Northeast in for a drenching as big storm system moves in
By
Alex Sosnowski, AccuWeather senior meteorologist
Published Apr 28, 2020 4:28 PM EST
The same storm system behind a severe weather outbreak across the Central states is pivoting through the northeastern United States with torrential rain and strong winds into Friday.
The setup may produce a "fire hose effect" with heavy rain being funneled through the region.
The radar snapshot shows a river of rain extending from eastern North Carolina to central New York state as of 2:30 p.m. EDT Thursday, April 30, 2020. The band of heavy rain will slowly shift eastward. For a time Thursday night, this band will be focused from the Chesapeake Bay region to the Catskill Mountains in eastern New York state.
"While widespread violent thunderstorms are not anticipated, we expect the storm to swing through the Northeast with heavy enough rain to cause flooding problems and strong enough winds to be of concern for sporadic power outages and fallen trees," AccuWeather Senior Storm Warning Meteorologist Brian Wimer said.
The storm will pivot slowly through the mid-Atlantic coast and the Hudson Valley of New York during Thursday night and finally New England on Friday.
The flooding potential is of regional concern for small streams and urban areas, rather than just an isolated event.
On Wednesday afternoon, a horse-drawn buggy overturned after attempting to cross a flooded stream in northeastern Kentucky, killing four children.
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Typically, a storm that brings 1-3 inches of rain over 24 to 48 hours would not cause problems. However, in this case the bulk of the rain may fall in 3-6 hours with an AccuWeather Local StormMax™ of 6 inches. The heaviest rain is likely to fall over the central Appalachians and southern New England.
With the ground saturated or at least rather wet, runoff will be substantial with rainfall of that intensity. Forecasters urge people who live near small streams to closely monitor warnings and water levels, and they warn people seeking an escape outdoors amid the pandemic to be cautious while hiking or camping along small streams. Creeks and small streams could rise several feet in a matter of minutes with this situation.
Adding to the wet ground is the recent snowfall over the northern parts of New York state and northern New England. Even though the rain may be less intense across the northern tier, recent snowmelt or rapidly melting snow during the rain will add extra runoff.
The rain will be a problem for motorists on the highway as well as for local commuters. Some street and highway flooding are likely. Motorists may want to avoid taking secondary roads that parallel or cross small streams during the storm as the water may rise rapidly and block access or even wash out some road surfaces.
The rain may be intense enough for a time to ground aircraft or delay landing, due to poor visibility and hydroplaning concerns, not only around New York City, Philadelphia, Washington, D.C., and Boston, but also the smaller regional hubs.
Strong southerly winds will precede the heavy rain. A strong difference in atmospheric pressure associated with a high pressure system and the approaching storm will cause the air to rush through the region. Since the wind will be aligned near the ground and aloft, strong gusts from aloft can reach down to the ground rather easily.
Frequent gusts between 40 and 50 mph are anticipated with an AccuWeather Local StormMax™ of 60 mph expected over the ridges, through the gaps in mountains, in open areas, south-facing shoreline, between buildings and over high bridges.
The strongest wind gusts are likely to occur in thunderstorms that develop from the eastern part of North Carolina through the Chesapeake and Delaware bay regions. Should the storms become severe, then the 60-mph peak wind threshold could be exceeded.
"There is a remote chance that storms become intense enough to produce an isolated tornado or two near the mid-Atlantic coast during the late afternoon and evening hours on Thursday," said AccuWeather Meteorologist Jake Sojda.
The combination of saturated ground, sap flowing up into the trees and high winds can create a top-heavy situation and lead to some trees coming down or large tree limbs breaking. Sporadic power outages are possible.
Soon after the heavy rain begins, winds may ease and shift out of the west.
In the wake of the storm, where the sun is able to come out for a few hours, it will feel and get noticeably milder. High temperatures are forecast to jump from the 40s and 50s to the 60s and 70s from one day to the next.
The transition from cool and damp conditions is likely to happen the fastest over the central Appalachians and mid-Atlantic on Saturday, but may wait over much of New England until Sunday.
The weather has been unusually cool in recent weeks, especially when compared to a long mild stretch that occurred late in the winter.
The period from March through April brings a dramatic rise in average temperatures. Typically, a degree Fahrenheit is added every two to three days.
Not only have warm days been very limited during April, but temperatures trended lower on some days as normal temperatures have trended upward.
For example, at New York City, the average temperature during March was 48 degrees Fahrenheit, which was 5.6 degrees above average. During the first 28 days of April, the average temperature was 50 degrees, or 2.6 degrees below average.
The end result is a feeling of being in limbo or not gaining warmth as the season progresses, but AccuWeather meteorologists say there is some light at the end of the tunnel for people who have been feeling cooped up amid the coronavirus pandemic in recent days.
The pattern will change a bit with the weather this weekend offering a bit of a clue with milder conditions anticipated. However, temperatures can still lag during cloudy days or when the ground remains wet during an upcoming pattern shift. But, when the sun is out during the middle to late spring, normal temperatures can be realized or bested.
Despite some milder weather for the weekend, AccuWeather's team of long-range forecasters remains pessimistic about big, long-lasting warmth through the middle of May.
"We should have some swings in temperature over the next two weeks or so, but the tendency will be for below-average temperatures in the long term over the Northeast," Paul Pastelok, AccuWeather's top long-range meteorologist, said.
There are some signs that the persistent southward dip in the jet stream responsible for the recurring chill in the Northeast may retreat toward the middle of May.
"Hot weather seems unlikely during mid- to late May in the Northeast, but the chill should ease up to the point where we get warmer days more often," Pastelok said.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Report a Typo
News / Severe Weather
Northeast in for a drenching as big storm system moves in
By Alex Sosnowski, AccuWeather senior meteorologist
Published Apr 28, 2020 4:28 PM EST
The same storm system behind a severe weather outbreak across the Central states is pivoting through the northeastern United States with torrential rain and strong winds into Friday.
The setup may produce a "fire hose effect" with heavy rain being funneled through the region.
The radar snapshot shows a river of rain extending from eastern North Carolina to central New York state as of 2:30 p.m. EDT Thursday, April 30, 2020. The band of heavy rain will slowly shift eastward. For a time Thursday night, this band will be focused from the Chesapeake Bay region to the Catskill Mountains in eastern New York state.
"While widespread violent thunderstorms are not anticipated, we expect the storm to swing through the Northeast with heavy enough rain to cause flooding problems and strong enough winds to be of concern for sporadic power outages and fallen trees," AccuWeather Senior Storm Warning Meteorologist Brian Wimer said.
The storm will pivot slowly through the mid-Atlantic coast and the Hudson Valley of New York during Thursday night and finally New England on Friday.
The flooding potential is of regional concern for small streams and urban areas, rather than just an isolated event.
On Wednesday afternoon, a horse-drawn buggy overturned after attempting to cross a flooded stream in northeastern Kentucky, killing four children.
CLICK HERE FOR THE FREE ACCUWEATHER APP
Typically, a storm that brings 1-3 inches of rain over 24 to 48 hours would not cause problems. However, in this case the bulk of the rain may fall in 3-6 hours with an AccuWeather Local StormMax™ of 6 inches. The heaviest rain is likely to fall over the central Appalachians and southern New England.
With the ground saturated or at least rather wet, runoff will be substantial with rainfall of that intensity. Forecasters urge people who live near small streams to closely monitor warnings and water levels, and they warn people seeking an escape outdoors amid the pandemic to be cautious while hiking or camping along small streams. Creeks and small streams could rise several feet in a matter of minutes with this situation.
Adding to the wet ground is the recent snowfall over the northern parts of New York state and northern New England. Even though the rain may be less intense across the northern tier, recent snowmelt or rapidly melting snow during the rain will add extra runoff.
The rain will be a problem for motorists on the highway as well as for local commuters. Some street and highway flooding are likely. Motorists may want to avoid taking secondary roads that parallel or cross small streams during the storm as the water may rise rapidly and block access or even wash out some road surfaces.
The rain may be intense enough for a time to ground aircraft or delay landing, due to poor visibility and hydroplaning concerns, not only around New York City, Philadelphia, Washington, D.C., and Boston, but also the smaller regional hubs.
Related:
Strong southerly winds will precede the heavy rain. A strong difference in atmospheric pressure associated with a high pressure system and the approaching storm will cause the air to rush through the region. Since the wind will be aligned near the ground and aloft, strong gusts from aloft can reach down to the ground rather easily.
Frequent gusts between 40 and 50 mph are anticipated with an AccuWeather Local StormMax™ of 60 mph expected over the ridges, through the gaps in mountains, in open areas, south-facing shoreline, between buildings and over high bridges.
The strongest wind gusts are likely to occur in thunderstorms that develop from the eastern part of North Carolina through the Chesapeake and Delaware bay regions. Should the storms become severe, then the 60-mph peak wind threshold could be exceeded.
"There is a remote chance that storms become intense enough to produce an isolated tornado or two near the mid-Atlantic coast during the late afternoon and evening hours on Thursday," said AccuWeather Meteorologist Jake Sojda.
The combination of saturated ground, sap flowing up into the trees and high winds can create a top-heavy situation and lead to some trees coming down or large tree limbs breaking. Sporadic power outages are possible.
Soon after the heavy rain begins, winds may ease and shift out of the west.
In the wake of the storm, where the sun is able to come out for a few hours, it will feel and get noticeably milder. High temperatures are forecast to jump from the 40s and 50s to the 60s and 70s from one day to the next.
The transition from cool and damp conditions is likely to happen the fastest over the central Appalachians and mid-Atlantic on Saturday, but may wait over much of New England until Sunday.
The weather has been unusually cool in recent weeks, especially when compared to a long mild stretch that occurred late in the winter.
The period from March through April brings a dramatic rise in average temperatures. Typically, a degree Fahrenheit is added every two to three days.
Not only have warm days been very limited during April, but temperatures trended lower on some days as normal temperatures have trended upward.
For example, at New York City, the average temperature during March was 48 degrees Fahrenheit, which was 5.6 degrees above average. During the first 28 days of April, the average temperature was 50 degrees, or 2.6 degrees below average.
The end result is a feeling of being in limbo or not gaining warmth as the season progresses, but AccuWeather meteorologists say there is some light at the end of the tunnel for people who have been feeling cooped up amid the coronavirus pandemic in recent days.
The pattern will change a bit with the weather this weekend offering a bit of a clue with milder conditions anticipated. However, temperatures can still lag during cloudy days or when the ground remains wet during an upcoming pattern shift. But, when the sun is out during the middle to late spring, normal temperatures can be realized or bested.
Despite some milder weather for the weekend, AccuWeather's team of long-range forecasters remains pessimistic about big, long-lasting warmth through the middle of May.
"We should have some swings in temperature over the next two weeks or so, but the tendency will be for below-average temperatures in the long term over the Northeast," Paul Pastelok, AccuWeather's top long-range meteorologist, said.
There are some signs that the persistent southward dip in the jet stream responsible for the recurring chill in the Northeast may retreat toward the middle of May.
"Hot weather seems unlikely during mid- to late May in the Northeast, but the chill should ease up to the point where we get warmer days more often," Pastelok said.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Report a Typo