Some final Irene thoughts

Watch Hill, RI      from Dave Wallen

Irene became the first Hurricane to make landfall in the United States since Hurricane Ike in 2008.  Early reports out of North Carolina are indicating some heavy damage.  Irene has already caused 3 deaths in North Carolina.  The wind field is still very large and the central pressure remains at 952.  The central pressure is the true indication of how strong a Hurricane is.  We will be in a long duration wind event.  The strength of the wind is not overwhelming; however the long duration and constant pounding of the winds will lead to significant tree and power line damage.  North Carolina is going on 24 hours of Irene.  The backside of Irene has been very powerful which is very rare for Hurricanes.

Track will come in to our west.  Expect 4-6 inches of rain to the east of the center with lesser amounts at the coast.  The winds will be sustained between 45-65 mph with gusts to 80.  The worst of the storm is between 6am and 3pm.  It will be raining long before the core of the Hurricane gets anywhere near New England.  A North Carolina man was killed driving around during Irene.  Please be smart and do not take any stupid risks.  Not much more to add.  See previous posts related to Irene for impact and effects.   Here's to good fortune for everyone's lives and property.

Look at all this rainfall surging northward.  Courtesy of NWS.  I can't stress how important the low central pressure of this system is.  Irene is NOT behaving the way many tropical cyclones behave.  She may have a trick or two up her sleeve.  If anything significant occurs I will post updates.

The Calm Before the Storm

Irene is a huge hurricane.  Hurricane Watches are now in effect for the entire Massachusetts, RI, and Connecticut coast

What does that mean?  It means that Tropical Storm force winds extend 425 miles from the center.  It means that Hurricane Force winds extend over 100 miles.  It also means that you need to ignore what Category the winds fall in.  The central pressure is the true indicator of strength in a large Hurricane like Irene.  Right now the central pressure is 946 mb.  This can support winds of up to ~140 mph which is a category 4 hurricane.  So why are Irene's winds "only" 105 mph?  The answer lies in the large wind field.

Watches/Warnings and wind field

In small, compact Hurricanes, they can really spin up and when the pressure goes low, the winds respond.  However the area that experiences heavy wind is limited.  In the case of Irene, she is distributing her power across a much larger area.  This is very similar to what happened to Hurricane Ike in 2008.  Ike devastated Galveston and the North Texas coast as a category 2 hurricane.  It wasn't the strong winds that caused the devastation, it was the storm surge, heavy rain, and consistent winds of category 1 strength for hours.  Ike caused $30 billion in damage in the United States and killed 123 people.

Irene will only slowly weaken as she makes her way up the East Coast.  The shape of the Hurricane should morph into a Nor'Easter looking cyclone.  This is typical of Hurricanes as they transition from the tropics to the mid latitudes.  So here is my first "impact map" of what we can expect.

Green= flooding rains

Light Purple= Sustained Hurricane Force gusts over 100

Brown= Brief sustained Hurricane winds, gusts 80-100

Red= Tropical Storm force Sustained, frequent gusts over 75

Blue= Moderate Storm surge impact

Dark Purple= Major Storm Surge impact

Black= forecast track. Areas east Tornado threat

The slightest shift makes all the difference.  If it spends more time over water than over land while coming up the coast impacts will be even worse.  There is a flood watch for Worcester County because 4-6 inches of rain should create some problems.  Its just that area's west of the center will be receiving more rain. 

Anywhere east of the black line will suffer widespread power outages and numerous down trees.  A major coastal flooding event is going to occur on the South New England coast.  Here is the National Weather Service forecast discussion for Hurricane Irene.  

Rainfall forecast from HPC

Timing is still a work in progress.  Some models are speeding the cyclone up, which does make sense, but I want to see if this trend continues.

Hurricane Irene- What's New

NHC track and Current storm info

If possible, the hurricane models continue to show a worst case scenario.  Yeah we are 3-4 days away, but there doesn't seem to be a way to send Irene out to sea.  Irene is forecast to smash the Outer Banks of North Carolina and then hug the Mid-Atlantic coast sending ferocious waves and devastating surge all along the shore.  The storm will then turn Northeast right into southern New England.  The west side of the storm will drop copious amounts of rainfall on areas that are already over saturated.  Mid-Atlantic flooding will be severe there is just no way around that.  New York City is going to be vulnerable to storm surge from Irene.  The south coast of New England is going to be extremely vulnerable to storm surge.

Storm Surge

Irene is a large Hurricane, with a large wind field.  Pressure is low in the storm so she is going to drive a lot of water toward the shore.  The surge will depend on how strong and fast Irene moves north.  If it is a strong Category 3 around the Outer Banks then the surge here in SNE will be damaging.  It is becoming apparent that everywhere from Worcester County and east will see strong winds, sustained at Tropical Storm force (39-73 mph) with gusts to Hurricane force (74 +).  If whatever is left of the eyewall crosses through Central Massachusetts the winds will be stronger.  Area north and northeast of the center will be vulnerable to tornadoes as well.  The fast spinning winds will interact with the land.  The friction will slow the winds down at the surface and turn them, meanwhile winds in the mid layers will remain unaffected.  As a result, tornadoes form due to this "shear".

Prepare your property, even inland, for this Hurricane.  I expect a Category 1 Hurricane to hit Long Island with winds of 85 MPH.  If the storm doesn't quite hug the coast the way the models are indicating then winds of up to 105 will be possible.  The hype for this is justified by uncanny model agreement and relative consistency of a Northeast direct strike.  The Bermuda high is blocking escape out to sea.  If the track does pull to the east at the last minute we will then be vulnerable to 5-10 inches of rain and flooding.  A lose/lose situation is developing.

48hr Precip totals

As long as computer guidance continues to stay consistent, I'll begin to be more specific with timing and impacts starting tomorrow.

Do not forget about today's rain showers and possible thunderstorms tonight.

106 EDT radar

Severe weather indices are enough to support storms today.  Calm before the storm tomorrow, increasing tropical air on Saturday.

PS
I have to disagree with a Hurricane going directly over NYC.  The last time that happened was 1893.  Models have a tendency to kick easy as the event approaches.  I don't want to tell people in the tri-state area not to prepare for the storm, rather I think the potential damage in southern New England is being underplayed.  Matt Noyes of NECN thinks New London, CT is where landfall will occur.  Don't bother watching any of the National Networks (FOX, CNN, etc) for New England impacts.  I've watched all of them and they continue to ignore New England.  Even if the storm does hit NYC Southern New England will get slapped with high winds storm surge and tornadoes.  Stick to the local networks or here at New England Weather.

Wednesday Night Irene Briefing

Irene is ravaging the Bahama's tonight with fierce 120 MPH winds and a central pressure of 952 mb.  Irene is currently undergoing an eyewall replacement cycle.  That means the strong inner core around the eye where the strongest winds are collapses and then reforms.  For a reference think that a Hurricane does Tommy John surgery on itself. After an ERC the storm can restrengthen bigger and badder than before.  I really do not have much more to add that I haven't said in the past few posts.  Its coming.

The center is likely to pass through the Blackstone Valley.  It may go right through Providence and Boston.  These are the details that will get worked out as Irene passes the Outer Banks.  Southeast Worcester County could have either flooding rains or damaging wind and tornadoes from Irene.  It depends on where the center passes.  Flashlights, batteries, food, and important documents must be taken care of by Saturday.  Do not wait. Hurricanes are the most powerful weather systems we have on earth.  Here are some maps...

Various models courtesy of Florida State

27/33 track over New England

Center right over Worcester County

Also not to forget here is tomorrow Storm Prediction Center thunderstorm forecast

These will first fire between 11 and 1 and move through MA around 3.  Then a second line of storms may come by when the front passes through.  Dewpoints will be in the 70's tomorrow.  A tornado cannot be ruled out either.  The front is going to stall off the coast and then return as a warm front in combination with Irene Saturday.  Talk about a double whammy.

I'll have a more detailed forecast tomorrow after the morning computer cycle

Hurricane Irene

Irene has already claimed one victim here in New England, the Sunday Kenny Chesney/Zac Brown Band concert in Foxboro.  The show has been moved to Friday due to the potential hazard of having an outdoor show in the middle of a Category 2 Hurricane.  Model guidance continues to suggest that a large Hurricane will miss the Outer Banks of North Carolina and make landfall in the Rhode Island/Southeast Massachusetts area on Sunday night.  Jim Cantore is being sent to Providence, RI.  You know if he is there, all of The Weather Channel's best meteorologists think that Irene is heading for Southern New England.

IR image of Irene

The latest computer model information is also surprising.  Most models are now indicating that a hurricane will make landfall on Long Island and then New England,  or just in New England.  The models are also picking up on the predecessor rain event (PRE) that I talked about last night.  So that means that Saturday night's Chesney/ZBB show will be wet.  The air is going to feel so tropical that for concert-goers that will be relief.  By the the afternoon on Sunday things will really begin to go downhill as heavy wind driven rain will begin to pelt the area.  Tornadoes will be spawn in some of the intense outer thunderstorm bands. Because of the PRE, it will be much easier for Irene's powerful winds to knock down trees.  Some of those trees will fall on onto power lines and therefore it is extremely important that people have enough food and water.  The south coast will be flattened by storm surge and 100 mph winds.  Officials will likely focus on potentially extreme damage in coastal Rhode Island and Massachusetts.  How extreme?  Please read the accounts of past New England Hurricanes.   It's all happened before when New England had less people and less coastal development.  Therefore, getting power restored in other areas of Massachusetts may take days.

National Hurricane Center Track and current info (click to enlarge)

If you live on the coast, evacuation is long frustrating process.  With the emerging consensus of a direct strike, my suggestion would be to leave if and when evacuations are issue.  For inland people, if you live in areas prone to river flooding please be ready to evacuate if rivers rapidly rise.  This is the best way to protect lives.  Do not be tempted to go to beach on Sunday to watch the waves.  This is extremely dangerous.   The models have trended west today, ending what had been a steady march east for the last few days.  What has changed?  NOAA and the Air Force were dropping weather instruments ahead of the path of Irene.  They also sampled the atmospheric players that will drive Irene.  With remarkable agreement at 4 -5 days, I do now believe its time to prepare for Irene like she will strike.

Please see this link- simply look at the location of 4 different major computer models Sunday at  8 pm

Upper Air pattern/energy 

The Upper Air (500 mb vorticity) shows the major players in where Irene will track.  High pressure in the Atlantic is blocking Irene from moving out to sea while high pressure in the southwest is allowing the short wave trough to dig in between the between the two to catch Irene and accelerate her north.  And here is the 48 hour rainfall forecast from Monday at 2 pm for one last image..

click to enlarge

There could also be some severe weather with the passage of a cold front tomorrow.  Other than that Friday looks to be the calm before the storm.  More tonight

Tuesday Night Weather and Irene Update

Not much has changed with Irene tonight, except the fact that Irene is increasing with strength at the moment.  Check out the latest Infrared radar...

Eye has developed in last three hours

This has long been expected.  The central pressure in the core of the Hurricane has dropped to 969 mb.  With the warm ocean, both at the surface and at depth, this storm will continue to get stronger.  In fact, Dr. Kerry Emanuel of MIT has a chart that suggests Irene could be as strong as a Category 5 all the way to the Outer Banks.  This won't happen because that map only takes into account oceanic heat content and nothing else.  There are other factors that will hold Irene back from approaching that strength.  That said, I also do not see any reason to change my forecast track.  Unfortunately there is a lot of guidance that suggest the minimal impacts from New England will still be dangerous.  After watching  NECN's Matt Noyes technical discussion tonight, I want to bring up another hazard that may occur with this storm.  I thank Matt for bringing this up because I never would have thought about it before hand.  That's why I follow experience meteorologists, there is a lot to learn  from them.

This hazard is a predecessor rain event.  We often see this in the winter when snowstorms are coming up the coast.  In these cases snow will overspread the area in front of the cyclone (nor'easter  in combination with the trough that is helping to pull the storm north.  In this case it will be rain, heavy tropical rain.  This will fall before the Hurricane/Tropical Storm hits!  Its  likely this will happen whether the storm tracks up the coast or over the water.  I still believe Long Island and New England will take a direct hit from a Hurricane.  However this will just add to flooding concerns.  This event would start Saturday afternoon or Saturday night.  So if indeed Irene surges north, preparations should be complete by early Saturday afternoon.

The models that we're once on the outside of the consensus model track are now coming into line and forecasting a hit from North Carolina to Cape Cod.  I can't stress how significant of an event this could be.  See previous posts for details.  I'll have more on Irene in the early afternoon after the morning computer models put out their data.

The weather for the next few days...warm and partly cloudy tomorrow, thunderstorms on Thursday (more on that tomorrow...maybe), and then warm Friday with increasing tropical air.  Its going to feel like Florida.

Just in...New England officially in the National Hurricane Center 5-day track.

This would be an absolute disaster.  

Hurricane Irene Tuesday Latest- 303 PM Earthquake update

People seem a little riled up over this earthquake.  There is some damage in the DC/Virginia area.  A water main break has caused mandatory evacuations at the Pentagon.  The airports are running slowly because air traffic control towers were evacuated.  Amtrak service is delayed because investigators have to check every single rail.  The earthquake was felt from Atlanta to Canada.  Is that rare?  Actually no not really.  While earthquakes in the east are rare, they do occur every few years.  The long ranging effects of the earthquake aren't that rare either.  The Earth's crust along the east coast is solid and relatively cool.  Therefore, the earthquake shock is able to travel far and fast.  

The EURO model is also in line with a North Carolina strike and then it hugs the Mid-Atlantic before crossing into New England.   This almost exactly what the NHC track is (see below). This would be a very bad track because PA, NJ, and NY have very saturated grounds right now.  This would lead to extreme flooding.  That would put the storm surge and winds on the New England side of the system.  As shown below I'm east of the EURO track but not by much.  What a day!

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NHC track, watches, warnings, winds, and movement

There have been interesting developments today with regard to Hurricane Irene.  Mainly that the latest American weather computer model (the GFS) scrapes the Outer Banks of North Carolina before making landfall on Long Island and then southeast Connecticut before crossing into northern RI/south central Massachusetts.  For those who live in the Blackstone Valley (like me) this is as close to worst case scenario as we are going to get.  This keeps southeastern New England on the east side of the Hurricane, which is the most intense side.  The direction of the track will also send heavy flooding rains into the region as the center pulls away.  Storm surge along the south coast could be significant depending on how strong Irene is.

So the question becomes now, how likely is this?  This is 5 days away and to expect a model to keep the same track for 5 days is a stretch.  With that said, the models have been consistent and fairly accurate with Irene since she formed.  NOAA research planes have sampled the other "players" who will have a say where Irene goes.  High pressure in the Atlantic, High Pressure near Texas, and an upper level trough entering the Pacific Northwest will steer this system.  Irene is about to strengthen as the cyclone moves over very warm waters in the Bahama's.  This strengthening can have an impact because the Hurricane will be releasing vast amounts of heat into the atmosphere.  Does this help break down the Atlantic High and cause Irene to accelerate to the north?  This is very difficult to determine, which is a 100 miles track error could be the difference between a tropical storm with flooding rains or just some rain and wind.

I'm going to keep my track from yesterday.  I don't see any reason to change it significantly, especially with the Hurricane Center coming east.

Irene is beginning to develop an eye

Visible Satellite of Irene, click to enlarge

And one last image to chew on

500 mb Vorticity, Sunday 11 PM

This post will be updated after the European model is released in an hour or so.  At this point its probably best to make a plan if you live on the coast.  If you have a boat plan to get it out of the coastal waters.  It wouldn't be bad to pick up some food and water.  At the very least get batteries and flashlights.  If the forecast doesn't pan out, no big deal.  Its certainly not time to panic.  However, if this is ignored and it does indeed hit, it will be much worse than hyping something that doesn't quite live up to expectations.  We do that everyday in our culture.  And then whenever a disaster hits we demand to know why we weren't prepared.  To me, the time to prepare is now.  If one extra person goes out and prepares for this storm early and it hits, then its worth it for me.