000
AXPZ20 KNHC 150950
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU MAY 15 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...
ITCZ AXIS ALONG 06N77W TO 07N90W TO 10N98W TO 08N108W TO 09N116W 
TO 02N130W TO 05N140W.  SCATTERED MODERATE CONVECTION WITHIN 90 
NM OF AXIS E OF 84W.  SCATTERED MODERATE TO STRONG CONVECTION S 
OF ITCZ TO 03N FROM 90W TO 105W.  

...DISCUSSION...
SUBTROPICAL PACIFIC...
LARGE AMPLITUDE UPPER LEVEL TROUGH DIGS DEEP INTO E PAC ALONG 
110W FROM 5N-26N WITH VERY DRY AIR MASS WITHIN 300 NM OF ITS 
AXIS.  TROUGH SPLITS MID-UPPER LEVEL RIDGE INTO TWO 
ANTICYCLONES...WEAK ONE NEAR 08N123W PRODUCING SOME DIFFLUENT 
FLOW ALOFT RIGHT OVER SURFACE TROUGH MOVING W ALONG THE ITCZ.  
SECOND ANTICYCLONE OVER YUCATAN PENINSULA NOT ONLY ENHANCES 
DIFFLUENT FLOW OF MOISTURE COMING OUT OF SOUTH AMERICAN 
CONTINENT...BUT ADVECTS ITS MOIST DEBRIS NE ACROSS BAY OF 
CAMPECHE INTO TEXAS COASTAL WATERS FEEDING AHEAD OF STRONG COLD 
ACROSS CENTRAL TEXAS.  NUMEROUS MODERATE TO STRONG CONVECTION IN 
SQUALLS RESULT IN THE CLASH OF AIR MASSES ALONG FRONTAL BOUNDARY 
MAINLY OVER LAND.  

AT THE SURFACE...AS 1032 MB RIDGE MOVES FURTHER N...STRONG N 
WINDS ALONG COAST OF CALIFORNIA WHICH EARLIER HAD BUILT LARGE 
SWELL TRAINS HAVE DIMINISHED WITH SEAS SUBSIDING BELOW 8 FT.  
FRESH TRADES FROM 08N-15N WILL WEAKEN AND SEAS ALSO SUBSIDE 
WITHIN NEXT 48 HRS.

HEALTHY COLD FRONT APPROACHES NW CORNER OF BASIN WITH LOW PRES 
CAUSING VERY LARGE SWELLS WHICH EVENTUALLY DRIFT INTO E PAC 
WITHIN NEXT 36 HRS AND LAST WELL BEYOND FORECAST PERIOD.    

PLEASE NOTE...MAY 15 MARKS THE BEGINNING OF THE EASTERN PACIFIC 
HURRICANE SEASON.  BASED ON THE LATEST AVERAGES...EVERY YEAR 15 
NAMED STORM FORM...9 OF WHICH BECOME HURRICANES AND 4 OF THOSE 
HURRICANES WOULD BE OF CATEGORY 3 OR GREATER IN STRENGTH ON THE 
SAFFIR-SIMPSON SCALE.  THE ATLANTIC HURRICANE SEASON BEGINS JUNE 
1ST WITH BOTH ATLANTIC AND EASTERN PACIFIC SEASONS ENDING 
NOVEMBER 30TH. 

$$
WALLY BARNES