Flhurricane.com - Central Florida Hurricane Center - Tracking Storms since 1995Hurricanes Without the Hype! Since 1995
The Atlantic is quiet
|
Show Selection: |
| #219455 (Received by flhurricane at: 4:34 AM 30.Sep.2008) TCDAT2 SUBTROPICAL STORM LAURA DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122008 500 AM EDT TUE SEP 30 2008 LAURA CONTINUES TO PRODUCE CONVECTIVE BANDS AROUND THE CENTER...WITH CLOUD TOPS COLDER THAN -60C TO THE NORTH AND NORTHEAST OF THE CENTER. A RECENT AMSU OVERPASS SHOWS A WELL-DEFINED MID/UPPER- LEVEL WARM CORE...SUGGESTING THAT LAURA IS BECOMING MORE TROPICAL. HOWEVER...WATER VAPOR IMAGERY SHOWS THAT THE SYSTEM IS STILL STRONGLY INVOLVED WITH AN UPPER-LEVEL LOW. ALSO...THERE ARE NO SIGNS OF THE ANTICYCLONIC UPPER-LEVEL OUTFLOW CHARACTERISTIC OF A TROPICAL CYCLONE. BASED ON THIS...THE SYSTEM IS STILL DESIGNATED A SUBTROPICAL STORM. SATELLITE INTENSITY ESTIMATES ARE UNCHANGED SINCE 6 HR AGO...SO THE INITIAL INTENSITY REMAINS 50 KT. LAURA HAS JOGGED TO THE LEFT AND ACCELERATED OVER THE PAST FEW HOURS...WITH THE INITIAL MOTION NOW 350/11. OTHER THAN THAT... THERE IS LITTLE CHANGE IN THE FORECAST PHILOSOPHY FROM THE PREVIOUS ADVISORY. A DEEP-LAYER RIDGE OVER THE NORTHEASTERN ATLANTIC AND A MID/UPPER-LEVEL TROUGH MOVING EASTWARD THROUGH NEW ENGLAND AND THE CANADIAN MARITIMES SHOULD STEER LAURA GENERALLY NORTH-NORTHEASTWARD FOR THE NEXT 48 HR OR SO...FOLLOWED BY A SHARP RIGHT TURN AS THE CYCLONE ENTERS THE WESTERLIES. WHILE THERE IS THE NORMAL AMOUNT OF SPREAD IN THE GUIDANCE...IT ALL AGREES WITH THIS SCENARIO. THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY...BUT NUDGED A LITTLE TO THE LEFT BASED ON THE CURRENT POSITION AND MOTION. LAURA WILL BE MOVING OVER STEADILY DECREASING SEA SURFACE TEMPERATURES DURING THE NEXT 36-48 HR...WITH THE SYSTEM LIKELY TO ENCOUNTER SSTS OF 12C BY 36 HR. THIS SUGGESTS THE SYSTEM SHOULD GRADUALLY WEAKEN AS THE FALLING SSTS CAUSE THE CONVECTION TO DECREASE. THE SYSTEM IS EXPECTED TO UNDERGO EXTRATROPICAL TRANSITION BETWEEN 24-48 HR...AND AFTER THIS IS COMPLETE THE LARGE-SCALE MODELS FORECAST SOME RE-INTENSIFICATION AS A BAROCLINIC LOW. IT SHOULD BE NOTED THAT NONE OF THE LARGE-SCALE MODELS CURRENTLY FORECAST LAURA TO PRODUCE STORM-FORCE...50 KT...WINDS AS AN EXTRATROPICAL LOW. BASED ON THIS...THE 120 HR FORECAST INTENSITY IS NUDGED DOWNWARD...AND ADDITIONAL ADJUSTMENTS TO THE FORECAST INTENSITY MAY BE NECESSARY IF THE CURRENT MODEL INTENSITY FORECASTS PERSIST. FORECAST POSITIONS AND MAX WINDS INITIAL 30/0900Z 40.3N 49.0W 50 KT 12HR VT 30/1800Z 42.0N 48.5W 50 KT 24HR VT 01/0600Z 44.6N 47.7W 50 KT 36HR VT 01/1800Z 47.5N 46.5W 45 KT...EXTRATROPICAL 48HR VT 02/0600Z 50.6N 44.5W 40 KT...EXTRATROPICAL 72HR VT 03/0600Z 55.0N 37.0W 45 KT...EXTRATROPICAL 96HR VT 04/0600Z 56.0N 25.0W 50 KT...EXTRATROPICAL 120HR VT 05/0600Z 56.0N 10.0W 50 KT...EXTRATROPICAL $$ FORECASTER BEVEN |
