000
WTPZ41 KNHC 022033
TCDEP1
TROPICAL STORM JOHN DISCUSSION NUMBER 22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112006
200 PM PDT SAT SEP 02 2006
RADAR DATA FROM GUASAVE INDICATES THAT THE CENTER OF JOHN IS IN THE
NORTHWESTERN PORTION OF THE WEAKENING DEEP CONVECTION SEEN ON
SATELLITE. THE TROPICAL CYCLONE HAS SPENT AT LEAST 12 HOURS OVER
LAND AND IT IS LIKELY TO HAVE DIMINISHED TO A TROPICAL STORM... SO
THE INITIAL INTENSITY WILL BE REDUCED TO 60 KT. STEADY WEAKENING IS
FORECAST AS THE CENTER SHOULD REMAIN OVER OR CLOSE TO BAJA
CALIFORNIA FOR THE NEXT DAY OR SO. THEREAFTER... COLDER WATERS
SHOULD KILL THE SYSTEM QUICKLY AFTER THE SEVERELY WEAKENED CYCLONE
EMERGES INTO THE EASTERN PACIFIC OCEAN. REGARDLESS OF THE EXACT
TRACK... MIDDLE TO UPPER-LEVEL MOISTURE FROM JOHN IS LIKELY TO
ENHANCE RAINFALL IN THE DESERT SOUTHWEST MONSOON AREAS.
THE INITIAL MOTION HAS SHIFTED A LITTLE MORE TO THE LEFT... NOW
315/7. THERE HAS BEEN NO CHANGE IN SYNOPTIC REASONING WITH A WEAK
RIDGE PERSISTING OVER THE SOUTHWESTERN UNITED STATES. MODEL
GUIDANCE HAS NOT BEEN CONSISTENT ON HOW MUCH OF A WESTWARD TURN...
IF ANY... TO EXPECT AFTER THE SYSTEM DEPARTS BAJA CALIFORNIA. THE
GFDL AND GFS IN PARTICULAR HAVE BEEN FLIP-FLOPPING FROM A MORE
NORTHERLY TO A WESTERLY TRACK FROM RUN-TO-RUN. LITTLE CHANGE HAS
BEEN MADE TO THE OFFICIAL FORECAST... WHICH IS JUST A LITTLE SOUTH
OF THE MODEL CONSENSUS.
FORECAST POSITIONS AND MAX WINDS
INITIAL 02/2100Z 25.0N 111.2W 60 KT...INLAND
12HR VT 03/0600Z 25.8N 112.1W 50 KT...INLAND
24HR VT 03/1800Z 26.8N 113.2W 40 KT...INLAND
36HR VT 04/0600Z 27.8N 114.3W 30 KT...INLAND
48HR VT 04/1800Z 28.7N 115.3W 25 KT...DISSIPATING
72HR VT 05/1800Z 29.5N 117.0W 20 KT...REMNANT LOW
96HR VT 06/1800Z 29.5N 119.0W 20 KT...REMNANT LOW
120HR VT 07/1800Z...DISSIPATED
$$
FORECASTER BLAKE/AVILA
