000
AXPZ20 KNHC 012143
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE JUN 01 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2015 UTC.

...TROPICAL WAVE...
A TROPICAL WAVE ALONG 80W N OF 03N IS MOVING W AT 10 KT. THE WAVE 
LIES UNDER AN AREA OF INCREASING UPPER LEVEL DIFFLUENCE AND IS 
EXPECTED TO BE A FOCUS FOR CONVECTION OVER THE NEXT FEW DAYS. 
CURRENTLY...THE WAVE IS SPAWNING SCATTERED MODERATE CONVECTION W OF 
ITS AXIS WITHIN 150 NM OF THE ITCZ AXIS BETWEEN 82W AND 85W AS WELL 
AS ONSHORE IN WESTERN PANAMA.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 06N82W TO 09N92W TO 
10N104W TO 09N115W TO 05N140W. SCATTERED MODERATE CONVECTION WAS 
WITHIN 90 NM N AND 45 NM S OF THE ITCZ AXIS BETWEEN 108W AND 114W. A 
1011 MB LOW PRES SYSTEM IS EMBEDDED IN THE ITCZ NEAR 11N116W AND 
SCATTERED TO NUMEROUS MODERATE CONVECTION WAS FOUND WITHIN 240 NM S 
SEMICIRCLE AND 150 NM NE QUADRANT OF THE LOW. 

...DISCUSSION...
AN UPPER LEVEL TROUGH DOMINATES THE NORTHERN PORTION OF THE 
DISCUSSION AREA EXTENDING FROM THE NORTHERN GULF OF CALIFORNIA NEAR 
32N114W TO 22N140W. THE TROUGH IS FORECAST TO GRADUALLY SHIFT E 
OVER THE NEXT TWO DAYS...ALLOWING THE UPPER LEVEL ANTICYCLONE 
CURRENTLY NEAR 30N144W TO SLIDE ALONG 30N TO 125W BY MID DAY THU. AT 
THE SURFACE...1027 MB HIGH PRES NEAR 29N147W WILL WEAKEN AS IT MOVES 
EASTWARD INTO THE FORECAST AREA TO NEAR 27N135W BY THU AFTERNOON. 
THE HIGH WILL BE HELD SOUTH OF 30N BY A COLD FRONT PASSING ALONG ITS 
NORTHERN EDGE AND WILL BE CHASED EASTWARD BY THE SYSTEM CURRENTLY 
NEAR THE DATE LINE THAT IS EXPECTED TO RACE EASTWARD INTO THE 
EASTERN PACIFIC THU. TRADE WINDS ARE EXPECTED TO DIMINISH TO LESS 
THAN 20 KT BY THU AS THE SURFACE HIGH WEAKENS AND MOVES E. EARLIER 
NW WINDS ALONG THE CALIFORNIA COAST HAS PRODUCED NW SWELL TO 8 FT IN 
NE FORECAST WATERS. THESE SEAS ARE EXPECTED TO SUBSIDE THIS 
EVENING...BUT WINDS AND SEAS WILL AGAIN INCREASE LATE WED INTO THU 
AS THE COLD FRONT CURRENTLY PASSING N OF THE SUBTROPICAL HIGH MOVES 
INTO THE WESTERN U.S. AND THE GRADIENT BUILDS BETWEEN ITS LOW PRES 
AND THE EASTWARD-SHIFTED SUBTROPICAL SURFACE HIGH.

IN THE DEEP TROPICS...A BROAD UPPER RIDGE EXTENDS FROM THE GULF OF 
HONDURAS THROUGH ANTICYCLONES LOCATED NEAR 15N95W...14N113W...AND 
12N134W. A 60-70 KT WESTERLY UPPER JET LIES BETWEEN THE RIDGE AND 
THE AFOREMENTIONED UPPER TROUGH OVER N WATERS. MEANWHILE...A 25-40 
KT EASTERLY JET CAN BE FOUND IN THE AREA S OF THE RIDGE GENERALLY S 
OF 10N E OF 120W. THE HIGH WIND SHEAR ASSOCIATED WITH THESE UPPER 
JETS HAS LIMITED THE DEVELOPMENT OF DEEP CONVECTION TO ALONG THE 
ITCZ. CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 80W IS 
DETAILED IN THE TROPICAL WAVE SECTION ABOVE. THE ONLY OTHER FOCUS 
FOR CONVECTION IS THE BROAD LOW PRES SYSTEM EMBEDDED IN THE ITCZ 
WITH A CENTROID NEAR 11N116W. VISIBLE SATELLITE IMAGERY ALONG WITH 
THE 1400 UTC ASCAT PASS SHOWED THE CENTER HAD MIGRATED NORTHWARD 
OVER THE LAST FEW HOURS. THIS LOW IS EXPECTED TO MOVE W AT 5-10 KT 
OVER THE NEXT FEW DAYS WITH LITTLE CHANGE SEEN IN THE AMOUNT OF 
CONVECTION AND THE AREA OF 20 KT WINDS ASSOCIATED WITH THIS LOW.

$$
SCHAUER