Presentation on theme: "HURRICANE FORECASTING: Another Perspective Jill F. Hasling, President Certified Consulting Meteorologist Weather Research Center 5104 Caroline St. Houston,"— Presentation transcript:
HURRICANE FORECASTING: Another Perspective Jill F. Hasling, President Certified Consulting Meteorologist Weather Research Center 5104 Caroline St. Houston, Texas
Using GIS to determine if there are more hurricanes. Conclusion: Since satellite use started after 1960, more hurricanes must be the result of satellites and not global warming Hurricanes East of 45W Hurricanes East of 45W
Category 5 Hurricanes in the Atlantic Basin
Atlantic Basin Category 5 Hurricanes 28 Category Hurricanes have occurred since 1900 Lowest Pressure – Hurricane Wilma mbs Highest maximum sustained winds - Hurricane Allen Knots Most Category Hurricanes per season Four- Emily, Katrina, Rita and Wilma Two – Carla and Hattie 1960 – Two – Donna and Ethel
SOLAR CYCLES 11.1 Year Cycle: Sun spot number at a minimum to a sun spot number at a maximum and back to a minimum 22.2 Year Cycle: Sun spots start at the minimum at opposite pole Year Gleissberg Cycle Year Jose Cycle - Includes 16 of the Suns orbits around the center of gravity of the solar systems or solar cycles.
SOLAR CYCLE Starts with the Sunspot Minimum – when few sunspots are observed on the sun. The number of observed sunspots increases until it reaches the sunspot maximum. Then the number of sunspots decrease until the sunspot minimum starts the next cycle. There are on average 11.1 years in each cycle.
In 1996, near the last solar minimum, the Sun is nearly featureless. By 1999, approaching maximum, it is dotted by sunspots and fiery hot gas trapped in magnetic loops. Solar max has also been tied to a 2 percent increase in clouds over much of the United States.
Sunspot Numbers from 1745
ORBITAL CYCLONE STRIKE INDEX The OCSI was developed in the mid 80s to predict which section of the United States Coast had the highest probability of experiencing landfall of a tropical storm or hurricane in a particular year. The index was developed using the sun spot cycle as an indication of the orbit of the sun around the center of the solar system and corresponds to the phases in the suns orbit. This leads to the premise is that the sunspot cycle is caused by orbital influences. Large scale circulation patterns of the earth are also subjected to these orbital influences which would then influence the tracks of cyclones. The OCSI index was developed using the year of the sunspot minimum as Phase 1 of the index.
ORBITAL CYCLONE STRIKE INDEX The index was created by sorting the Years from 1878 to 1985 by the phase of the solar cycle with the year of the sunspot minimum being Phase 1, the year after the sunspot minimum being Phase 2, etc. Those years are: 1878, 1889, 1901, 1913, 1923, 1933, 1944, 1954, 1964, 1976, 1986, 1996, 2008? The tracks of the tropical storms and hurricanes in these years were compared and the number of years a particular section of the coast experienced a landfall was tallied to give the percent chance of landfall.
Orbital Cyclone Strike Index [ OCSI]
WRC GRAY Updated Gray Fcst Number of Named Storms: Number of Storm Days: Number intensifying into Hurricanes: Number of Hurricane Days: US Landfalls: 4 Cat 3 or Higher Storms in the Atlantic: 50% Atlantic Hurricane Outlook Coast with the highest risk of landfall is Georgia to North Carolina with 90% Louisiana to Alabama has 60% chance of a landfall
PHASE YEAR HIGHEST 81993NE US 70% GA-NC 70% Emily 91994W FL 70% Alberto Beryl Gordon TX 70% W FL 70% Dean Allison Erin Opal 11996GA-NC 90% Arthur Bertha Fran 21997LA-AL 70% Danny 31998W FL (90%) Earl Mitch 41999LA-AL 90% WFL 70% Harvey Irene Floyd 52000W FL 70% LA-AL 70% Gordon Gordon Helene
PHASEYEAR HIGHEST 62001W FL 70% LA-AL 70% Gabrielle Allison 72002W FL 80% Hanna 82003NE US 70% GA-NC 70%* Isabel Isabel 92004W FL 70% Bonnie Charley Frances Ivan TX 70% W FL 70% Rita Dennis Wilma LA/AL 80% TX 66% LA-AL 66% WFL 66% Humberto Barry
23 Forecast Years out of the 23 years verified giving an accuracy rate of is 86.96% 3 out of the 23 years cyclones did not make landfall along the coast with the highest risk. [1987, 1992 and 2006] During these three years cyclones did make landfall in one of the coast with the second highest probability WFL 60% - Floyd 1992 LA-AL 60% - Andrew 2006 GA/NC 66% - Alberto/Ernesto
Other Cycles Used for Verification PHASEYEARHIGHEST RISK 11856GA/NC 90%- Strm# LA/AL - 70% 31858W. FL 90%-Strm# LA-AL 90% WFL 90% Strm# W FL 60% GA-NC 60% LA-AL 60% Strm#1 Strm#1/4/ W FL 70% LA-AL 70% Strm#6 Strm# W FL 80% NE US 70% GA-NC 70% Strm#6 Strm# W FL 70% TX 70% W FL 70% Strm#2/4 Strm# LA-AL 75%
PHASEYEARHIGHEST 11867GA/NC 90%- Strm# LA/AL - 70%- Strm# W. FL 90% 41870LA-AL 90% WFL 90% Strm#1 Strm#6/ W FL 60% GA-NC 60% LA-AL 60% Strm#6/7 Strm#3 Strm# W FL 70% LA-AL 70% Strm#5 Strm# W FL 80% - Strm#3/4/ NE US 70% GA-NC 70% Strm#6 Strm# W FL 70% -Strm# TX 70% W FL 70% Strm# LA-AL 75%- Strm#14
Forecast Verification Summary: Missed 4 out of the 11 years 63.64% Missed 1 out of the 11 years 90.9% Missed 2 out of the 10 years 80% Missed 1 out of the 12 years91.67%
WRC then used the OCSI to make a secondary predications: Number of tropical cyclones Number of hurricanes Number of hurricane days Number of storm days To compare the OCSI forecast with Colorado State Professor Gray and Climatology. The following graph indicates the over or under forecast of number of cyclones [tropical storms and hurricanes] each year. If the value is 0 then the forecast was correct. The purple lines indicates the forecast was within + or - 1 cyclone.
The following graph indicates the error + or – 1 of the forecast for the number of hurricanes each year. The purple lines indicates the forecast was within + or - 1 hurricane.
The following graph indicates the forecast of the number of storm days +_ or – 10 days each year. The purple lines indicates the forecast was within + or – 10 storm days.
The following graph indicates the forecast of the number of hurricane days + or – 5 days each year. The purple lines indicates the forecast was within + or – 5 hurricane days.
Summary of the number of years since 1984 that the forecast verified within +- range indicated. WRC OCSIClimateCo. State Gray # of Years the forecasts of the number of cyclones was w/in # of Years the forecasts of the number of hurricanes was w/in
Summary of the number of years since 1984 the forecast of storm days and hurricane days verified within the +- range indicated. WRC OCSIClimateCo. State Gray # of Years the forecasts of the number of hurricane days was w/in # of Years the forecasts of the number of storm days was w/in
Katrina as a Cat 5 on Hurricane Alicias track Highest Winds on the right of the track
As a hurricane makes landfall and moves inland, the sustained winds start to weaken as the winds at the surface interact with the rough surface. So the winds in the hurricane that you would see in a hurricane over water would be lower as the storm moves inland. The hurricane also is weakening because it is moving away from the warm water that allows it to maintain its intensity. Maximum Sustained 1 minute sustained wind. Galveston Coast Hobby Airport Downtown Houston Bush Airport 38 mph 28 mph 25 mph 19 mph 50 mph 38 mph 33 mph 25 mph 58 mph 43 mph 38 mph 29 mph 76 mph 57 mph 49 mph 38 mph 99 mph 74 mph 64 mph 50 mph 114 mph 86 mph 74 mph 58 mph 148 mph 111 mph 96 mph 74 mph