AccuWeather's Geoff Cornish breaks down the weather conditions that are expected to strengthen a coastal storm into a powerful system with destructive coastal flooding from Oct. 10-13.
00:00Now, let's go to Jeff with tonight's forecast feed.
00:05Well, we're going to take a look at how this weekend is likely to unfold with a damaging, destructive end to the weekend along the coast associated with a system that we're calling a tropical rain and wind storm.
00:19It'll have some tropical characteristics and also some not so tropical characteristics, but whether it gets an official name from the Hurricane Center or not, we're concerned about the impacts, and that is the name of the game here.
00:30And AccuWeather.
00:31So as we take a look at some of the influences in driving this system and organizing it, we're tracking a disturbance that's dipping through parts of the southeast right now, kind of a subtle feature on the map.
00:43That's this area of upper level low pressure, the puddle of cooler air aloft.
00:46We've had a front draped across the southeast, and that front is basically just kind of setting the table here for trouble.
00:55This is going to be the big developing storm system that eventually gets going just offshore.
01:00So as we move forward one more step here from Friday night to Saturday morning, we begin to see kind of, well, we will begin to see a new zone of low pressure at the surface just above the ocean surface organized here.
01:13We're going to call that our tropical rain and wind storm here.
01:16And you can see the surface winds are going to get going with that.
01:18But there's also a big player on the map that's going to energize this here later this weekend.
01:23That's a strong upper level low pressure system.
01:26And these two systems are going to interact that will strengthen the storm in a big way later this weekend, the second half of the weekend.
01:33So, again, our updated AccuWeather eyepath for this storm is going to take the center of circulation that forms on Sunday evening, and it pulls it north here through the next several days.
01:44And ultimately, it's going to be lurking very close to the Maryland-Virginia beach coastline here.
01:51And as this pulls north here, just this slow process, which is going to round the bend there from late Saturday night, Sunday, Sunday night, Monday.
02:00It won't travel a whole lot through that time.
02:02And, again, this counterclockwise circulation is going to hammer the coast of New Jersey with strong winds.
02:08And, again, this is what we've been really emphasizing, the coastal flooding.
02:11Friday night to Saturday, some issues here for the Outer Banks, and then things escalate farther north.
02:16We're very concerned about areas around the Chesapeake Bay, the Delaware Bay, a sandy hook there across from the New York City Harbor, and other areas of concern as well.
02:26So let's get into it with the models.
02:28And, again, just a precursor here, a quick look at that disturbance.
02:31This is the thing we were highlighting with that other graphic.
02:33That little dip in the jet stream, there's not much to it, but it's enough.
02:35It's certainly enough to aggravate things and strengthen this developing storm system, considering our front that's draped across the southeast coast right now.
02:46So that is going to be the big driver, low pressure, drifting across the region, encountering warm water.
02:53It's a puddle of cool air upstairs over warm water, perfect ingredients to get things rising in the atmosphere.
02:58And then we have the big low pressure system over the Great Lakes that's going to bring much more explosive development off the Carolina coast here.
03:06And you can see how these two systems interact here as we move forward from Saturday night to Sunday into the area around the mid-Atlantic coast.
03:16They kind of wrap up.
03:17The interior disturbance rotates around the base of the coastal trough, and that aggravates things in a way that becomes a pretty powerful storm.
03:24And then it ultimately kicks it out to sea.
03:25But let's take a look at how this may play out, some more specifics as we get down into some of the details.
03:31So here we have a strengthening storm system.
03:33This is the European model.
03:35And they're all pretty aligned with one another.
03:38The European, the GFS, even the NAM, the short range, shorter range model here.
03:42And it takes us out about three days.
03:44And you can see that Sunday morning, this is when the combination of strong high pressure, strong high pressure,
03:51just off the map up near Nova Scotia, interacting with the developing and strengthening coastal storm at this point.
03:57It's really going to lead to a stiff onshore wind.
04:00Look at all those isobars tightly packed together, stiff onshore wind leading to some coastal flooding.
04:05It's going to be plowing ocean water inland in a pretty meaningful way.
04:09Now, this is Sunday at 8 p.m., probably the height of the storm for New Jersey.
04:14That's the European.
04:16Here is the GFS.
04:17It's the center of the storm at that point is a little farther south, closer to Chickatee.
04:21And still an onshore wind for Long Island, New Jersey.
04:25But the center of the storm would be a little farther south.
04:27Third opinion, look at this.
04:28This is the NAM.
04:30It's way, way, way down into the southern part of the Outer Banks with some very heavy rain.
04:35Very different scenario.
04:37Very different solution.
04:38It would bring some strong onshore winds to New Jersey.
04:40Still coastal flooding.
04:41But this would lead to big-time flash flood concerns and also coastal flooding into the northern part of the Outer Banks.
04:49So those are three different scenarios.
04:51Looking at model forecasting here for some of the influences in our wind gust forecast.
04:57Here you can see the GFS 10 meters up, about 32 feet above the ground, up maybe near your rooftop level.
05:04You can see this is Sunday morning.
05:06Wind's beginning to really ramp up there for the Delmarva Peninsula, south Jersey, through Sunday, Sunday night, and into Monday, into Long Island.
05:14Now remember, that's the GFS.
05:16If the NAM is right, that's much farther south.
05:18But with the GFS, which is probably pretty representative of the consensus among the models right now,
05:25here is the max wind gust out through the forecast time frame.
05:28So through Sunday, through Sunday night, you can see this is in knots.
05:32This would produce a top wind gust in an area a little bit north of Toms River, New Jersey, of 53 knots.
05:39That translates to 59 miles per hour.
05:42Another state to check out here, North Carolina.
05:45Same model forecast.
05:47Here we have a 58-knot wind, which would be around 66, 67 miles per hour, somewhere not too far from Duck, North Carolina.
05:55So those are some problematic solutions here.
05:57Again, solutions being kind of like model depictions of the future.
06:02Either way, you dice it.
06:03We're looking at an AccuWeather real impact scale rating for hurricanes, even if it's not technically a full tropical system.
06:10We're calling it a tropical rain and windstorm of one.
06:13And again, the impacts are going to be significant along the coastline.
06:16Could become a billion-dollar disaster.
06:18And again, this compares to no official rating within the Saffir-Simpson hurricane wind scale.
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