Flhurricane.com - Central Florida Hurricane Center - Tracking Storms since 1995Hurricanes Without the Hype! Since 1995
The Atlantic is quiet
|
Show Selection: |
| #451695 (Received by flhurricane at: 7:20 PM 20.Aug.2011) TCDAT4 TROPICAL STORM IRENE SPECIAL DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011 700 PM AST SAT AUG 20 2011 AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INVESTIGATING THE TROPICAL WAVE EAST OF THE LESSER ANTILLES FOUND A SMALL LOW-LEVEL CIRCULATION CENTER JUST SOUTHWEST OF A LARGE CONVECTIVE BURST AND A MINIMUM PRESSURE OF ABOUT 1006 MB. THE PLANE ALSO MEASURED A MAXIMUM WIND OF 53 KT AT 1400 FT AND BELIEVABLE WINDS OF ABOUT 45 KT FROM THE SFMR. THUS ADVISORIES ARE BEING INITIATED ON TROPICAL STORM IRENE WITH AN INITIAL INTENSITY OF 45 KT. A ROUGH ESTIMATE OF INITIAL MOTION IS ABOUT 280/19. A LARGE MID-LEVEL RIDGE OVER THE CENTRAL AND WESTERN TROPICAL ATLANTIC IS EXPECTED TO STEER IRENE TOWARD THE WEST-NORTHWEST OVER THE NEXT TWO OR THREE DAYS. THIS RIDGE SHOULD WEAKEN DURING THAT TIME AND CAUSE IRENE TO GRADUALLY DECELERATE. THE GUIDANCE IS IN GOOD AGREEMENT ON A TRACK GENERALLY IN THE DIRECTION OF HISPANIOLA TO THE SOUTH OF PUERTO RICO. THEREAFTER...A MID-LATITUDE TROUGH MOVING OFFSHORE OF THE EASTERN UNITED STATES IS EXPECTED TO CAUSE A WEAKNESS IN THE RIDGE. THIS COULD ALLOW IRENE TO GAIN SOME LATITUDE...ALTHOUGH THE MODELS BEGIN TO SPREAD OUT LATE IN THE PERIOD. THE GFS AND ECMWF SHOW ENOUGH OF A WEAKNESS TO BRING THE STORM NORTH OF CUBA...WHILE THE UKMET AND THE CANADIAN HAVE ENOUGH RIDGING IN PLACE TO KEEP THE STORM IN THE CARIBBEAN SEA. THE NHC FORECAST WILL SPLIT THOSE TWO IDEAS AND LIES JUST TO THE WEST OF THE MODEL CONSENSUS. THE INITIAL VORTEX IS STILL IN ITS FORMATIVE STAGES AND IT WILL PROBABLY TAKE SOME TIME TO STRENGTHEN. HOWEVER...IRENE IS MOVING OVER RATHER WARM WATERS WITH LIGHT SHEAR EXPECTED. MOST OF THE RELIABLE GUIDANCE BRINGS THE STORM TO A HURRICANE BEFORE REACHING HISPANIOLA...AND THE OFFICIAL FORECAST IS IN AGREEMENT WITH THIS SCENARIO. THE INTENSITY FORECAST IN AT DAY 3 AND BEYOND IS RATHER CHALLENGING DUE TO THE POTENTIAL FOR LAND INTERACTION. ALTHOUGH THE NHC FORECAST WILL SHOW ONLY A SMALL AMOUNT OF RE-INTENSIFICATION...ENVIRONMENTAL CONDITIONS COULD BE QUITE FAVORABLE FOR STRENGTHENING IF IRENE AVOIDS SIGNIFICANT LAND INTERACTION. BASED ON THE OFFICIAL FORECAST...TROPICAL STORM WARNINGS HAVE BEEN ISSUED FOR MANY OF THE LEEWARD ISLANDS...THE VIRGIN ISLANDS AND PUERTO RICO. NOTE...THIS SPECIAL ADVISORY TAKES THE PLACE OF THE STANDARD 800 PM AST/0000 UTC INTERMEDIATE PUBLIC ADVISORY. THE NEXT ADVISORY WILL BE THE FULL ADVISORY PACKAGE ISSUED AT 1100 PM AST/0300 UTC. FORECAST POSITIONS AND MAX WINDS INIT 20/2300Z 14.9N 58.5W 45 KT 50 MPH 12H 21/0600Z 15.4N 61.1W 45 KT 50 MPH 24H 21/1800Z 16.1N 64.4W 50 KT 60 MPH 36H 22/0600Z 16.7N 67.0W 55 KT 65 MPH 48H 22/1800Z 17.5N 69.6W 65 KT 75 MPH 72H 23/1800Z 19.0N 74.0W 45 KT 50 MPH 96H 24/1800Z 21.5N 77.0W 45 KT 50 MPH 120H 25/1800Z 24.0N 79.5W 55 KT 65 MPH $$ FORECASTER BLAKE/BRENNAN |
