Wednesday, August 31, 2011

Wednesday Afternoon Tropical Update

I just wanted to give you a quick update after taking a look at some of the latest info coming in this afternoon.  We still have considerable uncertainty with the future track and intensity of the tropical disturbance in the Gulf, but there's increasing confidence that low pressure will develop south of the Louisiana coastline by Friday or Saturday.  There's also increasing confidence that whatever develops will be slow-moving or nearly stationary over the weekend and possibly into the first part of next week.  This points to significant heavy rain and coastal flooding threats if it pans out.  However, the areas that will be most under the gun are yet to be determined.

I've circled the area in the southeastern Gulf where there at least appears to be some weak rotation this afternoon.  The Hurricane Hunters are scheduled to investigate the disturbance on Thursday afternoon and should give us a better idea of its status.  Conditions still aren't terribly favorable for development over the central and northern Gulf with strong westerly winds at the upper-levels inducing some shear, but that shear is expected to let up by Friday.

The National Hurricane Center officially classified the disturbance as an 'invest' earlier this afternoon.  Most importantly, that means we'll begin to see runs of the tropical models.  We already saw the first few this afternoon, but we should have a full suite to look at later tonight.  Check back on for the latest models...we've added those and a few other tropical graphics to our site.

Bottom line...I'm becoming increasingly concerned about the threat for heavy rain and coastal flooding for some part of the Louisiana coastline by the weekend.  The intensity and long-term track still remain highly uncertain.  Stay with us folks...we'll keep you updated.

Gulf Disturbance...Anybody Got Some Darts?

I'm only half-joking here, but forecasting the future development and track of a system about to move into the Gulf is a bit like throwing darts in the dark right now.  We've got computer model solutions suggesting a landfall or near landfall anywhere from near Corpus Christi, TX to Tallahassee, FL.  Take a look at this graphic put together by Jeff Morrow showing 4 of the different possibilities:

Now, as you look at that graphic, consider that the top 2 panels (GFS and ECMWF) are models that we would generally give more weight to than the bottom 2 panels (Canadian [CMC] and Titan9 RPM).  That's not to say that the CMC and Titan9 RPM are bad models...they do fairly well with day-to-day weather...they just typically don't excel with tropical systems. So, for now, let's focus on the top 2 panels...the GFS and ECMWF ('European').

Disorganized t-storms in the NW Caribbean and southern Gulf near the Yucatan Peninsula are what could eventually give birth to a tropical system in the Gulf later this week.

The latest run of the GFS develops a weak low in the central Gulf, pushes it toward the SE Louisiana coastline, and then has it turn to the east-northeast, making landfall along the Florida panhandle. This is a big change from yesterday's run that brought a low to the LA coast then had it looping back to the south along the Texas coastline. The inconsistency from run-to-run and the fact that it's a bit of an outlier at this point leave me little reason to give it much weight at this time.

The European model develops low pressure in the western Gulf and then has it meandering there for most of next week!  Again, this is a bit difficult to buy, but I do lean more in the direction of a slow-moving system in the western or northern Gulf through the weekend and possibly even into early next week.  Because the European keeps it out over water for so long, it also produces a much stronger system by next week. Yesterday, this model kept it fairly weak.  Again, we see the inconsistency.

So by now you're probably saying, 'Just tell me where this thing is going, Steve!'  Here are my key thoughts going forward:
  • Expect little development today and tomorrow thanks to somewhat unfavorable upper-level winds. Friday looks to be the day when something may begin to happen.
  • Development will likely begin in the western Gulf.  A slow drift to the north or a meander appears most likely into the weekend.
  • High pressure that has dominated our weather this summer weakens and shifts north into the weekend. The key question becomes does this leave enough of a weakness along the western and northern Gulf coast for this system to be drawn northward?  Possibly...but that's a very difficult call at this point.
  • IF this system is left to meander in the Gulf, there will be a heavy rain threat somewhere along the Gulf Coast.  There would also likely be a sharp gradient from heavy rains along the coast to much lower totals inland.  Take a look at the 5-day rain potential from the NWS Hydrometeorological Prediction Center (HPC).

Reiterating some of my points from yesterday, there is MUCH higher than usual uncertainty both with the track and the intensity of this disturbance. I typically wouldn't put this much focus on a system that's yet to form, but with the upcoming holiday weekend and so many in the area traveling to Dallas for the football game, I want to make sure you are aware of a possible tropical threat. If you are leaving town, make sure your house is prepped just like you would for any other tropical system. Hopefully, that prep will turn out to be unnecessary, but it's the safe thing to do.
And, oh by the way, Katia looks to be on its way to becoming a hurricane later today. We're optimistic that it will move north of the Caribbean islands, but it's still too soon to completely rule out a U.S. threat.  Most of our guidance has Katia recurving well east of the U.S. East Coast, but there's still plenty of time to watch for any changes.

Tuesday, August 30, 2011

Tropical Development Possible in the Gulf

I don't want to make too much of this just yet, but since many of you, like me, will be leaving town later this week to head to Dallas, I wanted to give you an early heads up on the potential for some tropical development in the Gulf.

Over the last couple of days, several consecutive runs of some of our reliable computer models have indicated the potential for a tropical system to develop in the western Gulf very late this week or this weekend.  The origin of this potential tropical system is a disturbance currently seen on satellite moving through the western Caribbean.

Visible satellite image from 9 a.m. on Tuesday, Aug. 30, 2011. Courtesy: NASA.

The National Hurricane Center isn't mentioning this feature just yet in their 'Tropical Weather Outlook (TWO)', but there's good reason for that.  The TWO is meant to highlight features that could develop within the next 48 hours.  If anything happens with this system, it's likely to start just beyond that 48 hour window...that's why you won't see anything just yet.  But you'll likely see this feature added to the TWO in the next day or so.

As mentioned above, a couple of our more reliable computer models are indicating the potential for some development with this system, especially by the weekend.  First, take a look at this plot of the GFS (Global Forecast System) model.

GFS model plot, effective 1 a.m., Monday, Sept. 5th.  Courtesy: Florida State University

This particular run of the GFS shows what would likely be a healthy tropical storm off of the Louisiana coastline late Sunday night / early Monday morning (Labor Day).  You can also see 'Katia' out in the Atlantic.

Now, take a look at this plot of the 'European' model (ECMWF - European Centre for Medium-Range Weather Forecasts):

ECMWF model plot, effective 7 p.m., Sunday, Sept. 4th.  Courtesy: Florida State University

I know that all of the lines and colors can make this a bit difficult to interpret, but note that the ECMWF also shows a tropical system in the Gulf, but has it much farther southwest, closer to Brownsville.  It also shows the system a bit stronger than the GFS.

As you can see, there's a HIGH amount of uncertainty with the potential development and especially track of this system in the Gulf.  One important thing to mention is that the overall weather pattern will be changing later this week.  The ridge of high pressure that has kept us so hot and relatively dry most of this summer will finally break down and that could open the door for some potential impact along the western or northern Gulf Coast.  The eventual track and strength will have a lot to say about how much rain we see from late this week into the weekend.  It's also important to note that steering currents look to be pretty weak in the Gulf during this time period, meaning there's at least a chance this system could linger in the Gulf for several days. That could translate into a heavy rain/flooding threat for some portion of the Gulf Coast.

Bottom line...there's potential for a tropical system to develop in the Gulf late this week or this weekend.  The future track and intensity are highly uncertain...more so than normal.  Now is the time to make sure your home and family are prepared just in case we have to deal with a tropical system.  Those of you preparing to leave town for the LSU game should make sure your home is ready just in case something develops while you're gone.  Just to be safe, move any loose items in your yard indoors and secure anything else that can't be moved.

Finally, I had intended to devote today's blog to Irene, but obviously the threat of a tropical system in the Gulf takes precedence.  However, let me say this...there have been a lot of people over the last couple of days saying that Irene was 'overhyped'.  While it may not have turned out to be the mega disaster we feared at one point, it will still go down as one of the most significant storms to hit the East Coast in recent decades.  Consider these numbers:
  • At least 40 fatalities
  • Early damage estimates ranging from $7 to $10 billion.  That would make Irene one of the 10 costliest storms on record for the U.S.
  • Approximately 5 million customers experienced power outages
  • 14 states & the District of Columbia recorded tropical storm force wind gusts
  • 6 states recorded hurricane force wind gusts
    • Peak gusts:
      • Mt. Washington, NH: 120 mph (high elevation)
      • Cedar Island, NC: 115 mph
      • Fort Macon, NC: 92 mph
      • Sayville, NY: 91 mph
      • Conimicut, RI: 83 mph
      • East Milton, MA: 81 mph
      • Virginia Beach, VA: 76 mph
  • Record flooding all along the East Coast
    • Highest rain totals:
      • Virginia Beach, VA: 20.40"
      • Jacksonville, NC: 20.00"
And I could go on for days with the numbers...

So, while New York City and the major metropolitan areas of the Northeast may have weathered Irene fairly well, take a look at those numbers and tell me Irene was 'overhyped'.  Better yet...let's put it in local perspective.  Just about everything you see above either matches or surpasses what we experienced during Hurricane Gustav in 2008.  It's easy to call something 'overhyped' when you either don't experience it, or miss out on the worst of it.  But ask the people of the East Coast still without power today...the people who have lost their homes to record flooding...or even those who have lost loved ones in the storm if Irene was 'overhyped'.

Monday, August 29, 2011

Remembering Katrina - In front of and behind the camera

For those of us along the central Gulf Coast, August 29th is one of those dates that will always have special significance.  Just like 9/11 will always signify the horrific events of the terrorist attacks, or December 7th stirs memories of the bombing at Pearl Harbor, each year August 29th gets us thinking about where we were, what we were doing, and how Katrina changed our lives.

I could write an entire book on my experiences during the historic storm, but I wanted to share a few of the memories that still stand out for me today.

I worked both Friday, August 26th and Saturday, August 27th covering the evening shows for WAFB.  It was during this time that we really began to get a grasp on the significance of the threat from the blossoming hurricane.  But I don't think it was until Sunday afternoon that I first felt fear for what could happen in south Louisiana.  I had just looked at the satellite image below when Katrina was at peak intensity, with sustained winds up to 175 mph.  I took a moment to walk away from our Storm Center and gather's the first time in my 13-year broadcast career that I remember getting chills when looking at something weather-related.

Visible satellite image of Hurricane Katrina near peak intensity on Sunday, August 28, 2005.

As I walked down one of our main hallways at Channel 9, I heard a few laughs and saw a few too many smiles for my liking.  It prompted me to fire off an email to our entire building asking everyone to consider the gravity of what we were facing.  In reality, no one was doing anything was just a moment where I considered that my hometown could be wiped out and my family could lose everything they had.  I was angry, but not at anyone in particular...primarily just Mother Nature herself.  I held on to that email for a long time, but I wasn't able to locate it for this writing.

Katrina hit early on the morning of August 29th and our wall-to-wall coverage of the aftermath continued for days on end.  Once the storm passed, our coverage quickly changed from a weather focus to news covering the devastation in New Orleans and all along the Gulf Coast.  That left the Storm Team with little to do...just providing support in any way we could.

Feeling the need to get down to New Orleans and get a look at my hometown for myself, I approached our News Director, Vicki Zimmerman, about the possibility of putting on my reporter 'hat' and giving our weary crew in New Orleans some relief.  She was receptive to the idea, but the logistics took some time to work out.  It wasn't until Friday evening, Sept. 2nd that I made my way down to LaPlace with our crews to begin work in New Orleans the following morning.

Saturday was of course an eye-opener in New Orleans.  Water everywhere...people walking aimlessly and looking lost...and yes, even seeing the body of a Katrina victim on the streets.  It was not easy to see so much of the city I grew up in and loved in ruins.

After spending all day working on stories in the city, I asked my photographer, Cliff, if we could make a couple of stops in Metairie on our way back to our base in LaPlace.  Our first stop was at the 17th Street Canal levee breach.  My elementary school -- St. Louis King of France -- is 2 blocks from the breach on the opposite side.  It's an area I'm extremely familiar with.

Standing on the Jefferson Parish side of the 17th Street Canal, across from the breach that flooded Lakeview and a number of New Orleans neighborhoods.
We then went to check on family members' homes.  First stop was my Grandparents' looked fine.  Next brother' flooding or significant damage.  Final Dad's house...the home I grew up in.  This house is only about 3 blocks from the 17th Street Canal levee breach, but on the non-breached, Jefferson Parish side.  However, in what proved to be a massive failure of Jefferson Parish leadership, pump stations were not manned during the storm, allowing much of the Parish to flood from rainwater, and not breached levees or surge.  I walked into the house only to hear the dreaded 'squish' of wet carpet.  The water had since drained, but mold was already 3 feet up on most of the walls.  Below is a picture of the house taken by a neighbor who stayed.

 Picture of my childhood home (house on left) in Metairie taken on August 29, 2005.

While the first day was quite a test of my emotions, it was actually the following morning, Sunday, Sept. 4th that was most memorable.  We had 2 crews that set out pre-dawn to cover the latest in the city.  Jim Shannon was working with photographer Joe McCoy.  I was working with a photographer on loan from our sister station in Huntsville by the name of Jeff Gray.  We gathered on the street car tracks on Canal Street to come up with a plan.  Jim and Joe decided they would head in the direction of the 9th Ward to see what they could find.  Jeff and I would head in the direction of Charity and Tulane hospitals where there had already been some remakable stories.  Below is what Jeff and I found before even making it to the hospitals.

The story is a rough cut because we had some audio problems and also had to slap it together in a short amount of time to get it on air, but it did end up prompting an FBI investigation.  At the same time Jeff and I were having a gun brandished in our direction, check out what Jim and Joe found headed into the 9th Ward.  This was my favorite story (particularly the end) that any of our reporters did during Katrina.

As you can see, Sunday, September 4th, 2005 is an unforgettable day for me.

New Orleans now has a level of flood protection that surpasses anything ever seen in its history.  However, we've yet to see it tested and there are still weak spots.  While you might consider Katrina a once-in-a-lifetime storm, we never really know.  Ask those who experienced the same sort of flooding with Hurricane Betsy in 1965.

My hope is that the city will continue its comeback and that our elected officials have learned from mistakes of the past.  Sure, New Orleans has its problems, but the culture, the character, the people are unsurpassed anywhere in this country.

Check back tomorrow...I'll let you know what I think about those people who are saying Irene was 'overhyped'.

Friday, August 26, 2011

Size Really DOES Matter...In the Tropics

Whenever there's a hurricane threatening the coast, we tend to focus on the 'strength' of the storm.  How fast will the winds be?  What category hurricane are we talking about? And while those are key issues to consider, something that is often overlooked is the size of the hurricane.

We've had a couple of recent examples of the importance of size as it relates to hurricanes here along the Gulf Coast.  Most notably here in Louisiana, Katrina hammered home that point in 2005.  Consider that Katrina weakened from a rare Category 5 hurricane in the central Gulf to a still strong, but less rare Category 3 by the time it made landfall in LA and MS.  Yet, while it was 'only' a Category 3, Katrina produced a record storm surge along the coast, even surpassing the 'mother' of all hurricanes -- 1969's Camille.  So how did that happen?

    Side-by-side comparison of Camille near landfall (1969) and Katrina near landfall (2005). 

It's all about size, my friends.  At landfall, while Camille had maximum winds around 190 mph (strongest on record for any landfalling U.S. hurricane), the hurricane-force winds only extended about 60 miles from the center.  Katrina, on the other hand, had maximum winds around 125 mph at landfall, but the hurricane-force winds extended out about 120 miles from the center -- twice that of Camille.  The bottom line?  A larger wind field often results in a bigger storm surge, even if the wind speeds aren't as high.

And let's not also forget, a larger wind field simply means more areas and more people get impacted.  Both Katrina and Rita in 2005 had very large wind fields.  Even though Katrina moved well east of metro Baton Rouge and Rita well west of BTR, we had hours of wind gusts in the 50 to 60 mph range.

So, as we continue to follow Irene into the weekend, keep the above points in mind. While Irene may 'only' be a Category 2 hurricane at this point, the size of the wind field will likely result in storm surge and wind damage unlike anything we've seen from a tropical system along the East Coast in a long, LONG time.  And we're not even talking about the heavy rain threat.

Just how big is Irene?  Look at how the wind field compares to other big storms:

Hurricane Extent of T.S. Force Winds (near landfall) Extent of Hurricane Force Winds (near landfall)
Katrina 120 miles 230 miles
Rita 85 miles 205 miles
Ike 120 miles 275 miles
Irene 90 miles 290 miles
Katrina, Rita, & Ike numbers apply for each storm near landfall. Irene wind field numbers from the NHC advisory at 1 p.m. on August, 26, 2011.

NHC graphic showing the large size of Irene's wind field.

Thursday, August 25, 2011

Irene, New Depression & Blistering Heat

Hurricane Irene headlines the weather discussion for today and will continue to do so for days to come. As of 10 a.m. on Thursday, Irene is still a major Category 3 hurricane, with maximum sustained winds estimated to be around 115 mph. The storm has been barreling through much of the Bahamas for the better part of 24 hours and should finally lift north of the island-nation later today. The latest visible satellite image shows Irene passing over Abaco Island in the northwestern Bahamas.

The small bit of good news since late Wednesday is that Irene's intensity has leveled off for now.  Much of that seems to be related to an apparent 'eyewall replacement cycle'. In an eyewall replacement, an outer eyewall forms around the main eye, eventually causing it to collapse.  That process typically results in the storm intensity leveling off or even dropping off a bit.  However, the new eyewall often contracts with time and results in restrengthening of the storm if conditions allow.  Additionally, these eyewall replacement cycles often cause the wind field to expand and it appears that has been the case with Irene.

The latest run of computer models continue to paint a disturbing picture from the Mid-Atlantic into the Northeast.  The models are showing remarkable consistency and agreement in having Irene rake the coast from the Outer Banks of North Carolina to New England. In the image below, the 4 eastern-most tracks are among our less reliable models, so it's easy to see the threat that exists for much of the East Coast.

The official forecast calls for Irene to approach the Outer Banks as a major hurricane before weakening some as it tracks farther north and encounters cooler waters and some wind shear.  However, most of our guidance still shows a formidable hurricane impacting the Northeast.

If current trends continue, Irene could be a storm for the history books.  A number of major metropolitan areas -- including D.C., Baltimore, Philadelphia, New York City, and Boston -- could see significant impacts from the storm.  We would be talking about millions without power over the weekend.  Additionally, heavy rain and storm surge will be big threats.  It's not something we often think of, but even places like Long Island and Lower Manhattan are susceptible to storm surge with the right storm track.

And while our attention is rightfully focused on Irene, the season's 10th tropical depression quietly formed overnight in the far eastern Atlantic.  T.D. #10 could become Tropical Storm Jose in the next day or two, but for right now, the system appears destined to stay over the open Atlantic.

Chief Meteorologist Jay Grymes did some digging and found that if T.D. #10 does become Jose in the next day or so, we will be only slightly behind the pace of 2 of our most active seasons on record in terms of named storms -- 1995 (19 total named storms) and 2005 (28 total named storms).

And finally...can we do something to break this heat?  Unfortunately, there's no significant relief in sight.  Today looks to be our 24th straight day with a high temp of 95° or above in Baton Rouge.  We're now just adding on to a record for consecutive 95°+ days, having surpassed the previous mark of 21 days set in 1960.    We're also adding on to a record for the number of 95°+ days in a given summer.  Today will make 58 in the summer of 2011 for Baton Rouge, easily surpassing the previous record of 46 days in 1990.  Ouch!