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Eastern Pacific Tropical Weather Discussion (Text)



000
AXPZ20 KNHC 011605
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC SAT AUG 01 2015

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC. 

...SPECIAL FEATURES...                                           

AT 1500 UTC AUG 01...THE CENTER OF HURRICANE GUILLERMO IS NEAR 
13.5N 139.0W OR ABOUT 1145 MI ESE OF HILO HAWAII. GUILLERMO IS 
MOVING W OR 280 DEG AT 12 KT WITH A TURN TO THE WNW AND DECREASE 
IN FORWARD SPEED EXPECTED THIS AFTERNOON. THE MINIMUM CENTRAL 
PRES IS ESTIMATED AT 970 MB ALONG WITH MAXIMUM SUSTAINED WINDS 
OF 90 KT WITH GUSTS TO 110 KT. THE CLOUD PATTERN IS NOT AS 
IMPRESSIVE AS IT LOOKED YESTERDAY WHEN THERE WAS AN APPARENT EYE 
FEATURE OBSERVED ON SATELLITE IMAGERY. LATEST SATELLITE IMAGERY 
SHOWS NUMEROUS STRONG CONVECTION OCCURRING WITHIN 75 NM OF THE 
CENTER. SCATTERED STRONG CONVECTION IS ELSEWHERE WITHIN 180 NM 
OF THE CENTER. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS 
SEEN IN OUTER BANDS FROM 11N-17N BETWEEN 134W-136W...AND ALSO 
WITHIN 30 NM OF 16N129W. GUILLERMO IS FORECAST TO UNDERGO 
GRADUAL WEAKENING LATER TODAY AS IT NEARS 140W UNDER UNFAVORABLE 
UPPER LEVEL WINDS. SEE THE LATEST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADER MIATCMEP4/WTPZ24 KNHC FOR ADDITIONAL DETAILS.  

...TROPICAL WAVES...

THE SOUTHERN PORTION OF TROPICAL IS OVER SOUTHERN COSTA 
RICA...AND EXTENDS NORTHWARD TO ALONG THE COAST OF HONDURAS AND 
NICARAGUA...MOVING W 15 KT. ASSOCIATED CONVECTION IS DESCRIBED 
IN THE ATLANTIC TROPICAL WEATHER DISCUSSION.

A TROPICAL WAVE AXIS IS ANALYZED ALONG 108W FROM 06N-15N 
...MOVING W AT 15-20 KT. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS WITHIN 120 NM W OF WAVE FROM 09N-10N. BOTH 
SCATTEROMETER DATA AND FIRST VISIBLE IMAGERY SHOW A RATHER NICE 
DEFINED NE TO SE ORIENTATION OF THE LOW CLOUDS WITHIN 180NM-240 
NM ACROSS THE AXIS. MODELS SUGGEST THAT A WEAK SURFACE LOW MAY 
DEVELOP ALONG THE WAVE NEAR 10N DURING THE NEXT 24-48 HOURS... 
AND CONTINUE W WHILE THE WAVE LOSES IDENTITY.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...             
THE MONSOON TROUGH AXIS EXTENDS FROM THE FAR SW CARIBBEAN SEA TO 
OFF THE PACIFIC COAST OF COSTA RICA NEAR 09N85W...AND CONTINUES 
TO 08N92W TO 09N99W WHERE SCATTEROMETER WINDS INDICATE A 
TRANSITION TO AN ITCZ WHICH CONTINUES TO 09N108W AND BRIEFLY 
ENDS. IT BEGINS AGAIN AT 08N111W TO 06N120W TO 5N127W TO 
05N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS N OF 
03N BETWEEN 78W-81W...AND WITHIN 60 NM OF THE ITCZ W OF 137W. 

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ALSO OBSERVED  
WITHIN 60 NM OF THE PACIFIC COAST OF MEXICO FROM 17N-23N.

...DISCUSSION...

A 1018 MB SURFACE HIGH IS MEANDERING NEAR 27N126W WITH A RIDGE 
EXTENDING SEWD TO NEAR 18N115W. THE PRES GRADIENT BETWEEN THE 
RIDGE AND THE BAJA CALIFORNIA THERMAL TROUGH WILL ALLOW FOR NW 
15-20 KT WINDS TO EXIST WITHIN ABOUT 150 NM OF THE PACIFIC COAST 
OF THE BAJA CALIFORNIA PENINSULA THROUGH EARLY NEXT WEEK WITH 
SEAS OF 5-7 FT...GRADUALLY BUILDING TO 5-8 FT BY THIS EVENING 
AND CONTINUE THROUGH EARLY NEXT WEEK.

CROSS-EQUATORIAL SWELLS WITH COMBINED SEAS OF 7-8 FT WILL 
CONTINUE TO PROPAGATE N ACROSS THE TROPICS S OF 12N BETWEEN 95W-
130W TODAY THROUGH SUN...THEN BEGIN TO SUBSIDE. 

GULF OF PAPAGAYO...NE WINDS OF 15-20 KT THROUGH THE GULF ARE 
EXPECTED TO CHANGE LITTLE THROUGH MON...THEN MODEL GUIDANCE 
SUGGESTS THAT THESE WINDS INCREASE TO 20-25 KT BEGINNING MON 
NIGHT. INDUCED SEAS OF 7-8 FT FROM PREVIOUS 20-25 KT WINDS 
THROUGH THE GULF WILL CONTINUE TO PROPAGATE WSW AND MIX WITH THE 
LONG PERIOD CROSS EQUATORIAL SWELLS. 

GULF OF TEHUANTEPEC...EXPECT A BRIEF OCCURRENCE OF 15-20 KT NLY 
DRAINAGE FLOW WITH SEAS OF 5-7 FT EARLY ON SUN. 

$$
AGUIRRE

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Page last modified: Saturday, 01-Aug-2015 16:05:45 UTC