000
AXPZ20 KNHC 040940
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE NOV 04 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...
AXIS FROM 10N85W TO 06N98W TO 10N116W TO 06N126W TO 08N140W. 
SCATTERED MODERATE CONVECTION ISOLATED STRONG WITHIN 90 NM NE 
QUADRANT OF POLO. SCATTERED MODERATE WITHIN 90 NM N OF AXIS 
BETWEEN 127W AND 132W. SCATTERED MODERATE WITHIN 60 NM N OF AXIS 
W OF 137W.

...SPECIAL FEATURE...
TROPICAL STORM POLO CENTERED AT 9.6N 116.7W OR ABOUT 870 NM SSW 
OF SOUTHERN TIP OF BAJA CALIFORNIA AT 0900 UTC MOVING W OR 280 
DEG AT 12 KT.  ESTIMATED MINIMUM CENTRAL PRES 1005 MB.  MAXIMUM 
SUSTAINED WINDS 35 KT GUSTS 45 KT. A BURST OF CONVECTION HAS 
FLARED NEAR THE CENTER OF POLO OVER THE PAST FOUR HOURS. THE 
STORM IS CENTERED TO THE SOUTH OF A STRONG BOUNDARY LAYER 
RIDGE...RESULTING IN A MOVEMENT TO THE WEST...AND EVENTUALLY 
NORTHWEST. POLO CONTINUES TO EXPERIENCE MODEST WESTERLY 
SHEAR..BUT MAY STRENGTHEN SLIGHTLY INTO WED...BEFORE WEAKENING 
IN THE FACE OF COOLER WATERS AND STRONGER WESTERLY SHEAR. FOR 
MORE INFORMATION SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCPEP3/WTPZ33 KNHC AND FULL FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC. 

...DISCUSSION...

N OF 20N...A RIDGE IS BUILDING OVER THE EASTERN PACIFIC BEHIND A 
MID/UPPER TROUGH MOVING EAST ONTO THE CALIFORNIA COAST. 
ASSOCIATED SURFACE HIGH PRES IS ANALYZED BEHIND A COLD FRONT 
PUSHING INTO SOUTHERN CALIFORNIA. THE FRONT IS EXPECTED TO MOVE 
INTO NORTHERN BAJA AND THE GULF OF CALIFORNIA BY TONIGHT...BUT 
THEN WEAKEN AS THE UPPER TROUGH LIFTS TO THE NE OUT OF THE AREA. 
QUIKSCAT AND SHIP OBSERVATIONS SHOW 20 KT NW TO N WINDS ALONG 
THE NORTHERN BAJA COAST...ON THE EASTERN PERIPHERY OF THE 
SURFACE HIGH. THESE WINDS WILL PERSIST FOR THE NEXT COUPLE OF 
DAYS AS THE SURFACE HIGH PRES BUILDS EAST...IMPACTING THE 
NORTHERN GULF OF CALIFORNIA AS WELL. NORTHERLY SWELL UP TO 8 FT 
WITH 12 SECOND PERIODS WILL DECAY THROUGH TODAY WEST OF 
120W...AND GRADUALLY DECAY ALONG THE BAJA COAST INTO WED.

S OF 20N...A BROAD SWATH OF 20 KT TRADE WINDS WILL PERSIST INTO 
THU W OF 120W ON THE SOUTHERN PERIPHERY OF HIGH PRES TO THE 
NORTH. SE CROSS EQUATORIAL FLOW CONVERGES WITH THE NE TRADES TO 
ENHANCE SPORADIC CONVECTION ALONG THE ITCZ...TO INCLUDE A BROAD 
DISORGANIZED AREA OF CONVECTION ALONG THE ITCZ W OF 130W. E OF 
120W...LOW LEVEL CONVERGENCE IS NOT AS STRONG AND CONVECTION IS 
LIMITED TO A FEW MODEST CELLS ALONG THE ITCZ. ASIDE FROM THE 
DEVELOPMENT AND TRACK OF POLO MENTIONED ABOVE...THE MAIN ISSUE 
WILL BE THE POTENTIAL FOR STRONGER SW FLOW OVER THE AREA BETWEEN 
THE GALAPAGOS AND COSTA RICA BY WED IN RESPONSE TO POSSIBLE 
DEVELOPING LOW PRES OVER THE SW CARIBBEAN. FURTHER NORTH...GAP 
WINDS PERSIST IN THE GULF OF TEHUANTEPEC AROUND 20 KT...ALTHOUGH 
THIS FLOW WILL DIMINISH INTO WED AS HIGH PRES TO THE NORTH 
MODIFIES.

$$

CHRISTENSEN