Sunday, November 8, 2009

Hurricane Ida

500 mile radius circle:
its center is Huricane Ida, the red circle just east of Cancun;
it curves a bit beyond Miami and not quite as far as Orlando.

Here are some of this morning's specs on Hurricane Ida.  Note the central pressure, 983 millibars.
ESTIMATED MINIMUM CENTRAL PRESSURE 983 MB
EYE DIAMETER 20 NM
MAX SUSTAINED WINDS 80 KT WITH GUSTS TO 100 KT.
64 KT....... 15NE 0SE 0SW 15NW.
50 KT....... 40NE 30SE 20SW 30NW.
34 KT.......120NE 70SE 40SW 90NW.
12 FT SEAS..150NE 120SE 75SW 150NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

A fair day at sea level has a pressure rating of 1013 millibars. Right now, Miami is reporting 30.06 inches, 1018 mb; Orlando is reporting 30.18 inches, 1022 mb. So right now: ΔP = -35 mb from Orlando to the eye of Hurricane Ida. That is only a 3.4% dip, yet it is an enormous change in the weather. Total distance from Orlando to the eye is approximately 580 miles. Excellent.

Hurricane Ida to Orlando


  1. National Hurricane Center
  2. Orlando weather data
  3. Computer models: where will it go?
  4. Weather Channel update

Air pressure, the source of the F = ma that lifts a 747 carrying the space shuttle into flight. Amazing.