Hurricane Alex - July 31-August 4, 2004

Three distinct weather systems may have played a role in the genesis of Alex. On 26 July, shower
activity increased several hundred miles to the east of the northwestern Bahamas. This activity was
 associated with a weak surface trough, likely of mid-latitude origin. Disorganized showers persisted just
 to the east of the Bahamas, in the diffluent region to the east of an upper-level low, for the next couple
of days. On 28 July, when a tropical wave reached the area, the extent and organization of the convection
began to increase. Analyses show that a broad area of surface low pressure formed early on 30 July just
northeast of the central Bahamas. The low moved northwestward and over the next 36 hours the
circulation slowly became better defined. By the afternoon of 31 July, when the low center was located
about 175 n mi east of Jacksonville, the system had enough convective organization to be classified as
a tropical depression.

As the depression approached a break in the subtropical ridge early on 1 August, its forward motion
slowed, and the cyclone remained nearly stationary for the next day or so about 115 n mi east-southeast
 of Savannah.   The depression remained poorly organized initially, due to northeasterly shear and
 an environment characterized by subsidence and dry air. However, an upper-level trough was
approaching  from the west, and in advance of  this trough the northeasterly flow over the
cyclone began to relax.  During this transition the depression was  able to strengthen, and it
became a tropical storm early on the afternoon of 1 August.

Alex began to move northeastward early on 2 August, taking a track that would slowly approach the
coastline  of the Carolinas over the next 36 hours. The northeasterly shear continued to diminish
 during the day as upper-level southwesterlies approached. The deep convection, which had
 previously been confined to the southwest quadrant of the circulation, was now able to organize
in  bands to the east of the center. Alex strengthened, becoming a hurricane just past midnight on 3
August, when it was centered about 65 n mi south-southeast of Cape Fear.

Aided by warm Gulf Stream waters and light shear, Alex continued to strengthen on 3 August as it
neared  the North Carolina Outer Banks. The hurricane's maximum sustained winds reached 100 mph
(category 2 on the Saffir-Simpson Hurricane Scale) that morning, and the minimum pressure fell to
972 mb early in the afternoon. Alex made its closest approach to land just after noon, with its center
located about 9 n mi southeast of Cape Hatteras, while the western eyewall of the hurricane raked the
Outer Banks with sustained Category 1 hurricane force winds.

After passing the Outer Banks, Alex turned away from land and accelerated as it became embedded in a
 deep layer of west-southwesterly flow. Alex strengthened and became a major hurricane (Category 3) on
 the evening of 4 August, with winds of 120 mph and a minimum pressure of 957 mb. At this time Alex
 was at 38.5° N (385 n mi south-southwest of Halifax, Nova Scotia), moving east-northeastward near 25
mph,  and over waters just above 26°C - not factors normally associated with major hurricanes. Only
Hurricane Ellen of 1973 attained major hurricane status farther north. While the basic environmental
surroundings around Alex was low in shear, the cause of this unexpected strengthening remains

By late on 5 August Alex had moved north of the Gulf Stream over sub-20°C waters and was weakening
rapidly.  Moving at 50 mph, Alex weakened to a tropical storm after midnight on 6 August and became
extratropical a few hours later about 830 n mi east of Cape Race Newfoundland. The circulation of Alex
was absorbed into a larger extratropical low by the evening of 6 August.  Below is a track of the cyclone
provided by the National Hurricane Center.

Hurricane Alex (2004) track

The storm total rainfall map below was constructed using data from data provided from NWS River
Forecast Centers, as well as additional reports received by the National Hurricane Center.

Alex (2004) Storm Total Rainfall
Alex (2004) Filled Contour Rainfall
Alex (2004) Contoured Rainfall on White Background

Below are the calendar for Daily Precipitation Maps.  Note that the 24-hour periods end
at 12z that morning.

Sun Mon Tue Wed Thu Fri Sat