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Tropical Depression One-E (2009)
Encyclopedia
Tropical Depression One-E was the earliest known tropical cyclone
to impact the Mexican state of Sinaloa
. The first system of the 2009 Pacific hurricane season
, One-E formed out of an area of disturbed weather on June 18, 2009, and initially tracked slowly northwards. Throughout the day, convection
developed around the center of circulation
and the system was anticipated to become a tropical storm. Late on June 18, the National Hurricane Center noted that the system was on the verge of becoming a tropical storm; it would have been named Andres had this occurred. However, the following day, strong wind shear
caused the depression to rapidly degenerate into a trough
of low pressure before dissipating off the coast of Sinaloa.
Although no longer a tropical cyclone, the remnants of the depression brought moderate rainfall to parts of Sinaloa
, Nayarit
and Jalisco
. High winds accompanied the rainfall and left about 50,000 residences without power. Several trees were downed and some structures sustained damage from fresh water flooding. Landslides occurred along major highways and significant structural damage was reported around Mazatlán. However, there was no loss of life or reports of injuries.
that exited the coast of Africa on May 29. Little convective activity
was associated with the system as it traveled across the Atlantic Ocean
and Caribbean Sea
. On June 10, the wave crossed Central America
and entered the northeastern Pacific basin
. Over the following few days, the system gradually became better organized and on June 15, an area of low pressure
developed from the wave. The system continued to organize, and on June 17 the National Hurricane Center
(NHC) noted the likelihood for tropical cyclogenesis
; although, at the time, the circulation was not well-defined. It organized further, and on June 18, the NHC initiated advisories on the first tropical depression of the 2009 season about 350 miles (565 km) south-southwest of Mazatlán
, Sinaloa
. Deep convection
persisted near the southern portion of the depression; however, the northern portion of the depression was partially devoid of convective activity. The depression traveled northward along the periphery of a mid-level ridge
over Mexico and an unusually strong mid to upper-level trough
situated over the Baja California Peninsula
.
Later on June 18, forecast models indicated that the system might rapidly degenerate prior to landfall. However, the NHC continued to forecast that the depression would attain tropical storm-status before landfall. Shortly after, the depression became increasingly disorganized as convection separated from the center of circulation due to increasing wind shear
. Stable air ahead of the system inhibited the possibility of rapid development
as warm waters supported intensification. By the morning of June 19, the center of circulation was situated along the southern edge of deep convection, indicating that the depression was beginning to degenerate. Despite this, the NHC continued to anticipate intensification prior to landfall. Embedded within an easterly flow ahead of a mid-level trough, the storm turned towards the north-northeast and accelerated slightly. At 11:00 am PDT (1800 UTC), the depression reached its peak intensity with winds of 35 mph (55 km/h) and a barometric pressure of 1003 mbar (hPa; 29.62 inHg). Operationally, the depression was considered to be slightly stronger, having a minimum pressure of 1001 mbar (hPa; 29.56 inHg). Later that day, the depression began to degenerate into an open trough as it was situated underneath cirrus cloud
s instead of cumulonimbus cloud
s. Visible satellite imagery showed that the depression became increasingly ill-defined and the NHC estimated that the depression degenerated into a trough of low pressure near the Islas Marías
during the afternoon of June 19. The remnants of the depression were monitored by the United States Naval Research Laboratory
for several more hours until the system moved inland over Sinaloa
.
was declared by the Mexican Government for the Islas Marías
, as well as for areas between Topolobampo and El Roblito in Sinaloa
. The captain of the Mazatlán port advised ships to remain at port due to rough seas. A blue alert was declared for Sinaloa due to the possibility of deadly mudslides. Crews throughout the state quickly cleared debris from streams and streets to allow for better drainage. Shelters were prepped for possible evacuees but never opened. Late on June 18, a tropical storm warning was declared for the Islas Marías and the watch along Sinaloa was extended southward to Cabo Corrientes
in Jalisco
. The following day, the Government of Mexico discontinued the warning for the Islas Marías and the watch for areas south of El Roblito was also discontinued. Upon the storm's sudden dissipation later that day, the remaining watch areas were discontinued.
On June 19, 2.44 in (62 mm) of rain fell in Mazatlán
, near where the remnants of the depression moved ashore. Rainfall rates in the region exceeded 1 in/h (25 mm/h) at times. High winds in Mazatlán knocked down several trees, cutting power to local residents. Heavy rains also triggered street flooding throughout the city. Several hours after the storm, electric companies reported than an estimated 50,000 residences were without power. Following an assessment of damage to the power grid, 20 power poles were found to have been damaged, 15 circuit breakers were damaged and 15 sections of power lines were downed. Numerous villages were flooded, some requiring the evacuation of residents. Around 11:00 am PDT (1800 UTC) six people were stranded offshore Sinaloa. High winds caused significant structural damage throughout Mazatlán.
Traffic lights were downed by high winds, causing numerous traffic delays. Landslides along major roadways caused several accidents, one involving a bus that was damaged by rocks. One business was significantly damaged, with at least one main wall collapsing. To speed up the removal of debris, members of the Mexican army were deployed throughout Sinaloa. According to officials in Mexico, Tropical Depression One-E was the first known tropical cyclone to impact the state of Sinaloa during the month of June on record. With the system impacting land on June 19, it marked the earliest date that a tropical cyclone had impacted the state, with the average date of first impact being August 15.
Tropical cyclone
A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor...
to impact the Mexican state of Sinaloa
Sinaloa
Sinaloa officially Estado Libre y Soberano de Sinaloa is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 18 municipalities and its capital city is Culiacán Rosales....
. The first system of the 2009 Pacific hurricane season
2009 Pacific hurricane season
The 2009 Pacific hurricane season was an active event in the annual cycle of tropical cyclone formation, due to a moderate El Niño, unlike the 2009 Atlantic hurricane season, which was relatively quiet. The season officially started on May 15 in the eastern Pacific, and on June 1 for the central...
, One-E formed out of an area of disturbed weather on June 18, 2009, and initially tracked slowly northwards. Throughout the day, convection
Atmospheric convection
Atmospheric convection is the result of a parcel-environment instability, or temperature difference, layer in the atmosphere. Different lapse rates within dry and moist air lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to...
developed around the center of circulation
Eye (cyclone)
The eye is a region of mostly calm weather found at the center of strong tropical cyclones. The eye of a storm is a roughly circular area and typically 30–65 km in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the second most severe weather of a cyclone...
and the system was anticipated to become a tropical storm. Late on June 18, the National Hurricane Center noted that the system was on the verge of becoming a tropical storm; it would have been named Andres had this occurred. However, the following day, strong wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
caused the depression to rapidly degenerate into a trough
Trough (meteorology)
A trough is an elongated region of relatively low atmospheric pressure, often associated with fronts.Unlike fronts, there is not a universal symbol for a trough on a weather chart. The weather charts in some countries or regions mark troughs by a line. In the United States, a trough may be marked...
of low pressure before dissipating off the coast of Sinaloa.
Although no longer a tropical cyclone, the remnants of the depression brought moderate rainfall to parts of Sinaloa
Sinaloa
Sinaloa officially Estado Libre y Soberano de Sinaloa is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 18 municipalities and its capital city is Culiacán Rosales....
, Nayarit
Nayarit
Nayarit officially Estado Libre y Soberano de Nayarit is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 20 municipalities and its capital city is Tepic.It is located in Western Mexico...
and Jalisco
Jalisco
Jalisco officially Estado Libre y Soberano de Jalisco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is located in Western Mexico and divided in 125 municipalities and its capital city is Guadalajara.It is one of the more important states...
. High winds accompanied the rainfall and left about 50,000 residences without power. Several trees were downed and some structures sustained damage from fresh water flooding. Landslides occurred along major highways and significant structural damage was reported around Mazatlán. However, there was no loss of life or reports of injuries.
Meteorological history
Tropical Depression One-E originated from a tropical waveTropical wave
Tropical waves, easterly waves, or tropical easterly waves, also known as African easterly waves in the Atlantic region, are a type of atmospheric trough, an elongated area of relatively low air pressure, oriented north to south, which move from east to west across the tropics causing areas of...
that exited the coast of Africa on May 29. Little convective activity
Atmospheric convection
Atmospheric convection is the result of a parcel-environment instability, or temperature difference, layer in the atmosphere. Different lapse rates within dry and moist air lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to...
was associated with the system as it traveled across the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
and Caribbean Sea
Caribbean Sea
The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by Mexico and Central America to the west and southwest, to the north by the Greater Antilles, and to the east by the Lesser Antilles....
. On June 10, the wave crossed Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and entered the northeastern Pacific basin
Pacific hurricane
A Pacific hurricane or tropical storm is a tropical cyclone that develops in the northeastern part of the Pacific Ocean. For organizational purposes, the northern Pacific Ocean is divided into three regions: the eastern, , central , and western...
. Over the following few days, the system gradually became better organized and on June 15, an area of low pressure
Low pressure area
A low-pressure area, or "low", is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence which occur in upper levels of the troposphere. The formation process of a low-pressure area is known as...
developed from the wave. The system continued to organize, and on June 17 the National Hurricane Center
National Hurricane Center
The National Hurricane Center , located at Florida International University in Miami, Florida, is the division of the National Weather Service responsible for tracking and predicting weather systems within the tropics between the Prime Meridian and the 140th meridian west poleward to the 30th...
(NHC) noted the likelihood for tropical cyclogenesis
Tropical cyclogenesis
Tropical cyclogenesis is the term that describes the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which mid-latitude cyclogenesis occurs...
; although, at the time, the circulation was not well-defined. It organized further, and on June 18, the NHC initiated advisories on the first tropical depression of the 2009 season about 350 miles (565 km) south-southwest of Mazatlán
Mazatlán
Mazatlán is a city in the Mexican state of Sinaloa; the surrounding municipio for which the city serves as the municipal seat is Mazatlán Municipality. It is located at on the Pacific coast, across from the southernmost tip of the Baja California peninsula.Mazatlán is a Nahuatl word meaning...
, Sinaloa
Sinaloa
Sinaloa officially Estado Libre y Soberano de Sinaloa is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 18 municipalities and its capital city is Culiacán Rosales....
. Deep convection
Atmospheric convection
Atmospheric convection is the result of a parcel-environment instability, or temperature difference, layer in the atmosphere. Different lapse rates within dry and moist air lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to...
persisted near the southern portion of the depression; however, the northern portion of the depression was partially devoid of convective activity. The depression traveled northward along the periphery of a mid-level ridge
Ridge (meteorology)
A ridge is an elongated region of relatively high atmospheric pressure, the opposite of a trough....
over Mexico and an unusually strong mid to upper-level trough
Trough (meteorology)
A trough is an elongated region of relatively low atmospheric pressure, often associated with fronts.Unlike fronts, there is not a universal symbol for a trough on a weather chart. The weather charts in some countries or regions mark troughs by a line. In the United States, a trough may be marked...
situated over the Baja California Peninsula
Baja California Peninsula
The Baja California peninsula , is a peninsula in northwestern Mexico. Its land mass separates the Pacific Ocean from the Gulf of California. The Peninsula extends from Mexicali, Baja California in the north to Cabo San Lucas, Baja California Sur in the south.The total area of the Baja California...
.
Later on June 18, forecast models indicated that the system might rapidly degenerate prior to landfall. However, the NHC continued to forecast that the depression would attain tropical storm-status before landfall. Shortly after, the depression became increasingly disorganized as convection separated from the center of circulation due to increasing wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
. Stable air ahead of the system inhibited the possibility of rapid development
Rapid deepening
Rapid deepening, also known as rapid intensification, is a meteorological condition that occurs when the minimum sea-level atmospheric pressure of a tropical cyclone decreases drastically in a short period of time. The National Weather Service describes rapid deepening as a decrease of...
as warm waters supported intensification. By the morning of June 19, the center of circulation was situated along the southern edge of deep convection, indicating that the depression was beginning to degenerate. Despite this, the NHC continued to anticipate intensification prior to landfall. Embedded within an easterly flow ahead of a mid-level trough, the storm turned towards the north-northeast and accelerated slightly. At 11:00 am PDT (1800 UTC), the depression reached its peak intensity with winds of 35 mph (55 km/h) and a barometric pressure of 1003 mbar (hPa; 29.62 inHg). Operationally, the depression was considered to be slightly stronger, having a minimum pressure of 1001 mbar (hPa; 29.56 inHg). Later that day, the depression began to degenerate into an open trough as it was situated underneath cirrus cloud
Cirrus cloud
Cirrus clouds are atmospheric clouds generally characterized by thin, wispy strands, giving them their name from the Latin word cirrus meaning a ringlet or curling lock of hair...
s instead of cumulonimbus cloud
Cumulonimbus cloud
Cumulonimbus is a towering vertical cloud that is very tall, dense, and involved in thunderstorms and other inclement weather. Cumulonimbus originates from Latin: Cumulus "Heap" and nimbus "rain". It is a result of atmospheric instability. These clouds can form alone, in clusters, or along a cold...
s. Visible satellite imagery showed that the depression became increasingly ill-defined and the NHC estimated that the depression degenerated into a trough of low pressure near the Islas Marías
Islas Marías
The Islas Marías are an archipelago of four islands that belong to Mexico. They are located in the Pacific Ocean, some off the coast of the state of Nayarit. They are part of the municipality of San Blas, Nayarit...
during the afternoon of June 19. The remnants of the depression were monitored by the United States Naval Research Laboratory
United States Naval Research Laboratory
The United States Naval Research Laboratory is the corporate research laboratory for the United States Navy and the United States Marine Corps and conducts a program of scientific research and development. NRL opened in 1923 at the instigation of Thomas Edison...
for several more hours until the system moved inland over Sinaloa
Sinaloa
Sinaloa officially Estado Libre y Soberano de Sinaloa is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 18 municipalities and its capital city is Culiacán Rosales....
.
Preparations and impact
When the storm was declared a depression on June 18, a tropical storm watchTropical cyclone warnings and watches
Warnings and watches are two levels of alert issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local population and civil authorities to make appropriate...
was declared by the Mexican Government for the Islas Marías
Islas Marías
The Islas Marías are an archipelago of four islands that belong to Mexico. They are located in the Pacific Ocean, some off the coast of the state of Nayarit. They are part of the municipality of San Blas, Nayarit...
, as well as for areas between Topolobampo and El Roblito in Sinaloa
Sinaloa
Sinaloa officially Estado Libre y Soberano de Sinaloa is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 18 municipalities and its capital city is Culiacán Rosales....
. The captain of the Mazatlán port advised ships to remain at port due to rough seas. A blue alert was declared for Sinaloa due to the possibility of deadly mudslides. Crews throughout the state quickly cleared debris from streams and streets to allow for better drainage. Shelters were prepped for possible evacuees but never opened. Late on June 18, a tropical storm warning was declared for the Islas Marías and the watch along Sinaloa was extended southward to Cabo Corrientes
Cabo Corrientes
Cabo Corrientes is a cape on the Pacific coast of the Mexican state of Jalisco. It marks the southernmost point of the Bahía de Banderas, upon which the port and resort city of Puerto Vallarta stands. The municipality in which the cape lies is also called Cabo Corrientes.Cabo Corrientes is a...
in Jalisco
Jalisco
Jalisco officially Estado Libre y Soberano de Jalisco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is located in Western Mexico and divided in 125 municipalities and its capital city is Guadalajara.It is one of the more important states...
. The following day, the Government of Mexico discontinued the warning for the Islas Marías and the watch for areas south of El Roblito was also discontinued. Upon the storm's sudden dissipation later that day, the remaining watch areas were discontinued.
On June 19, 2.44 in (62 mm) of rain fell in Mazatlán
Mazatlán
Mazatlán is a city in the Mexican state of Sinaloa; the surrounding municipio for which the city serves as the municipal seat is Mazatlán Municipality. It is located at on the Pacific coast, across from the southernmost tip of the Baja California peninsula.Mazatlán is a Nahuatl word meaning...
, near where the remnants of the depression moved ashore. Rainfall rates in the region exceeded 1 in/h (25 mm/h) at times. High winds in Mazatlán knocked down several trees, cutting power to local residents. Heavy rains also triggered street flooding throughout the city. Several hours after the storm, electric companies reported than an estimated 50,000 residences were without power. Following an assessment of damage to the power grid, 20 power poles were found to have been damaged, 15 circuit breakers were damaged and 15 sections of power lines were downed. Numerous villages were flooded, some requiring the evacuation of residents. Around 11:00 am PDT (1800 UTC) six people were stranded offshore Sinaloa. High winds caused significant structural damage throughout Mazatlán.
Traffic lights were downed by high winds, causing numerous traffic delays. Landslides along major roadways caused several accidents, one involving a bus that was damaged by rocks. One business was significantly damaged, with at least one main wall collapsing. To speed up the removal of debris, members of the Mexican army were deployed throughout Sinaloa. According to officials in Mexico, Tropical Depression One-E was the first known tropical cyclone to impact the state of Sinaloa during the month of June on record. With the system impacting land on June 19, it marked the earliest date that a tropical cyclone had impacted the state, with the average date of first impact being August 15.