8:30 AM (Thursday) | *“Rain, rain, go away”...scratch that...”rain, rain, come this way...pour down for even just a day”*
Paul Dorian
“Abnormally Dry” to “Moderate Drought” conditions currently exist along the I-95 corridor region of the Northeast US and “Extreme Drought” is impacting portions of West Virginia. Data courtesy NOAA
Overview
October can be a dry month in the Northeast US with the usual overall cooling down of the atmosphere, but this one has been pretty ridiculous. While tropical moisture has inundated the Tennessee Valley/Appalachians and Southeast US during the past couple of weeks, nary a drop has fallen in the DC-to-Philly-to-NYC corridor and there is not much reason for hope in the next week or so. Perhaps...just perhaps...there may be some decent rainfall here around the end of the month as a strong cold frontal system heads this way from central Canada.
More than 58% of the land area across the northeastern states are now classified as being in some sort of drought condition as compared with only 16.76% a year ago. Data courtesy NOAA
Details
There has been no rainfall at all during the month of October at Philly’s official airport weather station (PHL), just a trace in New York City’s Central Park, and only two-hundredths of an inch at Reagan National Airport (DCA) in Washington, D.C. since the first day of the month. As a result, drought conditions have worsened in many parts of the Northeast US now being classified as “moderate-to-severe” in some coastal sections, and “extreme” across portions of West Virginia. In fact, more than 58% of the total land area across the northeastern states is now classified somewhere in the range of drought conditions being “abnormally dry” to “exceptional” and this compares with only 16% one year ago.
The tropical moisture fields of Hurricanes Francine (left) and Helene (right) never made it as far north as the Northeast US/Mid-Atlantic thanks in large part to blocking high pressure stationed over southern Canada. As a result of the block in the atmosphere, both tropical systems grinded to a halt and dissipated over the Tennessee Valley region. Plots courtesy NOAA, Wikipedia
One of the main causes of our recent dry stretch of weather has been a blocking pattern in the upper atmosphere with very strong high pressure persistently positioned over the southern part of Canada and/or northeastern part of the US. Indeed, this blocking high is one of the main reasons the copious amounts of tropical moisture from Hurricane Helene (and Hurricane Francine before that) could only make it as far north as the Tennessee Valley/southern Appalachians.
Very strong high pressure has dominated the scene in recent weeks across southern Canada and the northeastern US and will continue to do so for the foreseeable future resulting in generally rain-free conditions. Map courtesy NOAA, tropicaltidbits.com
The next several days do not show much promise in terms of rainfall with strong high pressure remaining in full control at all levels of the atmosphere. While this high-pressure system will indeed make for a very nice fall weekend in the Mid-Atlantic region (sunshine, 70’s for highs), it can only worsen the drought conditions now being experienced across much of the northeastern states.
Not too much hope for any kind of soaking rainfall over the next week to ten days across the Northeast US as strong high pressure will remain in control throughout all levels of the atmosphere. Map courtesy NOAA, tropicaltidbits.com
Looking ahead, there are signs that around the very end of the month, moisture may push into the Mid-Atlantic region associated with a strong cold frontal system that could drop southeastward from central Canada to the Great Lakes...but I wouldn’t bet the ranch on it at this point.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com
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