000 WTPZ43 KNHC 100243 TCDEP3 POST-TROPICAL CYCLONE CALVIN DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032011 800 PM PDT SAT JUL 09 2011 INFRARED AND MICROWAVE SATELLITE IMAGERY INDICATE THAT CALVIN HAS CONTINUED TO RAPIDLY DEGENERATE. THERE HAS BEEN NO ORGANIZED DEEP CONVECTION NEAR THE LOW-LEVEL CENTER FOR NEARLY 9 HOURS NOW...AND A 09/2037Z AMSU OVERPASS INDICATED THAT THE UPPER-LEVEL WARM CORE HAD DISSIPATED WITH ONLY A WEAK WARM CORE REMAINING NEAR THE 500 MB LEVEL. ALTHOUGH A SMALL THUNDERSTORM WITH TOPS COLDER THAN -70C HAS RECENTLY DEVELOPED ABOUT 70 NMI SOUTHWEST OF THE CENTER...THIS CONVECTION IS LIKELY NOT PROVIDING ANY POSITIVE FEEDBACK ON THE INNER CORE OF THE LOW. AS A RESULT...CALVIN HAS BEEN DECLARED A NON-CONVECTIVE REMNANT LOW PRESSURE SYSTEM. THE INITIAL INTENSITY IS SET AT 30 KT BASED ON AN EXPECTED SPINDOWN OF 35-40 KT WINDS THAT WERE NOTED IN AN EARLIER 09/1734Z ASCAT SATELLITE OVERPASS. THE INITIAL MOTION ESTIMATE IS 285/09. THE REMNANT LOW IS EXPECTED TO MOVE SLOWLY WEST-NORTHWESTWARD OVER COLDER WATER FOR THE NEXT 2 DAYS AS THE CIRCULATION REMAINS EMBEDDED IN SHALLOW LOW-LEVEL EASTERLY TRADE WIND FLOW. GIVEN MUCH COOLER WATERS AND MORE STABLE AIR AHEAD OF THE REMNANT LOW...REDEVELOPMENT OF ANY ORGANIZED DEEP CONVECTION NEAR THE LOW-LEVEL CENTER IS UNLIKELY. 12-FT SEAS RADII HAVE BEEN INCLUDED SINCE CALVIN ONLY RECENTLY LOST ITS STATUS AS A TROPICAL CYCLONE...AND IT WILL TAKE A FEW MORE HOURS FOR THE SEAS TO SUBSIDE. THIS IS THE FINAL NHC ADVISORY ON CALVIN. FOR ADDITIONAL INFORMATION ON THE REMNANT LOW...PLEASE SEE HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFEPI AND WMO HEADER FZPN02 KWBC. FORECAST POSITIONS AND MAX WINDS INIT 10/0300Z 17.7N 112.6W 30 KT 35 MPH 12H 10/1200Z 18.0N 113.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 24H 11/0000Z 18.5N 115.4W 20 KT 25 MPH...POST-TROP/REMNT LOW 36H 11/1200Z 19.0N 116.9W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 12/0000Z 19.5N 118.4W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 13/0000Z...DISSIPATED $$ FORECASTER STEWART 000 WTPZ43 KNHC 100243 TCDEP3 POST-TROPICAL CYCLONE CALVIN DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032011 800 PM PDT SAT JUL 09 2011 INFRARED AND MICROWAVE SATELLITE IMAGERY INDICATE THAT CALVIN HAS CONTINUED TO RAPIDLY DEGENERATE. THERE HAS BEEN NO ORGANIZED DEEP CONVECTION NEAR THE LOW-LEVEL CENTER FOR NEARLY 9 HOURS NOW...AND A 09/2037Z AMSU OVERPASS INDICATED THAT THE UPPER-LEVEL WARM CORE HAD DISSIPATED WITH ONLY A WEAK WARM CORE REMAINING NEAR THE 500 MB LEVEL. ALTHOUGH A SMALL THUNDERSTORM WITH TOPS COLDER THAN -70C HAS RECENTLY DEVELOPED ABOUT 70 NMI SOUTHWEST OF THE CENTER...THIS CONVECTION IS LIKELY NOT PROVIDING ANY POSITIVE FEEDBACK ON THE INNER CORE OF THE LOW. AS A RESULT...CALVIN HAS BEEN DECLARED A NON-CONVECTIVE REMNANT LOW PRESSURE SYSTEM. THE INITIAL INTENSITY IS SET AT 30 KT BASED ON AN EXPECTED SPINDOWN OF 35-40 KT WINDS THAT WERE NOTED IN AN EARLIER 09/1734Z ASCAT SATELLITE OVERPASS. THE INITIAL MOTION ESTIMATE IS 285/09. THE REMNANT LOW IS EXPECTED TO MOVE SLOWLY WEST-NORTHWESTWARD OVER COLDER WATER FOR THE NEXT 2 DAYS AS THE CIRCULATION REMAINS EMBEDDED IN SHALLOW LOW-LEVEL EASTERLY TRADE WIND FLOW. GIVEN MUCH COOLER WATERS AND MORE STABLE AIR AHEAD OF THE REMNANT LOW...REDEVELOPMENT OF ANY ORGANIZED DEEP CONVECTION NEAR THE LOW-LEVEL CENTER IS UNLIKELY. 12-FT SEAS RADII HAVE BEEN INCLUDED SINCE CALVIN ONLY RECENTLY LOST ITS STATUS AS A TROPICAL CYCLONE...AND IT WILL TAKE A FEW MORE HOURS FOR THE SEAS TO SUBSIDE. THIS IS THE FINAL NHC ADVISORY ON CALVIN. FOR ADDITIONAL INFORMATION ON THE REMNANT LOW...PLEASE SEE HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFEPI AND WMO HEADER FZPN02 KWBC. FORECAST POSITIONS AND MAX WINDS INIT 10/0300Z 17.7N 112.6W 30 KT 35 MPH 12H 10/1200Z 18.0N 113.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 24H 11/0000Z 18.5N 115.4W 20 KT 25 MPH...POST-TROP/REMNT LOW 36H 11/1200Z 19.0N 116.9W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 12/0000Z 19.5N 118.4W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 13/0000Z...DISSIPATED $$ FORECASTER STEWART