000
AXPZ20 KNHC 300956
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED JUN 30 2010

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 0945 UTC.

...TROPICAL LOWS....

THE REMNANT LOW PRES OF CELIA IS QUASI STATIONARY NEAR 16N124W  
AND ESTIMATED AT 1010 MB. WINDS ARE 20 TO 25 KT WITHIN ABOUT 150 
NM NW OF CENTER. SHOWERS ARE INDICATED WITHIN 150 NM OVER THE SW
SEMICIRCLE.  THE LOW IS EXPECTED TO GRADUALLY SPIN DOWN AND OPEN 
INTO A NW TO SE ORIENTATED TROUGH THU CONTINUING INTO SAT.

...TROPICAL WAVES...

A TROPICAL WAVE IS N OF 06N BETWEEN 88W AND 90W BUT ONLY FLARING 
CONVECTION ALONG THE COAST OF CENTRAL AMERICA AT THE MOMENT.

...ITCZ...

THE ITCZ AXIS APPEARS TO HUG THE COAST OF CENTRAL AMERICA 
BETWEEN 78W AND 9W AND IS MORE DISTORTED BY THE SOUTHERLY LOW 
LEVEL FLOW BETWEEN 90W AND 95W. THE AXIS IS SOMEWHAT EVIDENT 
FROM 15N96W T0 07N140W...BUT CURRENTLY LACKS SIGNIFICANT 
CONVECTION. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
OBSERVED E OF 80W AND WITHIN 60 NM OF 07N83W...ALSO WITHIN 120 
NM OF COAST FROM 88W TO 100W. 

...DISCUSSION...

AN UPPER CYCLONE IS CENTERED OVER NEW MEXICO NEAR 35N111W WITH A 
TROUGH EXTENDING S INTO A SMALLER UPPER CYCLONE OVER THE BAJA 
PENINSULA AT 25N112W...WITH THE TROUGH CONTINUING SW ALONG 
20N119W INTO AN UPPER CYCLONE AT 13N123W NEAR THE REMNANTS OF 
FORMER TROPICAL CYCLONE CELIA...WITH THE TROUGH CONTINUING SE TO 
A BASE AT 07N116W. 

AN UPPER ANTICYCLONE IS CENTERED AT 23N141W WITH A RIDGE 
AMPLIFYING NE TO A CREST OVER THE SW CONUS. A RIDGE ALSO EXTENDS 
SW TO OVER THE ITCZ WELL W OF AREA AT 07N166W...AND HAS BEEN 
ENHANCING CONVECTION ALONG THE ITCZ BETWEEN 130W AND 170W...WITH 
THE DEBRIS MOISTURE ADVECTED N...BUT EVAPORATING BEFORE IT 
REACHES ALONG 15N. OTHERWISE...THE UPPER LEVELS ARE VERY DRY N 
OF 20N W OF 108W...AND S OF 20N W OF 116W.   

AN UPPER ANTICYCLONE IS CENTERED OVER OLD MEXICO AT 25N103W AND 
ANOTHER UPPER ANTICYCLONE IS ESTIMATED AT 25N90W...ASSOCIATED 
WITH GULF OF MEXICO HURRICANE ALEX. THESE TWO ANTICYCLONES   
COMBINE INTO AN IMPRESSIVE ENVELOPE OF UPPER ANTICYCLONIC FLOW 
WHICH DOMINATES THE DISCUSSION AREA FROM 05S TO WELL N OF 32N 
BETWEEN 105W AND 76W. THE DEBRIS MOISTURE FROM CONVECTION 
ASSOCIATED WITH HURRICANE ALEX...AND FROM OTHER AREAS OF 
CONVECTION ENHANCED UNDER THIS LARGE AREA OF UPPER LEVEL 
DIFFLUENCE...IS ALL FANNING OUT MAKING THE UPPER LEVELS 
EXTREMELY MOIST UNDER THE PREVIOUSLY DESCRIBED ANTICYCLONIC 
ENVELOPE.

AT THE SURFACE...THE WEAK FRONTAL TROUGH PREVIOUSLY EXTENDING 
FROM 32N119W TO 24N126W IS BARELY EVIDENT IN THE OVERCAST LOW 
AND MID LEVELS CLOUDS...AND IS DROPPED FROM THE 06Z SURFACE 
ANALYSIS AS A SURFACE RIDGE IS ALREADY BRIDGING SE FROM 32N138W 
TO PERHAPS NEAR 22N115W. THE REMNANT TROUGH OF FORMER TROPICAL 
CYCLONE DARBY EXTENDS FROM ABOUT 12N100W TO THE COAST OF MEXICO 
AT 16N97W...BUT IS EXPECTED TO SOON EXPAND NE INTO THE HURRICANE 
ALEX. THE OPEN PAC WATERS NW OF THIS TROUGH TO ALONG THE BAJA 
PENINSULA AT 24N AND W TO ABOUT 113W...ARE EXPERIENCING NW WINDS 
AT 15 TO 20 KT WITH SEAS TO 8 FT. SW WINDS 15 TO 20 KT CONTINUE 
WITHIN ABOUT 360 NM SE OF THE TROUGH. S SWELL...DRIVING SEAS TO 
10 FT...COVER THE REMAINDER OF THE AREA S OF 15N BETWEEN 115W 
AND 80W. AS HURRICANE ALEX CONTINUES NW IN THE GULF OF MEXICO 
THE DARBY REMNANT TROUGH WILL SHIFT NW ALONG THE COAST OF MEXICO 
WITH WINDS AND SEAS ENHANCED WITHIN ABOUT 300 NM NW OF THE 
TROUGH. IN THE MEANTIME...THE PAC WATERS AFFECTED BY THE CROSS 
EQUATORIAL SOUTHERLY SWELLS IS EXPECTED TO INCREASE TO COVER THE 
ENTIRE AREA W OF 78W AND TO THE SE OF A LINE FROM 18N102W TO 
04N140W BY THU NIGHT.

$$
NELSON