On the heels of the disastrous Myanmar cyclone ten days ago, nature has had a busy week — with more human tragedy as a consequence.

We awoke this morning to reports of a massive quake near a Chinese city most Westerners have never heard of.    Sichuan Province may be better known to Americans as the home of the giant pandas, and for the region’s spicy cuisine.  But Chengdu, obscure to most of us over here, has a metro area larger than any in the U.S. except for New York and Los Angeles. 

At CNN, our first info on a quake anywhere in the world often comes from an automatic email warning system from the U.S. Geological Survey    The 7.8 quake, post-midnight on the East Coast but mid-afternoon in Sichuan Province, China, has a reported death toll in the thousands.   There have been several aftershocks, the largest in the 5 and 6 range on the intensity scale.  The main quake was felt over thousands of miles.

Numerically tame by comparison but just as tragic to those affected were this weekend’s tornadoes.  At least 22 Americans died in the Midwest and Southeast.  A relatively small twister ripped up some homes about ten miles from my own house in Ellenwood, Georgia.  Things were much worse in the midwest, where a storm estimated in the EF3 or EF4 range tore through a wide swath of lead-mining country in northeastern Oklahoma and southwestern Missouri.   The National Weather Service has counted 66 tornadoes over the weekend, and the one that ravaged Picher, Oklahoma stayed on the ground for 63 miles.  2008 is well ahead of pace for both the number of tornadoes (over 500), and the death toll they’ve produced — now 98 for the year.

Had enough?   Heavy rains combined with high tides to force evacuations along the Delaware coast.   On Sunday high winds and low humidity conspired to spark large, sudden wildfires along Florida’s East Coast, temporarily closing Interstate 95.

We cover all of this stuff through CNN’s domestic and international weather center.   One of our summer interns is starting her first day.  It will be a learning experience.

Peter Dykstra  Executive Producer   CNN Science, Tech, and Weather

In North America, we have tornadoes — a nearly unheard-of weather phenomenon in much of the rest of the world. Last week, CNN Meteorologist Rob Marciano and Producer Marsha Walton reported on them here, reminding us why the rest of the world should be grateful. One year ago last weekend, the mile-wide town of Greensburg, Kansas was obliterated by a mile and a half wide tornado.

An Aqua satellite image of a dust storm in Taklimakan Desert, Western China. Source: NASA

But there are some things that the rest of the world gets that most of us in North America never see. It’s sandstorm season in the Middle East. This week, a blustery weather system — common for April — caused problems from the Mediterranean to Kazakhstan, and just about everywhere in between.

NASA’s MODIS website features a remarkable gallery of near-real-time satellite photography from the agency’s AQUA and TERRA satellites. On Wednesday, each pass of the two satellites over the normally cloud-free Middle East and North Africa showed a parade of dust plumes — blowing sand moving away from the arid region.

Here are the best of the images:

A dust storm in Kazakhstan, blowing eastward over the Aral Sea;

A Gulf of Aden dust storm;

Persian Gulf ( at the bottom of frame);

The lower Red sea and Gulf of Aden;

Qatar, Saudi Arabia, and Persian Gulf (at the top of the frame);

Saharan sand blowing into the Mediterranean off of Libya.

Another image from China, taken on April 26, shows another of the world’s dust storm hot spots: The Gobi Desert. Expanding due to drought and poor farming practices, the Gobi routinely blows dust into the populated areas of Eastern China, and offshore — some of it reaching North America, accompanied by China’s legendary air pollution.

Dust or sand storms can impact aircraft — weather forecasters pay special attention to that. Commercial and military aircraft can incur a double risk from the storms — both visibility and engines can be affected. And it may be stating the obvious, but trying to live and breathe in a cloud of micro-particles can have a major respiratory impact for people as well.

If you’re really, really eager to see an American-made dust storm, they’re most common in the Southwest in mid-summer. Meteorologists call it a haboob, a name borrowed from the Sahara. They’re intense, fast-forming storms caused by a downdraft of high winds. Last July, a haboob brought traffic in Phoenix to a standstill with 50 mile-an-hour winds. The National Weather Service reported a dramatic temperature drop of 18 degrees in less than an hour. Since we’re talking about Arizona in July, that means it dropped to 91 degrees.

–Peter Dykstra Executive Producer CNN Sci-Tech & Weather

CNN’s Severe Weather Expert Chad Myers weighs in on the forecast for some very bad tornado weather — and then tells us what it all means:

A battle between hot and cold begins tonight in the western high plains and continues well into the Ohio Valley through Friday. Winter is trying to hold on as the heat and humidity of summer are trying to push the cold air back into the Arctic. Obviously, the warm air will eventually win, but tonight and tomorrow a blast winter will push all the way to the Gulf of Mexico. A severe weather outbreak will occur in the path of the clashing air masses.

The Storm Prediction Center expects a good chance of tornado activity today and tomorrow. This map shows the greatest risk for Thursday over a large area of the Lower Mississippi River Valley, including Memphis and St. Louis. Source: NOAA

Now there are many more ingredients necessary to make severe weather like tornadoes. You can’t make bread from flour and water….but it’ll make a good base. Same here….temperature clash will make the base and a jet stream, a vorticity max, a low level jet, and lots of humidity will be the yeast, eggs, salt and oil.

Technically speaking for the weather inclined, here’s the forecast from the Severe Storms Forecast Center (NOAA). I’ll translate at the end:

“INGREDIENTS ARE QUICKLY COMING INTO PLACE TO SUPPORT A SIGNIFICANT PERIOD OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE SOUTHERN PLAINS. IN RESPONSE TO THE APPROACH OF THE DEEPENING COLD TROUGH OVER THE SWRN U.S…A STRENGTHENING LOW LEVEL JET IS RAPIDLY TRANSPORTING QUALITY GULF MOISTURE INTO TX AND OK.

STALLED FRONTAL ZONE FROM SRN AR TO SWRN TX WILL RETURN NWD THIS AFTERNOON POSSIBLY TO RED RIVER VALLEY BY THIS EVENING. WITH DEWPOINTS RISING THRU THE 60S MLCAPES AOA 2500 J/KG COUPLED WITH STEEP MID LEVEL LAPSE RATES AND STRENGTHENING DEEP LAYER VEERING SHEAR PROFILES WILL BE SUPPORTIVE OF TORNADIC SUPERCELLS.

LARGE SCALE ASCENT IS INCREASING WITH APPROACH OF DIFFLUENT UPPER JET. NEAR SURFACE BASED SEVERE THUNDERSTORMS EXPECTED TO DEVELOP BY MID/LATE AFTERNOON. STORMS THAT DEVELOP VICINITY OF THE WARM FRONT WILL QUICKLY BECOME SUPERCELLS GIVEN THE QUALITY OF THE AIR MASS AND STRONG DEEP VEERING SHEAR PROFILES.

LARGE HAIL…AND TORNADOES ARE EXPECTED WITH STORMS THAT DEVELOP VICINITY WARM FRONT THIS AFTERNOON. THE POTENTIAL OF LONG LIVED SUPERCELLS AND STRONG TORNADOES WILL BE POSSIBLE AS STORMS TRACK ACROSS N TX INTO SRN OK THIS EVENING VICINITY SURFACE FRONTAL ZONE.

SURFACE LOW DEVELOPS SWRN TX THIS AFTERNOON AND THEN DEEPENS NEWD INTO OK TONIGHT AS THE INTENSE TROUGH BECOMES NEGATIVELY TILTED AND MOVES INTO SRN HI PLAINS BY 12Z THU. SEVERE THUNDERSTORMS WILL REDEVELOP BACK IN TX PANHANDLE AND SWRN TX TO E OF DRY LINE/COLD FRONT OVERNIGHT. GIVEN THE STRENGTH OF FORCING…A SEVERE SQUALL LINE WITH ENHANCED WIND DAMAGE THREAT WILL BE MOST LIKELY MODE. HOWEVER EMBEDDED SUPERCELLS AND TORNADOES ARE ALSO LIKELY AS THE SHEAR AND INSTABILITY WILL STILL BE MORE THAN SUFFICIENT…EVEN WITH THE NORMALLY UNFAVORABLE TIME OF DAY.

DURING THE AFTERNOON AND EVENING ADDITIONAL STRONG/SEVERE THUNDERSTORMS WILL DEVELOP VICINITY FRONTAL ZONE FURTHER E ACROSS AR/NRN LA. WHILE SHEAR WILL BE MARGINALLY FAVORABLE FOR ORGANIZED STORMS…MDT INSTABILITY WITH MLCAPES AROUND 2000 J/KG AND STEEP MID LEVEL LAPSE RATES WILL SUPPORT AT LEAST MULTICELLULAR STORMS WITH LARGE HAIL POTENTIAL.”

Wow, so what does all that mean? Let’s go piece by piece.

First Paragraph: Ingredients are coming together….you can have humidity, cold air, a jet stream, and all of the other parameters of severe weather, but if they are not in the right alignment, you will only get rain. In this case the “cold trough” (a dip in the jet stream) and the “Low Level Jet” (a strong wind from the south at 2000 feet) are working together.

Second Paragraph: A stationary front across central Texas will move north tonight to the Red River. This move will bring humidity to the north…closer to the cold air coming in from the north. The rest of the paragraph refers to the profile of the atmosphere with respect to potential volatility of a developing storm.

Third Paragraph: “Large scale ascent” means the air at the surface is rising to higher levels. Rising air makes clouds …sinking air makes clear skies. “Diffluent upper jet” means the air at, let’s say 30,000 ft., is diverging…moving apart…this movement apart causes lower pressure….lower pressure draws more air up from the surface…(remember rising air causes clouds…and in this case storms). “Storms that develop near the warm front will quickly become supercells” — The air mass by the warm front is warm and humid and the winds aloft change direction with height. This causes rotating thunderstorms that are not in a line with other storms and they are called supercells.

Fourth Paragraph: Self explanatory.

Fifth Paragraph: A Low pressure area (rising motion) develops in southwest Texas and gets stronger as it moves into Oklahoma tonight. The words “negatively tilted” refer to the shape of the jet stream. “Positively tilted” troughs will produce less severe weather. See this link: http://www.theweatherprediction.com/habyhints/127/

A “dry line” is a dry air “front” that blows out of the high plains east of the Rocky Mountains. It pushes air up just like a cold front.

Sixth paragraph: Other storms will develop over the Ark-La-Tex, but will not contain large tornadoes, but will contain hail.

That’s just for tonight and tomorrow morning. More tornadoes are likely Thursday and Friday.

We’re in Daytona Beach watching NASCAR teams prepare for the 50th running of the Great American Race. What a rush its been so far… Day one we rode in the pace car for a few “hot laps”. Which basically means you’re hauling you know what round the track up to 140 mph. Wow that was a fast and very bumpy ride. Definitely rougher than you would think. The banks are 31 degrees which allows the big speed. We stopped on one turn and could barely stand on it. Our driver Brett Bodine winked and said “yup its like racing on the moon”.

Back in the garage teams work on cars like surgeons with high tech precision making adjustments and trying to gain an edge. They run hard in practice and qualifying with average speeds round 180 mph. Ear plugs are a definite…rolling thunder would be a extreme understatement.

We followed the 5 car and Casey Mears for our high speed story pegged to weather. They don’t run in the rain but temperature, sunshine, air pressure, and winds definitely play a huge role. Making adjustments/decisions based on changing weather conditions could put your car in Victory Lane.

– CNN’s Rob Marciano and Alex Walker