000 WTNT44 KNHC 091444 TCDAT4 TROPICAL STORM HUMBERTO DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013 1100 AM AST MON SEP 09 2013 VISIBLE SATELLITE IMAGERY INDICATES THAT HUMBERTO STILL HAS AN ELONGATED LOW-LEVEL CIRCULATION...WITH THE CENTER NEAR THE EASTERN EDGE OF THE DEEP CONVECTION. THIS WAS CONFIRMED BY TWO ASCAT PASSES FROM EARLIER THIS MORNING...BUT THE SCATTEROMETER DATA ALSO INDICATED THAT MAXIMUM WINDS HAVE INCREASED TO 40 KT. THIS ESTIMATE IS ALSO SUPPORTED BY AN AVERAGE OF THE DVORAK ESTIMATES FROM TAFB AND SAB. HUMBERTO IS LOCATED TO THE SOUTH OF A STRONG AZORES HIGH AND CONTINUES TO MOVE 280/10 KT. THE TRACK FORECAST THINKING HAS NOT CHANGED. THE RIDGE IS EXPECTED TO WEAKEN DURING THE NEXT 48 HOURS...GIVING WAY TO TWO CLOSED MID/UPPER-LEVEL LOWS THAT WILL DEVELOP NORTH OF THE CANARY ISLANDS AND OVER THE CENTRAL ATLANTIC. THIS PATTERN SHOULD CAUSE HUMBERTO TO TURN SHARPLY NORTHWARD BY DAY 3. AFTER THAT TIME...HIGH PRESSURE AGAIN BUILDS NEAR THE AZORES...FORCING HUMBERTO TO TURN BACK TO THE WEST-NORTHWEST BY DAY 5. THE GLOBAL MODELS ARE TIGHTLY CLUSTERED THROUGH THE FIRST 48 HOURS BUT THEN DIVERGE WITH THE GFS...FLORIDA STATE SUPERENSEMBLE...GFDL...AND HWRF INDICATING A SHARPER TURN TOWARD THE NORTH. THE GUIDANCE SUPPORTS A SLIGHT NORTHEASTWARD SHIFT FROM THE PREVIOUS FORECAST AT THE LATTER END OF THE FORECAST PERIOD. THE EAST-NORTHEASTERLY SHEAR AFFECTING HUMBERTO IS EXPECTED TO ABATE WITHIN THE NEXT 12 HOURS...AND THE THERMODYNAMICS APPEAR SUFFICIENTLY CONDUCIVE TO SUPPORT ADDITIONAL INTENSIFICATION DURING THE NEXT 72 HOURS. THE SHIPS AND LGEM MODELS CONTINUE TO SHOW THE MOST AGGRESSIVE STRENGTHENING...BUT THAT IS COUNTERED BY THE HWRF...GFDL...AND FLORIDA STATE SUPERENSEMBLE WHICH EITHER DO NOT OR JUST BARELY MAKE HUMBERTO A HURRICANE. THE OFFICIAL FORECAST STILL LIES BETWEEN THESE TWO SCENARIOS AND IS JUST A TAD HIGHER THAN THE INTENSITY CONSENSUS. THE OFFICIAL FORECAST IS GENERALLY AN UPDATE OF THE PREVIOUS ONE...AND IS UNCHANGED FROM DAYS 3 THROUGH 5. FORECAST POSITIONS AND MAX WINDS INIT 09/1500Z 13.6N 24.1W 40 KT 45 MPH 12H 10/0000Z 13.9N 25.5W 50 KT 60 MPH 24H 10/1200Z 14.5N 27.3W 60 KT 70 MPH 36H 11/0000Z 15.5N 28.5W 70 KT 80 MPH 48H 11/1200Z 17.3N 29.1W 75 KT 85 MPH 72H 12/1200Z 21.5N 30.0W 80 KT 90 MPH 96H 13/1200Z 24.5N 31.0W 70 KT 80 MPH 120H 14/1200Z 26.0N 34.5W 60 KT 70 MPH $$ FORECASTER BERG/PASCH