Steve's blog

The vast majority of North Atlantic Tropical Storms originate in North Africa and travel generally westward across the Atlantic gaining strength to do their damaging works in North America.  A sub-class of storms, like 2011’s Rina, are American born.  These start life in the warm waters of the southwest Caribbean and usually drift straightaway to the northwest to about the latitude of Cuba (See the map). From there, these storms can veer  in any direction from west to northeast.

I recently posted a large number of probabilistic wind forecasts for Hurricane Irene. Here are similar predictions for Hurricane Katia - Maximum Sustained Wind expected at 25% probability.

From the statistics of all historical storm tracks and storm strengths,  I have developed a method to forecast wind exceedence probabilities given a current storm position, velocity and maximum sustained wind. 

Here is a recent forecast for Hurricane Irene.  Red lines are potential tracks based on previous storm statistics and current storm parameters. By running many potential tracks, wind exceedence probabilities can be deduced.

I’ve blogged previously about the hazards associated with dam-break floods. A curious case is the 1963 Vaiont Flood Disaster. In just minutes on one autumn evening, 20% of the water (30 million m³) held in Vaiont reservoir spilled out.  What’s the curious aspect about the affair?  -- This was no dam break! In fact, the dam still stands intact today.   Puzzled?  Then read on.

I’ve blogged before about reservoirs where I considered their ultimate hazard, -- complete dam failure. Other, less catastrophic hazards associate with them too. One is seismic slosh. “Slosh happens”  -- I’m told --  whenever a standing body of fluid gets shaken from below. Recall that fancy dinner party when soup was just served? Someone (I still claim that it wasn’t me!) bumped the table leg and many bigwigs watched bouillabaisse elope from their bowls. 

Previously, I blogged about hurricane wind hazard. Everyone knows however, that hurricanes pack a double dose of trouble -- wind and storm surge. Surge is a temporary increase of local sea level associated with the storm. In essence, the ocean turns into a river flowing inland. A disastrous prospect if you or your property stand in the way.

We’ve all tuned into the 6 or 11 o’clock TV news to catch the weather forecast. Is that storm going to hit? Maybe I should cancel my round of golf. Is a freeze likely tonight? I’d better cover the roses. Will tomorrow be a scorcher? Perhaps I get in that family beach trip. 

Hurricanes are one of the most damaging natural hazards that exist. While we can’t stop hurricanes from happening, we can take steps to mitigate their consequences. To formulate a balanced mitigation program however, we need a hazard forecast.

After seeing all the dramatic footage of devastation from the March 2011 tsunami in Japan, anyone living near an ocean coastline wonders, “What if that happened here?”

Fortunately, by means of computer simulation we don’t have to wait for the real thing to glimpse an answer.

For illustration, imagine a five meter high tsunami wave, 26 km across heading toward the San Francisco Bay Area from the west.  How would the Pacific Coast fair? How much of the wave penetrates through the Glolden Gate?