000
WTPZ42 KNHC 202037
TCDEP2
 
TROPICAL STORM GREG DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP072011
200 PM PDT SAT AUG 20 2011
 
GREG HAS CHANGED LITTLE ON SATELLITE IMAGERY DURING THE PAST SIX
HOURS...WITH LIMITED DEEP CONVECTION STUBBORNLY PERSISTING NEAR THE
CENTER. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB BOTH CAME
IN AT 30 KT...THOUGH A COINCIDENT ASCAT PASS DETECTED WINDS AROUND
35 KT IN THE NORTHERN SEMICIRCLE. THUS...THE INITIAL INTENSITY HAS
BEEN HELD AT 35 KT...AND GREG REMAINS A TROPICAL STORM.
 
THE INITIAL MOTION IS 285/08. GREG WILL BE STEERED ON A NEARLY DUE
WEST TRACK TONIGHT BY THE NORTHEAST PACIFIC SUBTROPICAL HIGH. THE
HIGH WILL BE WEAKENING SLIGHTLY OVER THE NEXT COUPLE OF DAYS AS A
MID TO UPPER LEVEL TROUGH DIGS OFF THE WEST COAST. THIS IS EXPECTED
TO HAVE LITTLE IMPACT ON GREG...WHICH WILL BECOME INCREASINGLY
SHALLOW AND SHOULD BE STEERED TO THE WEST-SOUTHWEST BY THE HIGH.
THE FORECAST TRACK IS ESSENTIALLY DOWN THE MIDDLE OF THE FULL
GUIDANCE ENVELOPE...NEAR THE PREVIOUS FORECAST TRACK.
 
GREG WILL BE WEAKENING OVER COOL WATERS TONIGHT AND SUNDAY. SSTS
WILL BE HOVERING AROUND 23C DURING THE NEXT COUPLE OF DAYS AS
STABLE AIR IS INGESTED FROM THE NORTH. AS A RESULT...GREG SHOULD
WEAKEN INTO A TROPICAL DEPRESSION TONIGHT AND GRADUALLY SPIN DOWN
INTO A REMNANT LOW PRESSURE SYSTEM BY 24 HOURS OR SO.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/2100Z 19.9N 120.5W   35 KT  40 MPH
 12H  21/0600Z 19.9N 121.6W   30 KT  35 MPH
 24H  21/1800Z 19.7N 123.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  22/0600Z 19.3N 124.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  22/1800Z 18.9N 125.9W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  23/1800Z...POST-TROP/REMNT LOW
 
$$
FORECASTER WROE/AVILA