Featured Images

Hurricane Season 2008: Dolly (Atlantic Ocean)
 
July 28, 2008

Dolly's Remnants Causing Flooding Problems in New Mexico

Chart showing TRIMM-measured rainfall totals for Dolly Credit: Hal Pierce (SSAI/NASA GSFC)
> Larger image
Heavy rainfall from what was once Hurricane Dolly, has brought flooding to southern Texas and New Mexico over the weekend of July 26-27, and continued to do so on Monday, July 28, 2008.

El Paso, Texas, reported flooding on Saturday, July 26, as more than three inches of rain fell from Dolly's remnants. Meanwhile, portions of eastern New Mexico received as much as six inches of rainfall.

Eastern New Mexico was under a flash flood watch through midmorning today (July 28) after a weekend of flooding that caused evacuations of hundreds of people in Ruidoso. Ruidoso is located in the south central part of the state and is northeast of the White Sands National Monument.

Similar to the song "The River Unbroken" from the storm's namesake, Dolly Parton, (on her 1987 CD "Rainbow") the Ruidoso River (Rio Ruidoso) has been unbroken and flooded. The National Weather Service says Rio Ruidoso remained above flood stage this morning. Over the weekend, more than 500 people were evacuated after Rio Ruidoso overflowed its banks. According to CNN, seven people have been swept away from the overflowing river, and flooding in Ruidoso is severe.

Dolly came ashore Wednesday, the 23rd of July 2008, over South Padre Island, just north of the Texas-Mexico border, as a category 2 hurricane with sustained winds of 100 mph. The barrier island was hit hardest with extensive roof, window and tree damage. One of the biggest fears, however, was that the storm could cause serious flooding in the Rio Grande river valley along the border between Texas and Mexico. However, despite dumping heavy rain over parts of south Texas that resulted in localized flooding, the flooding was not widespread such that so far none of the levees along the Rio Grande have been breached.

The Tropical Rainfall Measuring Mission (or TRMM) satellite was launched back in November of 1997 with the primary mission of measuring rainfall from space using both passive microwave and active radar sensors. The TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA) at the NASA Goddard Space Flight Center provides estimates of rainfall over the global Tropics. TMPA rainfall totals associated with Dolly are shown for the period July, 20-25.

The solid black line shows the path of the storm with appropriate storms symbols marking the 00 and 12Z (8 p.m.-8:00 a.m. EDT) positions and intensity. The highest rainfall totals for the period (shown in red) are located offshore as Dolly was approaching the coast. Over land the heaviest rain fell near the coast near the southern tip of Texas and was on the order of 150 mm (~6 inches, shown by the small orange area). Locally upwards of 16 inches (~400 mm) of rain was reported in Cameron County northeast of Brownsville, Texas. Significant areas of 100 mm (~4 inch) amounts (shown in yellow) are located right along the coast and further inland north of the Texas-Mexico border. Amounts drop off further inland as the system continued to track westward into northern Mexico. So far, 2 persons have died as a result of the storm, both in Mexico.

TRMM is a joint mission between NASA and the Japanese space agency JAXA.

Text credit: Rob Gutro/Steve Lang, NASA's Goddard Space Flight Center



July 25, 2008

Dolly's Remnants Hovering and Fading Near Texas/Mexico Border

AIRS image of Dolly fading over Texas/Mexico border Credit: NASA/JPL
> Larger image
Dolly was hanging around the Texas/Mexico border during the morning hours of Friday, July 25, 2008, and continuing to dump heavy rain in the Texas "Big Bend" area. By Sunday, July 27, residents in southwestern Texas hope to be singing Dolly Parton's remake of "We'll Sing in the Sunshine," from her "Great Pretender" CD, as Tropical Depression Dolly is expected to fade by then.

The National Hurricane Center issued its last advisory on Dolly during the evening hours of Thursday, July 24, so the National Weather Service's Hydrometeorological Prediction Center (HPC) in Camp Springs, Maryland is now posting updates on their web page.

According to the HPC, at 4:00 a.m. CDT on July 25, Dolly, now a tropical depression was located near the Texas/Mexico border, just to the south of the "Big Bend." She was near latitude 28.6 north and longitude 103.6 west, which is approximately 100 miles south-southeast of Marfa, Texas. Maximum sustained winds were near 20 mph with gusts to 30 mph. The minimum central pressure was 1004 millibars.

Dolly is expected to continue producing additional rain accumulations of 1 to 3 inches over portions of southwest Texas and northeastern Mexico through Friday.

According to CNN, Tropical Storm Dolly left hundreds of thousands of people without power and forced thousands into temporary shelters in South Texas. Fifteen south Texas counties were declared federal disaster areas. Agence France-Presse reported that Dolly downed trees and powerlines, tore off rooftops and caused hundreds of millions of dollars in estimated damages.

Agence France-Presse (AFP) reported Dolly's wrath in northeast Mexico. AFP said that Dolly caused extensive flooding in the border city of Matamoros. In that city, "tens of thousands of people lacked electricity and drinking water." One fatality was reported there, due to electrocution, likely from downed power lines. In the town of Nuevo Laredo, Dolly's winds damaged the main water treatment plant, leaving 250,000 residents without drinking water.

This infrared image of Dolly was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was created on July 25 at 8:35 UTC (4:35 a.m. EDT).

The AIRS images show the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of Tropical Depression Dolly. The AIRS data creates an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



July 24, 2008

Dolly Now a Tropical Storm, Shattered Brownsville Rainfall Records

Satellite image of Dolly Credit: NASA/JPL
> Larger image
After making landfall yesterday afternoon as a Category 2 hurricane, Dolly has weakened into a tropical storm and continues dumping heavy rains inland over Texas and northeastern Mexico. Dolly Parton's song "Steady as the Rain" from her "Grass is Blue" CD is very appropriate for this storm as it broke the record in Brownsville, Texas for the wettest single day ever!

At 8:00 a.m. EDT today, Thursday, July, 24, 2008, Tropical Storm Dolly was located about 50 miles east-southeast of Laredo, Texas. Laredo is a border town on the U.S.-Mexico line, on the Rio Grande.

Dolly's center was near latitude 27.2 degrees north and longitude 98.9 west, over northeast Mexico. Rainbands are currently affecting Eagle Pass, Texas, about 124 miles to the northwest of Laredo.

To See Dolly's Rainfall as it Happens Today, July 24...

For current radar out of Laughlin Air Force Base, Texas, visit:
http://radar.weather.gov/radar.php?product=NCR&rid=dfx&loop=yes

Dolly Breaks Rainfall Records for Brownsville

Satellite image of Dolly Credit: NASA/JPL
> Larger image
According to the National Weather Service in Brownsville, Texas, "Yesterday's rainfall total in Brownsville was 6.68 inches. It was the wettest single July day in Brownsville history and the 11th wettest day ever. The single day total for July 23 was more than the monthly July totals for all years back to 1878 except for two years."

Dolly is expected to produce total rainfall accumulations of 8 to 12 inches with isolated amounts of 20 inches over portions of south Texas and northeastern Mexico as she continues on her inland track. These rains are very likely to cause widespread flooding.

Dolly Moving Further Into Mexico

At 8:00 a.m. EDT, July 24, Dolly was moving toward the west-northwest near 7 mph. A continued motion toward the west-northwest is expected during the next day or so, with a slight increase in forward speed until the system dissipates on Friday, July 25 over north central Mexico.

Dolly's maximum sustained winds have decreased to near 50 mph with higher gusts. She will continue to weaken as she moves farther inland and is expected to become a tropical depression later today. Estimated minimum central pressure is 995 millibars.

What Do These NASA Satellite Images Show?

These infrared and visible images of Dolly were created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. They were created on July 23 at 19:47 UTC (3:47 p.m. EDT) after Dolly made landfall in south Texas. Dolly is clearly seen in a "perfect hurricane shape," especially in the infrared image that shows Dolly in blue and purple.

The AIRS images show the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of Dolly. The AIRS data creates an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



July 23, 2008, third update

NASA's QuikScat Looks at Hurricane Dolly's Winds - She Makes Landfall in South Texas

QuikSCAT image of Dolly's winds Credit: NASA/JPL
> Larger image
At 3:00 p.m. EDT, Wednesday, July 23, 2008, Hurricane Dolly made landfall in South Padre Island and is moving farther inland over southern Texas.

This image from NASA's QuikSCAT satellite was taken at 8:24 p.m. EDT July 22 (12:24 UTC on July 23). It depicts Dolly's wind speed in color and wind direction with small barbs. White barbs point to areas of heavy rain. The highest wind speeds, are shown in purple, which indicate winds over 40 knots (46 mph).

At 3:00 p.m. EDT, Wednesday, July 23, the eye of Hurricane Dolly was located near latitude 26.4 north and longitude 97.3 west. This position is over Laguna Madre about 35 miles north-northeast of Brownsville, Texas and 30 miles east southeast of Raymondville. She's moving west-northwest near 7 mph.

Maximum sustained winds are near 95 mph, slightly slower because of the friction generated from Dolly raking over land. Dolly is a strong category one hurricane, and is expected to weaken further as she moves inland.

Harlingen, Texas measured 54 mph sustained winds with gusts to 74 mph. Minimum central pressure reported by an air force reconnaissance plane at landfall was 967 millibars.

Dolly's rain totals are expected to be quite high- between 8 and 12 inches, with isolated amounts to 20 inches over areas of south Texas and northeastern Mexico. This will continue over the next couple of days. In fact, Brownsville, Texas National Weather Service Doppler radar estimated up to a foot of rain so far over portions of coastal far south Texas. Meanwhile, coastal storm surge flooding between 6 and 8 feet above normal tide level is expected near and to the north of her Landfalling eye. Isolated tornadoes are also possible, and south Texas has already experienced one.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



July 23, 2008, second update

Category 2 Hurricane Dolly Crosses South Padre Island, Texas

At 12:00 p.m. CDT (1:00 p.m. EDT) Dolly's eye was located near latitude 26.2 north and longitude 97.0 west or about 35 miles northeast of Brownsville, Texas, and she was crossing South Padre Island.

Dolly has been meandering for the past hour or so but it should begin to move toward the west-northwest near 7 mph on the forecast track. The eye of Hurricane Dolly will be crossing the coast along the southern Texas coast in the early-mid afternoon hours).

Maximum sustained winds remain near 100 mph with higher gusts. Dolly is a category two hurricane on the Saffir-Simpson scale. At 1:00 p.m. EDT, Port Isabel Airport measured 58 mph sustained winds with gusts to 70 mph. Minimum central pressure reported by an air force reconnaissance plane was is 967 millibars.

She's expected to maintain hurricane strength over the southern tip of Texas and weaken to a depression over the Mexico line early Thursday.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



July 23, 2008, first update

Hurricane Dolly Already Making Landfall; Tornado Reported in South Texas

Satellite image of Dolly Credit: NASA/JPL
> Larger image
Tropical Storm Dolly strengthened into a Category One Hurricane with 85 mph maximum sustained winds and may get even stronger before her eye makes landfall this morning (July 23, 2008). Dolly's center will be along the coast near the Texas/Mexico border around midday today, according to the National Hurricane Center, but she's already generated one tornado in south Texas this morning.

At 7:00 a.m. EDT, tropical storm force winds were already affecting coastal Texas and northeastern Mexico. The center of hurricane Dolly was located near latitude 25.8 north and longitude 96.6 west or about 55 miles (90 km) east of Brownsville, Texas.

Dolly is moving toward the northwest near 8 mph (13 km/hr) and northwestward to west-northwestward motion with a slight decrease in forward speed is expected today. Minimum central pressure is 972 millibars.

Where are the Warnings and Watches?

A hurricane warning remains in effect for the coast of Texas from Brownsville to Corpus Christi and for the northeastern coast of Mexico from Rio San Fernando northward to the border between Mexico and the U.S. Tropical Storm Warnings are posted for areas north and south of the hurricane warning area.

What Weather Conditions Are Expected?

At 8:00 a.m. EDT, the city of Brownsville, Texas was under a Flood Watch, Hurricane Wind Warning, Tornado Watch, and already a Tornado Warning.

At 7:04 a.m. CDT, The National Weather Service doppler radar indicated a tornado 7 miles north of Harlingen Valley Airport and moving southwest at 46 mph.

In the warning areas, Dolly is expected to produce total rainfall accumulations of 6 to 10 inches, with isolated amounts of 15 inches over portions of south Texas and northeastern Mexico over the next few days. These rains will likely cause widespread flooding across portions of south Texas and northeast Mexico.

Coastal flooding is another problem. Dolly's storm surge along the coasts will range from 4 to 6 feet above normal tide levels. There will also be large and dangerous battering waves near and north of the center's landfall point.

As with any land-falling hurricane, isolated tornadoes are also possible. Portions of south Texas and northern Mexico may experience isolated tornadoes today and tonight.

For Current Radar out of Brownsville, Texas, visit:
http://radar.weather.gov/radar.php?rid=BRO&product=NCR&overlay=11111111&loop=yes

What Does This NASA Satellite Image Show?

This infrared image of Dolly was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was created on July 22 at 19:05 UTC (3:05 p.m. EDT) and Dolly was located in the Gulf of Mexico headed toward the Texas/Mexico border. Dolly is seen to the left side of this image.

The AIRS images show the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of Dolly. The AIRS data creates an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



July 22, 2008, second update

Dolly Poised to Hit South Texas, Northern Mexico as Hurricane

Satellite image of Dolly Credit: Hal Pierce (SSAI/NASA GSFC)
> Larger image
The 2008 Atlantic hurricane season has become a lot more active recently, first with the formation of Tropical Storm Cristobal off of the Carolina coast and now with Tropical Storm Dolly in the Gulf of Mexico poised to strike near the border between Texas and Mexico. Dolly, which became a tropical storm in the western Caribbean on the morning (local time) of 20 July 2008, originated from an African easterly wave that had emerged off of the coast of Africa back on the 12th of July before propagating westward across the tropical Atlantic and into the Caribbean. After forming in the western Caribbean, Tropical Storm Dolly maintained a generally west-northwestward track, which took the center across the very northern tip of the Yucatan Peninsula early on the morning (local time) of July 21st. Despite passing over land and being somewhat disorganized, Dolly maintained moderate tropical storm intensity with sustained winds estimated at 45 knots (52 mph) by the National Hurricane Center (NHC). Dolly re-emerged over the warm open waters of the western Gulf of Mexico later on the morning of the 21st. Combined with low atmospheric wind shear, conditions were favorable for intensification. The only real inhibiting factor was the sprawling nature of the storm itself. Without a well-organized core, storms take longer to respond to favorable conditions. None-the-less, Dolly began to slowly strengthen as is took aim at the Texas-Mexico border.

Satellite image of Dolly Credit: Hal Pierce (SSAI/NASA GSFC)
> Larger image
The Tropical Rainfall Measuring Mission satellite (also known as TRMM) has been in service for over 10 years now and continues to provide valuable images and information on tropical cyclones around the Tropics using a combination of passive microwave and active radar sensors, including the first precipitation radar in space. These unique images were captured by TRMM at 12:44 UTC (7:44 am CDT) 22 July 2008 while Dolly was in the western Gulf of Mexico. The first image shows the horizontal pattern of rain intensity within the storm. Rain rates in the center swath are based on the TRMM Precipitation Radar (PR), and those in the outer swath on the TRMM Microwave Imager (TMI). The rain rates are overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS). TRMM reveals that Dolly has a rather large wavy eye with most of the moderate to heavy rain (green and red areas, respectively) wrapping around the southern side of the storm.

The second image was collected at the same time and shows a 3D perspective of the storm via the TRMM PR. The eye is clearly visible by the deep center (in blue), which is completely surrounded by a ring of moderately high precipitation areas (green). A few somewhat taller towers are visible in red within the eastern eyewall. At the time of these images, Dolly was a moderate tropical storm with maximum sustained winds reported at 55 knots (63 mph) by NHC. Dolly is expected to continue off to the west-northwest and make landfall in the vicinity of Brownsville, TX as a minimal hurricane before turning more westward over central northern Mexico.

TRMM is a joint mission between NASA and the Japanese space agency JAXA.

Text credit: Steve Lang, SSAI/NASA GSFC



July 22, 2008, first update

Dolly Eyeing Landfall Wednesday at Texas/Mexico Border as a Hurricane

AIRS image of Dolly in the Gulf of Mexico Credit: NASA/JPL
> Larger image
Tropical Storm Dolly is strengthening in the warm waters of the Gulf of Mexico, and is expected to become a hurricane by Wednesday, July 23. The National Hurricane Center is forecasting landfall that day near Brownsville, Texas, which is on the border between Texas and Mexico.

Where is Dolly Now?
At 5:00 a.m. EDT (4:00 a.m. CDT) on Tuesday, July 22, the center of Tropical Storm Dolly was located near latitude 23.3 north and longitude 93.8 west or about 295 miles (475 km) southeast of Brownsville, Texas. Dolly's maximum sustained winds are near 60 mph (95 km/hr) with higher gusts. Additional strengthening is forecast, and Dolly is expected to become a hurricane prior to landfall.

Dolly is moving toward the west near 15 mph (24 km/hr). Later today, July 22, she's expected to turn to the west-northwest is expected later today, then veer northwest on the 23rd. Minimum central pressure is 997 millibars.

Where Are The Warnings Posted?
A hurricane warning is in effect for the coast of Texas from Brownsville to Port O'Connor. There's a warning also for the northeast coast of Mexico from Rio San Fernando, northward to the border between Mexico and the U.S. A hurricane warning means that hurricane conditions are expected within the warning area within the next 24 hours.

A tropical storm warning is in effect from north of Port O'Connor to San Luis Pass. A tropical storm warning means that tropical storm conditions (winds between 39-73 mph) are expected within the warning area within the next 24 hours.

What Will Dolly Bring to Texas and Mexico?
Like the Dolly Parton song "Wild Texas Wind" from her "Something Special" album of 1995, Texas and Mexico will likely be experiencing hurricane force winds over the next few days.

The National Hurricane Center expects Dolly to produce total rain accumulations of 4 to 8 inches with isolated amounts of up to 15 inches over much of south Texas and northeastern Mexico over the next few days. Dolly is expected to produce additional amounts of 1 to 3 inches over the Northern Yucatan Peninsula.

Dangerous coastal conditions are expected as Dolly approaches the coast. Coastal storm surge flooding of 4 to 6 feet above normal tide levels along with large and dangerous battering waves can be expected near and to the north of where the center makes landfall.

What Does This NASA Satellite Image Show?
This infrared image of Dolly was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was created on July 22 at 8:05 UTC (4:05 a.m. EDT) and Dolly is located in the Gulf of Mexico, some 275 miles southeast of Brownsville, Texas (at the southern-most tip of the state).

The AIRS images show the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of Dolly. The AIRS data creates an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

Text Credit: Rob Gutro
Goddard Space Flight Center



July 21, 2008

Tropical Storm Dolly, Here You Come Again…

AIRS satellite image of Dolly Credit: NASA/JPL
> Larger image
Like the number one song by Dolly Parton, "Here You Come Again," six years ago, there was a tropical storm Dolly, now the name has returned on the official six year name hurricane list. Dolly is the name of the Atlantic Hurricane Season's fourth named storm and she means business in the Gulf of Mexico.

Dolly started out as a tropical depression on Sunday, July 20th and by 11:45 a.m. EDT that day, she strengthened into a tropical storm and got her name.

By 8:00 a.m. EDT on Monday, July 21, 2008, Dolly had moved off the Yucatan Peninsula, Mexico, and is located between there and Cuba. She's now poised to enter the Gulf of Mexico's warm waters and could become a hurricane by Tuesday, July 22.

At 8:00 a.m. EDT on July 21, Dolly's center was located near 21.6 degrees north latitude and 88.7 degrees west longitude, or 65 miles (105 km) east-northeast of Progreso, Mexico. Dolly is moving toward the west-northwest near 16 mph (26 km/hour), and a west-northwest motion is expected over the next couple of days. She's also expected to slow down in forward speed.

Dolly's maximum sustained winds are near 50 mph (85 km/hour) with higher gusts, and the warm waters of the Gulf of Mexico will strengthen her into a hurricane over the next day. Her estimated minimum central pressure is 1005 millibars.

She's expected to produce a good amount of rainfall across the northern Yucatan and western Cuba, between 4 and 6 inches. There will also be areas that could receive as much as 10 inches of rain.

This infrared image of Dolly was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was created on July 21 at 7:23 UTC (3:23 a.m. EDT) and Dolly is located between the Yucatan and Cuba poised to enter the Gulf of Mexico.

The AIRS images show the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of Dolly. The AIRS data creates an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

Text Credit: Rob Gutro
Goddard Space Flight Center