Hurricane Danielle became the first major hurricane of the 2010 Atlantic hurricane season overnight as it continued to make its way through the central Atlantic.

Danielle, which had been a Category 2 storm the day before with sustained winds estimated at around 95 knots (~110 mph) by the National Hurricane Center, quickly intensified overnight and by morning was a power Category 4 hurricane on the Saffir-Simpson scale with sustained winds of 115 knots (132 mph).

“The TRMM satellite passed directly over Danielle during the night and captured remarkable images as the storm was in the process of intensifying,” said Steve Lang, research meteorologist on the TRMM team in the Mesoscale Atmospheric Processes Branch at NASA’s Goddard Space Flight Center in Greenbelt, Md.

Two images were taken from TRMM at 06:46 UTC (2:46 a.m. EDT) on August 27. The first image showed a top-down view of the horizontal pattern of rain intensity within the storm. Rain rates in the center of the swath are from the TRMM Precipitation Radar (PR), and those 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), and are created at NASA Goddard. TRMM is managed by both NASA and the Japanese Space Agency, JAXA.

The  storm known formerly as Tropical Depression 6E, or TD6E, has been downgraded into a remnant low pressure system in the Eastern Pacific Ocean. On July 16 when NASA’s Aqua satellite flew over TD6E, the infrared imagery showed a small area of strong convection in the storm.

The image, captured on July 15 at 2105 UTC 5:05 p.m. EDT was captured when 6E was still a tropical depression. By July 16, 6E was a remnant low pressure area and had maximum sustained winds near 25 knots (28 mph). It was located near 18 North and 111 West hundreds of miles from the southwestern coast of Mexico. 6E was moving west-northwestward near 10 knots (11 mph). The estimated minimum central pressure is 1006 millibars.

On July 16, the National Hurricane Center indicated that scattered moderate isolated strong convection is occurring within 300 nautical miles in the western semicircle. On July 15, NASA infrared imagery showed the strongest convection to the south of the center of circulation.

6E is a large remnant low, about 600 nautical miles in diameter, and is being “stretched” and elongated because of strong vertical wind shear. It’s the wind shear, coupled with dry air and cooler waters (that 6E is moving into) that make strengthening back into a tropical storm very unlikely.

A creepy montage of post-Katrina New Orleans

Hurricane Katrina made landfall on August 29, 2005, in southeastern Louisiana, with maximum sustained winds of 140 mph. Hurricane-force winds extended outward up to 105 miles from the center of the storm. Coastal storm surge flooding of 20 to 30 feet above normal tide levels, along with large and dangerous battering waves, occurred near and to the east of where the center of the storm made landfall. Widespread damage occurred, including beach erosion and damage and/or destruction of homes and infrastructure.

In the wake of this devastating event, the Federal Emergency Management Agency (FEMA) initiated a project to produce high-resolution maps that show flood impacts from the storm for portions of St. Tammany, Tangipahoa, St. John the Baptist, St. Charles, Jefferson, Orleans, St. Bernard, and Plaquemines Parishes. The Hurricane Katrina Surge Inundation and Advisory Base Flood Elevation Maps (also referred to as “Katrina Recovery Maps”) can be viewed at the Maps link on this site. These maps show preliminary high water mark flood elevations and flood inundation limits from Hurricane Katrina.

Note: Much of the Louisiana coast was subject to surge flooding again when Hurricane Rita struck near the Louisiana-Texas line in September. Areas where Hurricane Rita’s coastal flooding was documented as being more severe than that of Katrina were mapped separately; see the Recovery Data page for information about Rita Recovery Maps.

In addition to information about Hurricane Katrina’s impacts, the Katrina Recovery Maps also show coastal Advisory Base Flood Elevations (ABFEs). These ABFEs are based on a flood frequency analysis completed by FEMA that updates the flood risk data with information on storms that have occurred in the 25+ years since the Flood Insurance Rate Maps (FIRMs) were published, including (but not limited to) Hurricane Katrina.

These Katrina Recovery Maps are intended to help state and local officials, as well as homeowners, to identify existing and increased flood hazards caused by Hurricane Katrina and other storms that have struck this region in the last 25 years, and to use this information during recovery and redevelopment to avoid future flood damages.

Flood inundation limits were created for the coastal Louisiana parishes by mapping the coastal HWM elevations onto digital, pre-storm, topographic contour data developed from recent Light Detecting and Ranging (LIDAR) surveys. These inundation limits represent an estimate of the inland extent of flooding caused by Hurricane Katrina’s storm surge. In areas where the coastal HWMs were close together but elevations differed significantly (more than 2-3 feet), engineering judgment was used to interpolate the inundation limit between coastal HWMs. At the time of this project, post-hurricane topography was not available for the study area. In addition, inundation limits have only been developed for areas outside of levees.

Please note: FEMA used the best data available at the time this project was completed to develop the Katrina surge inundation limits, including eyewitness observations provided by some local officials and citizens. However, because of inherent variability in HWM elevations, the scarcity of available HWMs in some areas, and small-scale variations in topography, the extent of the surge inundation shown on the Katrina Recovery Maps may over- or underestimate the actual coastal flooding that occurred. Thus, this information should be considered approximate and may be subject to change as additional data become available.