000
AXPZ20 KNHC 081017
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE JUL 08 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.

...TROPICAL WAVES...
TROPICAL WAVE OVER NICARAGUA AND HONDURAS ALONG 85W N OF 08N 
MOVES W AT 15 KT.  THE PREVIOUS SCATTERED MODERATE ISOLATED 
STRONG CONVECTION HAS DECREASED AS WAVE MEETS CONFLUENT FLOW 
ALOFT ON NRN HALF BUT REMAINING CONVECTION ON SRN HALF HOLDING 
ITS OWN.  DIFFLUENT FLOW ALOFT EXPECTED TO DRIFT W GIVING WAVE 
MORE TIME UNDER INCREASED FAVORABLE UPPER CONDITIONS THAT SHOULD 
ENHANCE SRN HALF OF WAVE...OVER E PAC...DEVELOPMENT.  GLOBAL 
MODELS FORM LOW PRES 1006 MB EMBEDDED IN WAVE WITHIN NEXT 48 HR 
WHICH WOULD INCREASE SW WINDS BRINGING WARM MOIST TRPCL AIR MASS 
INTO SCENE.  SCENARIO IS CREDIBLE GIVEN ACTUAL INITIALIZATION OF 
MODELS AND PRESENT CONDITIONS...BUT DON'T FEEL LIKE GOING AS 
AGGRESSIVE AS GFS MODEL DOES. 

TROPICAL WAVE W OF GULF OF TEHUANTEPEC AND BAY OF CAMPECHE ALONG 
101 N OF 08N MOVING W AT 15 KT.  DEEP CONVECTION ONLY NOTED AT 
INTERSECTION WITH ITCZ WHERE MODERATELY DIFFLUENT FLOW ALOFT IS. 

...ITCZ...
ITCZ AXIS 004N77W TO 05N83W TO 12N96W TO 13N109W TO 08N130W TO 
07N140W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 
240 NM N OF AXIS E OF 110W. SCATTERED MODERATE CONVECTION WITHIN 
45 NM OF AXIS FROM 110W-120W.

...DISCUSSION...
COMBINATION OF DIGGING UPPER LEVEL TROUGH AND BROAD UPSTREAM 
MID-UPPER LEVEL ANTICYCLONE PRODUCING WIDESPREAD MODERATE TO 
STRONG SUBSIDENCE AND DRY AIR MASS N OF 12N W OF 120W.  NOT EVEN 
ITCZ IS ABLE TO BREAK CAP ON CLOUDS AND CONVECTION.  E OF 120W 
UPPER ANTICYCLONE OVER CENTRAL MEXICO ENHANCING CONVECTION ALONG 
ITCZ AS EXPLAINED IN TROPICAL WAVES SECTION.  

...ELSEWHERE AT THE SURFACE...
HEALTHY HIGH PRES CENTER 1029 MB WELL N OF AREA CONTINUES 
PRODUCING STRONG NLY WINDS ALONG CALIFORNIA COAST.  NLY SWELLS 
SPILL INTO E PAC S OF 32N FROM 120W-135W. WARM CROSS EQUATORIAL 
WINDS CONTINUE ADVECTING MOISTURE INTO ITCZ WITH FRESH SW FLOW 
FROM 100W-120W.    

$$
WALLY BARNES