000 WTNT42 KNHC 082031 TCDAT2 TROPICAL STORM FRED DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072009 500 PM AST TUE SEP 08 2009 HIGH-RESOLUTION METEOSAT VISIBLE IMAGERY SHOW THAT FRED REMAINS A WELL-ORGANIZED TROPICAL CYCLONE WITH PROMINENT BANDING AND EXPANDING OUTFLOW IN ALL QUADRANTS. THE BIGGEST CHANGE DURING THE PAST SEVERAL HOURS IS THAT A CENTRAL DENSE OVERCAST FEATURE HAS FORMED NEAR THE CENTER. A 1514Z AMSR-E MICROWAVE PASS ALSO SHOWS THE BEGINNING STAGES OF AN EYEWALL. ALTHOUGH DVORAK INTENSITY ESTIMATES ARE UNCHANGED...THE IMPROVED STRUCTURE ON MICROWAVE IMAGES SUGGESTS SOME STRENGTHENING HAS OCCURRED AND THE INITIAL INTENSITY IS RAISED TO 60 KT. THE INTENSITY FORECAST IS A BIT TRICKY THIS AFTERNOON WITH SOME CONFLICTING SIGNALS PRESENT. THE AFOREMENTIONED AMSR-E PASS SHOWED A CLOSED RING PATTERN ON THE 37 GHZ CHANNEL...WHICH HAS BEEN A HARBINGER OF RAPID INTENSIFICATION BEFORE. IN COMBINATION WITH WARM WATERS AND LOW SHEAR...IT IS TEMPTING TO FORECAST SIGNIFICANT STRENGTHENING. HOWEVER...SOME GLOBAL MODELS ARE SHOWING THE SHEAR INCREASING BY TOMORROW...WHICH COULD LIMIT FURTHER DEVELOPMENT. THERE IS A FAIR AMOUNT OF SPREAD IN THE INTENSITY GUIDANCE THIS AFTERNOON WITH THE SHIPS/LGEM SHOWING ONLY A LITTLE MORE INTENSIFICATION WHILE THE HWRF/GFDL STILL HAVE FRED REACHING CATEGORY 2 STATUS. THE NHC FORECAST WILL BE CLOSER TO THE DYNAMICAL MODELS...SHOWING A PEAK INTENSITY IN ABOUT 24-36 HRS BEFORE THE SHEAR INCREASES. THEREAFTER...COOLER WATERS...STRONGER SHEAR AND DRIER AIR SHOULD SIGNIFICANTLY WEAKEN FRED...AND IT WOULD NOT BE SURPRISING IF FRED WAS ONLY A REMNANT LOW BY DAY 5. THE INITIAL MOTION IS ABOUT 280/12. A NARROW RIDGE OVER THE EASTERN ATLANTIC IS CURRENTLY THE PRIMARY FEATURE STEERING FRED. HOWEVER A MID- TO UPPER-LEVEL TROUGH IS EXPECTED TO ERODE THE RIDGE...CAUSING THE TRACK OF THE STORM TO GRADUALLY BEND FROM WEST-NORTHWEST... NORTHWEST...THEN TO THE NORTH BY DAY THREE. MODEL GUIDANCE IS IN BETTER AGREEMENT ON THIS SCENARIO THAN THIS MORNING. AFTER 72 HR...GLOBAL MODELS ARE GENERALLY SUGGESTING MORE OF A MOTION TOWARD THE NORTHEAST THAN EARLIER...PERHAPS DUE TO THEIR DEPICTION OF A STRONGER CYCLONE INTERACTING MORE WITH THE TROUGH. THE OFFICIAL FORECAST HAS BEEN SHIFTED TO THE NORTHEAST IN THE LONGER-RANGE... BUT IS STILL SOUTH OF THE MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 08/2100Z 12.1N 29.8W 60 KT 12HR VT 09/0600Z 12.8N 31.3W 70 KT 24HR VT 09/1800Z 13.9N 32.8W 80 KT 36HR VT 10/0600Z 15.2N 33.9W 80 KT 48HR VT 10/1800Z 16.4N 34.4W 70 KT 72HR VT 11/1800Z 18.0N 34.0W 55 KT 96HR VT 12/1800Z 19.5N 33.5W 45 KT 120HR VT 13/1800Z 22.0N 34.0W 30 KT $$ FORECASTER BLAKE