Multiscale Analyses of Inland Tropical Cyclone Midlatitude Jet Interactions: Camille (1969) and Danny (1997)

Multiscale Analyses of Inland Tropical Cyclone Midlatitude Jet Interactions: Camille (1969) and Danny (1997) Matthew Potter, Lance Bosart, and Daniel Keyser Department of Atmospheric and Environmental Sciences University at Albany, State University of New York, Albany, NY 46 th CMOS Congress 25 th Conference on Weather Analysis and Forecasting 30 May 2012 UCAR/NCEP Grant# S1071092

Outline Motivation and Objectives Data and Methodology TC Camille (1969) Case Study TC Danny (1997) Case Study Concluding Remarks

Motivation Interactions between inland tropical cyclones and midlatitude jets are not fully understood Severe inland flooding associated with TC Camille (1969) has not been given as much attention as other more recent events: Agnes (1972), Fran (1996), Floyd (1999) Inland reintensifying TCs, such as TC Danny, are rare events

Objectives Document the synoptic and mesoscale processes that led to: the inland flooding associated with TC Camille the inland reintensification of TC Danny Compare and contrast the two events

Data and Methodology Maps and cross sections were constructed using reanalysis datasets: 1.125 ERA-40 (TC Camille) 0.5 NCEP Climate Forecast System Reanalysis (CFSR) (TC Danny)

Data and Methodology Radar data Hourly radar summary charts are used in the Camille case study to track the evolution of the precipitation over west-central Virginia WSR-88D radar datasets are used to identify structural changes in the convective and stratiform precipitation as Danny reintensified A potential vorticity (PV) perspective is used to document synoptic and mesoscale processes

TC Camille (1969) Overview Severe inland flooding (153 fatalities) 690 mm of rain over west-central Nelson County in a 12-h period starting 0000 UTC 20 August 0000 UTC 18 August 909 hpa 165 kt 0000 UTC 20 August 1005 hpa 25 kt 0000 UTC Locations

TC Camille (1969) Overview 250-hPa wind speed (shaded, m s -1 ), 1000 500-hPa thickness (dashed red, dam), and MSLP (solid black, hpa) 06 UTC 20 August - TC Camille was juxtaposed with the equatorward jet-entrance region - Strong cold-air advection in the equatorward jet-entrance region

Cross Section and Dynamic Tropopause Map 12 UTC 19 August PV Tower Associated with TC Camille Vertical cross section of PV (shaded every 1 PVU), θ (solid black every 4 K), and the wind component normal to the cross section (dashed green every 5 m s -1 starting at 15 m s -1 ) 12 UTC 19 August Potential temperature on the 2 PVU surface (shaded every 5 K), 850 200-hPa wind shear (barbs, kt), and 925 850- hpa layer-averaged relative vorticity (solid black every 0.5 10-4 s -1 starting at 0.5 10-4 s -1 ) Quasi-stationary PV Anomaly

Cross Section and Dynamic Tropopause Map 00 UTC 20 August Weakening PV Tower Vertical cross section of PV (shaded every 1 PVU), θ (solid black every 4 K), and the wind component normal to the cross section (dashed green every 5 m s -1 starting at 15 m s -1 ) Quasi-stationary PV Anomaly 00 UTC 20 August Potential temperature on the 2 PVU surface (shaded every 5 K), 850 200-hPa wind shear (barbs, kt), and 925 850- hpa layer-averaged relative vorticity (solid black every 0.5 10-4 s -1 starting at 0.5 10-4 s -1 ) Higher Shear Environment

Cross Section and Dynamic Tropopause Map 12 UTC 20 August Weakening PV Tower Vertical cross section of PV (shaded every 1 PVU), θ (solid black every 4 K), and the wind component normal to the cross section (dashed green every 5 m s -1 starting at 15 m s -1 ) Potential temperature on the 2 PVU surface (shaded every 5 K), 850 200-hPa wind shear (barbs, kt), and 925 850- hpa layer-averaged relative vorticity (solid black every 0.5 10-4 s -1 starting at 0.5 10-4 s -1 ) Quasi-stationary PV Anomaly 12 UTC 20 August

Cross Section and Dynamic Tropopause Map 00 UTC 21 August Weakening PV Tower Vertical cross section of PV (shaded every 1 PVU), θ (solid black every 4 K), and the wind component normal to the cross section (dashed green every 5 m s -1 starting at 15 m s -1 ) Potential temperature on the 2 PVU surface (shaded every 5 K), 850 200-hPa wind shear (barbs, kt), and 925 850- hpa layer-averaged relative vorticity (solid black every 0.5 10-4 s -1 starting at 0.5 10-4 s -1 ) Quasi-stationary PV Anomaly 00 UTC 21 August

Radar Summary Charts 2345 UTC 19 August 0445 UTC 20 August 40 2345 UTC 19 August TRW TRW 2345 UTC 19 August 40 TRW TRW+ RW- TRW+ 35 TRW TRW 35 TRW 12 km echo tops 80 75 Adapted from NMC (National Meteorological Center) radar summary charts Scattered thunderstorms associated with the frontal boundary started to affect northern Virginia around 0000 UTC 20 August Thunderstorms became more numerous around 0500 UTC 20 August as TC Camille entered the region 80 75

Radar Summary Charts 40 0945 UTC 20 August 2345 UTC 19 August RW- TRW+ 35 RW 80 75 Adapted from NMC (National Meteorological Center) radar summary charts Thunderstorms moved east of west-central Virginia around 1000 UTC 20 August

Moisture Transport Precipitable water (shaded, mm), 700-hPa vertical motion (ω; light blue contour every 2 10-3 hpa s -1, negative values only), 925-hPa geopotential height (Z; solid black, dam), potential temperature (θ; dashed red every 2 K), and winds (barbs, kt) 06 UTC 20 August Southerly winds

Moisture Transport Precipitable water (shaded, (mm), 700-hPa mm), 700-hPa Omega (light vertical blue motion contour (ω; every light blue -2 contour 10-3 hpa every s -1 ), 925-hPa 2 10-3 hpa s -1, heights negative (contoured values only), in black), 925-hPa θ (dashed geopotential red every height 2 K), (Z; and solid winds black, (barbs, dam), kt) potential temperature (θ; dashed red every 2 K), and winds (barbs, kt) 06 UTC 20 August Baroclinic zone

Moisture Transport Precipitable water (shaded, (mm), 700-hPa mm), 700-hPa Omega (light vertical blue motion contour (ω; every light blue -2 contour 10-3 hpa every s -1 ), 925-hPa 2 10-3 hpa s -1, heights negative (contoured values only), in black), 925-hPa θ (dashed geopotential red every height 2 K), (Z; and solid winds black, (barbs, dam), kt) potential temperature (θ; dashed red every 2 K), and winds (barbs, kt) 06 UTC 20 August Nearly 60 mm of PW

Moisture Transport Precipitable water (shaded, (mm), 700-hPa mm), 700-hPa Omega (light vertical blue motion contour (ω; every light blue -2 contour 10-3 hpa every s -1 ), 925-hPa 2 10-3 hpa s -1, heights negative (contoured values only), in black), 925-hPa θ (dashed geopotential red every height 2 K), (Z; and solid winds black, (barbs, dam), kt) potential temperature (θ; dashed red every 2 K), and winds (barbs, kt) 06 UTC 20 August Upward vertical motion

Moisture Transport Precipitable water (shaded, (mm), 700-hPa mm), 700-hPa Omega (light vertical blue motion contour (ω; every light blue -2 contour 10-3 hpa every s -1 ), 925-hPa 2 10-3 hpa s -1, heights negative (contoured values only), in black), 925-hPa θ (dashed geopotential red every height 2 K), (Z; and solid winds black, (barbs, dam), kt) potential temperature (θ; dashed red every 2 K), and winds (barbs, kt) 06 UTC 20 August Southerly winds Baroclinic zone Nearly 60 mm of PW Upward vertical motion

Moisture Transport Precipitable water (shaded, (mm), 700-hPa mm), 700-hPa Omega (light vertical blue motion contour (ω; every light blue -2 contour 10-3 hpa every s -1 ), 925-hPa 2 10-3 hpa s -1, heights negative (contoured values only), in black), 925-hPa θ (dashed geopotential red every height 2 K), (Z; and solid winds black, (barbs, dam), kt) potential temperature (θ; dashed red every 2 K), and winds (barbs, kt) 06 UTC 20 August Favorable conditions for inland flooding

Ageostrophic Circulation and Frontogenesis Frontogenesis [shaded, K (100 km) -1 (3 h) -1 ], θ (solid black every 4 K), ω (dashed red every 2 10-3 hpa s -1, negative values only), winds normal to the cross section (solid orange, m s -1 ) and the ageostrophic wind component tangential to the cross section (arrows, m s -1 ) 06 UTC 20 August Upper-level jet Diverging ageostrophic winds Approximate location of hardest hit area 5 cm/s

Ageostrophic Circulation and Frontogenesis Frontogenesis [shaded, K (100 km) -1 (3 h) -1 ], θ (solid black every 4 K), ω (dashed red every 2 10-3 hpa s -1, negative values only), winds normal to the cross section (solid orange, m s -1 ) and the ageostrophic wind component tangential to the cross section (arrows, m s -1 ) 06 UTC 20 August Tropospheric-deep ascent Lower-tropospheric frontogenesis 5 cm/s

Camille Summary The inland flooding associated with TC Camille can be attributed to: Tropospheric-deep ascent beneath the equatorward entrance region of a downstream 45 m s 1 upper-tropospheric jet Moist, lower-tropospheric southerly flow that ascended a lower-tropospheric baroclinic zone Frontogenesis and mesoscale ascent associated with a lower-tropospheric baroclinic zone Heavy upslope precipitation in the mountains

TC Danny (1997) Overview Track where TC Danny reintensified inland 960 mm of rain over Dauphin Island in a 72-h period starting 1200 UTC 18 July 1800 UTC 24 July 1000 hpa 40 kt 0000 UTC 24 July 1012 hpa 20 kt 0000 UTC 19 July 984 hpa 70 kt 0000 UTC Locations

TC Danny (1997) Overview 250-hPa wind speed (shaded, m s -1 ), 1000 500-hPa thickness (dashed red, dam), and MSLP (solid black, hpa) 18 UTC 24 July - TC Danny was juxtaposed with the equatorward jet-entrance region - Weak warm-air advection in equatorward jet-entrance region

Cross Section and Dynamic Tropopause Map 00 UTC 23 July Vertical cross section of PV (shaded every 1 PVU), θ (solid black every 4 K), and the wind component normal to the cross section (dashed green every 5 m s -1 starting at 15 m s -1 ) 00 UTC 23 July Potential temperature on the 2 PVU surface (shaded every 5 K), 850 200-hPa wind shear (barbs, kt), and 925 850-hPa layeraveraged relative vorticity (solid black every 1 10-4 s -1 starting at 1 10-4 s -1 ) Relatively Low Shear Environment

Cross Section and Dynamic Tropopause Map 12 UTC 23 July Strengthening PV Tower Vertical cross section of PV (shaded every 1 PVU), θ (solid black every 4 K), and the wind component normal to the cross section (dashed green every 5 m s -1 starting at 15 m s -1 ) 12 UTC 23 July Potential temperature on the 2 PVU surface (shaded every 5 K), 850 200-hPa wind shear (barbs, kt), and 925 850-hPa layeraveraged relative vorticity (solid black every 1 10-4 s -1 starting at 1 10-4 s -1 )

Cross Section and Dynamic Tropopause Map 00 UTC 24 July Strengthening PV Tower Vertical cross section of PV (shaded every 1 PVU), θ (solid black every 4 K), and the wind component normal to the cross section (dashed green every 5 m s -1 starting at 15 m s -1 ) 00 UTC 24 July Potential temperature on the 2 PVU surface (shaded every 5 K), 850 200-hPa wind shear (barbs, kt), and 925 850-hPa layeraveraged relative vorticity (solid black every 1 10-4 s -1 starting at 1 10-4 s -1 ) Amplifying PV Trough

Cross Section and Dynamic Tropopause Map 12 UTC 24 July Strengthening PV Tower Vertical cross section of PV (shaded every 1 PVU), θ (solid black every 4 K), and the wind component normal to the cross section (dashed green every 5 m s -1 starting at 15 m s -1 ) 12 UTC 24 July Potential temperature on the 2 PVU surface (shaded every 5 K), 850 200-hPa wind shear (barbs, kt), and 925 850-hPa layeraveraged relative vorticity (solid black every 1 10-4 s -1 starting at 1 10-4 s -1 ) Amplifying PV Trough Increase in lower-tropospheric vorticity

Cross Section and Dynamic Tropopause Map 18 UTC 24 July Strengthening PV Tower Vertical cross section of PV (shaded every 1 PVU), θ (solid black every 4 K), and the wind component normal to the cross section (dashed green every 5 m s -1 starting at 15 m s -1 ) 18 UTC 24 July Potential temperature on the 2 PVU surface (shaded every 5 K), 850 200-hPa wind shear (barbs, kt), and 925 850-hPa layeraveraged relative vorticity (solid black every 1 10-4 s -1 starting at 1 10-4 s -1 ) Amplifying PV Trough Increase in lower-tropospheric vorticity

Radar and Satellite Imagery KBMX Base Reflectivity 0013 UTC 23 July GOES-8 Visible Image 2315 UTC 22 July

Radar and Satellite Imagery KFFC Base Reflectivity 1218 UTC 23 July GOES-8 Visible Image 1215 UTC 23 July

Radar and Satellite Imagery KGSP Base Reflectivity 0015 UTC 24 July GOES-8 Visible Image 2315 UTC 23 July

Radar and Satellite Imagery KAKQ Base Reflectivity 1318 UTC 24 July GOES-8 Visible Image 1313 UTC 24 July

Radar and Satellite Imagery KAKQ Base Reflectivity 1814 UTC 24 July GOES-8 Visible Image 1815 UTC 24 July

Organization of convection around TC Danny led to an increase in the magnitude of diabatic heating Vertical profiles of diabatic heating imply an increase in cyclonic vorticity and PV below the level of maximum heating and an increase in ascent Role of Diabatic Heating Pressure (hpa) 100 200 300 400 500 600 700 800 900 CFSR 6-h Forecasts of Diabatic Heating Calculated in a 3 3 Box around TC Danny Valid at: 23/00 23/12 24/00 24/12 1000-25.0-20.0-15.0-10.0-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Diabatic Heating (K day -1 )

Role of Diabatic Heating (1800 UTC 24 July) 250-hPa wind speed (shading, kt), 250-hPa PV (solid gray every 1 PVU), 250-hPa relative humidity (gray shading, %), 600 400-hPa layer-averaged ω (solid red every 4 10-3 hpa s -1, negative values only), 300 200-hPa layer-averaged irrotational wind (vectors starting at 5 m s -1 ) 18 UTC 24 July Diabatically induced outflow at 250 hpa acts to advect lower values of PV to the northwest and implies a strengthening jet

Ageostrophic Circulation and Frontogenesis Frontogenesis [shaded, K (100 km) -1 (3 h) -1 ], θ (solid black every 4 K), ω (dashed red every -- 4 10-3 hpa s -1 ), wind component normal to the cross section (solid orange, m s -1 ), and the ageostrophic wind component tangential to the cross section (arrows, m s -1 ) 18 UTC 24 July Upper-level jet Diverging ageostrophic winds Approximate Location of TC Danny 5 cm/s

Ageostrophic Circulation and Frontogenesis Frontogenesis [shaded, K (100 km) -1 (3 h) -1 ], θ (solid black every 4 K), ω (dashed red every -- 4 10-3 hpa s -1 ), wind component normal to the cross section (solid orange, m s -1 ), and the ageostrophic wind component tangential to the cross section (arrows, m s -1 ) 18 UTC 24 July Tropospheric-deep ascent Lower-tropospheric Frontogenesis 5 cm/s

Danny Summary The inland reintensification of TC Danny can be attributed to: Frontogenesis along a lower-tropospheric baroclinic zone and associated tropospheric-deep ascent beneath an entrance region of a 35 m s 1 upper-tropospheric jet Diabatic heating arising from deep convection that reinforces ascent near the storm center and increases lower-tropospheric PV Negative PV advection by the diabatically driven uppertropospheric outflow that acts to strengthen the downstream across-jet PV gradient and associated jet

Conclusions Similarities TCs Camille and Danny were situated underneath a jetentrance region Lower-tropospheric baroclinic zone was present in both cases Differences Weaker synoptic features present in the TC Danny case compared to the TC Camille case; however, TC Danny reintensified Strong cold- (weak warm-) air advection was seen poleward of TC Camille (TC Danny) Weak-shear environment preserved TC Danny s preexisting vortex and associated convection

Thank You! Questions?

Precipitation Evolution 40 35 Pittsburgh, Pa Radar Site RW- TRW TRW RW- 11,300 m 11,600 m RW RW 9,100 m Washington, RW- D.C. Radar Site RW- RW TRW TRW+ TRW+ TRW+ 9,100 m TRW+ TRW+ 11,600 m 10,700 10,700 m m 12,600 m RW TRW- RW TRW TRW TRW+ TRW 80 75 Location of echo region (color contour) and maximum echo top (colored dot, m) at: 0045 UTC 20 August T RW - (no sign) + 0245 UTC 20 August 0445 UTC 20 August 0645 UTC 20 August 0845 UTC 20 August Thunderstorms Rain Showers Light Moderate Heavy Precipitation Intensity Heavy rain showers and thunderstorms associated with echo tops reaching 10 12 km persisted around the location of heaviest rainfall

Surface Analysis Surface conditions at 0600 UTC 20 August: MSLP (solid black every 2 hpa), winds (barbs, kt), dew point (dashed green every 2 C), and temperature (dashed red every 2 C) 06 10 12 08

Conceptual Models TC Camille TC Danny 500-hPa Z + PV Anomaly 500-hPa Z Cold-air Advection Orographic Enhancement >45 mm PW >20 kt LL Jet 45 m s 1 Upper- Tropospheric Jet Surface Baroclinic Zone Heaviest Precipitation Diabatically Driven Outflow Prior Low-Shear Environment + PV Anomaly >45 mm PW Surface Baroclinic Zone Weak Warm-air Advection