000
AXPZ20 KNHC 130351
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU MAY 13 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 
0330 UTC.

...ITCZ...

ITCZ AXIS ALONG 05N77W TO 06N90W TO 06N106W TO 08N120W TO 
07N140W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE 
AXIS AND 75 NM S OF THE AXIS BETWEEN 91W AND 94W. SCATTERED 
MODERATE CONVECTION WITHIN 120 NM N OF THE AXIS BETWEEN 113W AND 
116W...WITHIN 180 NM N OF THE AXIS BETWEEN 119W AND 124W...AND 
WITHIN 180 NM S OF THE AXIS BETWEEN 124W AND 126W. SCATTERED 
MODERATE WITHIN 90 NM N OF THE AXIS BETWEEN 131W AND 134W...AND 
WITHIN 60 NM EITHER SIDE OF THE AXIS W OF 137W.

...DISCUSSION...

A SHARP AND DEEP UPPER LEVEL TROUGH EXTENDS FROM WESTERN NEW 
MEXICO TO NW OLD MEXICO NEAR 30N110W TO 27N116W TO 25N130W TO 
21N140W. RELATIVELY DRY AIR IS IN PLACE N OF THE TROUGH AXIS TO 
30N WITH A SWATH OF MOIST AIR IN PLACE FROM 30N TO 32N AHEAD OF 
A WEAKER UPPER TROUGH EXTENDING FROM 32N130W TO 31N137W.

A BROAD UPPER LEVEL TROPICAL ANTICYCLONE IS POSITIONED NEAR 
07N126W WITH A RIDGE AXIS EXTENDING ALONG 07N BETWEEN 94W AND 
140W. CONVECTION IS BEING ENHANCED ALONG AND S OF THE RIDGE 
UNDER UPPER DIFFLUENCE ALONG THE ITCZ MAINLY W OF 113W. A 70 TO 
90 KT JETSTREAM IS BETWEEN THE ANTICYCLONE CENTER AND THE ABOVE 
MENTIONED DEEP UPPER LEVEL TROUGH PRODUCING PLENTIFUL MID TO 
UPPER LEVEL MOISTURE WHICH IS BEING ADVECTED FROM THE ITCZ TO 
THE NE ACROSS CENTRAL MEXICO.

A WEAK UPPER LEVEL TROUGH EXTENDS FROM BELIZE TO ACROSS 
GUATEMALA TO 10N93W. VERY DRY AIR IS EVIDENT N OF 08N BETWEEN 
87W AND 97W. ANOTHER UPPER LEVEL TROUGH EXTENDS FROM THE SW 
CARIBBEAN SEA TO THE SW ACROSS WESTERN COSTA RICA TO 08N88W. AN 
UPPER LEVEL RIDGE EXTENDS FROM COLOMBIA TO THE W NEAR 07N87W. 
UPPER LEVEL DIFFLUENCE UNDER THIS RIDGE IS ENHANCING ITCZ 
CONVECTION E OF 87W.
 
AT THE SURFACE...A BROAD RIDGE AXIS DOMINATES THE MAJORITY OF 
THE DISCUSSION AREA WITH ITS AXIS MEANDERING FROM NEAR 32N135W 
TO 12N106W. NE TRADES IN THE 20-25 KT ARE SW OF THE RIDGE AXIS 
FROM 09N TO 25N W OF 120W. 20 KT NW-N WINDS ARE OCCURRING NE OF 
THE RIDGE AXIS N OF 25N BETWEEN THE BAJA PENINSULA AND 124W. NE 
AND NW SWELLS ARE THE PRIMARY SWELLS OVER THE WATERS WHERE THE 
TRADES AND NW-N WINDS ARE OCCURRING WITH A SERIES OF LONG PERIOD 
CROSS EQUATORIAL SOUTHERLY SWELL GROUPS DOMINATING THE REMAINDER 
OF THE DISCUSSION AREA. THE HIGHEST COMBINED SEAS OF UP TO 12 FT 
ARE OCCURRING ALONG 10N W OF 130W.

1007 MB LOW PRES IS CENTERED NEAR 04.5N82W WITH A TROUGH 
EXTENDING FROM 06.5N77W TO 02.5N86W. SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION IS WITHIN 240 NM NW OF THE LOW AND 
TROUGH. THE LOW IS EXPECTED TO DISSIPATE DURING THE NEXT 24 
HOURS WHILE THE TROUGH SLOWLY DRIFTS TO THE W-NW THROUGH THE 
NEXT 48 HOURS.

NW TO N WINDS TO 20 KT IN THE GULF OF CALIFORNIA FROM 26N TO 30N 
WERE CAPTURED BY AN EARLIER ASCAT SCATTEROMETER PASS ALTHOUGH 
THESE WINDS SHOULD DIMINISH WITHIN THE NEXT 6 HOURS.

GAP WINDS...NE TO E WINDS AT 20 TO 25 KT ARE SURGING OVER THE 
GULF OF PAPAGAYO AND DOWNWIND TO NEAR 10N91W AND ARE EXPECTED TO 
GRADUALLY DIMINISH TO LESS THAN 20 KT BY 48 HOURS.

$$
LEWITSKY