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Eastern Pacific Tropical Weather Discussion (Text)

000
AXPZ20 KNHC 300246
TWDEP 

TROPICAL WEATHER DISCUSSION                                   
NWS NATIONAL HURRICANE CENTER MIAMI FL                       
0405 UTC WED JUL 30 2014

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0215 UTC.

...TROPICAL WAVES...                                            
A TROPICAL WAVE IS OVER SOUTH-CENTRAL MEXICO ALONG 98W N OF 12N 
MOVING W AT 15-20 KT. A CLUSTER A MODERATE TO ISOLATED STRONG 
CONVECTION IS AHEAD OF THE WAVE AXIS OVER EASTERN GUERRERO 
MEXICO. ISOLATED TO SCATTERED MODERATE CONVECTION IS NEAR THE 
SOUTHERN END OF THE WAVE AXIS FROM 12N TO 14N BETWEEN 98W AND 
100W. 

A SECOND TROPICAL WAVE IS ALONG 113W FROM 06N TO 15N. A 1010 MB 
LOW PRES IS ALONG WAVE AXIS NEAR 11N. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION IS FROM 06N TO 11N BETWEEN 113W AND 
120W. THE WAVE AND ASSOCIATED LOW PRES WILL CONTINUE TO MOVE 
WESTWARD AT 10-15 KT REACHING 120W LATE WED. ENVIRONMENTAL 
CONDITIONS ARE CONDUCIVE FOR GRADUAL DEVELOPMENT OF THIS SYSTEM 
DURING THE NEXT SEVERAL DAYS. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH EXTENDS FROM 08N78W TO 07N91W. THE ITCZ CONTINUES 
FROM 07N91W TO LOW PRES NEAR 11N113W TO LOW PRES NEAR 11N128W TO 
11N136W. OUTSIDE OF THE CONVECTION ASSOCIATED WITH THE LOW PRES 
SYSTEMS AND TROPICAL WAVES...NO SIGNIFICANT CONVECTION IS NOTED 
ALONG THE MONSOON TROUGH/ITCZ.

...DISCUSSION...

THE REMNANT LOW OF HERNAN IS ANALYZED AS A 1011 MB LOW PRES ON 
THE 0000 UTC SURFACE MAP NEAR 24N122.5W. A WELL DEFINED SWIRL OF 
LOW CLOUDS IS STILL ASSOCIATED WITH THIS FEATURE. AN AREA OF 
FRESH TO STRONG WINDS WITH SEAS OF 8-11 FT PERSISTS WITHIN 120 
NM N SEMICIRCLE OF THE LOW CENTER. WINDS AND SEAS ARE FORECAST 
TO GRADUALLY DIMINISH IN ASSOCIATION WITH THIS SYSTEM...AND THE 
LOW PRES IS EXPECTED TO DISSIPATE IN ABOUT 36-48 HOURS. 

A 1010 MB LOW PRES IS WITHIN THE ITCZ NEAR 11N128W. CONVECTION 
HAS SLIGHTLY DIMINISHED DURING THE PAST FEW HOURS AND NOW 
SCATTERED MODERATE CONVECTION IS OBSERVED FROM 10N TO 12N 
BETWEEN 130W AND 133W. SATELLITE IMAGERY SHOWS SOME BANDING 
FEATURES AND AN EARLIER ASCAT PASS INDICATED WINDS OF 20-25 KT 
WITHIN 120 NM NW QUADRANT OF THE LOW CENTER WITH SEAS TO 8 FT. 
ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR SOME SLOW 
DEVELOPMENT OF THIS SYSTEM DURING THE NEXT SEVERAL DAYS AS THE 
LOW MOVES GENERALLY WESTWARD. AN AREA OF FRESH TO STRONG WINDS 
IS FORECAST TO PERSIST WITHIN AROUND 120 NM TO THE N OF THE 
CENTER.

ANOTHER 1011 MB LOW PRES IS LOCATED NEAR 15N139W. PRES GRADIENT 
BETWEEN THE LOW PRES AND A RIDGE OVER THE NW WATERS IS RESULTING 
IN AN AREA OF FRESH TO STRONG WINDS OF 20-25 KT FROM 15N TO 20N 
W OF 135W WITH SEAS OF 8-10 FT. THE LOW IS FORECAST TO MOVE W OF 
140W OVERNIGHT TONIGHT. WINDS AND SEAS WILL DIMINISH ACROSS THE 
FORECAST AREA IN ABOUT 12-24 HOURS.  

ALOFT...AN UPPER LEVEL TROUGH REMAINS IN PLACE ACROSS THE N-
CENTRAL PART OF THE AREA EXTENDING FROM 30N128W TO 25N124W TO 
20N124W TO 15N125W. MOSTLY DRY AIR ACCOMPANIES THIS TROUGHING 
GENERALLY N OF 15N BETWEEN 125W AND 131W. SLY WINDS AHEAD OF 
THIS TROUGH CONTINUES TO IMPACT THE REMNANT OF HERNAN. AN UPPER 
LEVEL RIDGE IS IN THE WAKE OF THE TROUGH WITH AXIS ROUGHLY ALONG 
133W. AN ANTICYCLONIC CIRCULATION IS NOTED OVER NORTHERN 
CHIHUAHUA MEXICO WITH A RIDGE EXTENDING ACROSS NORTHERN MEXICO 
AND NORTHERN BAJA CALIFORNIA INTO THE EPAC TO NEAR 24N115W. THE 
UPPER-LEVEL LOW THAT WAS LOCATED OVER SOUTH-CENTRAL MEXICO 
YESTERDAY HAS MOVED WWD AND NOW IS CENTERED NEAR 19N109W. UPPER 
DIFFLUENCE IS HELPING TO INDUCE CONVECTION ALONG THE ITCZ AND 
NEAR THE LOW PRES SYSTEMS PREVIOUSLY MENTIONED. A RIDGE ANCHORED 
BY AN ANTICYCLONE OVER THE BAY OF CAMPECHE DOMINATES SE MEXICO 
AND NORTHERN CENTRAL AMERICA. ELY WINDS ALOFT ARE E OF 100W.

MIXED SW AND SE SWELL FROM THE SOUTHERN HEMISPHERE CONTINUES TO 
IMPACT THE SOUTH-CENTRAL WATERS S OF 02N BETWEEN 112W AND 120W 
WITH SEAS TO 8 FT. SEAS WILL SUBSIDE BELOW 8 FT IN ABOUT 12 
HOURS.

FRESH TO STRONG WINDS WILL CONTINUE TO PULSE ACROSS THE GULF OF 
PAPAGAYO...PARTICULARLY DURING THE OVERNIGHT AND EARLY MORNING 
HOURS WITH THE ASSISTANCE OF THE NOCTURNAL DRAINAGE FLOW. WINDS 
HAVE DIMINISHED TO 20 KT OR LESS ACROSS THE GULF OF TEHUANTEPEC 
AS THE TROPICAL WAVE MOVES W OF THIS REGION. 

$$ 
GR