000
AXPZ20 KNHC 310320
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON MAY 31 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 13N88W TO 06N106W TO 09N115W TO 07N125W TO 07N140W. 
SCATTERED MODERATE TO STRONG WITHIN 120 NM EITHER SIDE OF AXIS E OF 
91W. SCATTERED MODERATE ISOLATED STRONG WITHIN 120 NM N OF AXIS 
BETWEEN 99W AND 103W. SCATTERED MODERATE WITHIN 90 NM EITHER SIDE OF 
AXIS BETWEEN 109W AND 115W.

...DISCUSSION...

AN UPPER LEVEL TROUGH DOMINATES THE NORTHERN WATERS EXTENDING FROM 
32N118W SW OF THE CALIFORNIA CHANNEL ISLANDS TO 28N128W TO 24N140W 
AND SW OF THE DISCUSSION AREA TO THE ISLAND OF HAWAII. VERY DRY AIR 
IS NOTED WITHIN 420 NM SE OF THE TROUGH AXIS WITH BROAD RIDGING AND 
MID TO UPPER LEVEL MOISTURE NOTED NW OF THE TROUGH AXIS. 

AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 13N117W WITH A RIDGE 
AXIS EXTENDING TO 10N140W AND EASTWARD TO 12N106W. A JETSTREAM WITH 
CORE WIND SPEEDS OF 70-80 KT ENTERS THE AREA NEAR 17N140W EXTENDING 
TO THE NE AROUND THE NORTHERN PERIPHERY OF THE ABOVE MENTIONED 
ANTICYCLONE. UPPER LEVEL DIFFLUENCE ON THE SE SIDE OF THE 
ANTICYCLONE IS ENHANCING ITCZ CONVECTION BETWEEN 110W AND 119W. MID 
TO UPPER LEVEL MOISTURE IS BEING ADVECTED FROM THE DEEP TROPICS UP 
AHEAD OF THE JET.

ANOTHER UPPER LEVEL RIDGE IS CENTERED IN THE NW CARIBBEAN SEA NEAR 
THE HONDURAS/NICARAGUA BORDER WITH A RIDGE AXIS EXTENDING TO 12N93W 
TO 10N103W. UNDERNEATH THIS RIDGE AT THE SURFACE ARE THE REMNANTS OF 
AGATHA WHICH CONTINUE TO PRODUCE TORRENTIAL RAINFALL OVER GUATEMALA 
EL SALVADOR...AND HONDURAS. DANGEROUS FLASH FLOODING AND MUDSLIDES 
MAY CONTINUE TO RESULT FROM THE HEAVY RAINFALL.

ELSEWHERE AT THE SURFACE...1028 MB HIGH PRES IS CENTERED NEAR 
29N143W WITH A BROAD RIDGE EXTENDING SE TO NEAR 20N110W. A SMALL 
AREA OF NE TO E TRADES OF 20 KT EXIST FROM 08N TO 21N W OF 132W AND 
THIS AREA OF 20 KT TRADES WILL WEAKEN SLIGHTLY IN ABOUT 48 HOURS. 
CROSS EQUATORIAL SOUTHERLY SWELL OF UP TO 9 FT IS PROPAGATING 
THROUGH THE WATERS S OF 18N W OF 110W...AND S OF 10N BETWEEN 95W AND 
110W. ALSO...20 KT SOUTHERLY WINDS S OF THE ITCZ BETWEEN 93W AND 
110W WILL GRADUALLY DIMINISH TO LESS THAN 20 KT DURING THE NEXT 
12-24 HOURS.

A WEAK TROUGH NORTH OF OUR AREA EXISTS JUST OFFSHORE OF SOUTHERN 
CALIFORNIA. A TIGHT PRES GRADIENT EXISTS BETWEEN THE TROUGH AND HIGH 
PRES TO THE W WITH 20 KT NORTHERLY WINDS OCCURRING N OF 26N BETWEEN 
122W AND 128W. THESE WINDS AND HIGH N TO NW SWELL WILL DIMINISH IN 
ABOUT 48 HOURS.

A WEAK 1011 MB LOW NEAR 09N117W IS ACCOMPANIED BY SCATTERED MODERATE 
ISOLATED STRONG WITHIN 120 NM OF LOW CENTER.  THE 18 UTC GFS AND 
NOGAPS AS WELL AS THE 12 UTC ECMWF AND UKMET MAINTAIN THIS LOW AND 
SHOW SOME DEVELOPMENT IN ABOUT 48 HOURS.  ACCORDINGLY...THIS FEATURE 
IS ADDED TO THE HIGH SEAS FORECAST WITH WINDS UP TO 25 KT AND SEAS 
TO 10 FT.

FINALLY...THE 18 UTC GFS SHOWS A STRONG ENHANCEMENT OF THE SW 
MONSOONAL SURFACE WINDS OF UP TO 25 KT AND SEAS TO 12 FT SOUTH OF 
PANAMA IN 36 TO 48 HOURS.  HOWEVER...NONE OF THE OTHER MODEL 
GUIDANCE SHOWS THIS FEATURE AND IT IS DISCOUNTED IN THE HIGH SEAS AT 
THIS TIME AS BEING SPURIOUS.

$$
LEWITSKY/LANDSEA