'Cut-Off' Low to Bring Persistent Clouds, Rain to the East

Brian Donegan
Published: September 28,2016
A prolonged period of unsettled weather appears to be setting up for the second half of this week, and likely into the weekend, across a large swath of the East.
A "cut-off" low, or an area of low pressure that is cut off from the main jet stream, will be meandering over the Ohio Valley, Northeast and mid-Atlantic states for the next several days.
The National Weather Service (NWS) has hoisted flash flood watches from south-central Pennsylvania southward into much of Maryland, Washington D.C., parts of Virginia and the eastern West Virginia panhandle. This includes Baltimore, Washington D.C. and Charlottesville, Virginia.

Current Radar, Watches and Warnings

This sluggish system will bring persistent clouds, occasional rain and gusty winds to these regions into Sunday.
The most persistent rain looks likely to set up across Ohio, Pennsylvania, New Jersey, western and southern New York, Delaware, Maryland, Virginia, West Virginia and southern New England.
However, it will not be raining at all times, and there could be long periods of dry time. Despite this, it would still be wise to take the umbrella and rain coat with you for at least the next few days.
A broad swath of 1 to 3 inches of rain is expected across these states through Sunday, with some areas seeing upwards of 3 to 5 inches (locally higher) in more-persistent areas of rain.
(MAPS: 7-Day National Rainfall Forecast)

Rainfall Forecast

According to the latest U.S. Drought Monitor, parts of New Jersey, Pennsylvania and Ohio are still suffering from moderate to severe drought conditions after the hot, dry summer of 2016. However, the areas that need rain the most are western New York and eastern Massachusetts where they are classified under extreme drought conditions, the second worst drought category.
The rainfall late this week will be beneficial and put a dent in some of the rainfall deficits in the mid-Atlantic states, parts of New York state, New England and the Ohio Valley. However, some rain may become excessive, at times, triggering flash flooding, particularly in highly-urban areas with poor drainage.
(FORECAST: Cleveland | Pittsburgh | Philadelphia | Baltimore | Rochester, New York | Atlantic City, New Jersey | Hartford, Connecticut)

This weather pattern is a polar opposite of what the Northeast experienced just last week, when a large ridge of high pressure (bulge in the jet stream) dominated the region. For example, on the first day of fall last Thursday, Philadelphia recorded a high of 87 degrees. The next day, Sept. 23, Philadelphia reached 89 degrees, which was 14 degrees above average for the date.
(MORE: How Temperatures, Daylight 'Fall' From Late September to Late December)
Due to considerable cloudiness across the Northeast, mid-Atlantic and Ohio Valley the next few days, temperatures will be near or slightly below average, in the 60s to low 70s. Fall is definitely in the air right now across much of the East.
In addition, cooler temperatures have also made their way into the South. After suffering through a brutal summer, it finally feels a bit more like fall.
(MORE: Late-Week Break From Brutal Southern Heat Has Arrived)
Highs will be mainly in the 70s to low 80s over much of the region, except for the Gulf Coast and Florida, late this week. Lows will drop into the 50s from Arkansas and Tennessee to the western Carolinas.

MORE: Northeast Rainbows