000 WTNT41 KNHC 031433 TCDAT1 HURRICANE FELIX DISCUSSION NUMBER 13 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062007 1100 AM EDT MON SEP 03 2007 SATELLITE IMAGES DEPICTED SOME WARMING OF THE CLOUD TOPS WHICH COULD BE INDICATIVE OF SLIGHT WEAKENING. A NOAA RECONNAISSANCE PLANE MEASURED 162 KT WINDS AROUND 11Z WHICH WOULD STILL SUPPORT 145 KT AT THE SURFACE. HOWEVER SUBSEQUENT TO THAT OBSERVATION THE CENTRAL PRESSURE HAS RISEN A BIT AND THE EYE IS NOT AS WELL DEFINED ON VISUAL IMAGERY. SO THE CURRENT INTENSITY IS ADJUSTED DOWNWARD SLIGHTLY...TO 140 KT. FLUCTUATIONS IN STRENGTH DUE TO INNER CORE PROCESSES ARE TYPICAL IN INTENSE HURRICANES. THERE HAS NOT BEEN MUCH EVIDENCE OF CONCENTRIC EYEWALLS OR AN EYEWALL REPLACEMENT THUS FAR BUT SUCH AN EVENT COULD OCCUR...AND IT WOULD HAVE AN INFLUENCE ON THE INTENSITY OF FELIX. HOWEVER THESE EYEWALL CYCLES ARE DIFFICULT TO TIME OR TO PREDICT. THE LARGE SCALE ENVIRONMENT... IN TERMS OF WIND SHEAR AND OCEANIC HEAT CONTENT...SHOULD REMAIN CONDUCIVE TO THE MAINTENANCE OF CAT 4/5 INTENSITY UNTIL INTERACTION WITH LAND. THE FORECAST INTENSITY AT 36 HOURS AND BEYOND IS HIGHLY UNCERTAIN BECAUSE IT DEPENDS ON THE TRACK OF THE CENTER WITH RESPECT TO THE LAND MASS OF CENTRAL AMERICA AND MEXICO. CLEARLY IF FELIX MOVES MORE TO THE RIGHT OF OUR FORECAST IT WILL REMAIN STRONGER AND IF IT MOVES TO THE LEFT OF THE NHC TRACK IT WOULD BE MUCH WEAKER. INDEED...IF THE CYCLONE FAILS TO EMERGE OVER THE BAY OF CAMPECHE...IT COULD DISSIPATE BEFORE THE END OF THE FORECAST PERIOD. LATEST FIXES SHOW THAT THE FAST WESTWARD MOTION...280/18... CONTINUES. THE NHC TRACK FORECAST AND SYNOPTIC REASONING ARE BASICALLY UNCHANGED. GLOBAL MODEL FORECAST FIELDS MAINTAIN SUFFICIENT MID-TROPOSPHERIC RIDGING TO THE NORTH OF FELIX SO THAT...IF THESE FORECASTS VERIFY...THE TROPICAL CYCLONE WILL BE UNABLE TO GAIN MUCH LATITUDE OVER THE NEXT FEW DAYS. THE OFFICIAL TRACK FORECAST IS SIMILAR TO THE PREVIOUS ONE AND ROUGHLY IN THE MIDDLE OF THE GUIDANCE ENVELOPE. A HURRICANE WARNING HAS BEEN ISSUED FOR PORTIONS OF NORTHEASTERN NICARAGUA. DATA SHOWS THAT THE CENTRAL PRESSURE HAS COME UP A BIT FORECAST POSITIONS AND MAX WINDS INITIAL 03/1500Z 14.3N 77.8W 140 KT 12HR VT 04/0000Z 14.6N 80.4W 150 KT 24HR VT 04/1200Z 15.1N 83.2W 145 KT 36HR VT 05/0000Z 15.8N 85.9W 90 KT...INLAND 48HR VT 05/1200Z 16.3N 88.0W 90 KT 72HR VT 06/1200Z 17.5N 92.0W 50 KT...INLAND 96HR VT 07/1200Z 19.0N 95.5W 60 KT 120HR VT 08/1200Z 20.5N 99.0W 30 KT...INLAND $$ FORECASTER PASCH