A Few Hypotheses from High School
These date to junior year in high school, I think.
1) The energy released by a hurricane after landfall is directly proportionate both to its strength just before landfall and its past history as a system, that is, a Category 3 hurricane that weakened from a Category 5 hurricane will release more energy upon landfall than a Category 3 hurricane that strengthened from a Category 1 hurricane. There may also be some temporal considerations: a hurricane that was stronger longer will release more energy than one that failed faster.
2) As hurricanes make landfall, their surface winds swiftly weaken due to both the loss of heat energy from the water and high friction from land surfaces. Energy dissipated by means of friction with land will produce surface heat, leading to convection and enhanced precipitation.
3) Therefore, hurricanes that have been very strong during their history will be tremendous rainmakers after landfall, no matter what their strength (as measured by wind speed and central pressure) is at the time.
For salient examples, please search for information on Hurricane Donna (1960) and Hurricane Floyd (1999).
Isabel
(1) Isabel was not expected by the NHC to maintain its strength for more than twelve hours. I had more faith in it. Although it may be slightly less organized, it has maintained winds of 160 mph for 24 hours (minimum central pressure of 920 mb, as measured by hurricane hunter aircaft, which are now in range of the system). It is now 565 km NE of the Leeward Islands. At the moment, I am convinced that the NHC forecasts too much weakening during the next 72 hours. Hence, I expect its top winds to be 130 mph in 120 hours.
(2) and (3) The major forecast models have chosen either a northern or southern track. I favor a compromise. Isabel will make landfall as a 110 mph (minimum central pressure of 962 mb) hurricane near Cape May, NJ in 176 hours.
These date to junior year in high school, I think.
1) The energy released by a hurricane after landfall is directly proportionate both to its strength just before landfall and its past history as a system, that is, a Category 3 hurricane that weakened from a Category 5 hurricane will release more energy upon landfall than a Category 3 hurricane that strengthened from a Category 1 hurricane. There may also be some temporal considerations: a hurricane that was stronger longer will release more energy than one that failed faster.
2) As hurricanes make landfall, their surface winds swiftly weaken due to both the loss of heat energy from the water and high friction from land surfaces. Energy dissipated by means of friction with land will produce surface heat, leading to convection and enhanced precipitation.
3) Therefore, hurricanes that have been very strong during their history will be tremendous rainmakers after landfall, no matter what their strength (as measured by wind speed and central pressure) is at the time.
For salient examples, please search for information on Hurricane Donna (1960) and Hurricane Floyd (1999).
Isabel
(1) Isabel was not expected by the NHC to maintain its strength for more than twelve hours. I had more faith in it. Although it may be slightly less organized, it has maintained winds of 160 mph for 24 hours (minimum central pressure of 920 mb, as measured by hurricane hunter aircaft, which are now in range of the system). It is now 565 km NE of the Leeward Islands. At the moment, I am convinced that the NHC forecasts too much weakening during the next 72 hours. Hence, I expect its top winds to be 130 mph in 120 hours.
(2) and (3) The major forecast models have chosen either a northern or southern track. I favor a compromise. Isabel will make landfall as a 110 mph (minimum central pressure of 962 mb) hurricane near Cape May, NJ in 176 hours.
0 Comments:
Post a Comment
Subscribe to Post Comments [Atom]
<< Home