2005 Hurricane Season Marches on with Alpha and Beta
Hurricane Season 2005: Beta
The records for most number of named storms and most number of hurricanes
in a season were tied with the appearance of Hurricane Wilma. However, the
astonishing 2005 hurricane season has continued on, setting new records with
Tropical Storm Alpha and Hurricane Beta. With Wilma, the list of Atlantic
storm names was completely exhausted for the first time since the National
Hurricane Center (NHC) began naming storms. Subsequent storms are therefore
named following the Greek alphabet.
Tropical Storm Alpha, the twenty-second named storm of the season, started out as
a tropical depression in the central Caribbean on 22 October 2005
southeast of the Dominican Republic. Alpha had little room to develop and
after moving northwest crossed over the island of Hispaniola on October 23 as
a tropical storm with maximum sustained winds reported at 52 mph
The Tropical Rainfall Measuring Mission (TRMM) satellite has been monitoring
the extraordinary activity in the Atlantic. Armed with an array of sensors,
TRMM can provide unique images and information on tropical cyclones over the
This first image (right) was taken by TRMM as Tropical Storm Alpha
was approaching Hispaniola. The image was taken at 7:08 pm EDT
22 October 2005 and shows the horizontal distribution of the rain intensity
associated with Alpha. Rain rates in the central part of the swath are from
the TRMM Precipitation Radar (PR), the only radar that can measure rainfall
from space. Rain rates in the outer swath are from the TRMM Microwave Imager
(TMI). The rain rates are overlaid on infrared (IR) data from the TRMM Visible
Infrared Scanner (VIRS). TRMM reveals that Alpha is rather small and that
its circulation is not well developed.
Alpha does not have a closed eye,
and very little curvature is visible in the rain field. At the time of the
image, Alpha was a minimal tropical storm with NHC reporting maximum sustained
winds at just 40 mph. However, as Alpha crossed Hispaniola, it
triggered flash floods, killing 26 people in Haiti and the Dominican Republic.
The TRMM-based, near-real time Multi-satellite Precipitation Analysis (MPA) at
the NASA Goddard Space Flight Center provides estimates of rainfall over the
global Tropics. MPA rainfall totals due solely to Alpha are shown for the
period 22 to 24 October 2005 with storm symbols marking the its track (image left).
Rainfall totals are generally less than 6 inches (green and blue areas) over
Hispaniola, but terrain and deforestation make the area vulnerable to mudslides.
After crossing the moutainous island, Alpha weakened back into a depression
before being drawn into the circulation of Hurricane Wilma and a midlatitude
low pressure system.
Beta, the 13th hurricane and 23rd named storm of the season, formed from a
tropical wave into a depression on the evening of 26 October (local time)
in the far southwestern Caribbean west of Nicaragua. Beta quickly became a
tropical storm on the morning of October 27 as it drifted northward. The storm
then took a more westerly course and began to intensify, becoming a minimal
Category 1 hurricane in the early morning hours of the October 29.
this image (right) of Beta at 7:39 am EDT 29 October soon after it became
a hurricane. Although the center does not fall within the PR swath, the TMI
shows that Beta has a closed eye structure with a solid ring of moderate
intensity rain (green ring) surrounding the center. The overall rain area
associated with Beta is not very large at this time however. As the system
continued westward, it also continued to intensify and briefly reached
Category 3 intensity on the morning of October 30 with sustained winds of 115 mph. Beta made landfall later that day on the central east
coast of Nicaragua as a Category 2 storm with winds estimated at 104 mph by the hurricane center.
MPA rainfall totals from Beta are shown (image left) for the period 27 to 31 October 2005.
The heaviest amounts, on the order of 12 inches (red area), occurred off shore
and were a direct result of Beta's slow forward speed. Rain amounts over
land are generally 6 inches (green areas) or less. So far only 4 persons
were reported missing as a result of Beta. Hurricane Mitch triggered massive
mudslides in the region back in 1998, which led to a large loss of life. TRMM is a joint mission between NASA and the Japanese space agency JAXA. Images produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang
Beta Crawls Towards Nicaragua and Honduras, Landfall Expected Over Weekend
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this photo-like image of Tropical Storm Beta at 2:50 p.m. EDT on October 27, 2005. At the time, Beta had winds of 60 mph.
By 11 a.m. EDT on Friday, Oct. 28, Beta’s winds strengthened to 65 mph, and forecasters say that Beta could strengthen to a hurricane later today or tonight as it moves slowly over the western Caribbean Sea. Beta’s center was located about 45 miles northeast of San Andres Island and about 185 miles east-northeast of Bluefields, Nicaragua. Estimated minimum central pressure is 993 millibars.
The storm is crawling northward at 5 mph. A gradual turn toward the northwest is expected during the next 24 hours. This motion should bring the center of Beta near Colombia’s island of Providencia later today.
Currently, Hurricane warnings and watches are in effect in the region. A hurricane warning remains in effect for the islands of San Andres and Providencia. A tropical storm warning and a hurricane watch remain in effect for the entire Caribbean coast of Nicaragua from the border with Costa Rica northward to Cabo Gracias a Dios near the Nicaragua/Honduras border and adjacent islands. A Tropical storm watch has also been posted for the northeastern coast of Honduras from Limon, eastward to Cabo Gracias a Dios near the Nicaragua/Honduras border.
Conditions Expected This Weekend
On the islands of San Andres and Providencia, forecasters are expecting 4 to 7 feet of storm surge flooding above normal tide levels from Beta. Those islands and northeastern Honduras and Nicaragua can expect up to 10 to 15 inches of rainfall, with isolated maximum amounts of 20 inches.
Beta is expected to make landfall in northeast Nicaragua and southeast Honduras by Sunday, October 30 at 7 a.m. EDT. By Monday, Beta is expected to be downgraded into a tropical depression over Honduras.
Record Twenty-Third Tropical Storm Forms, Another Pending?
Image to right: This image from the National Hurricane Center shows the predicted track for Tropical Storm Beta for the next five days. This graphic is dated October 27, 2005. Click on image to enlarge. Credit: NOAA/NHC
Tropical Storm Beta broke the record that Tropical Storm Alpha broke last week. Beta has now become the 23rd named storm of this hurricane season, breaking Alpha's record for the most named storms of any hurricane season.
Beta formed as a depression by 11 p.m. EDT Wednesday, Oct. 26 in the southwestern Caribbean Sea. At that time, Beta had maximum sustained winds of 35 mph and was located about 100 miles south of Colombia's San Andres Island. Beta was also about 170 miles east-southeast of Bluefields, Nicaragua.
"Records are made to be broken," as the saying goes, and because hurricane season still has another month (it ends November 30) its still possible that we could see a tropical storm "Gamma," the next name in the Greek Alphabet. After the 2005 Atlantic hurricane name list was exhausted with Wilma, forecasters began using the letters of the Greek alphabet.
When Beta Got Its Name
Tropical depressions are given names when their winds increase to 38 mph, and by 8 a.m. on Thursday, Oct. 27, Beta was named. Beta's maximum sustained winds were near 40 mph (65 km/hr) with higher gusts, and forecasters expect some strengthening in the next 24 hours. By 11 a.m. EDT, Beta winds had strengthened to 50 mph (85 km/hr) and more strengthening is forecast.
Beta was drifting northward toward San Andres, and at 11 a.m. was located near latitude 11.5 north and longitude 81.3 west, 175 miles east of Bluefields, Nicaragua. Minimum central pressure was 1000 millibars.
Beta the Soaker
Tropical Storm Beta is expected to produce rainfall totals of 10 to 15 inches across western Panama, Costa Rica, northeastern Honduras, Nicaragua, and Colombia's San Andres and Providencia Islands. Isolated maximum amounts of 20 inches of rain are possible.
Forecasters expect storm surge flooding of 3 to 5 feet above normal tide levels at San Andres and Providencia as the center of Beta passes nearby.
The government of Colombia has issued a hurricane warning for the islands of San Andres and Providencia. The government of Nicaragua has issued a hurricane watch for the entire Caribbean coast of Nicaragua from the border with Costa Rica northward to Cabo Gracias A Dios near the Nicaragua/Honduras border and adjacent islands.
Gamma in the Wings?
Forecasters are keeping a watchful eye over the entire Atlantic Ocean in case Tropical Storm Gamma develops. They're keeping an eye on a tropical wave approaching the Lesser Antilles, with a 1008 millibar low pressure area along the wave. According to forecasters, upper level winds are becoming more favorable for tropical development as the tropical wave moves into the Caribbean Sea. Currently, scattered showers and isolated thunderstorms are moving over the Leeward Islands.
What Are the Next Names for Tropical Storms and Hurricanes?
The next letters of the Greek alphabet are Gamma, Delta, Epsilon and Zeta. For the complete list of names, please visit on the Internet:
For the latest advisories on tropical cyclones, please visit the National Hurricane Center website at:
Goddard Space Flight Center