Roxanne was the first October
hurricane
that formed and reached Category 3 intensity on the
Saffir/Simpson Hurricane Scale (SSHS) in the western Caribbean Sea since
Hurricane Hattie
(Category 4) in October 1961 (113K GIF). After hitting the Yucatan peninsula,
Roxanne meandered in the Bay of Campeche for several days causing
death and destruction along the coast of Mexico from the States of
Yucatan through Campeche and Tabasco.
a. Synoptic History
Roxanne formed from a complex combination of several synoptic-scale features
(a broad low-pressure area, a tropical wave
and an upper trough) which interacted over the western Caribbean.
Formation of tropical cyclones
from this combination has been commonly observed in the western Caribbean
during previous decades, (e.g., 1930, 1940).
As early as 6 October, radiosonde data from the western
Caribbean indicated a broad well-established low- to middle-level
cyclonic circulation with cloudiness and showers between the Cayman
Islands and Honduras. A distinct tropical wave, tracked from the
coast of Africa on 26 September, became convectively active over
the central Caribbean on 4 October. The wave reached the western
Caribbean early on the 7th and interacted with the pre-existing
area of disturbed weather. A slow-westward moving upper-level
trough was at that time located over the Windward Passage, to the
east of an upper-level anticyclone centered over the southeastern Gulf
of Mexico and left by Hurricane Opal. This combination
of the high and the trough aloft resulted in diffluent northerly winds
over the low-level disturbance. Dunn (1960) and Riehl (1951)
recognized this pattern as favorable for the development of
incipient disturbances by.
The 200 and 850 mb data for 1200 UTC 6
October and the schematic pattern suggested by Dunn are displayed
in Fig. 1 (80K GIF). Note that the
prevailing meteorological conditions on that day were similar to those suggested in
Fig. 1c.
On 6 October, the National Hurricane Center (NHC) surface
analysis showed a broad 1004 mb low not too far from the east coast
of Nicaragua. Associated winds were only 10 to 15 knots. Satellite
images indicated a gradual increase in organization and cloud
banding features began to develop early on the 7th as the tropical
wave reached the area. It is estimated that the system became a
tropical depression
at 1800 UTC 7 October just east of Nicaragua. The next day, a reconnaissance
plane confirmed the presence of a tropical depression with a pressure
center of 1004 mb and 30 knot
winds. Satellite images and surface observations indicated a
steady intensification. The depression became
Tropical Storm
Roxanne at 0000 UTC 9 October and a hurricane by 0600 on the 10th.
During that period, data from reconnaissance planes indicated that
the pressure dropped to 989 mb and by 1200 UTC on the 10th the
pressure was down to 972 mb. Prior to intensification, the low-level
center was located on the northern edge of the deep convection due to
the northerly winds produced by the upper high over the Gulf of Mexico.
However, the upper trough previously located over the Windward Passage
became a cut-off low and moved west-southwest into Central America. This
allowed the outflow to become established in all quadrants.
Initially, Roxanne was a threat to Cuba and the Cayman Islands
as it moved northward in response to a weak trough over Florida and
the eastern Gulf of Mexico. The trough moved eastward and was
replaced by a high pressure system. Roxanne turned northwestward
and then westward toward the Yucatan peninsula and intensified. A
similar abrupt change in motion, not expected by climatology, was
taken by Hurricane Hattie in 1961.
During the early afternoon of the 10th, a well-defined
eye became apparent on satellite images.
Roxanne reached its maximum intensity of 100 knots
and a minimum pressure of 956 mb about 2152 UTC just to the southeast of Cozumel.
Figure 2 (43K GIF) shows the northern
eyewall viewed from the Cancun radar,
crossing Cozumel at 2340 UTC 10 October. Roxanne
made landfall just north of Tulum, on the mainland, Mexico just to the
southwest of Cozumel about 0200 UTC 11 October. The hurricane
continued westward over the Yucatan peninsula and emerged over the
Gulf of Campeche as a minimal hurricane. It then temporarily
weakened to tropical storm status. Once the center of circulation
was completely over the waters, the tropical cyclone regained
hurricane intensity and maintained that status for about 60 hours.
It gradually weakened to a tropical storm and then to a tropical depression.
The steering currents were weak when Roxanne was in the Bay of
Campeche. Consequently, the hurricane meandered within an area of
less than 250 n mi for almost a week. During that period, several
shortwave troughs and ridges rapidly passed by to the north of
Roxanne, forcing the tropical cyclone to swing either southeastward
or northwestward. Feeder bands and waves of 15 to 20 feet were
pounding the coastal section from the State of Campeche to Veracruz
throughout that time. Eventually, Roxanne was forced to move
southward into the area near Veracruz by an approaching strong cold
front. The remnants of the tropical cyclone moved southwestward
into Mexico.
Roxanne's track is shown in Fig. 3
(43K GIF). Table 1 is a listing, at six-hour intervals, of the
"best-track" position, estimated minimum
central pressure and maximum 1-min sustained surface wind speed.
b. Meteorological Statistics
The best track pressure and wind curves as a function of time,
shown in Figures 4 and 5 (52K GIF),
are primarily based on reconnaissance aircraft,
satellite intensity estimates
from the National Hurricane Center (NHC),
Satellite Analysis Branch
(SAB) and the
Air Force Global Weather Central (AFGWC). The analysis used numerous
observations taken from ships in the northwestern Caribbean and the Gulf of Mexico.
The maximum intensity occurred about 2152 UTC 10 October when
a reconnaissance plane measured 956 mb and wind of 114 knots at the 700 mb level.
Table 2 lists ship reports with 34 knot winds or
higher and Table 3 lists selected surface observations
associated with Roxanne. Information provided by the Servicio Meteorologico
de Mejico indicated that an automatic station near Merida reported
sustained winds of 65 knots with gusts to 109 knots at 1900 UTC 11
October. A weather station in Veracruz reported nearly 12 inches
of rain and the Tabasco Observatory reported 9.5 inches. The other
reports from the region affected by Roxanne indicate that the
rainfall totals were of only one or two inches there.
Very interesting observations were collected by Mr. Dan
Hartman during the passage of Roxanne. He was located at 20 deg 30'N
86 deg 57'W, (southwest of Cozumel and along the coast of Yucatan).
Pressure was measured with a HUGER mercury barometer. Wind speed
was obtained from a Rainwise wind speed/direction receiver located
on the roof of Mr. Hartman's home which is the top floor of a two
story dwelling. The rain gauge is an All-Weather made to "U.S
Weather Bureau specifications" and was located on the roof in an
unobstructed location. The Log and Comments of Mr. Hartman are:
"On Sunday Oct. 8 approximately 5-6 PM (All times are local time which are two
hour earlier than EST) winds from the north 0-10 mph.
1:45 PM Tuesday |
pressure |
1000 MB |
and winds NW 30-40 MPH |
3:30 PM |
pressure falling |
988 MB |
winds NW 30-40 MPH |
4:30 PM |
|
980 MB |
winds NW 40-74 MPH |
5:00 PM |
| 978 MB |
winds shifting to NE and for a short time the winds seemed to decrease, then wind gusts
increased to over 100 MPH (limit of the wind gage) |
6:00 PM | |
983 MB |
winds likely over 100 MPH coming from anywhere from NE to SE. At
this point the wind gauge had blown over and it became very
difficulty to tell true wind direction. From various windows
we have I could estimate wind direction by the rain blowing
into the house. |
6:45 PM | | 988 MB |
winds still decreasing from NE to SE. |
7:10 PM | | 991 MB |
winds dropping |
8:00 PM | | 995 MB | |
8:35 PM | |
998 MB | |
9:00 PM | | 999 MB | |
12:00 AM Wednesday | | 1002 MB | |
1:30 AM | | 1003 MB | |
6:30 AM | | 1010 MB |
overcast scattered showers, winds E-SE |
The various times of the barometric reading are irregular due to problems dealing
with the hurricane as it impacted our home. It is quite possible that the actual
barometric pressure was lower than 978 MB that I recorded. I just was too busy to
spend too much time taking notes every 5 minutes. Likewise the wind speeds. As a
subjective observation the winds in the storm seem to rise and fall quite a bit.
It was not a steady wind force of so many miles and hour rather than ebbs and
flows which build up into a higher tempo as the storm approached. Rainfall was
also not a large factor. My readings showed approximately 5.4 inches falling from
Monday night till Wednesday morning when I took the final readings. I did record
2.4 inches of this total falling Monday night. The storm surge
on the east side of the island appears to have been on the order of 10 feet. This is based on my
estimate of the high between the water line and the high water mark of the storm
as shown by the trash line".
c. Casualty and Damage Statistics
Mixed reports of damage have been received at the NHC. The death
toll so far is 14 according to the Ft. Lauderdale Sun-Sentinel, 20
October, 1995. U.S. Coast Guard, a C-130 reconnaissance plane
investigating Roxanne and Mexican helicopters searched for people
missing from a petroleum work-barge that sank with 245 people on
board. Five of these 14 deaths appear to be related to this event
including one American. According to Mexican authorities, more
than 40,000 homes were damaged by Roxanne in the States of
Campeche, Quintana Roo, Tabasco Veracruz and Yucatan. Numerous
crops were damaged, cattle drowned and roads were washed out or
blocked by mud and rock slides. The road between the City of
Carmen and Campeche was completely destroyed. Thousands of people
were evacuated. There are unconfirmed reports that many hotel
lobbies in Cancun and Cozumel were damaged from pounding waves.
Extensive tree damage was observed in Cozumel.
Storm tides
and swollen rivers caused the worst flooding in Campeche and Tabasco
since 1927. It appears the worst damage was produced by the
pounding of 15 to 20 foot waves along the shore for several days.
The waters from the Gulf of Mexico surged hundred of yards inland.
This area had previously been affected by Hurricane Opal
a week or two before and it is difficult to separate the damage
caused by Opal and Roxanne. Best estimate of
the combined damage in the Yucatan peninsula is $1.5 billion, according
to insurance company estimates.
d. Forecast and Warning Critique
Table 4 lists the watches and warnings
associated with Roxanne. Initially when Roxanne was in the western Caribbean
moving northward, watches and warnings were issued for portions of
Cuba and the Cayman Islands. In the advisories, the NHC emphasized
that Roxanne was expected to turn toward the northwest and west and
that the threat was the greatest for the Yucatan peninsula.
Numerical models provided excellent guidance when forecasting the
turn to the left toward Yucatan, even when Roxanne was moving
northward 4 to 8 knots (See Fig. 6)
[27K GIF]. Track models generally kept the hurricane moving west or northwest
south of 25°N and almost never suggested a U.S. landfall.
Due to the erratic motion of the tropical cyclone in the Bay
of Campeche, watches and warnings had to be extended, discontinued
and reissued for portions of the coast of Mexico. Overall, Mexico
was under watches and warnings almost continuously for 10 days. A
hurricane warning
for the landfall area near Cozumel was issued 23 hours in advance.
The individual errors of each track model as well as the
errors of the official forecast are shown in Table 5.
The official forecast was generally comparable with the past 10-year average,
but slightly better than average for the 72-h period. It is
interesting to note that in the case of Roxanne, the models A90E
and BAMD performed better than the usually more reliable
GFDL at
the 72-h period. Most of the largest model and official forecast
track errors occurred when Roxanne was meandering in the Bay of
Campeche and steering currents were weak.
As occurred in other storms this season,
the tropical cyclone intensified faster than forecast during the early stage. There
was a negative bias (underforecast) at the 72-h period throughout much
of Roxanne's lifetime.
Table 4. Tropical Cyclone watch and warning summary, Hurricane Roxanne
Date/Time (UTC) | Action | Location |
9/1500 | Tropical Storm Warning issued |
Cayman Islands |
9/2100 | Tropical Storm Warning and
Hurricane Watch issued |
Pinar del Rio and the Isle of Youth, Cuba |
Hurricane Watch issued |
Chetumal to Cabo Catoche, Yucatan, Mexico |
10/0300 | Hurricane Warning issued |
Chetumal northward and westward to Progreso |
10/1500 | Hurricane Watch issued |
West of Progreso to City of Carmen |
Tropical Storm warning and Hurricane Watch discontinued |
Cayman Islands and Cuba except for extreme western Cuba |
10/2100 |
Tropical Storm Warning issued |
Belize City northward to just south of Chetumal |
Tropical Storm Warning discontinued |
Extreme western Cuba |
11/0600 | Tropical Storm Warning discontinued |
Belize City to just south of Chetumal |
11/1500 |
Hurricane Warning issued |
City of Carmen to Coatzacoalcos |
Tropical Storm Warning and
Hurricane Watch issued | West of Coatzacoalcos to Tuxpan |
Hurricane Warning discontinued | Chetumal to Progreso |
11/2100 | Hurricane Warning issued |
West of Coatzacoalcos to Tuxpan |
12/1500 | Tropical Storm Warning and
Hurricane Watch |
City of Carmen to Tampico |
Hurricane Warning discontinued |
West of Coatzacoalcos to Tuxpan |
13/2100 | Tropical Storm Warning and
Hurricane Watch issued |
North of Tampico to La Pesca |
14/0300 |
Tropical Storm Warning and Hurricane Watch discontinued |
City of Carmen to Veracruz |
14/1500 | Tropical Storm Warning and
Hurricane Watch issued |
Veracruz to Progreso |
Tropical Storm Warning and Hurricane Watch discontinued |
North of Tampico |
14/1800 | Hurricane warning issued |
Progreso to Tampico |
16/0300 | Hurricane Warning replaced by
Tropical Storm Warning |
Progreso to Tampico |
18/1500 | Tropical Storm Warning discontinued |
Progreso to Tampico |
18/2100 | Tropical Storm Warning issued |
Tuxpan to San Fernando |
19/1500 | Tropical Storm Warning discontinued |
Tuxpan to San Fernando |