ivan trmm and vis images

Ivan is one bad mother______. The National Hurricane Center's forecast discussion this past weekend had an admission that caught Gothamist's eye. The forecaster said something to the effect that "we don't have enough information from storms this size to have confidence in our forecasts." That statement may have also caught the Times attention, as they have a story in this morning's paper on why the hurricane prediction maps look like inverted teardrops and how five-day forecasts are as accurate as three-day forecasts were 15 years ago. The image above is the current visible satellite image overlain with NASA TRMM satellite data mentioned in the Times article.

Like all sciences meteorology depends on good and plentiful observations upon which to build theories. While we have a good grasp on the basic laws of physics, and how pressure, temperature and humidity variations cause hurricanes to form, move and dissipate, there have only been three Category 5 storms to hit the United States. The 1935 Florida Keys storm, Camille in 1969, and Andrew in 1992 are our only source of reference for how extremely intense hurricanes interact with their surrounding environment. The 1935 storm was before the advent of radar and satellite observations and satellite imagery wasn't all that sophisticated by the time Camille rolled ashore. Not a whole lot of information to go on, which is why forecasters use lots of cautionary language, and why Ivan will be studied for years to come.

Speaking of Camille, it was thirty five years and one month ago that she made landfall over Pass Christian, Mississippi. Camille killed 256 people; 143 on the Gulf Coast where it pushed a wall of water 24 feet high inland, and 113 from flash floods in Virginia. Wind gusts were estimated to be 200mph but nobody knows how high Camille's wind speeds were as all the recording anemometers were destroyed.

As of last night Ivan had a minimum pressure of 914 millibars (mb), it has since raised to 932 mb. That's the third lowest pressure ever recorded, surpassed only by Camille and the 1935 Florida Keys storm. Normal sea level pressure is a bit over 1000mb. A pressure of 914mb means that Ivan is sucking out roughly ten percent of the atmosphere above it.

Our weather? Pretty non-descript, cloudy with highs in the mid-70s today and tomorrow.