Offspring of Isaac drifts back into Gulf; multiple cold fronts to push into tropical moisture over Southwest Virginia
Your comments and our discussion on the last thread about the “hype” surrounding Hurricane Isaac inspired me to write about that in today’s Weather Journal column (linked here).
Isaac — which we first started to talk about on Aug. 21 — just won’t go quietly into that good night. The former hurricane split into two circulation centers inland, one now a low-pressure system over the Northeast. The southern piece has wobbled southward back to the Gulf Coast and may drift back over the Gulf of Mexico today. The National Hurricane Center gives this “son of Isaac” a 20 percent chance of redeveloping into a tropical cyclone. If it were to redevelop and then strengthen into a tropical storm, it would be a judgment call by the forecasters at the National Hurricane Center whether to simply call it Tropical Storm Isaac or to move on down to the next name on the list, Nadine, which would make it a “daughter of Isaac” I suppose. (There is a Tropical Storm Michael now, in the open Atlantic — and Tropical Storm Leslie, which may hit Bermuda and possibly Newfoundland later this week). In 2004, Hurricane Ivan came inland in the Florida Panhandle, then broke into 2 pieces over Virginia. One piece of it moved back over the Atlantic, got carried south and then west over Florida, then regained tropical storm characteristics in the central Gulf of Mexico before making a second landfall as the controversally renamed Tropical Storm Ivan over eastern Texas. (Ivan’s loopy 2004 track linked here.) Other tropical cyclones that develop from a fragment of a former tropical system have been given a new name, if it’s determined it’s more of a by-product of the old storm rather than a main part of it. Chances are still slim that it will become a tropical storm, so this discussion may be moot, just something interesting to consider.
Meanwhile, back home, a weak cold front is pushing into some of Isaac’s leftover moisture in our mountains, and we are seeing some enhanced showers this morning. Cold fronts will start to be our weather focus, with at least 3 different ones affecting us through early next week, the last of which will bring a shot of cooler, drier weather that may push some fall-like temperatures (60s-70s highs, 50s lows, some 40s) into our region the early to middle part of next week. Until that final push of Canadian air makes it through, we won’t entirely get rid of this sticky tropical moisture, and showers and storms will be a threat most days — though perhaps there will be one summelike warm to hot (80s, some low 90s) and mostly dry day on Friday. These fronts should also shunt Isaac’s offspring eastward toward the Florida Peninsula.
September 5, 2012 - 8:42 AM
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Well so much for shifting the discussion away from Isaac.
Joe and Jamey Singleton added some interesting comments at the end of the last thread, after I declared it a day and went to sleep, so be sure and go back and see those and the other 81 comments if you haven’t already.
If these big A/C units keep cranking over the Gulf it could freeze over by 2015 and we’ll have polar bears in Florida. LOL
That actually wouldn’t be good for all the snow lovers on the board. The warm Gulf helps supply thick moisture when the jet stream dips far enough south and the big lows sweep it up in the winter. Frozen-over Gulf = cold, dry hand-busting weather.
I finally had some rain at my house this morning. My hubby pulled out around 6:15 and it had not rained. When I loaded the kiddos up for school this morning, I had standing water in front of my driveway. Apparently it was a quick shower, but dumped quite a bit of rain in SW County. As I told Mr. Griggs yesterday, I don’t think there is any hope of saving my back yard this season though. It is still brown and crunchy!
And Kevin, back to the last thread. Only 6 weeks to possibly seeing snow flakes below 4000ft! I’ll take it LOL
This is a perplexing day for someone who makes a living by working outside. I keep thinking that today will be a rain-out, but the showers seem to be losing intensity and coverage as they make their way into the NRV.
I can’t figure out what to do.
The solid line in Illinois / Indiana is moving roughly 30mph…Futurecast not really picking it up at this point. Kevin, any thoughts it makes it this far east?
Nate, an old man that worked for me for years told me more than once. “Boy, you’ll lose more time waiting for it to rain than you’ll lose because it starts raining”
Isaac = the Zombie storm. It dies but never quite goes away!
After having only .55 inches from Isaac over the past 4 days, a nice extended storm just dumped an inch on our house in Goodview. We are now at 1.11 for the day, 1.66 since this began. In Jordantown, Dad has .43 today for an Isaac total of 1.95
Rain, I actually got rain. There was 0.40″ in Wytheville this morning. I work 10 miles away and not a drop at work. Fine. I’ll take some more by the weekend though, for my recent grass seeding project.
That is a healthy bow echo crossing the Ohio River from Indiana to Kentucky that Paul points out. Right now, it’s projected to build more southward than just continue eastward, and there is some drying aloft between us and it, so it’s not expected to arrive here, fully intact at least. But worth keeping an eye on just to see if it gets some eastward momentum.
Bring on the cool fall weather!! How does OLD Salem days look Saturday Matt??
Not sure about who the Matt is you refer to, but Olde Salem Days will probably be dodging some storms — not constantly, but a chance at any time. To get from the tropical soup to the cooler, drier more fall-like weather next week, we’ll have to have some storms in between.
There’s some good eastward movement on that KY bow echo, but there’s also 250 miles to go to the NRV.
At the moment I don’t see that pulse from the Ohio Valley weakening, looks like plenty of moisture and heat to feed it at least to Western VA. Not much discussion on the NOAA sites beyond Central Kentucky, but possibly here in the ROA after the midnight hours. NOAA mentions several more pulses to develop overnight in far Western Kentucky.
Thanks for the info about that bow echo heading this way. I have been watching it today and wondering if it would make it over the mountains intact. We will keep an eye on it.
Not a ton of severe reports coming in from the MCS: http://www.spc.noaa.gov/climo/reports/today.html
Only 4 severe t-storm warnings currently along the entire line. Ideally for those wanting rain it would get in here late as a rainmaker with no severe weather. I am doubting it makes it. Maybe west of I-77 gets something.
What a hot humid day,high so far 89,just checked the temps Winchester and Dulles both hit 90 today.Dew points are terible up here! Finally had a day without rain,started out a little cloudy this morning,but it quickly turned sunny by mid morning.Kevin when is this humidty going to break?Thanks,Mike
Just watched Mr. Watts on “7.” He showed that very impressive line of what is now intense T-storms in KY and I think southern Indiana. REALLY moving fast. He thinks it is very possible that they will hit (fairly) far SW Virginia. Michael Hoback, you wanted more rain just a week or so ago, and you got it big time, and I for one think it is likely that you get some more tonight. I will be hoping (against hope?) that you get at least a 1/4 inch, too, Rick.
Nurse Snow, you and I live less than 2 miles from each other as the weather travels, and I probably got more than your yard got on Saturday night. This morning you got more than me. There was some sign of dampness here, but that’s all. But I am glad that this one hit you harder …. definitely sounds like you needed it more.
The storm cluster does have its own cold pool pushing it, so it has a chance to go farther than it would just on the upper-air flow. The storms are primarily heavy rain makers — no severe warnings in Kentucky currently, a few in Tennessee. West of I-77 has the best shot of seeing some of these storms.
I normally don’t keep up with totals. My yard tells me what I got. And it said it needs mowing again. SOON!!!!!
I went ahead and went out into the woods today, and was rained on once at noon, the other (which was rather heavy) at 3:30. I’m happy to be in dry clothes.
Getting a solid downpour now in the Bonsack area…
Radar showing 1-plus inch rain totals in last hour just north of Roanoke into southern Botetourt County.
Chance of “Isaac offspring” becoming tropical cyclone raised to 40 percent, with hurricane hunter aircraft now slated for Thursday afternoon visit.
http://www.nhc.noaa.gov/gtwo_atl.shtml
I’m hearing it’s likely to be named Nadine, not Isaac.
Getting a second cell now…training going to be a problem tonight .
NASA planning to use Global Hawk drone to release dropsondes into gulf disturbance…NASA 872…beginning tomorrow eve about this time..
Flash flood warning for northeast Roanoke County and southwest Botetourt County until 10:15 p.m. as a result of the nearly stalled, training heavy rain cells.
On cell…sorry…google nasa global hawks 2012 hurricane study..
The eastern part of the MCS is really starting to come apart now in eastern Kentucky. The severe thunderstorm watch has been lifted. Perhaps some influence of that could continue to trigger showers and storms downstream overnight.
Well, let me qualify that: There are plenty of clustering storms in eastern Kentucky and West Virginia, but more of the slow-moving, heavy-rain-dumpers like we’ve been seeing, not a bow echo or squall line.
Looks like the activity now in eastern KY is holding enuf energy to keep it together into the Roa vly..much more easterly component to that area.
It’s kinda merged into the storm clusters that had formed out ahead of it in West Virginia, the more tropical-like downpour stuff we’ve been dealing with. In any event, doesn’t look like a severe-level MCS blasting through, but hopefully some rain for the folks who want it and haven’t gotten it yet this week.
There is one tornado warning in SE Kentucky near Corbin, linked to a spotter report of a funnel cloud near Cumberland Falls State Park.
Have been outside and could see the big puffy white clouds north of Roanoke. Now as it is getting dark, we can see the lightning in them. Guess they are the ones that are in Botetourt County.
That stalled cell hit my work (north end of Plantation Rd) just as I was trying to leave. It was very hard to see. Needless to say all of the streams around that area were full or almost full. It looked like a river in front of the old Sunnybrook Restaurant (think it’s called the Plantation now). I need to find a portable rain gauge for my vehicle
I think the “Matt” above was meant to be “Myatt”. I’d never think about forecasting here, I just enjoy reading the collective wisdom! NHC has upped the “son of Isaac” to a 50% chance of development (the same storm that wasn’t supposed to survive the trip over Hispaniola). Wouldn’t there be a ton of hype if it reformed and did a 180 and went back over New Orleans!
What do you think, Weather Wizard, do you agree with joe that Pulaski, Blacksburg, and Salem/ SW Roanoke County might get at least 1/10th of an inch later tonight? Or do you think that the rain will dissipate before it gets here?
I know, joe, you did not precisely predict that …. but I think I saw that you commented that the storms were headed for Bburg/ROA, which they indeed are.
I have just looked at the radar and it looks as though most of the city of Roanoke is about to get a pretty nice downpour. First, I would be delighted as we still haven’t gotten anything more than a sprinkle in weeks. Second, I could have predicted this months ago. My better half only travels out of town on business once a year. It never fails, when he goes out of town it storms. Let the rains begin.
I think it’s going to be spotty, streaky stuff like usual, Doug. Line continues to weaken with loss of daytime heating. But there could be some remnants, or even some new development with the upper-level energy, as it moves through.
Weather Wizard speaks, and sure enough, I looked closely at the leading edges of rain near Pikeville, KY and Beckley, WV. And {hey, Captain Quagmire, are you looking in here tonight?} it almost looks like “The Black Knight” from the “Monty Python and The Holy Grail” movie is out there directing rainstorm traffic. He is the guy who threateningly warned King Arthur (and Patsy) that “NONE SHALL PASS!!” (The character ended up losing both arms and both legs in a swordfight with Arthur, by the way.)
Anyway, in both areas the rain suddenly seems to be having a lot of trouble moving eastward. The one cell that continues to move was up in northern Craig heading ENE into Botetourt …. away from us, Leo Lady, Nurse Snow, wd, Doppler Carol and me.
Spent a lot of time on the S.C. Coast the month of August on weekends this year. In the past this month is known for very little wind so much so that when we used to sail on a small catamaran August was a month to avoid. This year however the southeast wind always seemed to be ever present . If my memory is correct then this is a new occurrence . I wonder if this is a harbinger of things to come for fall and the upcoming winter. Anyone have an opinion on this .
The National Hurricane Center has mentioned on its Facebook page today that if the system in the Gulf regenerates into a tropical storm, it would be called Nadine, not a second helping of Isaac.
Here is the National Hurricane Center Facebook post on why new storm in Gulf would be Nadine and not renamed Isaac:
“There have been quite a few inquiries about whether the name ‘Isaac’ would be given to the area of disturbed weather currently located along the northern coast of the Gulf of Mexico, if it were to develop into a tropical cyclone. The short answer is no, it would get a new name.
“Our analysis of the satellite, surface, and lower-tropospheric radiosonde data suggested that the disturbance we’re currently following originated within Isaac’s broad circulation, but that it had its own surface pressure minimum distinct from Isaac’s. This was perhaps most apparent late in the day on Monday, when the residual surface center of Isaac was located over western Kentucky while a second weak low was located over northern Mississippi and Alabama. Isaac’s circulation continued to weaken after that and became difficult to track, while the new disturbance moved slowly toward the Gulf coast. So what basically happened here is that a little piece of Isaac broke away and moved south.
“OK, now everybody get your lawyer and grammar hats on. The National Weather Service rule that applies here reads: ‘if the remnant of a tropical cyclone redevelops into a tropical cyclone, it is assigned its original number or name’.
“Notice the rule says ‘the’ remnant, and not ‘a’ remnant. This means that the storm’s primary remnant (and not just any old part of it) has to re-develop in order for the name to be retained. Since the primary remnant of Isaac was still in Kentucky when the new low formed and broke away, the rule dictates that the new low is not entitled to the name Isaac.
“This rule actually makes a lot of sense. If a storm died and each of two parts re-developed, we couldn’t give the same name to both parts. Only the primary remnant would retain the name, while a lesser remnant or part would get a new name.”
Really interesting info about Isaac/Nadine, thanks for sharing.
Well we received about .40″ of rain this afternoon sometime. Can’t decide if I think the rest of these showers will make it here or not; what’s everyone’s thoughts? I thought it wouldv’e fallen apart already.
Here’s what NWS-Blacksburg says about tonight’s rain complex:
SHOWERS AND STORMS WILL CONTINUE ON A ENE TRACK MOSTLY HITTING SE WEST VA FROM NE KY AND SW WV. ALTHOUGH THESE WILL BREAK IF THEY CROSS THE APPLN MTNS…SOME MAY SURVIVE INTO THE NEW RIVER AND ROANOKE VALLEYS LATER TONIGHT. THE NORTHERN REMNANTS OF THE SQUALL LINE WHICH MOVED ACROSS KY EARLIER TODAY COULD GET TO EXTREME SW VA AND NW NC AROUND MIDNIGHT.
Have a little line of storms that have developed ahead of the storms from Kentucky. Seem to be running from Ashville,NC to Sparta,NC…may make it to me in Woodlawn…
Had sprinkles and light showers off and on all day in Abingdon. Got home around 5 pm and found .60″ in my gauge. I could tell by the radar that the Chapel was getting more than Abingdon. Tonight we have had quite a light show out of Eastern KY and when I went to close up the chickens for the night, I heard thunder in the distance. These storms have weakened but I feel they will give the Chapel another dose of rain tonight. We are up to 2.80″ since Saturday.
I’m keeping a very close eye on the weather this weekend. I hope to be sitting at the NRV Skyfest Air Show in Dublin with clear skies. I’ll settle for no rain.
Don’t know if I’d go for clear skies. Hope you get enough periods of partly cloudy for a good air show.
Finally picked up some decent rainfall today at my location in Blue Ridge. As of 11PM, I recorded 0.97″, which makes my monthly total 1.28″.