9:30 AM (Tuesday) | *****“Isaias” racing to the northeast…wild weather winds down later this afternoon in much of the Mid-Atlantic region, but continued very rough going until then*****
Paul Dorian
Tropical Storm “Isaias” is now racing along to the north-northeast at 33 mph as of the last official report. Images courtesy NOAA, College of DuPage
Overview
The good news is that “Isaias” is accelerating to the northeast and the wild weather should wind down later this afternoon in much of the Mid-Atlantic region. In fact, the sun could actually return in portions of the Mid-Atlantic region later today. The bad news is that there is another several hours to get through before we get to that point with some pretty rough weather including more flooding rainfall, powerful and potentially damaging wind gusts, numerous power outages and isolated tornadoes. By later tonight, “Isaias” will race across interior New England on its way to southeastern Canada and the weather in the Mid-Atlantic region will improve markedly overnight and on Wednesday.
Still another several hours to get through with heavy rainfall in the Mid-Atlantic region associated with Tropical Storm “Isaias”. Even after the rainfall ends, there will continue to be flooding issues in many areas. Map courtesy NOAA, University of Wisconsin
Details
As is pretty typical of tropical systems as they reach the higher latitudes, “Isaias” is accelerating and its torrential rainfall and powerful winds should wind down later this afternoon in much of the Mid-Atlantic region. In fact, don’t be surprised to see some sunshine later today in portions of the I-95 corridor (e.g., DC metro region) as the tropical storm pushes rapidly to the northeast. However, there is still plenty of rough weather to get through until the weather begins to settle down including the very real threat of tornadoes.
Unfortunately, power outages will be an important result of the passage of Tropical Storm “Isaias” with more than 335,000 already reported across eastern Virginia as of mid-morning.
As of the last official report by NOAA’s National Hurricane Center, “Isaias” forward speed had actually increased to 33 mph in a north-northeast direction. Despite the fast movement of “Isaias”, it has already produced torrential rainfall and widespread problems with respect to flash flooding with numerous “flash flood warnings” in effect across the Mid-Atlantic region. Take it slow on the roadways today and turn around if approaching high water levels which could be rising rapidly. In addition to the excessive rainfall with 6+ inches on the table in spots, isolated tornadoes have developed as “Isasis” races to the northeast including a couple confirmed reports in the Delmarva Peninsula. The greatest threat for tornadoes from a fast-moving tropical system pushing to the north/northeast is usually on the eastern side of the storm track. Hence, the most vulnerable areas today for isolated tornadoes will be along and southeast of I-95 to the coastal locations. Specifically, this puts the highest chance of tornadic activity over the next few hours in places like the Delmarva Peninsula, eastern Pennsylvania and New Jersey before that threat extends up along the eastern sections of the Northeast US.
All kinds of “watches and warnings” in the Mid-Atlantic as “Isaias” races through the region. Map courtesy Philadelphia National Weather Service (NOAA)
“Isaias” re-gained hurricane strength last night reaching category 1 status before making landfall near Ocean Isle Beach, North Carolina. Since that time, “Isaias” has weakened only very slowly as it interacts with a strong upper-level jet and becomes an “extratropical” system. As a result, its winds have maintained quite a bit of strength with the latest official reading still showing 70 mph maximum sustained winds – not far under minimum hurricane status requirements. Winds in the Mid-Atlantic region over the next several hours can reach 50+ mph in interior locations and 70+ mph at coastal sections of the Delmarva, New Jersey and Long Island (NY) with numerous power outages likely. In fact, as of mid-morning, there have already been nearly 400,000 customers reportedly without power across eastern Virginia, Maryland and Delaware.
Maximum wind gusts reported as of mid-morning with 60"+ mph at the Chesapeake Bay and coastal Delmarva, New Jersey. Map courtesy NOAA, Washington Post/CWG (Twitter)
The remains of “Isasis” will push through interior New England by later tonight on the way to southeastern Canada and the weather in the Mid-Atlantic/NE US will quite down considerably later tonight and Wednesday. One final note of caution, even after the rains ends and perhaps the sunshine returns, there can be significant flooding issues for an extended period of time in some areas.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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