Dan’s Wild Wild Science Journal

I enjoy the stories but the day to day forecast is worthless.

I always enjoy reading the stories in the Farmers Almanac. It’s been around for a LONG time and they have good basic astronomical info in it. Although you can get much more precise info from free programs like Stellarium.

About this time every year they release their forecast for the upcoming winter. TV stations everywhere gobble it up and do news stories on what the coming winter will be like.

Great free publicity!

Just to be clear here, the day to day forecasts are made up. They will not have any accuracy over that of a pure guess.

Some real science: An average of all moderate to strong La Nina's shows a milder than normal winter for much of the U.S. and Eastern Canada.

If you want to know what the winter will be like, the only think I can tell you is that with a moderate to strong La Nina brewing, the Southeast will likely have a drier and slightly milder than  normal winter. The odds of this are about 65%. That means there is a 35% chance it will be colder than normal here!

Other parts of the country will vary. See the graphics.

This kind of long range forecast is only possible because the La Nina pattern of colder than normal water in the Equatorial Pacific will cause a fairly predictable shift in the storm track over North America. The affects will actually be felt world wide.

Temperature anomalies for January during La Nina events. Images from NOAA. Click for full size image.

However, not every La Nina winter is the same. Each one is slightly different. Sometimes the La Nina pattern will hardly show up at all in some areas. Sometimes the expected warm areas are super warm.

The temperature anomalies in January for La Nina years shows that it’s quite warm in the Southeast U.S. most of the time but not always. The La Nina winters of 1971 and 1976 were slightly below normal over the Eastern U.S.

A scientific forecast would be for a good chance of having a mild winter in the Southeast. For those of you in Western Canada, a colder than normal winter seems like a good bet. Sometimes it is a super cold winter as well.

Just what you folks in Edmonton wanted to hear, isn’t it!

Later,
Dan

Hurricane Danielle in the Mid Atlantic and a strong tropical wave near the coast of Africa. Image from Meteosat (Dundee Univrsity ground station).

We are now in the peak of the hurricane season and the Tropical Atlantic is heating up. The second hurricane of the season formed this afternoon in the mid Atlantic.

Hurricane Danielle will likely re-curve though and not affect North America. There is a slight chance of it approaching the NE coast of the U.S. or Canada.

More interesting is the strong tropical wave coming off of Africa behind it. Satellite images this evening show that it is very organized and we will likely see a tropical depression form soon after it gets away from the coast of Africa.

Dan

From NASA GISS

From NASA GISS

NASA released the July global temp data this evening. The last 7 months are the warmest January – July on record. The thermometer record goes back to 1880. Before 1880 there are proxies for temperature. Tree rings and ice cores for example. These proxies  (See Oldest Ice Core Recovered from Greenland) indicate we are very possibly in the warmest period in at least one thousand years.

The temperature anomalies map shows that the higher latitudes are continuing to warm the fastest. This comes on the 30th anniversary of a now famous paper by Wally Broecker back in 1980. Broecker predicted in 1975 that the slight cooling trend of the 1970’s would reverse itself and a significant warming trend would begin due to increasing greenhouse gases. The blog Real Climate (written by several climate experts) has details on this. You can also read the paper for yourself.

July 2010 was the warmest July on the record for the Northern Hemisphere as well.

Click image for full resolution. Image from NASA Aqua satellite.

The amazing and unprecedented Russian heat wave continues. Moscow hit 34C today, which is cooler than the near 38C (100°F) temperatures of the last few days. The fires burning in the drought ravaged peat bogs and forests around Moscow continue to cover Western Russia in a thick pall of smoke.

The intense heat can also be seen from the MODIS sensor on the NASA Terra satellite. This sensor allowed researchers to measure the average ground temperature over Russia from July 20-27th. They then compared that with the normal temperatures you would expect in late July to produce the map below.

Red areas indicate above normal temperatures. Blue is areas where the temp. was below normal from 20-27 July 2010. Image from NASA Terra satellite. Click for higher resolution.

There are some strong indications that the storm track over Russia is about to change and allow some cooler air to reach Moscow. It looks like it will stay quite warm but when you are breaking the record high by 19 degrees day after day, anything cooler is welcome. Keep in mind too that at Moscow’s latitude almost no one has an air conditioner. Until this year they would only be needed a couple of days a year!

Coverage of the heatwave on the BBC is worth reading and do check out the podcast of FOC (From our Own Correspondent) for a first hand account.

As for the climate change connections, see my last post on the Moscow heat. It still holds.

Here in Huntsville, we set a new record today. Today makes 37 days in a row with the morning low at 21C (70F) or higher. We also just had the hottest 10 days ever recorded here. Greenland is looking very nice right now!

Dan

NASA Modis image of tropical disturbance off of Florida. Pressures are dropping and upper level winds are favourable for development.

There are strong signs that the area of disturbed weather in the Gulf is beginning to get organized today. Pressures are dropping and there seems to be a circulation already present. I suspect the the folks at the NHC in Miami will begin advisories on it later today.

Tropical Cyclone heat potential is based on the depth of the warm water, not just the surface sea water temp.

If it makes it to tropical storm strength it will be named Danielle.

While it is a bit early to talk about the track, the GFDL model is indicating that a landfall somewhere around Louisiana or Mississippi is possible late Friday night. Keep in mind, that the steering currents are very weak and this could change dramatically.

HOW STRONG COULD IT GET?

Could this system reach hurricane status? Yes, but it would be tough to get that strong by landfall. The Gulf is very warm but the tropical cyclone heat potential is not overly impressive. Still it is near the Gulf loop current and that may be helpful.

A good tropical storm may actually be quite helpful to farmers in the southeast who are suffering through an intense heatwave and drought. It’s 37.5C here in Huntsville as I type this.

That’s 100°F on the old scale.

More soon…

Dan