June 07, 2020 – NASA Analyzes Tropical Storm Cristobal Temperatures, Water Vapor
NASA scientists can analyze tropical cyclones in a variety of ways that include temperature and water vapor content. NASA’s Aqua satellite provided that data on Tropical Storm Cristobal as it approached the mouth of the Mississippi River on Sunday, June 7, 2020.
The National Hurricane Center (NHC) forecasts Cristobal to track northward through the Gulf of Mexico and toward Louisiana’s coast. Watches and warnings have gone into effect.
Watches and Warnings
On June 7 as Tropical Storm Cristobal was near the U.S. Gulf coast warnings were in effect. A Storm Surge Warning is in effect from the mouth of the Mississippi River to Ocean Springs, Mississippi and Lake Borgne. A Storm Surge Watch is in effect from east of Morgan City, Louisiana to the mouth of the Mississippi River. A Tropical Storm Warning is in effect from Intracoastal City, Louisiana to the Okaloosa/Walton County, Florida line and for Lake Pontchartrain and Lake Maurepas.
What the NASA Satellite Views Show
On June 7 at 3:50 a.m. EDT (0750 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite showed several areas of powerful thunderstorms where temperatures were as cold as or colder than minus 63 degrees Fahrenheit (minus 52.7 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall. At the time of the imagery, all of those strongest storms were over the Gulf of Mexico, with the exception of an area over the southeastern Louisiana.
At the same time, a water vapor image of Tropical Storm Cristobal was taken from NASA’s Aqua satellite. The water vapor imagery confirmed the cloud top temperatures and showed where the greatest water content was in the storms.
Water vapor analysis of tropical cyclones tells forecasters how much potential a storm has to develop. Water vapor releases latent heat as it condenses into liquid. That liquid becomes clouds and thunderstorms that make up a tropical cyclone. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and stronger they are.
Looking at NASA and other satellite imagery, forecasters at NOAA’s National Hurricane Center (NHC) noted that Cristobal continues to resemble a subtropical cyclone more than a tropical cyclone. At 5 a.m. EDT on June 7, the convection near the center remains limited, although it has become a little better organized during the past several hours.
Cristobal’s Status on June 7, 2020
At 8 a.m. EDT (1200 UTC), NHC noted that the center of Tropical Storm Cristobal was located by an Air Force Reserve reconnaissance aircraft near latitude 28.2 degrees north and longitude 89.9 degrees west. That puts the center about 70 miles (110 km) south of Grand Isle, Louisiana and about 75 miles (125 km) south-southwest of the mouth of the Mississippi River.
Cristobal was moving toward the north near 12 mph (19 kph) and this general motion is expected to continue today, followed by a gradual turn toward the north-northwest late today or tonight. Data from NOAA Doppler weather radars indicate that maximum sustained winds remain near 50 mph (85 km/h) with higher gusts. Tropical-storm-force winds extend outward up to 205 miles (335 km) mainly to the east of the center. The minimum central pressure recently measured by the reconnaissance aircraft was 994 millibars.
Storm Surge, Rainfall, Winds, Tornadoes, Ocean Swells
NHC provided detailed information about expected storm surge, rainfall totals, winds, isolated tornadoes and ocean swells. For those details visit: www.nhc.noaa.gov.
NHC forecasters said, “A combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide.
Cristobal is expected to produce total rainfall accumulations of 4 to 8 inches across portions of the central Gulf Coast into the Lower Mississippi Valley, with isolated amounts to 12 inches. Rainfall totals of 2 to 4 inches with local amounts to 6 inches are expected across portions of the eastern Gulf Coast, along with the Mid to Upper Mississippi Valley and Northern Plains near and in advance of Cristobal.
Tropical storm conditions are expected within the Tropical Storm Warning area along the northern Gulf coast today and tonight. A few tornadoes are possible today and tonight across eastern Louisiana, southern Mississippi, southern Alabama, and northern Florida.”
In addition, ocean swells generated by Cristobal will affect portions of the northern and eastern Gulf coast during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions.
Cristobal’s Forecast Path
Little change in strength is forecast before Cristobal makes landfall and weakening will begin once Cristobal moves inland. On the NHC forecast track, the center of Cristobal will approach the northern Gulf of Mexico coast during the afternoon of Sunday, June 7, then move inland across Louisiana late today through Monday morning [June 8] and northward across Arkansas and Missouri Monday afternoon into Tuesday [June 9].
Typhoons/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.
For updated forecasts, visit: www.nhc.noaa.gov