right up through Thanksgiving Day if not into the start of the post holiday weekend.


I'm curious and wondering if The Weather Channel will name this "fish" storm?