Life-Cycle of Tropical Storm Erin (2007) Thomas J. Galarneau, Jr., and Lance F. Bosart University at Albany, State University of New York Albany, NY *with contributions from Roger Edwards, SPC 9th Annual Northeast Regional Operational Workshop 8 November 2007

Motivation Widespread post-landfall rainfall and wind associated with Tropical Storm (TS) Erin during 16–23 August 2007

Goals Overview large-scale environment Examine aspects of TS Erin life-cycle in more detail: –Incipient development to landfall along TX coast –Widespread TX rains/reintensification over OK –“PRE” over WI –KY rains and VA/NC MCS

Goals Overview large-scale environment Examine aspects of TS Erin life-cycle in more detail: –Incipient development to landfall along TX coast –Widespread TX rains/reintensification over OK –“PRE” over WI –KY rains and VA/NC MCS

Data Sources 2.5  NCEP–NCAR Reanalysis from ESRL 1.0  NCEP–GFS final analysis from NCAR Soundings from University of Wyoming Standard surface data from UAlbany OK Mesonet data from OK Climo Survey Radar imagery from NCAR and SPC Precipitation analyses from NPVU Trajectories from NOAA HYSPLIT model

250 hPa  (dam) mean and anomaly and vector wind (standard barbs) mean 9–23 August  NCEP–NCAR Reanalysis Erin track

250 hPa  (dam) mean and anomaly and vector wind (standard barbs) mean 9–23 August  NCEP–NCAR Reanalysis landfall 06Z/16 reintensification 00–06Z/19 PRE 00–12Z/19 MCS 21Z/21–06Z/22 intense rains 06Z/21–18Z/21 intense rains 12Z/16–18Z/18

landfall reintensification over Oklahoma, and Wisconsin PRE North Carolina/Virginia MCS Kentucky rains 1.0  GFS Final Analyses Azimuth average of DT  (K), 850 hPa–DT wind shear (m s  1 ), and CI (K) DT  (K) 850–DT shear (m s  1 ) and CI (K) Time/Date (UTC)

Incipient development–landfall 0000 UTC 8–1200 UTC 16 Aug 2007

DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 ) 1200 UTC 7 August  NCEP–GFS Analyses x L=“Erin” X=DT disturbance =DT trough

1200 UTC 8 August  NCEP–GFS Analyses x L=“Erin” X=DT disturbance =DT trough L DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 )

1200 UTC 9 August  NCEP–GFS Analyses x x L=“Erin” X=DT disturbance =DT trough L DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 )

1200 UTC 10 August  NCEP–GFS Analyses x x x L=“Erin” X=DT disturbance =DT trough L DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 )

1200 UTC 11 August  NCEP–GFS Analyses x x L=“Erin” X=DT disturbance =DT trough L DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 )

1200 UTC 12 August  NCEP–GFS Analyses x x L=“Erin” X=DT disturbance =DT trough L DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 )

1200 UTC 13 August  NCEP–GFS Analyses x x L=“Erin” X=DT disturbance =DT trough L DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 )

1200 UTC 14 August  NCEP–GFS Analyses x L=“Erin” X=DT disturbance =DT trough L DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 )

1200 UTC 15 August  NCEP–GFS Analyses x x x L=“Erin” X=DT disturbance =DT trough L DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 )

1200 UTC 16 August  NCEP–GFS Analyses x x x L=“Erin” X=DT disturbance =DT trough L DT  (K), 850–DT shear (knots), and 925–850 hPa  (10 -4 s -1 )

TX rains and OK reintensification 0000 UTC 17–0000 UTC 20 Aug 2007

DT  (K) and vector wind (knots), and 925–850 hPa  (10 -4 s -1 ) 1200 UTC 17 August  NCEP–GFS Analyses Erin Source: NPVU

DT  (K) and vector wind (knots), and 925–850 hPa  (10 -4 s -1 ) 1200 UTC 18 August  NCEP–GFS Analyses Erin Source: NPVU

DT  (K) and vector wind (knots), and 925–850 hPa  (10 -4 s -1 ) 1200 UTC 19 August  NCEP–GFS Analyses Erin Source: NPVU

Source: NCAR image archive 12Z/16

Source: NCAR image archive 18Z/16

Source: NCAR image archive 00Z/17

Source: NCAR image archive 00Z/17 FWD DRT 1000 J kg J kg -1

Source: NCAR image archive 06Z/17

Source: NCAR image archive 12Z/17

Source: NCAR image archive 18Z/17

Source: NCAR image archive 00Z/18

Source: NCAR image archive 00Z/18 FWD MAF 1800 J kg J kg -1 00Z/18

Source: NCAR image archive 06Z/18

Source: NCAR image archive 12Z/18

Source: NCAR image archive 18Z/18

Source: NCAR image archive 00Z/19

Source: NCAR image archive 00Z/19 FWD 1300 J kg -1 OUN 1800 J kg -1

Source: NCAR image archive 06Z/19

Source: NCAR image archive 12Z/19

Surface  and 12Z/19 L Erin baroclinic zone

X  (10  5 s  1 ),  (K), and vector wind (knots)

Source: Roger Edwards, NOAA/NWS/SPC 0400–1300 UTC 19 August 2007 BREF and OK Mesonet Observations

Source: Roger Edwards, NOAA/NWS/SPC 0500–1300Z/19 L L

Wisconsin “PRE” 0000–1200 UTC 19 August

Erin PRE 06Z/19 Source: NCAR image archive

Erin PRE baroclinic zone L Surface  and 06Z/19

Source: NPVU 24 h Total Precipitation (in.) ending 12Z/19 Erin PRE

Source: NPVU 24 h Total Precipitation (in.) ending 12Z/19 Erin PRE OAX 12Z/19 SGF 00Z/19

700  (dam), 1000–500 , 850–500 wind (knots), and Precipitable Water (mm) 1200 UTC 16 August  NCEP–GFS Analyses L

700  (dam), 1000–500 , 850–500 wind (knots), and Precipitable Water (mm) 1200 UTC 17 August  NCEP–GFS Analyses L

700  (dam), 1000–500 , 850–500 wind (knots), and Precipitable Water (mm) 1200 UTC 18 August  NCEP–GFS Analyses L

700  (dam), 1000–500 , 850–500 wind (knots), and Precipitable Water (mm) 1200 UTC 19 August  NCEP–GFS Analyses L

Summary Pre-landfall key points: –Disturbance possibly originated from convection over South American continent at 00Z/8 –Upper-level disturbance on DT inhibited intensification of pre-TS Erin prior to 15 August –Erin became minimal TS on 15 August just prior to landfall (at 06Z/16)

Summary Erin moved around periphery of continental anticyclone during 16–23 August Post-landfall key points: –Produced 4–8” rains over TX 12Z/16–00Z/19 –Reintensified to TS strength over OK 00–12Z/19 –Contributed tropical moisture to WI PRE 00–12Z/19 –Generated 2–4” rains over KY 12–18Z/21 –Triggered severe MCS over VA/NC 18Z/21–00Z/22

Concluding Remarks Link between continental MCVs and TS Erin TS Erin at 12Z/19 Mature MCV at 18Z/11 June 2003  (10  5 s  1 ),  (K), vector wind (knots)

Concluding Remarks Possible physical mechanism for reintensification Intense cyclonic vorticity maxima develop beneath convective towers. These cyclonic vorticity maxima wrap into “main” cyclonic circulation. (e.g., Montgomery and Enagonio (1998); Hendricks et al. (2004); Conzemius et al. (2007) = cyclonic vorticity maxima 09Z/1912Z/19