000
AXPZ20 KNHC 010300
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE JUN 01 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...

AXIS IS ALONG 07N78W TO 10N94W TO 07N106W TO 09N116W TO 06N132W TO 
07N140W. SCATTERED MODERATE WITHIN 60 NM OF AXIS E OF 80W. SCATTERED 
MODERATE WITHIN 60 NM OF AXIS BETWEEN 93W AND 100W. SCATTERED 
MODERATE ISOLATED STRONG WITHIN 90 NM N OF AXIS BETWEEN 105W AND 
108W. SCATTERED MODERATE TO STRONG WITHIN 120 NM EITHER SIDE OF AXIS 
BETWEEN 111W AND 116W.

...DISCUSSION...

AN UPPER LEVEL TROUGH DOMINATES THE NORTHERN PORTION OF THE AREA 
STRETCHING FROM NORTHERN BAJA CALIFORNIA NEAR 32N113W TO 27N120W TO 
24N140W. VERY DRY AIR IS NOTED WITHIN 300 NM SE OF THE TROUGH AXIS 
WITH MID TO UPPER LEVEL MOISTURE N OF THE TROUGH AXIS.

AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 13N117W WITH A RIDGE 
AXIS EXTENDING W TO NEAR 09N140W AND NE TO 15N110W. ITCZ CONVECTION 
IS BEING ENHANCED ON THE SE-S SIDE OF THE ANTICYCLONE UNDER UPPER 
LEVEL DIFFLUENCE BETWEEN 110W AND 120W. A SUBTROPICAL JET ENTERS THE 
AREA NEAR 20N140W AND EXTENDS NE-E AROUND THE NORTHERN PERIPHERY OF 
THE ANTICYCLONE ACROSS SOUTHERN BAJA CALIFORNIA AND INTO MEXICO. 
CORE WINDS SPEEDS OF 70-85 KT EXIST WITH THIS JET AND MID TO UPPER 
LEVEL MOISTURE IS BEING ADVECTED FROM THE DEEP TROPICS OUT AHEAD OF 
THE JET AXIS.

A WEAK UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 12N102W WITH ITCZ 
CONVECTION BEING ENHANCED SE-S OF THE ANTICYCLONE BETWEEN 94W AND 
103W. AN UPPER LEVEL RIDGE EXTENDS FROM AN ANTICYCLONE POSITIONED IN 
THE NW CARIBBEAN SEA SW ACROSS HONDURAS AND GUATEMALA TO NEAR 
13N95W. 

AT THE SURFACE...A BROAD RIDGE EXTENDS FROM NEAR 30N140W TO 19N118W. 
THE PRES GRADIENT IS RATHER WEAK N OF THE ITCZ UNDER THIS RIDGE WITH 
ONLY A SMALL AREA OF NE 20 KT TRADES OCCURRING FROM 09N TO 19N W OF 
136W. THESE TRADES WILL REMAIN CONFINED TO A SMALL AREA DURING THE 
NEXT DAY AND DROP BELOW THE 20 KT THRESHOLD IN 48 HOURS. OTHERWISE 
CROSS EQUATORIAL SOUTHERLY SWELL OF UP TO 9 FT IS PROPAGATING 
THROUGH THE SOUTHERN WATERS...MAINLY S OF 15N. 
MEANWHILE...NORTHWESTERLY SWELL OF UP TO 9 FT REMAINS N OF 22N 
BETWEEN 121W AND 126W AND THIS SWELL WILL DECAY TO LESS THAN 8 FT BY 
24 HOURS.

1011 MB LOW PRES IS CENTERED NEAR 09N117W AND WILL DRIFT SLOWLY 
TOWARD THE WNW DURING THE NEXT TWO DAYS. 20 KT WINDS ARE OCCURRING 
WITHIN ABOUT 120 NM OF THE CENTER. SCATTERED MODERATE TO STRONG 
CONVECTION IS NOTED WITHIN 180 NM OF THE CENTER. THIS LOW IS 
MAINTAINED NEARLY STEADY STATE DURING THE NEXT 48 HOUR BY THE 18 UTC 
GFS AND 12 UTC ECMWF AND UKMET MODELS...WHILE THE 18 UTC NOGAPS 
DECAYS THE SYSTEM TO A TROUGH.  THE SHARP GRADIENT OF CLOUD TOP 
TEMPERATURES ON THE EAST SIDE OF THE DEEP CONVECTION IS LIKELY 
INDICATIVE OF MODERATE EASTERLY VERTICAL SHEAR AND THE LOW LEVEL 
CENTER BEING DISPLACED EASTWARD OF THE DEEP CONVECTION.

SOUTH OF PANAMA...THE 18 UTC GFS ENHANCES THE CROSS EQUATORIAL SW 
SURFACE WINDS TO 25 KT DURING THE NEXT TWO DAYS IN ASSOCIATION WITH 
A LOW IN THE SW CARIBBEAN.  WAVE HEIGHTS REACH UP TO 12 KT FROM THE  
WAVEWATCH BASED UPON THESE STRENGTHENED WINDS.  HOWEVER...NONE OF 
THE OTHER MODEL GUIDANCE SUGGESTS THAT THE SW WINDS WILL EVEN REACH 
OUR 20 KT THRESHOLD.  THEREFORE...THE FORECAST KEEPS THE WINDS IN 
THE REGION BELOW 20 KT AND MAINTAINS THE CURRENTLY EXISTING 8 TO 9 
FT SW SWELL.

$$
LEWITSKY/LANDSEA