Area Mesonet from existing networks

1
Tropical Weather Outlook
Hurricane Season 2008 Another YearAnother
Threat.

HURRICANE IVANS LIFE CYCLE
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• Season Officially Begins June 1st
• Earliest Date of a Named Storm (Tropical Storm
  Ana)
• April 20-24, 2003
• Winds of 58 mph.
• Ana was the first Atlantic tropical storm of
  record to form in April. It moved generally
  eastward across the central Atlantic.
• Season Officially Ends November 30th
• Latest Date of a Named Storm (Tropical Storm Zeta
  2005 and Hurricane Alice 1954)
• Both Formed on December 30 as Tropical Storms
• Alice wound up increasing to a Hurricane later in
  January 1955
• Zeta remained a Tropical Storm through January 6
  2006.

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Normal Season

• Average from 1950 2005
• 11 Named Storms
• 6.2 Hurricanes
• 2.7 Major Hurricanes
• Category 3 or greater

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1970-1994 vs. 1995-2007

• 1970 to 1994
• 8.6 Named Storms
• 3.6 of those namedbecome Hurricanes
• 1.5 of the Hurricanesbecome Major Hurricanes
  (Category 34or 5).
• In 1983, there were only 4 Tropical Storms, of
  which 3 became Hurricanes. There was only 1 major
  Hurricane.
• 1995 to 2007
• 13 Named Storms
• 7.7 of those namedbecome Hurricanes
• 3.6 of the Hurricanesbecome Major Hurricanes
  (Category 34or 5)
• In 2005, there were a record 28 Tropical Storms,
  of which 15 became Hurricanes. There were 7 major
  Hurricanes.

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Why Have There Been So Many More Systems Since
1995?
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Reasons for Stark Differences

• First Type of Climate Pattern Used for Strength
  of
• Hurricane Season
• Atlantic Multi-Decadal Oscillation (25 to 40 year
  period of increased activity)
• Natural occurrence and has been documented for at
  least the last 150 years.
• Active Phase (1995-Present, 13th year)
• Produces lower wind shear (changing winds with
  height)
• - This wind shear was extremely low during June
  and July of 2005
• Produces warmer waters
• across the tropical Atlantic
• Produces conducive winds
• coming off the west coast of
• Africa.
• Non-Active Phase (1970-1994)
• Higher wind shear
• Cooler waters
• Weak flow off the African
• Coast.
• Active Phase (1950 to 1969)
• Several Category 5

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Reasons for Stark Differences

• Second Type of Climate Pattern Used for Strength
• of a Hurricane Season
• ENSO (El Niño/Southern Oscillation)
• Also known as the (El Niño/ La Niña) cycle (Dr
  Gray of Colorado State discovered the cycle in
  1984)
• El Niño - refers to a periodic warming of the
  ocean waters over the central equatorial Pacific.
  (SST of 0.5 above climate average.
• Strong El Niño conditions will strengthen
  hurricane activity in the Pacific, while
  inhibiting Atlantic activity. Main reason is the
  change in wind shear and differences in water
  temperatures.
• La Niña - refers to a periodic cooling of those
  waters.
• Cooling of sea surface temperatures in the
  Central and Eastern Pacific with an observed SST
  of -0.5 below climatic average.
• La Niña conditions tend to develop in spring to
  early summer with greatest impacts later in the
  year.
• A La Niña usually last for a period of 1 to 3
  years
• La Niña conditions can tend to favor hurricane
  development in the Atlantic due to lack of shear
• Strong La Niña conditions will inhibit activity
  in the Pacific and strengthen activity in the
  Atlantic. Oceans are cyclical so when one
  waterway is cool another one would show the
  reverse trend.
• According to the latest trends according to NOAA,
  and using data since 1950, the La Niña currently
  in place (2007-2008) may begin to break down,
  giving way to ENSO neutral as early as
  July-August.
• El Niño conditions are not expected at this time.

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The Tropics During La Niña

• 1950 through 2001
• 14 tropical systems have impacted central Alabama
• 3 Summer storms
• 2 were late August into September 1 in July
• 11 Autumn storms (Sep Nov)

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Other Influences on a Hurricane Season?
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Other Influences

• Sea Surface Temperatures (SST)
• (Generally 80 Degrees)
• The warmer the water the more Fuel for the
  hurricane to develop in.
• The higher the temperaturethe more fuel for
  the production.
• The SST can also lead to lower sea level
  pressure.
• Type of Climate Pattern
• Atlantic Multi-Decadal Oscillation
• ENSO (El Niño/Southern Oscillation)
• El Niño / La Niña Cycle
• Madden-Julian Oscillation
• The MJO is a naturally occurring component of our
  coupled ocean-atmosphere system and the typical
  length of the MJO cycle or wave is approximately
  30-60 days
• Tropical Rainfall Periods that influence
  temperatures and clouds in the Inter Tropical
  Convergence Zone (favorable for Hurricane
  Production)
• Strong MJO patterns are usually associated with
  ENSO-Neutral or weak La Niña cycles.
• Limiting Factors
• Wind fields coming off the coast of
  Africa.Saharan Air Layer (SAL).
• Develop easterly winds in the Inter-Tropical
  Convergence Zone (ITCZ)
• These winds bring in dry air from the Saharan
  Desert.

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2008What is Expected?
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WhyInfluences for 2008

• Climate Factors
• Atlantic Tropical Multi-Decadal Oscillation
• We are currently in the ACTIVE PHASE. (13th year
  of a 25 40 year cycle)
• Weakening La Niña Conditions (Trending to more
  Neutral Pattern)
• As of July 1, 2008, the official 3 moth index
  (ONI) indicated a weak La Niña pattern was in
  place.
• The current numbers are around -0.7. Again the
  criteria for a La Niña is -0.5 for 5 consecutive
  months.
• Over the past few months, the pattern continues
  to decrease, with warming across all the region.
• Model forecast calls for a continued increase in
  water temperatures.
• The model consensus keeps the numbers between 0.5
  and -0.5 ( A few models hint at a neutral pattern
  in place by August while other models actually
  increase the La Niña pattern by the end of
  August).
• This will need to be monitored over the next
  several months to see the overall trend.
• Madden-Julian Oscillation
• As of July 1, 2008, an incoherent pattern is in
  place.
• No change is expected for the next few weeks.
• Sea-Surface Temperatures (SST)
• As of July 1, 2008
• On a whole current Atlantic SSTs are 0.5 degrees
  C (1 degree F) below normal.
• SSTs in the Gulf of Mexico range from 83 to 87
  (with up 88 along the eastern coastline)
• degrees F.
• SSTs in the in the Caribbean range from 83 to 87
  degrees F.

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Predictions for 2008
NHC is forecasting a 65 chance of an Above
Average Season
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Hurricane Scale
15
2008 A Look AheadTropical Storm and Hurricane
Names for 2008
A little Tropical Trivia 2005 was a record
year. There were 28 named storms that year. 15
of these were hurricanes. The record was 21
named storms back in 1933.
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What are the Most Well Known Hurricanes to Impact
Alabama Since 1969?
Hurricane Camille
Hurricane Katrina
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Hurricanes from 1969 to 1994

• Hurricane Camille (August 17, 1969) Retired
• Category 5 at landfall in MS (Second lowest
  pressure at landfall)
• Highest Winds 190 mph along the coastline
• Heaviest Rain Heaviest along SW Alabama
• Hurricane Eloise (September 23, 1975) Retired
• Category 3 at landfall (Only Hurricane to hit the
  US in 1975)
• Highest Winds 120 mph in Ozark (Lee County)
• Heaviest Rain 5 to 7 inches central and southern
  Alabama
• Hurricane Frederic (September 12-13, 1979)
  Retired
• Category 4 at strongest Category 3 at landfall
• Highest Winds 125 mph across Dauphin Island
  (Mobile County)
• Heaviest Rain 7 to 10 inches across Mobile
  County
• Hurricane Elena (September 2-3, 1985) Retired
• Category 3 at landfall in SE Mississippi
• Highest Winds 100 mph across Dauphin Island
  (Mobile County)
• Heaviest Rain 1 to 3 inches across Mobile County
• Hurricane Juan (October 30-November 1, 1985)
• This hurricane was not retired but the name was
  retired later
• Category 1 with landfall in LA Tropical Storm
  with landfall in SW AL/FL (Latest date of an
  impact to Alabama)

Hurricane Frederic
Hurricane Camille
Hurricane Elena
Hurricane Juans Track
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Hurricanes from 1995 to 2004

• Hurricane Erin (August 2-4, 1995)
• Category 2
• Highest Winds 60 mph across southern Alabama
• Heaviest Rain 7 inches across southwest Alabama
• Hurricane Opal (October 4-5, 1995) Retired
• Category 4 at strongest Category 3 at landfall
• Highest Winds in Central Alabama 90 mph in
  Montgomery (Montgomery County)
• Highest Winds in Alabama95 mph at Fort Rucker
  (Dale County)
• Heaviest Rain in Central Alabama 6.30 inches in
  Clanton (Chilton County)
• Heaviest Rain in Alabama 8.10 inches in
  Evergreen (Conecuh County)
• Hurricane Danny (July 18-23, 1997)
• Category 4 at strongest Category 1 at landfall
  (Stalled out in Mobile Bay)
• of Tornadoes 1 F0 in Central Alabama
• Highest Winds 70 mph across southwestern Alabama
• Heaviest Rain 43 inches on Dauphin Island in
  Mobile County
• Hurricane Georges (September 28-29,1998) Retired
• Category 4 at strongest Category 2 at landfall
• of Tornadoes 8 Total (8 F0s) in Central
  Alabama
• Highest Winds 70 mph in southwest Alabama

Hurricane Ivan
Hurricane Danny
Hurricane Opal
Hurricane Georges
Hurricane Isidore
Hurricane Erin
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2005 One for the Record Books Impacts Across
Central Alabama

• Tropical Storm Arlene (June 11-12, 2005)
• Tropical Storm
• Highest Winds 40 mph at Tuscaloosa (Tuscaloosa
  County)
• Heaviest Rain 4.60 inches at Newbern (Hale
  County)
• Hurricane Cindy (July 6, 2005)
• Category 1
• of Tornadoes 8 Total (6 F0s and 2 F1s) in
  Central Alabama
• Highest Winds 29 mph at Tuscaloosa (Tuscaloosa
  County)
• Heaviest Rain 5.01 inches at Tallassee (Elmore
  County)
• Hurricane Dennis (July 10-11, 2005) Retired
• Category 4 at strongest Category 3 Landfall
• Highest Winds 52 mph at Montgomery (Montgomery
  County)
• Heaviest Rain 8.63 inches at Sylvan Springs
  (Jefferson County)
• Hurricane Katrina (August 29-30, 2005) Retired
• Category 5 at strongest Category 3 at landfall
• of Tornadoes 4 Total (2 F0s and 2 F1s) in
  Central Alabama
• Highest Winds 80 mph at Cuba (Sumter County)
• Heaviest Rain 4.82 inches at Hamilton (Marion
  County)
• Hurricane Rita (September 25, 2005) Retired

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Quick Facts

• Top Ten Lowest Pressure Hurricanes
• through 2006
• 4 of the top 10 impacted
• Alabama
• (Highlighted in red)
• 4 of the top 10
• occurred in the
• 2004 and 2005
• included the
• lowest of all-time
• (Wilma, 2005)

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Quick Facts (Gulf of Mexico)
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Be Prepared

• Stay tuned to the changing weather (through
  televisionradiointernetor NOAA Weather Radio)
• Inland tropical systems have a tendency to
  produce tornadoesstrong windsas well as
  flooding rains.
• Develop an Emergency Supply Kit
• This can be used year round with severe weather
  as well.
• Make sure you have plenty of batteries for
  flashlights.
• Develop a Family Disaster Plan
• Know what to do and when to do it.
• Websites to visit
• http//www.nhc.noaa.gov
• http//www.cpc.ncep.noaa.gov
• http//www.weather.gov/glossary
• http//www.srh.noaa.gov/bmx
• http//hurricane.atmos.colostate.edu/Forecasts/
• http//www.nhc.noaa.gov/HAW2/english/intro.shtml
  (Hurricane Preparedness)