Show Selection: |
#631937 (Received by flhurricane at: 4:53 AM 14.Sep.2013) TCDAT5 TROPICAL STORM INGRID DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL AL102013 400 AM CDT SAT SEP 14 2013 SATELLITE IMAGERY SUGGESTS THAT INGRID HAS BECOME A LITTLE BETTER ORGANIZED DURING THE PAST SEVERAL HOURS...WITH CLOUD TOPS OF COLDER THAN -80C NEAR THE CENTER AND INCREASING OUTER BANDING IN ALL QUADRANTS EXCEPT THE SOUTHWEST. A TRMM OVERPASS AT 0420 UTC SHOWED A PARTIAL EYEWALL IN THE WESTERN SEMICIRCLE....ALTHOUGH DATA FROM THE MEXICAN RADAR IN ALVARADO SUGGESTS THIS FEATURE MAY HAVE BEEN TRANSIENT. SATELLITE INTENSITY ESTIMATES ARE 65 KT FROM TAFB AND 45 KT FROM SAB. THE INITIAL INTENSITY IS HELD AT 50 KT...PERHAPS CONSERVATIVELY...PENDING THE ARRIVAL OF NOAA AND AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IN THE NEXT FEW HOURS. INGRID HAS STARTED TO MOVE SLOWLY NORTH-NORTHEASTWARD WITH AN INITIAL MOTION OF 015/3. A GENERAL NORTHWARD MOTION IS EXPECTED FOR THE NEXT 12 HOURS OR SO...FOLLOWED BY A TURN TOWARD THE NORTHWEST AND THEN THE WEST AS THE STORM ENCOUNTERS STRONG LOW/MID-LEVEL RIDGING OVER THE SOUTHERN UNITED STATES. THE TRACK GUIDANCE GENERALLY AGREES WITH THIS SCENARIO...ALTHOUGH WITH SOME NOTABLE ISSUES OF SPREAD. FIRST...THE GFS AND ECMWF CALL FOR A MORE NORTHEASTWARD INITIAL MOTION BEFORE THE WESTWARD TURN...WITH BOTH MODELS LYING TO THE EAST OF THE NEW FORECAST TRACK. SECOND...THE GUIDANCE LANDFALL POINTS IN MEXICO ARE SPREAD FROM TUXPAN TO NORTH OF LA PESCA. THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK AND LIES NEAR THE CENTER OF THE GUIDANCE ENVELOPE. HOWEVER...THE MODEL SPREAD INDICATES A LOWER-THAN-NORMAL CONFIDENCE IN THE FORECAST. THE DYNAMICAL MODELS FORECAST THAT INGRID WILL CONTINUE TO EXPERIENCE WESTERLY VERTICAL SHEAR DURING THE NEXT COUPLE OF DAYS. THE SHIPS MODEL FORECAST 15-25 KT OF SHEAR DURING THE FIRST 24 HOURS...WHILE THE ECMWF FORECASTS LESS SHEAR. THE INTENSITY GUIDANCE IS IN RELATIVELY POOR AGREEMENT. THE SHIPS AND LGEM MODELS FORECAST INGRID TO BECOME A HURRICANE BY 36 HOURS...WHILE THE GFDL AND HWRF MODEL FORECAST THE SYSTEM TO PEAK IN 24 HOURS AND SUBSEQUENTLY WEAKEN BEFORE LANDFALL. SINCE THE CURRENT SHEAR HAS NOT STOPPED INGRID FROM INTENSIFYING...THE NEW INTENSITY FORECAST FOLLOWS THE PREVIOUS FORECAST...ALONG WITH SHIPS AND LGEM...AND MAKES INGRID A HURRICANE IN 36 HOURS. THE INTENSITY FORECAST IS AT THE UPPER EDGE OF THE INTENSITY GUIDANCE. IN ADDITION TO THE WIND THREAT...THE COMBINATION OF THE MOIST FLOW FROM BOTH INGRID AND TROPICAL STORM MANUEL IN THE EASTERN PACIFIC WILL PRODUCE TORRENTIAL RAINS...AND LIFE- THREATENING FLOODING OVER EASTERN MEXICO WILL REMAIN A SIGNIFICANT HAZARD OVER THE NEXT COUPLE OF DAYS. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 19.8N 95.0W 50 KT 60 MPH 12H 14/1800Z 20.5N 95.0W 55 KT 65 MPH 24H 15/0600Z 21.5N 95.7W 60 KT 70 MPH 36H 15/1800Z 22.2N 96.6W 65 KT 75 MPH 48H 16/0600Z 22.4N 97.7W 70 KT 80 MPH...NEAR COAST OF MEXICO 72H 17/0600Z 22.5N 99.5W 30 KT 35 MPH...INLAND 96H 18/0600Z...DISSIPATED $$ FORECASTER BEVEN |