Dan's Wild Wild Science Journal

NASA Modis image of the oil slick. The southern part is approaching the Gulf Loop Current. Click image for much larger version.

The Gulf Loop current may very well be picking up the oil slick in the Gulf. This would bring the oil down through the Florida Keys and into the Gulf Stream. Eventually passing between Florida and the Bahamas.

NOAA ocean current model showing the Gulf Loop Current. (Brighter blue.)

Oil in this area could cause severe damage to ocean reefs in the Keys and near the Bahamas. The ocean current models show the path of the loop current very well.

This image from the Real Time Ocean Forecast System (RTOFS) is a forecast of the current late Wednesday afternoon. It’s for water about 100 meters beneath the surface. The loop current is at the surface of the Ocean as well.

Although some oil is now being captured, at least 80% of the leak and probably much more is still flowing into the Gulf. Large plumes of oil are now being detected beneath the surface.

Wind forecast near the coasts, based on numerical weather prediction models. (NOAA NWS)

There is a large amount of oil now west of the Miss. Delta. The wind forecast will continue to push it toward areas along the coast as well. In general the slick seems to be spreading out in a North/South direction.

View of the Iceland ash cloud taken Saturday midday by NASA Terra Satellite. Click image for full res.

The winds aloft are blowing the ash mainly over the Atlantic today.

Wind flow at around 18,000 feet (500hpk) for Midnight Sunday. NOAA Numerical Weather model (GFS). (The red and blue shading is vorticity-weather geek stuff, just look at the black lines and my arrow toward the UK.)

Some of it is rotating around an upper level low and causing problems in Spain. The wind flow in the mid levels of the atmosphere will blow it more toward the UK and Europe starting late Sunday.  Heathrow and Gatwick could very well be affected.

The ash is up to around 5,000 meters today. Transatlantic flights can get above it. If it gets higher (above 30,000 feet), then more widespread disruptions are likely.

The same satellite also passed over the Gulf just before Noon. It got a great shot of the oil.

See below.

Oil slick is visible at the middle bottom of the pic. Click image for full resolution.

Late word tonight is that the attempt to put a cover over it has failed. Ice is forming in it.

This is probably from the sudden drop in pressure as the oil escapes the sea bed. The tremendous pressure differences between the sub surface and the sea bed are likely involved. The same differences in pressure from the sea floor to the surface will also make this EXTREMELY difficult.

You can demonstrate this to yourself by rapidly letting the air out of your car tires while holding onto the valve. Feel how cold it gets??

Dan

Image of Gulf oil slick at 1640 GMT today. It's much bigger. The mouth of the Mississippi is on the left. NASA image.

Tornadoes hit Arkansas last night and today and have also done damage in Miss. and Tennessee. Incredible rainfall totals of near or over 10 inches have ben reported across a wide swath of Tennessee. I just saw a recent report of a destroyed mobile home seen FLOATING down I-24 near Nashville.

Estimated rainfall from the Doppler radar in Nashville. Over 8 inches have fallen just SW of Nashville. I-40 is covered by water and closed in sections. Image from NWS Nexrad 88D NE of Nashville.

A pass by one of NASA’s MODIS satellites at 11:40am (1640GMT) shows the oil slick in the Gulf has gotten much larger.

A wider view of Gulf oil slick from NASA MODIS. Click for larger image.

NOAA has now issued a rare PDS Tornado Watch for Arkansas and Louisiana. PDS stands for Particularly Dangerous Situation. More flooding rains along with tornadoes are likely overnight.

Please remember if you know someone who lives in a mobile home, tell them to NEVER stay in it during a tornado warning. It’s also a good idea to keep in mind that more people die each year driving into a flooded road than are killed by tornadoes.

Dan

Dan's photo.

The EF 3 tornado that hit Albertville developed very rapidly. It first touched down just west of the city. It was on the ground for about 30 minutes and lifted near Geraldine in Dekalb County. We were able to give nearly 30 minutes warning for the folks in Geraldine. Albertville had 7 to 8 minutes.

That may not sound like much, but for a town at the beginning of the track, that is actually very good. Especially in this case.

Look at the radar images.

Velocity data shows a weak and ragged circulation, at 10:07 PM, as the storm enters Marshall County.

At 10:07 PM the velocity data showed a ragged circulation in the storm as it entered Marshall County Alabama. It takes the radar about 6 minutes to do a complete scan at several elevations. This is called a volume scan.

One volume scan later at 10:14 PM a strong circulation has developed. The NWS office in Huntsville issues a Tornado Warning. We had been keeping a weary eye on this cell.  I was doing the 10 PM  weather and we immediately urged the folks in Albertville to “take cover right now!”.

One volume scan of the radar later- a strong circulation is present. Tornado Warning being issued.

At 10:22 pm the radar data shows a very intense circulation with winds over 100 knots. The circulation is very near Albertville.

10:21 PM: An intense rotation is near Albertville. The tornado struck at 10:22 PM. (Pink is high winds away from the radar, and cyan is strong wind toward the radar. Radar located at top of image.

I talked with an Albertville city councilman who is also a state trooper.  He was off duty, but looked at his watch as he saw the tornado lift a giant tree out of the ground.

It was 10:22pm.

Albertville had around 7-8 minutes of warning.

Much more than most cities right at the beginning of a track will usually get.

This is why you should have a NOAA weather radio. Even if you have the TV on, you may be in another room or preoccupied. That warning siren might give you enough time to get to shelter. If you are very close to where the tornado is developing, you may only have seconds.

When it comes to tornado warnings, 7 minutes is a lifetime to a severe weather nowcaster.

Severe weather threat area for Saturday from the Storm Prediction Center (NOAA)

A deadly weekend tornado outbreak is becoming more likely this evening. Conditions are coming together for potentially violent long track tornadoes across much of Mississippi and Alabama on Saturday. Tennessee, Arkansas and Louisiana are also threatened.

It is quite possible conditions may reach the threshold for a rare High Risk outlook from the Storm Prediction Center (NOAA) in Norman.

Several of the tornado watches tomorrow will be PDS watches. (Particularly Dangerous Situation).

Significant Tornado Parameter forecast from a NOAA NWP Model. This is for 4PM CDT Saturday. Courtesy Earl Barker.

As I mentioned in my previous post last night, the parameters for an outbreak of strong and long track tornadoes are quite high. The numbers have actually increased some. One of these parameters that forecasters look at is the significant tornado algorithm.

This index looks at instability and wind shear along with low level moisture to indicate areas where the highest threat is. Based on this index, a high risk may be needed for NW Alabama and nearby areas on Saturday.

There are already severe thunderstorms with possible tornadoes developing in Mississippi.

The greatest threat for tornadoes will be during the day and early evening tomorrow. It is very possible that more tornadic storms could develop across Arkansas and Louisiana before sunrise.

Don’t get in the “fraidy” hole yet, but you might want to vacuum the carpet in it…