000 WTNT43 KNHC 150243 TCDAT3 TROPICAL STORM KARL DISCUSSION NUMBER 2 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL132010 1000 PM CDT TUE SEP 14 2010 THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING KARL EARLIER THIS EVENING FOUND PEAK 925 MB FLIGHT-LEVEL WINDS OF 49 KT AND SEVERAL BELIEVABLE 34-39 KT SFMR SURFACE WINDS JUST NORTH OF THE CENTER AS IT EXITED THE STORM. THESE DATA WERE THE BASIS FOR THE INCREASE IN INTENSITY IN THE 0000 UTC INTERMEDIATE ADVISORY. THE ORGANIZATION OF THE CYCLONE HAS CHANGED LITTLE SINCE THAT TIME...THEREFORE THE INITIAL INTENSITY REMAINS 40 KT. THE NEXT AIR FORCE RESERVE RECONNAISSANCE MISSION IS SCHEDULED TO REACH KARL AROUND 0600 UTC. THE AIRCRAFT FIXES AND A COUPLE OF RECENT SSMIS MICROWAVE IMAGES SHOW THAT THE CENTER IS LOCATED NEAR THE EASTERN EDGE OF THE SMALL MASS OF DEEP CONVECTION...WHICH SUGGESTS THAT THERE IS SOME LIGHT EASTERLY SHEAR. THE SHEAR...HOWEVER...IS NOT EXPECTED TO BE INHIBITIVE FOR STRENGTHENING...AND SOME INTENSIFICATION IS POSSIBLE BEFORE KARL REACHES THE EAST COAST OF THE YUCATAN PENINSULA. OVER THE SOUTHWESTERN GULF OF MEXICO...WATERS ARE WARM AND THE SHEAR IS EXPECTED TO BE LIGHT...THEREFORE STRENGTHENING IS EXPECTED. THE GFDL...LGEM...SHIPS...AND FLORIDA STATE SUPERENSEMBLE ALL SHOW KARL AT HURRICANE STRENGTH BEFORE IT REACHES THE COAST OF MAINLAND MEXICO IN ABOUT 72 HOURS. THERE IS STILL SOME UNCERTAINTY ABOUT WHAT KIND OF STRUCTURE KARL WILL HAVE AFTER CROSSING THE YUCATAN PENINSULA...HOWEVER GIVEN THE FAVORABLE CONDITIONS AND MODEL AGREEMENT...THE OFFICIAL FORECAST BRINGS KARL TO HURRICANE STATUS AT THAT TIME. THE INITIAL MOTION IS 290/13. THE TRACK FORECAST PHILOSOPHY REMAINS UNCHANGED. KARL IS EXPECTED TO MOVE GENERALLY WEST-NORTHWESTWARD AROUND THE SOUTHERN PORTION OF A DEEP-LAYER RIDGE ALONG THE NORTHERN GULF COAST. THE TRACK GUIDANCE IS IN GOOD AGREEMENT THROUGH 48 HOURS...WITH INCREASED SPREAD THEREAFTER...AS SOME OF THE MODELS TURN KARL WEST-SOUTHWESTWARD NEAR THE COAST OF MAINLAND MEXICO. THE NEW NHC TRACK IS ESSENTIALLY AN UPDATE OF THE PREVIOUS ADVISORY AND IS IN GOOD AGREEMENT WITH THE GFS AND ECMWF MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 15/0300Z 18.6N 85.5W 40 KT 12HR VT 15/1200Z 19.2N 87.3W 50 KT 24HR VT 16/0000Z 20.0N 89.5W 30 KT...INLAND 36HR VT 16/1200Z 20.7N 91.6W 35 KT 48HR VT 17/0000Z 21.1N 93.4W 50 KT 72HR VT 18/0000Z 21.5N 96.7W 65 KT 96HR VT 19/0000Z 21.5N 100.5W 25 KT...INLAND 120HR VT 20/0000Z...DISSIPATED $$ FORECASTER BROWN