2005 Tropical Weather Impacts to the Memphis CWA Jonathan L. Howell – Jason F. Beaman National Weather Service - Memphis, TN

Memphis Tropical Impacts Overview of Impacts From Hurricanes Katrina & Rita –Satellite, Radar, & Track Overviews –Synoptic Weather Patterns Responsible for Steering of Tropical Systems –Mesoscale Weather Environments Katrina – Pressure Gradient Winds Rita – Convective/Severe Weather Environment –Impacts to Memphis County Warning Area –WFO Operations Performance Overview of Impacts From Hurricanes Katrina & Rita –Satellite, Radar, & Track Overviews –Synoptic Weather Patterns Responsible for Steering of Tropical Systems –Mesoscale Weather Environments Katrina – Pressure Gradient Winds Rita – Convective/Severe Weather Environment –Impacts to Memphis County Warning Area –WFO Operations Performance

Hurricane Katrina

Hurricane Katrina’s Track

Katrina Weather Impacts Weather Impacts to North Mississippi –7 Hours of Tropical Storm Force Wind Gusts (22z-06z) at Tupelo, MS ASOS (KTUP) –Maximum Gust – 46 Kts. – KTUP – 2350z/0148z –Unofficial Wind Gust Reports > 50 Kts. –Lowest Pressure – 980 mb. – KTUP – 07z –Rainfall Amounts Ranged Between 4”-8” Isolated Higher –Rain Gauge Measurements of 3”-6” Underestimated Actual Totals Due to High Winds Weather Impacts to North Mississippi –7 Hours of Tropical Storm Force Wind Gusts (22z-06z) at Tupelo, MS ASOS (KTUP) –Maximum Gust – 46 Kts. – KTUP – 2350z/0148z –Unofficial Wind Gust Reports > 50 Kts. –Lowest Pressure – 980 mb. – KTUP – 07z –Rainfall Amounts Ranged Between 4”-8” Isolated Higher –Rain Gauge Measurements of 3”-6” Underestimated Actual Totals Due to High Winds

Katrina Damage Across Memphis CWA Damage Across North Mississippi –Structural Damage – Mainly Trees Falling on Structures –Hundreds of Trees Downed/Uprooted –Powerlines Downed – 100,000+ Customers Without Power –Flash Flooding/Minor River Flooding Water Over Secondary Highways 5 River Points to Flood –Buttahatchie / Tombigbee / Noxubee / Town Cr. Damage Across North Mississippi –Structural Damage – Mainly Trees Falling on Structures –Hundreds of Trees Downed/Uprooted –Powerlines Downed – 100,000+ Customers Without Power –Flash Flooding/Minor River Flooding Water Over Secondary Highways 5 River Points to Flood –Buttahatchie / Tombigbee / Noxubee / Town Cr.

Katrina Weather Impacts Weather Impacts to West Tennessee –Tropical Storm Force Wind Gusts at Memphis (KMEM) & Jackson (KMKL) 6 Hours at KMEM (03z-09z) 3 Hours at KMKL (05z-08z) –Maximum Gust 47 Kts. – KMEM – 0641z 38 Kts. – KMKL – 0538z –Unofficial Wind Gust Reports > 50 Kts. –Lowest Pressures Recorded KMEM – 989 mb. (0653z) KMKL – 987 mb. (0953z) –Rainfall Amounts Ranged Between 3-6 Inches Weather Impacts to West Tennessee –Tropical Storm Force Wind Gusts at Memphis (KMEM) & Jackson (KMKL) 6 Hours at KMEM (03z-09z) 3 Hours at KMKL (05z-08z) –Maximum Gust 47 Kts. – KMEM – 0641z 38 Kts. – KMKL – 0538z –Unofficial Wind Gust Reports > 50 Kts. –Lowest Pressures Recorded KMEM – 989 mb. (0653z) KMKL – 987 mb. (0953z) –Rainfall Amounts Ranged Between 3-6 Inches

Katrina Damage Across Memphis CWA Damage Across West Tennessee –Minor Structural Damage –Several Trees Downed/Uprooted –Powerlines Downed – 77,000 Customers Without Power in Memphis/Shelby County –Additional Power Outages Across Remainder West TN –Flash Flooding/River Flooding Water Over Secondary Highways 1 River Point to Flood –S.F. Forked Deer Damage Across West Tennessee –Minor Structural Damage –Several Trees Downed/Uprooted –Powerlines Downed – 77,000 Customers Without Power in Memphis/Shelby County –Additional Power Outages Across Remainder West TN –Flash Flooding/River Flooding Water Over Secondary Highways 1 River Point to Flood –S.F. Forked Deer

Hurricane Rita

Hurricane Rita’s Track

The Difference Aspects of Rita There were three significant meteorological impacts to the Mid-South –Heavy Rain –Tropical Storm Force Wind Gusts –Severe Weather/Mesocyclone Development There were three significant meteorological impacts to the Mid-South –Heavy Rain –Tropical Storm Force Wind Gusts –Severe Weather/Mesocyclone Development

Heavy Rain

Tropical Storm Force Wind Gusts Numerous tropical storm wind gusts –KMEM Z –KTUP Z –Other unofficial reports of 35 to 45 kt winds primarily over north Mississippi Gusts produced by convective downdrafts (50-55 dbz cores up to 10,000 feet) Numerous tropical storm wind gusts –KMEM Z –KTUP Z –Other unofficial reports of 35 to 45 kt winds primarily over north Mississippi Gusts produced by convective downdrafts (50-55 dbz cores up to 10,000 feet)

Convective Winds

VAD Wind Profile

Concerns as Rita Approached the Mid-South Although Rita was a depression as it approached the Memphis CWA, it moved at a very favorable heading for producing tornadoes ( degrees). (Malkin and Schulz, Jr., 1966) Forecasters at WFO Memphis were tracking many mesocyclones across Arkansas and central Mississippi. Would conditions be right for tornadoes to occur in the Memphis CWA? With this in mind, we’ll take a look at the mesoscale environment as Rita progressed into the Mid-South The focus will be on the morning of September 25 th. Although Rita was a depression as it approached the Memphis CWA, it moved at a very favorable heading for producing tornadoes ( degrees). (Malkin and Schulz, Jr., 1966) Forecasters at WFO Memphis were tracking many mesocyclones across Arkansas and central Mississippi. Would conditions be right for tornadoes to occur in the Memphis CWA? With this in mind, we’ll take a look at the mesoscale environment as Rita progressed into the Mid-South The focus will be on the morning of September 25 th.

1844z SRM

1855z SRM

1906z SRM

1917z SRM

Rita Damage Light to moderate damage across E AR, W TN, and N MS Damage confined to downed trees and power lines (mainly in N MS) 3 to 6 inches of rain caused road and isolated residential flooding Total damage estimated at $100K + Light to moderate damage across E AR, W TN, and N MS Damage confined to downed trees and power lines (mainly in N MS) 3 to 6 inches of rain caused road and isolated residential flooding Total damage estimated at $100K +

Summary Katrina damage primarily from gradient winds Tropical storm wind gusts occurred well west of center Total Katrina damages in hundreds of thousands Damages to structures, trees, & power lines Katrina damage primarily from gradient winds Tropical storm wind gusts occurred well west of center Total Katrina damages in hundreds of thousands Damages to structures, trees, & power lines

Summary Rita damage primarily from convective wind gusts Tropical storm force wind gusts occurred primarily in bowing line segments & mesocyclones Total Rita damages > $100K Damage mainly to trees and power lines Rita damage primarily from convective wind gusts Tropical storm force wind gusts occurred primarily in bowing line segments & mesocyclones Total Rita damages > $100K Damage mainly to trees and power lines