000
AXPZ20 KNHC 170952
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JUN 17 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...SPECIAL FEATURES...
A BROAD AREA OF LOW PRESSURE CONTINUES OVER THE PACIFIC WATERS S 
OF THE MEXICAN AND GUATEMALA BORDER...AND IS ANALYZED AS AN 1007 
MB SURFACE LOW NEAR 13N95W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS CURRENTLY FLARING WITHIN 90 NM OF 13N93W AND ALONG 
THE COAST OF EL SALVADOR AND GUATEMALA. MODEL GUIDANCE SUGGESTS
GRADUAL DEVELOPMENT OF THIS SURFACE LOW OVER THE NEXT SEVERAL 
DAYS AS IT DRIFTS WEST...WITH THE POSSIBILITY OF TROPICAL 
CYCLONE FORMATION.  
  
...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 10N86W TO 13N95W TO 10N122W  
WHERE LOW LEVELS WINDS INDICATE THAT THE ITCZ BEGINS AND EXTENDS 
SW TO BEYOND 06N140W. LOCALLY OVERCAST LOW AND MID LEVEL CLOUDS 
ARE NOTED N OF 02N E OF 95W WITH SEVERAL CLUSTERS OF SCATTERED 
MODERATE CONVECTION AND ISOLATED STRONG CONVECTION. SIMILAR 
CONVECTION IS OBSERVED FROM 08N TO 12N BETWEEN 100W AND 109W.

...DISCUSSION...
AN UPPER TROUGH EXTENDS SW FROM SOUTHERN CALIFORNIA TO 30N122W 
INTO AN UPPER CYCLONE AT 26N133W WITH THE UPPER TROUGH 
CONTINUING S TO BASE OVER THE TROPICS AT 14N134W. UPPER MOISTURE 
IS OBSERVED WITHIN 120 NM OF THE CYCLONE...AND ACCOMPANIES THE 
UPPER TROUGH...WITH THE LEADING EDGE OF MOISTURE ABOUT 120 NM NW 
OF THE TROUGH AXIS.  

AN UPPER ANTICYCLONE IS OVER W CENTRAL OLD MEXICO AT 23N106W 
WITH ITS ENVELOPE OF ANTICYCLONIC FLOW DOMINATING THE DISCUSSION 
AREA BETWEEN 103W AND 120W. A 240 NM WIDE BAND OF UPPER 
MOISTURE...ORIGINATING FROM CONVECTION ALONG 10N...IS NOTED 
ALONG THE PERIPHERY OF THE RIDGE...ALONG POINTS 12N118W TO 
20N119W TO 28N115W...THEN CONTINUES NE ACROSS SOUTHERN NEW 
MEXICO AND W TEXAS. 

AN UPPER TROUGH EXTENDS SW ACROSS THE EASTERN GULF OF MEXICO TO 
A BASE OVER OLD MEXICO AT 17N96W. AN UPPER ANTICYLONE IS OVER 
THE SW CARIBBEAN RESULTING IN BROAD RIDGING AND UPPER DIFFLUENCE 
OVER THE TROPICAL PACIFIC E OF 94W. THE UPPER LEVELS ARE VERY 
MOIST E OF 94W AND ALONG THE MONSOON TROUGH FROM 05N TO 16N 
BETWEEN 94W AND 117W. CONVECTION IS LIKELY TO CONTINUE TO FLARE 
IN THE AREA S OF 18N E OF 107W FOR THE NEXT DAY OR SO.

ELSEWHERE AT THE LOW LEVELS...A BROAD RIDGE COVERS THE AREA W OF 
115W. THE GRADIENT IS SUPPORTING N TO NE WINDS AT 15 TO 20 KT N 
OF THE RIDGE...ROUGHLY N OF 22N W OF 117W...WITH SEAS 8 TO 11 FT 
IN MIXED N AND S SWELL. THE WINDS AND SEAS SHOULD DIMINISH IN 
THE THIS AREA OVER THE NEXT 48 HOURS.

$$
NELSON