000
WTPZ43 KNHC 032038
TCDEP3
TROPICAL STORM POLO DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP182008
100 PM PST MON NOV 03 2008
 
DEEP CONVECTION WITHIN POLO HAS REMAINED MINIMAL THIS AFTERNOON AND
AN EXPOSED LOW-LEVEL CENTER HAS BECOME APPARENT IN VISIBLE
SATELLITE IMAGERY.  DVORAK T-NUMBERS FROM TAFB AND SAB HAVE
DROPPED...THOUGH THE CI NUMBERS STILL SUGGEST A 35 KT TROPICAL
STORM.  A 1337Z QUIKSCAT PASS DID CONFIRM THE RATHER TINY
STRUCTURE...20 NMI RADIUS OF TROPICAL STORM FORCE WINDS...OF THE
CYCLONE...QUITE SIMILAR TO THE EARLIER ATLANTIC TROPICAL STORM
MARCO.  THE QUIKSCAT ALSO PROVIDED A PEAK BELIEVABLE-LOOKING VECTOR
OF 40 KT.  HOWEVER...BECAUSE OF RAINFALL CONTAMINATION...IT IS NOT
KNOWN IF THIS WAS A TRUE WIND OR SOMEWHAT INFLATED BECAUSE OF RAIN. 
CURRENT INTENSITY REMAINS 35 KT.

THE INITIAL MOTION IS A RATHER CONFIDENT 280 DEGREES AT 10 KT...AS
POLO IS BEING STEERED BY A MID TO LOW-LEVEL RIDGE TO ITS NORTHWEST. 
A DEVELOPING WEAKNESS IN THE RIDGE IS ANTICIPATED TO TURN POLO
TOWARD THE WEST-NORTHWEST IN ABOUT 24 TO 36 HOURS.  AFTER THIS
TIME...THE GFDL AND HWRF HURRICANE MODELS CONTINUE TO RECURVE POLO
AS A SUBSTANTIAL CYCLONE TOWARD THE NORTH-NORTHEAST THROUGH THE
WEAKNESS IN THE RIDGE.  IN CONTRAST...THE GLOBAL MODELS INSTEAD
MOVE POLO AS A WEAKENING CYCLONE WESTWARD AS IT BECOMES STEERED BY
THE LOW-LEVEL EASTERLIES.  THE FORECAST TRACK IS BASED UPON THE
CONSENSUS OF THE GLOBAL MODELS AND IS SOMEWHAT TO THE SOUTHWEST OF
THE PREVIOUS ADVISORY.  

STRONG NORTHWESTERLY VERTICAL SHEAR SHOULD BEGIN IMPACTING POLO IN
ABOUT 48 HOURS...ACCORDING TO ALL OF THE GLOBAL MODELS. 
HOWEVER...CIRRUS VECTORS OVER THE STORM INDICATE THAT THE CYCLONE
MAY ALREADY BE EXPERIENCING MODERATE SHEAR.  THE THERMODYNAMICS ARE
ALSO NOT VERY CONDUCIVE WITH POLO MOVING OVER WARM SSTS BUT
EMBEDDED WITHIN A FAIRLY DRY AND STABLE AIRMASS.  ALL OF THE
INTENSITY GUIDANCE HAVE BACKED OFF SIGNIFICANTLY THIS AFTERNOON AND
NOW NONE ARE CALLING FOR POLO TO REACH HURRICANE INTENSITY.  THE
FORECAST INTENSITY IS BASED UPON THE ICON MODEL CONSENSUS AND IS
WEAKER THAN FORECAST PREVIOUSLY.  AN ALTERNATIVE SCENARIO...
BECOMING MORE PLAUSIBLE...IS THAT POLO HAS ALREADY PEAKED IN
INTENSITY AND THAT IT MAY BECOME A REMNANT LOW MUCH SOONER THAN
ADVERTISED...IF THE CONVECTION DOES NOT RE-EMERGE THIS EVENING.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/2100Z  9.2N 114.2W    35 KT
 12HR VT     04/0600Z  9.5N 115.7W    40 KT
 24HR VT     04/1800Z 10.1N 117.7W    45 KT
 36HR VT     05/0600Z 10.9N 119.4W    45 KT
 48HR VT     05/1800Z 11.7N 121.1W    40 KT
 72HR VT     06/1800Z 12.5N 124.0W    35 KT
 96HR VT     07/1800Z 13.0N 127.0W    30 KT
120HR VT     08/1800Z 13.5N 130.5W    25 KT...REMNANT LOW
 
$$
FORECASTER LANDSEA/PASCH