Irene continues to weaken

By: Dr. Jeff Masters , 8:46 PM GMT on August 26, 2011

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Satellite data and measurements from the Hurricane Hunters show that Irene continues to weaken. A 1:32 pm EDT center fix by an Air Force Reserve aircraft found that Irene's eyewall is still gone, and the central pressure had risen to 951 mb from a low of 942 mb this morning. The winds measured in Irene near the surface support classifying it as a strong Category 1 hurricane or weak Category 2. Satellite imagery shows a distinctly lopsided appearance to Irene's cloud pattern, with not much heavy thunderstorm activity on the southwest side. This is due to moderate southwesterly wind shear of 10 - 20 knots. This shear is disrupting Irene's circulation and has cut off upper-level outflow along the south side of the hurricane. No eye is visible in satellite loops, but the storm's size is certainly impressive. Long range radar out of Wilmington, North Carolina, shows that the outermost spiral bands from Irene have moved ashore over North Carolina. Winds at buoy 41004 100 miles offshore from Charleston, SC increased to 47 mph, gusting to 60 mph at 3 pm EDT, with significant wave heights of 25 feet.


Figure 1. MODIS satellite image of Hurricane Irene taken at 11:50 am EDT Friday August 26, when Irene was a Category 2 hurricane with 105 mph winds. The eyewall collapsed several hours before this image was taken, and no eye is apparent. Image credit: a href=http://rapidfire.sci.gsfc.nasa.gov/gallery/ NASA.


Figure 2. Distribution of Irene's wind field at 3:30 pm EDT Friday August 26, 2011, as observed by the Hurricane Hunters and buoys. The right front quadrant of the hurricane had about 90% of the storm's hurricane-force winds (yellow and warmer colors, bounded by the heavy black line between the "50" and "60" knot thin black lines.) Tropical storm-force winds (heavy black like bounding the light blue area) extended out 290 miles from the center of Irene. Image credit: NOAA/AOML/HRD.

Forecast for Irene
With its eyewall collapsed and just 18 more hours over water before landfall, Irene does not have time to build a new eyewall and intensify. The storm is too large to weaken quickly, and the best forecast is that Irene will be a strong Category 1 hurricane at landfall in North Carolina on Saturday. Based on the latest wind analysis from NOAA's Hurricane Research Division (Figure 2) and Irene's continued weakening trend, I predict that the 80-mile section of North Carolina coast to the right of where Irene makes landfall will receive sustained hurricane-force winds of 75 - 85 mph on Saturday at landfall; the 80-mile section of coast to the left will receive 55 - 75 mph winds. High wind shear of 30 knots will begin ripping into Irene Sunday morning when it is near Southern New Jersey, and more rapid weakening will occur. By the time Irene arrives on Long Island Sunday afternoon, it will probably have top sustained winds in the 65 - 75 mph range. However, since Irene is such a huge storm--tropical storm force winds extend out up to 290 miles from the center--it has set a massive amount of the ocean's surface in motion, which will cause a much larger storm surge than the winds would suggest. At 3:30 pm EDT this afternoon, a wind analysis from NOAA/HRD (Figure 2) indicated that the potential storm surge damage from Irene still rated a 5.0 on a scale of 0 to 6. This is equivalent to the storm surge a typical Category 4 hurricane would have. While this damage potential should steadily decline as Irene moves northwards and weakens, we can still expect a storm surge one full Saffir-Simpson Category higher than Irene's winds when it impacts the coast. Since tides are at their highest levels of the month this weekend due to the new moon, storm surge flooding will be at a maximum during the high tidal cycles that will occur at 8 pm Saturday night and 8 am Sunday morning. Wherever Irene happens to be at those times, the storm surge damage potential will be maximized. I continue to give a 20% chance that a 3 - 4 foot storm surge high enough to over-top the Manhattan flood walls and swamp the New York City subway system will occur on Sunday. The latest 11 am probabilistic storm surge map from NHC shows a 20 - 30% chance of a storm surge in excess of 3 feet in New York Harbor (Figure 4.) Keep in mind that these maps are calculated for normal tide level, and this weekend's high tides will be nearly 1 foot above normal.

Insurance company AIR-Worldwide is estimating that insured damages from Irene in the U.S. will be $1.5 - $6 billion. They estimate losses in the Caribbean at $0.5 - $1.1 billion from Irene.


Figure 3. Storm surge heights, in feet above normal tide level, which have a 20 percent chance of being exceeded during the next 3 days.  The graphic is based upon an ensemble of Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model runs using the current National Hurricane Center (NHC) official hurricane advisory. The exceedance heights depend on the historical accuracy of NHCs forecasts of hurricane track, and wind speed, and an estimate of storm size. Image credit: NOAA.


Figure 4. Overall chance that storm surges will be greater than 3 feet above normal tide levels during the next 3 days.  The graphic is based upon an ensemble of Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model runs using the current National Hurricane Center (NHC) official hurricane advisory.  Storm surge probabilities depend on the historical accuracy of NHCs forecasts of hurricane track, and wind speed, and an estimate of storm size. Image credit: NOAA.

Links
For those of you wanting to know your odds of receiving hurricane force or tropical storm force winds, I recommend the NHC wind probability product.

Wunderground has detailed storm surge maps for the U.S. coast.

The National Hurricane Center's Interactive Storm Surge RIsk Map, which allows one to pick a particular Category hurricane and zoom in, is a good source of storm surge risk information.

Wunderblogger Mike Theiss is in Nassau, documenting the storm's impact on the Bahamas.

Internet radio show on Irene at 4:30pm EDT
Wunderground meteorologists will be discussing Hurricane Irene on a special edition of our Internet radio show, the Daily Downpour, today (Friday) at 4:30pm EDT. Shaun Tanner , Tim Roche, Angela Fritz, and Rob Carver will take your questions. The email address to ask questions is broadcast@wunderground.com.

Jeff Masters

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Quoting P451:


Was gonna say you left out a letter but then I realized something... Very good P451, and please stay safe.
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Quoting Beachfoxx:
{{{Aqua}}}

Yep, Beel is Buzzing!
and the Misled Person should have donated their supplies yesterday since they don't think they will need them.... hehehehe


lmao
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Quoting Orcasystems:


I wish you guys would quit telling him that its not there yet... this is a perfect setup for a Darwin :)

I would tell the idiot to go down to the beach for a swim.
Might be the best solution. I have this guy made for a Troll and if that word gets me kicked out so be it. Anybody listening to this guy is being seriously miss lead.
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1698. TX2FL
Quoting SeKelly84:
Hey Guys. I live up here in Portland Maine and though the worse seems to be hitting in New York and CT...we are expecting gusts up to 90 MPH here, should the storm miss the outerbanks and slam into CT. A little self promotion, I work for Delta and I apparently have to work Sunday. I'll be driving in, and I will have a live stream going on my drive, and I plan to check out the ocean. If you want to check it out bookmark me Link

I'll be live around 1pm Eastern. My drive is roughly an hour...I'll be near the ocean at 2pm Eastern.


WHY are they not cancelling flights there? I work for another airline and no one has to work on Sunday unless you are volunteering, and in our area we are 45-55 mph winds with 70 gusts... Crazy..
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Quoting shoreacres:


Dumb and misled? Well, you got it half right, anyhow.


Ok I understand u some of u guys think preparing is the right thing and assure me doing it next time is the right thing to do thanks I appreciate the advice.

To the people taking personal shots... I could go for a jog right now if I didn't mind a light shower. Nothings happening. The beach is another story but 5 miles inland we r A okay. And as far as misled... A hurricane warning means hurricane conditions r expected. We have barely received tropical storm conditions and if u look at the radar we've received our heaviest part of the storm.
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The size and scope of this cyclone are incredible. The first bands are going to hit all of Jersey, and Long Island, BEFORE the storm's center hits the SC/NC border.
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My forecast..

Irene brushes the Outer Banks (as I originally forecast on my last run) with winds of 100-110 mph. She may strengthen..

Then Irene connects with the jet, while getting slightly sheared by southwesterly wind shear.. Landfall Sunday on western Long Island, winds at 85-100 mph. Potentially remaining a dangerous Hurricane. The jet may keep her strength going.

Please don't call me a doomcaster, The track has been my forecast for 2/3 days now, intensity dropped due to the slight weakening Irene has encountered; however, she seems to be far enough away from the dry air that she should be able to strengthen a bit more.

My last REED run made a few of days ago, in which I have nailed it, so far..



Irene looks better tonight..


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1694. 900MB
Quoting BaltimoreBrian:


I'll agree with that. I'll give NYC a solid 60 mph.


East of NYC, but slightly stronger, but I''l go w your OBX #'s
Member Since: June 11, 2006 Posts: 0 Comments: 684
New Bird in the Air from NOLA
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1692. Skyepony (Mod)
0900 PM TROPICAL STORM CHARLESTON 32.78N 79.94W
08/26/2011 CHARLESTON SC BROADCAST MEDIA

THE FOLLOWING STREETS ARE FLOODED DUE TO COASTAL
FLOODING... WASHINGTON... SOCIETY... MORRISON...
JACKSON... HARRIS... MARKET...

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1691. Ldog74
Quoting want2lrn:
lurking and reading but i thought i would jump in for two quick questions. What do you mean when yoou sa "extrapolated" presure and the weather man here just said the ridge is here in Texas is "breaking down and booking out" next week for a while. Ia that correct? He better not be teasing me! LOL




I'm not an expert, but talk recently has been that the ridge in Texas may be breaking over the next week or so. Who knows though, that thing has been impervious all summer. Extrapolated pressure, is for all intents and purposes, the pressure at that time, its just determined using a different method than the true pressure per se. I suppose it could be slightly less accurate, but not significantly to the point where strengthening/weakening trends wouldn't be apparent.
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pulling away from this buoy over 100 miles away.

Station 41004
NDBC
Location: 32.501N 79.099W
Conditions as of:
Sat, 27 Aug 2011 02:50:00 UTC

Winds: NW (320°) at 38.9 kt gusting to 50.5 kt
Atmospheric Pressure: 29.32 in and rising
Air Temperature: 78.6 F
Dew Point: 72.9 F
Water Temperature: 82.9 F
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1689. Skyepony (Mod)
0545 PM TROPICAL STORM SULLIVANS ISLAND 32.77N 79.84W
08/26/2011 CHARLESTON SC BROADCAST MEDIA

HIGH SURF UNDERMINED SEVERAL HOMES ON SULLIVANS ISLAND.


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Quoting want2lrn:
lurking and reading but i thought i would jump in for two quick questions. What do you mean when yoou sa "extrapolated" presure and the weather man here just said the ridge is here in Texas is "breaking down and booking out" next week for a while. Ia that correct? He better not be teasing me! LOL


An extrapolated pressure means that the hurricane hunters are not directly measuring the minimum central pressure at the surface, but are using the pressure levels from flight level and other mandatory levels in the atmosphere to calculate what the pressure likely is at the surface level through a complex formula.

And with regards to the high pressure over Texas, I have seen a couple of model runs in the last 24 hours which show the ridge sliding out of the region gradually by late next week.
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Quoting ProgressivePulse:
Noticing Irene taking a steeper angle NNE than anticipated.




In the NHC discussion, they state extra ridging in the next 12-24 hours will keep Irene along the coastline - so if this verifies, you should see Irene bend a little more to the left once around the OBX area - this will keep it riding the coastline from Maryland/Delaware, to New Jersey and then New York.

Radar suggests she is on path to landfall in the OBX.
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Quoting want2lrn:
lurking and reading but i thought i would jump in for two quick questions. What do you mean when yoou sa "extrapolated" presure and the weather man here just said the ridge is here in Texas is "breaking down and booking out" next week for a while. Ia that correct? He better not be teasing me! LOL


Extrapolated means taken from a point of origin and extended further outward in time or distance. Pressure meaning the reading was taken at a higher elevation and estimated (Extrapolated) down to the surface. It's basically and educated estimate.
Member Since: August 19, 2005 Posts: 5 Comments: 5449
Quoting P451:
Seems to be quite a strong storm and right on track.



Is it moving now more to the east (NE)?
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1684. 900MB
Night everyone! NYC checking out.

I'm sure I will be on between 5 and 8 in the am. Parting thoughts:

-Will barely scrape outer banks and path will adjust to Eastern Long Island by 8 am.

-Next few hours will be interesting. If there is an intensity boost it is between now and 8 am.

-A boost before NC means a stronger storm for Long Island and Eastern NE. But, doubt intensity picks up more than a tick given the lousy presentation.

-Christie and Bloomberg will be more defensive than the Jets and the Giants come Monday night :)
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1683. Levi32
Quoting want2lrn:
lurking and reading but i thought i would jump in for two quick questions. What do you mean when yoou sa "extrapolated" presure and the weather man here just said the ridge is here in Texas is "breaking down and booking out" next week for a while. Ia that correct? He better not be teasing me! LOL


Since the airplane is flying above the surface, they are measuring air pressure at flight-level. They then have to perform an "extrapolation" or an "estimate" of what the air pressure would be at the surface of the ocean, based on what the pressure is at flight-level.

I haven't studied the future pattern much because we have had Irene, but the GFS ensembles do hint at the Texas ridge breaking down for a little while in the 7-10 day period.
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*tucks Foxx tail between legs in shame & heads to the den* You are right - most of the Sharks I know prefer YOLOers & Surfers.......
Quoting Orcasystems:


Shame on you.. what did the poor shark do to you.
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For the person with the skunked dog. Go to your nearest Auto Supply. Get a LARGE bottle of GoJo hand cleaner. Work into fur of wet dog till you have suds all over, will take more than shampoo would. Rinse and dry dog. If one treatment doesn't get it a second should. Old Coon Hunter trick. Much better than OJ.
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Quoting CarolinaHurricanes87:
Wilmington has been spared and I am safe. Wrightsville may have had worse impacts And I wish them good news tomorow but I'm shocked how weak Irene is here in wilmingon. I think the NE will be in for a big surprise they've evacuated for nothing. Just how I bought $150 of supplies for nothing.

Next time I'll trust my instincts and gut and live with what happens. I feel dumb and misled right now.


Dumb and misled? Well, you got it half right, anyhow.
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Quoting CarolinaHurricanes87:
Wilmington has been spared and I am safe. Just how I bought $150 of supplies for nothing.

Next time I'll trust my instincts and gut and live with what happens. I feel dumb and misled right now.


Count your blessings, donate the supplies to a food pantry or keep for the next storm (hurricane season has three months left. Consider it a rehersal for the next hurricane that statistically one day will hit.

Meteorologists are scientists--not seers. Each storm adds new data for their models but they are not perfect. It is better to feel dumb than dead. :)
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1677. zawxdsk
HAME ON YOU
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Windows in FL along coast are designed to withstand 140MPH Sustained winds... some of the most stringent building codes in the USA.
Quoting rv1pop:
Answering in reverse. Wind blow out(and WTC for that matter) are 70% or more at a given level and exposure. WTC included fire blowing out windows. And I am not a structural engineer, but I did read code books and blueprints. Windows are considered a part of the shear walls. My illustration was total based as I said on the buildings I was responsible for. Everett WA area, 12 miles inland, 475 feet above sea level, and six miles into the plateau. Window size and feet above ground also were figured in. The four day class I had to take, the week before I retired, spent parts of 2 days and all of the third analyzing the preliminary documentation of the collapse of the WTC towers. I am certain the Gulf Coast and Florida building standards are much more stringent than those in Western Washington. Where I now live in Eastern Washington codes are more stringent on the East side of Hwy 97 than on the West side, because the West side has trees, the East side does not.
Buildings built after the code changes in 2006, anywhere in the United States, could be considerably stronger than those built before.
While this is somewhat on topic, to speak anymore will go way off....
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Quoting Beachfoxx:
ROFL -- > Shark Food?


Shame on you.. what did the poor shark do to you.
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I think the mandatory evacuations of hundreds of thousands of people in NJ and NY is overdoing it. I'm just not seeing such high surges as possible.

I think the real killer will be river flooding inland where people think they are safe.
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ROFL -- > Shark Food?
Quoting Orcasystems:


I wish you guys would quit telling him that its not there yet... this is a perfect setup for a Darwin :)

I would tell the idiot to go down to the beach for a swim.
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Would someone respond to 1581 please and thank you.
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ihave my NC beaches mixdupp,sorry...
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{{{Aqua}}}

Yep, Beel is Buzzing!
and the Misled Person should have donated their supplies yesterday since they don't think they will need them.... hehehehe
Quoting aquak9:
hi foxx!!

Beell's gotta buzz?? well worth losing sleep over to watch this! :)

and to the "misled" person- save your hurricane supplies and donate them to a food pantry come thanksgiving.
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1666. GatorWX
Does anyone think the gfdl scenario is plausible to some extent? Initially, it's off quite a bit (initialized the trough to be too weak) showing Irene moving north from the beginning of the run, and also I expect more of a ne heading as the storm moves through the mid atlantic into ne, but overall, the model is hinting at the storm bending back to the left as the current trough pulls out. I highly doubt she'll make landfall in NJ and move inland, but I am interested in how the model builds a bit of ridging after the current trough moves out. What I disagree with is the model not showing much, if any influence from the midwest trough approaching the storm, and I think if she does move in a more northerly direction, it would be brief because of the approaching trough.
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Quoting aislinnpaps:
I'm off for the night as well. HC87, count your blessings. You're breathing. There is one dead already who would love to be in your shoes and before this is over there will be many more.


is that the one from where i am or are there more already...then add those in FL, one critical that was just standing on the pier and it wasnt even supposed to do anything in FL...
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Quoting Beachfoxx:
Irene has not even knocked on your door yet......


I wish you guys would quit telling him that its not there yet... this is a perfect setup for a Darwin :)

I would tell the idiot to go down to the beach for a swim.
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Quoting aquak9:
hi foxx!!

Beell's gotta buzz?? well worth losing sleep over to watch this! :)

and to the "misled" person- save your hurricane supplies and donate them to a food pantry come thanksgiving.


I bet he has a lampshade on his head as we speak.
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1662. rv1pop
Quoting Methurricanes:

1) Windows have nothing to do with any highrises integrity.
2) the Towers had damage a lot deeper than windows, and to compare them to buildings that have a few blown out windows is insane.
Answering in reverse. Wind blow out(and WTC for that matter) are 70% or more at a given level and exposure. WTC included fire blowing out windows. And I am not a structural engineer, but I did read code books and blueprints. Windows are considered a part of the shear walls. My illustration was total based as I said on the buildings I was responsible for. Everett WA area, 12 miles inland, 475 feet above sea level, and six miles into the plateau. Window size and feet above ground also were figured in. The four day class I had to take, the week before I retired, spent parts of 2 days and all of the third analyzing the preliminary documentation of the collapse of the WTC towers. I am certain the Gulf Coast and Florida building standards are much more stringent than those in Western Washington. Where I now live in Eastern Washington codes are more stringent on the East side of Hwy 97 than on the West side, because the West side has trees, the East side does not.
Buildings built after the code changes in 2006, anywhere in the United States, could be considerably stronger than those built before.
While this is somewhat on topic, to speak anymore will go way off....
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Quoting KeyWestwx:
friend of mine has a coworker who lives on deleware bay just s. of Philly. She's not leaving her house. Yikes! He lives in an apt. complex on a river 35 miles West of Philly and they are evacuating the complex tomorrow.


A friend of ours in Philly said all they got told at their apt complex was "Get that &^%! off the balcony!"

Evacuating tomorrow? My brother in Jersey said half the gas stations were out of gas this afternoon. Here in Pensacola, we're used to that Third World stuff. The Tri-State area? Not so much. And where on earth are they going to go?

I think I said "Oy" already, right? It's gonna be awful.
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Quoting stillwaiting:
im still stickn tomy 90mph obx landfall and nyc at 50-60mph


I'll agree with that. I'll give NYC a solid 60 mph.
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I don't know if this has been posted yet but there's MANDATORY EVACUATIONS FOR 300,000 ON LONG ISLAND along the South Shore mainly, but it does include an area 10 miles inland where I used to live.

Here's the more specific town by town list, plus the whole chunk in the SW corner.
Link
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I'm off for the night as well. HC87, count your blessings. You're breathing. There is one dead already who would love to be in your shoes and before this is over there will be many more.
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1656. aquak9
hi foxx!!

Beell's gotta buzz?? well worth losing sleep over to watch this! :)

and to the "misled" person- save your hurricane supplies and donate them to a food pantry come thanksgiving.
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Quoting CarolinaHurricanes87:
Wilmington has been spared and I am safe. Wrightsville may have had worse impacts And I wish them good news tomorow but I'm shocked how weak Irene is here in wilmingon. I think the NE will be in for a big surprise they've evacuated for nothing. Just how I bought $150 of supplies for nothing.

Next time I'll trust my instincts and gut and live with what happens. I feel dumb and misled right now.


What you should feel dumb about is thinking that you are safe when the hurricane's center isn't even close to passing by you yet.

If you're "gut instinct" tells you to stay when a major hurricane is coming, don't listen to it. Go with logic and don't risk your life and your family's life on gut instinct. Many people have made that mistake and ended up paying that ultimate price.
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ok...imma go to bed...didnt sleep much last night and i am whipped...good night to all, stay safe if you are in the path and prayers to everyone
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.