000
AXPZ20 KNHC 030236
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU JUN 03 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 
0115 UTC.

...TROPICAL WAVE...

A TROPICAL WAVE FROM 03N84W THROUGH 09N82W AND INTO THE SW 
CARIBBEAN IS MOVING W AT 10 KT. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION WAS WITHIN 300 NM W OF THE WAVE N OF 08N 
INCLUDING OVER WESTERN COSTA RICA. SCATTERED MODERATE WITHIN 180 
NM E OF WAVE N OF 06N INCLUDING OVER WESTERN PANAMA. THE WAVE 
WILL REMAIN UNDER BROADLY DIFFLUENT UPPER FLOW THROUGH 
THU...ALLOWING CONVECTION TO CONTINUE NEAR THE WAVE. THE WAVE 
WILL ENCOUNTER INCREASED NORTHEASTERLY SHEAR BY FRI. THIS WILL 
DIMINISH THE CHANCE OF CONVECTION.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS WAS ANALYZED FROM 09N94W 
TO 11N94W TO 09N109W TO 10N120W TO 06N140W. SCATTERED MODERATE 
CONVECTION WAS BETWEEN 75 NM AND 210 NM S OF THE ITCZ AXIS 
BETWEEN 87W AND 95W...WITHIN 90 NM S AND 45 NM N OF THE ITCZ 
AXIS W OF 136W...AND WITHIN 150 NM N OF THE ITCZ AXIS BETWEEN 
114W AND 116W.

...DISCUSSION...

SUBTROPICS...
AN UPPER LEVEL TROUGH DOMINATES THE NORTHERN PORTION OF THE 
DISCUSSION AREA EXTENDING FROM THE SOUTHERN GULF OF CALIFORNIA 
NEAR 25N110W TO 23N134W. THE TROUGH IS FORECAST TO SHIFT E AND 
AMPLIFY OVER THE NEXT TWO DAYS...ALLOWING THE UPPER LEVEL 
ANTICYCLONE CURRENTLY NEAR 29N134W TO SLIDE E ALONG 29N/30N TO 
123W BY THU EVENING AND BUILD AS IT DRIFTS NE TO 32N118W FRI 
EVENING WHEN THE UPSTREAM TROUGHING DIGS FROM THE NW GULF OF 
MEXICO THROUGH CABO CORRIENTES...MEXICO. AT THE SURFACE...1024 
MB HIGH PRES NEAR 28N140W WILL WEAKEN AS IT MOVES EASTWARD INTO 
THE FORECAST AREA TO NEAR 28N135W BY THU AFTERNOON. THE HIGH IS 
BEING HELD SOUTH OF 30N BY THE COLD FRONT PASSING ALONG ITS NW 
EDGE THIS EVENING AND WILL BE CHASED EASTWARD OVERNIGHT AND 
INTO THU BY A SYSTEM CURRENTLY PASSING N OF HAWAII THAT WILL 
RACE EASTWARD INTO THE EASTERN PACIFIC. WINDS AND SEAS WILL 
INCREASE EARLY THU OVER NE WATERS 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. TRADE WINDS WILL 
DIMINISH TO LESS THAN 20 KT LATE THU AS THE SURFACE HIGH WEAKENS 
AND MOVES E. THE SURFACE PATTERN IS EXPECTED TO CHANGE LITTLE 
FROM THU EVENING THROUGH FRI...WITH A SLOW MOVING COLD FRONT 
HELD N OF THE AREA AND 1022 MB HIGH PRES LINGERING NEAR 28N132W.

TROPICS..
TWO UPPER LEVEL ANTICYCLONES...ONE NEAR 15N93W AND ANOTHER NEAR 
13N110W...HAVE BANDED TOGETHER TO FORM A FLAT AND BROAD 
ANTICYCLONIC GYRE OVER THE EASTERN HALF OF THE TROPICAL PORTION 
OF THE FORECAST AREA. A 40-60 KT WESTERLY UPPER JET LIES BETWEEN 
THIS GYRE AND THE AFOREMENTIONED UPPER TROUGH OVER N WATERS. 
MEANWHILE...A 20-30 KT EASTERLY JET CAN BE FOUND IN THE AREA S 
OF THE GYRE GENERALLY S OF 10N E OF 115W. 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 FROM 03N84W TO 09N82W IS DETAILED IN THE 
TROPICAL WAVE SECTION ABOVE. THE OTHER PRIMARY FOCUS FOR 
CONVECTION IS A 1012 MB LOW PRES SYSTEM EMBEDDED IN THE ITCZ. A 
TROUGH PASSES THROUGH THIS LOW FROM 12N116W TO 08N122W AND 
SCATTERED MODERATE CONVECTION WAS FOUND WITHIN 90 NM N AND 75 NM 
S OF THIS TROUGH AND BETWEEN 150 NM AND 240 NM SE QUADRANT OF 
THE LOW. THIS LOW IS EXPECTED TO MOVE W AT 5-10 KT OVERNIGHT AND 
INTO THU...WITH THE LOW DISSIPATING AND ONLY A TROUGH FORGING ON 
LATE THU INTO FRI.

$$
SCHAUER