WunderBlog Archive » Category 6™
Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.Debby dumps 20 inches of rain; 105° in Denver: hottest day on record
Florida, the Sunshine State, continues to be the thoroughly sodden state, thanks to torrential rains from slow-moving Tropical Storm Debby. On Monday, Debby spawned an area of intense thunderstorms that blew up over the Florida Panhandle, just east of Apalachicola. A weather station in Wakulia County, 4 miles east of Saint Marks, Florida, recorded 12.99" on rain in just 12 hours, bringing the 48-hour rainfall total at the site to 20.96". Several other stations in Wakulia Country also recorded rainfall amounts in excess of 20 inches, and the heavy rains caused moderate to major flooding on area rivers. Debby did not spawn any tornadoes on Monday, thankfully.
Figure 1. Radar-estimated rainfall from Tropical Storm Debby shows an area of extreme rainfall in excess of 15 inches has affected the Florida Panhandle.
Dry air and high wind shear continue to disrupt Debby. Our Wundermap for the surrounding ocean areas shows that winds at almost all buoys and coastal stations along the Gulf Coast were below 25 mph at 7 am EDT. Visible satellite loops show Debby has virtually no heavy thunderstorms near its center of circulation, which will severely limit its potential for intensification. The heavy thunderstorms of Debby are mostly on the east and north sides. Upper-level winds out of the west creating a high 20 - 25 knots of wind shear that continues to drive dry air into Debby's core. This dry air can be seen on Water vapor satellite loops. Ocean temperatures are about 27.5°C (81°F) in the Northern Gulf of Mexico, which is about 1°F above average, but these waters do not extend to great depth, which will limit how strong Debby can get.
Figure 2. True-color visible Terra satellite image of Debby taken at 12:30 pm EDT Monday June 25, 2012. At the time, Debby had top winds of 45mph. Note the heavy thunderstorms on the north side of the center, which were dumping extremely heavy rains over the Florida Panhandle that caused major flooding on area rivers. Image credit: NASA.
Forecast for Debby
Debby's slow motion will make rainfall the primary threat from the storm, though tornadoes will continue to be a threat over the next few days. NOAA's Storm Prediction Center has placed most of Florida in its "Slight Risk" area for severe weather today. The slow motion of Debby will inhibit intensification of the storm by stirring up cooler waters from the depths to the surface. Debby's close proximity to land places a portion of its circulation over land, which will also tend to slow down intensification. Wind shear is expected to remain in the high range through Wednesday, and given the storm's other problems, significant intensification before landfall on Florida's Gulf Coast is unlikely.
Denver's 105°: hottest temperature in city history
The mercury soared to 105° in Denver, Colorado on Monday, tying the record for the hottest temperature ever measured in the city. The city also hit 105° on July 20, 2005 and August 8, 1878. Yesterday's 105° reading was the city's fourth consecutive day in the triple digit heat. The city's record streak of 100°+ days is five, set in 1989 and again in 2005. Denver's forecast today calls for highs of 100 - 104°, so the city will likely tie its all-time mark for consecutive 100°+ days.
In many respects, the extreme heat that has scorched Colorado since Saturday is the state's most intense heat wave in recorded history. According to wunderground's weather historian Christopher C. Burt, Saturday's 114° reading in Las Animas tied for the hottest temperature ever measured in the state of Colorado. Two other 114° readings have occurred in Colorado history: in Las Animas on July 1, 1933, and in Sedgwick on July 11, 1954. Colorado Springs tied its all-time record for warmest temperature ever measured on both Saturday and Sunday, with readings of 100°. The record heat in Colorado has exacerbated numerous destructive wildfires, and the Governor reported over the weekend that half of the nation's firefighting fleet has been deployed to Colorado. On Sunday, a wildfire that grew to more than 3 square miles near Colorado Springs drove 11,000 residents (2% of the city's population) out of their homes. In Fort Collins, the mercury hit 102° on Sunday, just 1° below the city's all-time hottest temperature of 103° set on Jul 21, 2005. The heat did no favors for firefighters struggling to the contain the massive 81,000 acre High Park fire fifteen miles northwest of Fort Collins. The fire is the second largest and most destructive wildfire in Colorado's history, and is 45% contained. La Junta, CO hit 110° on Sunday, tying its all-time hottest temperature record, set on June 28, 1990. Today is the last day of exceptional heat for Colorado, as the ridge of high pressure responsible slides to the east, bringing record-breaking heat to the Midwest instead.
Jeff Masters
Figure 1. Radar-estimated rainfall from Tropical Storm Debby shows an area of extreme rainfall in excess of 15 inches has affected the Florida Panhandle.
Dry air and high wind shear continue to disrupt Debby. Our Wundermap for the surrounding ocean areas shows that winds at almost all buoys and coastal stations along the Gulf Coast were below 25 mph at 7 am EDT. Visible satellite loops show Debby has virtually no heavy thunderstorms near its center of circulation, which will severely limit its potential for intensification. The heavy thunderstorms of Debby are mostly on the east and north sides. Upper-level winds out of the west creating a high 20 - 25 knots of wind shear that continues to drive dry air into Debby's core. This dry air can be seen on Water vapor satellite loops. Ocean temperatures are about 27.5°C (81°F) in the Northern Gulf of Mexico, which is about 1°F above average, but these waters do not extend to great depth, which will limit how strong Debby can get.
Figure 2. True-color visible Terra satellite image of Debby taken at 12:30 pm EDT Monday June 25, 2012. At the time, Debby had top winds of 45mph. Note the heavy thunderstorms on the north side of the center, which were dumping extremely heavy rains over the Florida Panhandle that caused major flooding on area rivers. Image credit: NASA.
Forecast for Debby
Debby's slow motion will make rainfall the primary threat from the storm, though tornadoes will continue to be a threat over the next few days. NOAA's Storm Prediction Center has placed most of Florida in its "Slight Risk" area for severe weather today. The slow motion of Debby will inhibit intensification of the storm by stirring up cooler waters from the depths to the surface. Debby's close proximity to land places a portion of its circulation over land, which will also tend to slow down intensification. Wind shear is expected to remain in the high range through Wednesday, and given the storm's other problems, significant intensification before landfall on Florida's Gulf Coast is unlikely.
Denver's 105°: hottest temperature in city history
The mercury soared to 105° in Denver, Colorado on Monday, tying the record for the hottest temperature ever measured in the city. The city also hit 105° on July 20, 2005 and August 8, 1878. Yesterday's 105° reading was the city's fourth consecutive day in the triple digit heat. The city's record streak of 100°+ days is five, set in 1989 and again in 2005. Denver's forecast today calls for highs of 100 - 104°, so the city will likely tie its all-time mark for consecutive 100°+ days.
In many respects, the extreme heat that has scorched Colorado since Saturday is the state's most intense heat wave in recorded history. According to wunderground's weather historian Christopher C. Burt, Saturday's 114° reading in Las Animas tied for the hottest temperature ever measured in the state of Colorado. Two other 114° readings have occurred in Colorado history: in Las Animas on July 1, 1933, and in Sedgwick on July 11, 1954. Colorado Springs tied its all-time record for warmest temperature ever measured on both Saturday and Sunday, with readings of 100°. The record heat in Colorado has exacerbated numerous destructive wildfires, and the Governor reported over the weekend that half of the nation's firefighting fleet has been deployed to Colorado. On Sunday, a wildfire that grew to more than 3 square miles near Colorado Springs drove 11,000 residents (2% of the city's population) out of their homes. In Fort Collins, the mercury hit 102° on Sunday, just 1° below the city's all-time hottest temperature of 103° set on Jul 21, 2005. The heat did no favors for firefighters struggling to the contain the massive 81,000 acre High Park fire fifteen miles northwest of Fort Collins. The fire is the second largest and most destructive wildfire in Colorado's history, and is 45% contained. La Junta, CO hit 110° on Sunday, tying its all-time hottest temperature record, set on June 28, 1990. Today is the last day of exceptional heat for Colorado, as the ridge of high pressure responsible slides to the east, bringing record-breaking heat to the Midwest instead.
Jeff Masters
One of Debbie's tornados
TS Debbie on Bayshore
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.