Dan's Wild Wild Science Journal

Hurricane Darby in the Pacific (120 mph sustained winds) and a tropical wave south of cuba that may be developing. NOAA GOES image.

It seems we may have our first Atlantic Basin tropical system forming this evening. I’ve been here in Miami all week at the annual AMS Conference on Broadcast Meteorology. This is the 38th Broadcast Conference and one of the best I’ve attended.

The Director of the National Hurricane Center and many of their forecasters put on an excellent seminar Wednesday on tropical meteorology.  Director Bill Read also spoke at our luncheon today.

View from my room of Miami Beach.

The NOAA forecasters and broadcast meteorologists like myself know how important our jobs are in hurricane season. It really is helpful to both groups to understand the problems we each face. Many are very similar and some are rather different.

Tonight, we’re all interested in a system that seems to be organizing in the Western Caribbean. An Air Force Reserve plane is currently investigating to see if a tropical depression has formed.

With a La Nina brewing and record warm waters in the oceans, a late June storm would not be surprising. We get one about 50% of the time. Most of the hurricanes form after August 1st each year.

It’s too early to say much about this system but if it forms it might enter the western Gulf in a few days. Swell from a storm would likely have a big impact on the work around the oil spill, so this could be of extreme importance.

I met the Director of the NHC for the first time today. Say what you will about government, but they got the right man for that job. The forecasters and researchers who work under him are top notch as well, and all of the broadcasters were VERY appreciative of the tremendous seminar and presentations the hurricane specialists put together.

Without doubt we all have one thing in common. We are all very passionate about giving the best information possible to the public.

I’ll post an update if the plane finds a closed circulation.

Update 7:22 PM EDT Fri 25 June:

The recon plane has found a closed circulation and the NHC has begun advisories on TD One. The latest probabilities on tropical storm force winds are below:

From NOAA/TPC/NHC Forecast from Friday evening. Do not use after tonight.

More soon.

Rainfall estimates from the Oklahoma City NOAA WSR88D radar. Over 10 inches caused massive flooding in the city yesterday.

I wrote a post awhile back (See TENNESSEE FLOODS- CLIMATE RELATED?) on the possible climate connections to the Nashville flood. Since then we have had another two major events.  One in Arkansas that killed 20 and just this week a deluge in Oklahoma City that caused all three major interstates to be closed and a day of rescues.

As I said in the previous post, you cannot blame any one weather event on climate change, but with the atmosphere holding about 7% more water vapor (Because the planet is warmer) it is very suspicious that we are seeing so many 100 and 1000 year floods.

Joe Romm over at the blog Climate Progress has an interview with Kevin Trenbirth of NOAA NCAR that is well worth listening to. My buddy Stu Ostro at the Weather Channel gets a mention too.

It’s about this very topic. This on the same day that NOAA announces that May 2010 like April was the warmest on the thermometer record.

The data seems to be adding up. As far as normal weather goes, we live in a different world than existed in the 1950′s and 1960′s.

Dan

Digital rainfall estimation off of the Doppler Radar in Little Rock, Arkansas. Nearly 20cm (8 inches) of rain fell overnight in the Ouachita National Forest.

There are many similarities to the flash flood that hit Montgomery County, Arkansas last night and the Big Thompson Canyon flood in Colorado in 1976. Both were National Forest campgrounds near streams. 145 campers died on 31 July in 1976 in the Colorado flood. The death toll now stands at 16 in Arkansas.  Some are still missing.

IR satellite image at 12:45 AM Friday showing the MCS over SW Arkansas. The heavy rain lasted for nearly 5 hours. The dark purple indicates clouds with a temp. of -70C. Clouds that cold would be very high (Over 50,000 feet.)

What Caused It

The flood was caused by what meteorologists call an MCS.

MCS stands for Mesoscale Convective System. In other words, a big cluster of thunderstorms. These systems can produce heavy rains as thunderstorms redevelop over the same place for hours. Last night the winds aloft that steer the storms were very light and this contributed to the heavy rainfall.

The MCS was kicked off by a very slow moving upper level low that has been drifting northeast across Texas for the past few days. It moved into Arkansas last night. A flood  gauge near the campground showed a rise in the river of 2.4 meters in one hour! The total rainfall is nearly 20cm or around 7.5 inches of rain.

It’s Happened Before

I was working on-air in Tulsa, Oklahoma during one of these events.  It was Memorial Day weekend in 1984. That night is burned in my memory. That flash flood killed 14 people.

These events are why you should always have a weather radio with you when camping. There are some excellent and inexpensive models available now.

Stream discharge from a river gauge near the campground. (USGS)

Budget Cuts May Impair Warnings

Another part to this story is the flood gauges on rivers. Most of these are put in place by the USGS. Budget cuts are forcing the removal of many of them.  This means there will be fewer gauges that forecasters can rely on to issue short fused warnings. Some gauges with many years of data will no longer be maintained.

Here is a stream gauge near the site of the deadly flood. The stream discharge triples in just a few hours!

The public is always worried about getting hit by a tornado when in reality the main weather killers in America are lightning and flash floods.

A Climate Connection?

One last thing.

If someone tells you this was caused by climate change they are wrong. If someone tells you this was NOT caused by climate change they are also wrong. The atmosphere is holding more water vapor now than it did 40 years ago. What you can say is that as the planet gets warmer, we will likely see heavier and more frequent extreme rainfall events.

Like this one.

Would it have happened anyhow? Possibly. No one can say for sure about any one event.

Dan

Doppler Velocity image of a deadly tornado in Oklahoma this afternoon. The storm was repsonsible for at least three deaths and millions in damage. The triangle is the location of the strongest wind shear. Blue is wind toward the radar and red is wind away from the radar. One of the most incredible velocity images of a tornado I have seen. Click for full res. WSR88D Doppler Radar at Tinker AFB near OKC,OK.

It’s been a busy month for those of us who forecast weather.  Tracking volcanic ash using upper level wind forecast and using ocean current models to track the growing oil slick in the Gulf. Today it was a little of all three.

Oklahoma was hit by a swarm of tornadoes today. At least 4 are dead. Many people have lost there homes. Cars and large trucks were flipped in the air along I-35 and I-40. With modern technology, I could watch the same radar images that forecasters in Oklahoma were looking at. Large tornadoes show up very well on Doppler radar. Today they were very easy to spot.

In the Hollywood movie “TWISTER” the town of Wakita, Oklahoma is hit by a big tornado. Today, Wakita really WAS hit by a large tornado. See the radar image below.

Hook echo approaching the town of Wakita, Oklahoma. Fortunately, it appears there were no deaths. Warnings DO make a difference!

As for the oil in the Gulf…

NASA Modis view of the oil slick in the Gulf. Taken Monday 10 May.

The slick is noticeably bigger on the NASA Terra satellite images today.

Ocean current models continue to indicate the oil will spread toward Louisiana. There is already oil spreading westward of the Mouth of the Mississippi and Northward onto Dauphin Island in Alabama.

The oil is showing up as gray and a dark color surrounding it in the middle right of the image to the left.

You can click the image and see a much larger version.

Now for the Volcano in Iceland…

It’s still erupting and the only reason air traffic is not snarled, is the upper level winds are blowing it south into the mid Atlantic. If the winds change and start blowing the ash toward Europe again…

Here is a pic from the NASA Terra satellite today.

From NASA Modis sensor on the TERRA satellite. Ckick for full res.

There are several towns in Iceland that have been covered in thick ash from the volcano. That is not getting nearly the coverage that the flight delays are. You have to feel for those folks…

The nearby Katla volcano usually erupts within a few months of it’s neighbor. It’s eruptions are much bigger. MUCH BIGGER.

No sign of that happening…yet…

Dan

The Iceland Volcano ash cloud is clearly visible in this image taken from space today. Image from NASA Aqua satellite in true colour. click image for much bigger version.

The ash is back.

Ireland has just announced airspace closings for tomorrow and there is now concern that the ash may start to seriously effect flights in the UK. If Gatwick and Heathrow in London shut down the impact will be felt worldwide.

Winds at 10,000 feet for tomorrow night. Wind will flow paralell to the black lines. Model data ctsy. Penn State.

Looking at the model data tonight, the greatest threat seems to be Ireland but there may be a narrow window late tomorrow when the ash will be funneled by the upper level winds toward the UK. Late in the week a high will build south of Iceland and this should keep the ash away from Europe for a few days.

One bit of good news. The ash is mainly below 20,000 feet. This means a transatlantic flright from Amsterdam or Paris will be able to fly well above it.

The airspace shut down a couple of weeks ago was much more severe because the ash was up to 34,000 feet. (I know I usually do all metric on this blog but air traffic around the world still uses flight levels in feet)

Now another image from the same satellite.

In the previous post I showed the image from the Aqua satellite pass over Nashville today.

I went back and grabbed a shot taken just about a year ago of the same area. The before and after images show very well the magnitude of the floods.

Here is the image from May 21 2009.

AQUA image of Nashville and Middle TN. on 21 May 2009. Nashville is dead center in the image. The Cumberland River is visible but not easily. Click for full res. Ctsy. NASA.

Now here is the image from my previous post showing the same area today at 1850 GMT (1:50 pm local Nashville time).

The image taken today shows the magnitude of the severe flood.

Could this flood be related to climate change? Possibly. I wrote a post on that a few days ago.

More soon,

Dan