000
AXPZ20 KNHC 262205
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC SUN MAY 26 2013

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH AXIS EXTENDS FROM 09N79W TO 10N87W TO LOW PRES 
NEAR 12N94W 1009 MB TO 10N101W TO LOW PRES NEAR 11N111W 1009 MB 
TO 10N120W. ITCZ BEGINS AT 10N120W TO 10N130W TO 10N140W. 
SCATTERED STRONG CONVECTION IS WITHIN 120 NM S OF THE AXIS 
BETWEEN 129W-133W. 
 
...DISCUSSION...

...SPECIAL FEATURE...

A 1008 MB LOW IS EMBEDDED WITHIN THE MONSOON TROUGH SITUATED NEAR 
12N94W...OR WITHIN A COUPLE HUNDRED MILES S OF THE GULF OF 
TEHUANTEPEC MOVING SLOWLY NW. THIS LOW HAS A RATHER TIGHT AND 
SMALL CIRCULATION AS SEEN IN THE LATEST SATELLITE VISIBLE 
IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 
180 NM OF THE LOW IN THE NE QUADRANT...AND WITHIN 90 NM OF HE 
LOW IN THE NW QUADRANT. THE LOW IS UNDERNEATH THE SW PERIPHERY 
OF AN UPPER LEVEL ANTICYCLONE CENTERED OVER GUATEMALA. COMPARED 
TO 24 HOURS AGO...IT APPEARS THE LOW HAS ATTAINED MORE MOMEMTUM 
IN TERMS OF VORTICITY AS IT CONTINUES PULL FURTHER AWAY FROM THE 
MONSOON TROUGH. THERE IS A MEDIUM PROBABILITY OF TROPICAL 
CYCLONE FORMATION WITH THIS SYSTEM DURING THE NEXT 48 HOURS. SEE 
LATEST TROPICAL WEATHER OUTLOOKS FOR PROBABILITY CONDITIONS 
RELATING TO THIS LOW.

ALOFT...AN UPPER TROUGH EXTENDS FROM THE PACIFIC NW REGION SW TO 
32N129W TO AN ELONGATED UPPER LEVEL LOW W OF THE AREA AT 
19N145W. TO THE SE OF THE TROUGH...BROAD ANTICYCLONIC FLOW 
COVERS THE AREA BETWEEN 106W-127W WITH THE ASSOCIATED 
ANTICYCLONE SLOWLY LIFTING NE NEAR 19N114.5W. AN UPPER LEVEL 
TROUGH IS NOW E OF THE DISCUSSION AREA ACROSS NORTH/CENTRAL 
MEXICO WITH ITS SRN PORTION PROTRUDING S TO NEAR 16N102W. SWLY 
FLOW ALOFT BETWEEN THE TROUGH ACROSS THE PORTION AND THE 
ANTICYCLONE CONTINUES TO ADVECT DEEP TROPICAL MOISTURE FROM THE 
CENTRAL PACIFIC NEWD TO ACROSS THE FAR WRN AND N CENTRAL 
PORTIONS OF THE DISCUSSION AREA TOWARDS FAR SRN CALIFORNIA AND 
NRN PORTION. OVER THE ERN PORTION...ANOTHER ANTICYCLONE CENTERED 
OVER GUATEMALA COVERS SE MEXICO AND NORTHERN CENTRAL AMERICA. 
UPPER DIFFLUENCE ASSOCIATED WITH THIS RIDGE IS HELPING TO 
SUSTAIN INCREASING CLUSTERS OF MODERATE TO STRONG CONVECTION NOW 
COVERING MUCH OF SERN PORTION OF THE AREA FROM ABOUT 08N TO 16N 
BETWEEN 91W AND 101W...AND ALSO FROM 09N TO 15N BETWEEN 101W AND 
109W. THIS ENCOMPASSES THE SPECIAL FEATURE LOW DESCRIBED ABOVE.

IN ADDITION TO THE SPECIAL FEATURE LOW...ANOTHER LOW PRES 
FEATURE IS ANALYZED NEAR 11N111W WITH PRES OF 1009 MB. A CLUSTER 
OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS W OF THIS 
LOW WITHIN 45 NM OF 11N113W. THE 1722 UTC ASCAT PASS FROM THIS 
AFTERNOON SUGGESTED THAT THIS LOW IS RATHER ILL-DEFINED...AND 
HAS APPARENTLY BECOME STRETCHES NE TO SW ALONG THE MONSOON 
TROUGH AXIS. MODELS CONTINUE TO SUGGEST THAT BOTH MENTIONED LOWS 
WILL DEVELOP OVER THE NEXT 48 HRS...WITH THE GFS MODEL STILL 
QUITE AGGRESSIVE IN DEVELOPING THE ERN MOST SPECIAL FEATURE LOW 
DESCRIBED ABOVE. REFER TO LATEST TROPICAL WEATHER OUTLOOKS FOR 
PROBABILITY CONDITIONS RELATING TO THIS LOW.

ELSEWHERE AT THE SURFACE...A 1030 MB HIGH IS ANALYZED JUST NW OF 
THE AREA AT 32N140W WITH A RIDGE EXTENDING SEWD THROUGH 26N125W 
AND TO NEAR 21N116W. THE 1030 MB HIGH CENTER IS FORECAST TO DROP 
A LITTLE TO THE S OVER THEN NEXT 24-36 HRS...AND REMAIN AT 1030 
MB AS THE UPPER TROUGH UNDER THE ALOFT SECTION SHIFTS TO THE 
FAR ERN PORTION OF THE AREA ALLOWING FOR RIDGING ALOFT TO BECOME
ESTABLISHED OVER THE NW PORTION ALSO. WITH THIS SCENARIO TAKING 
PLACE...EXPECT NE TRADES TO CONTINUE BETWEEN THE SRN PERIPHERY 
OF THE RIDGE AND THE ITCZ W OF ABOUT 130W INTO THE EARLY PART OF 
THE UPCOMING WEEK WITH SEAS UP TO 9 FT ATTRIBUTED MAINLY TO A NE 
SWELL COMPONENT. NW WINDS OF AROUND 20-25 KT ARE EXPECTED TO 
MATERIALIZE OVER THE FAR NE PART OF THE AREA N OF ABOUT 25N AND 
E OF 122W TO THE COAST OF BAJA CALIFORNIA PENINSULA DUE TO A 
TIGHT PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES OVER MEXICO.
THESE CONDITIONS ARE EXPECTED TO LAST WELL INTO NEXT WEEK.

LONG PERIOD CROSS EQUATORIAL SW SWELLS AT 16-18 SECONDS DOMINATE 
MOST OF THE FORECAST WATERS E OF 115W. THESE SWELLS ARE MERGING 
WITH NW SWELLS THAT COVER THE REMAINDER OF THE FORECAST WATERS. 
 
$$ 
AGUIRRE