000
AXPZ20 KNHC 091508
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC SUN AUG 09 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 
1400 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 98W FROM 04N TO 12N MOVING W AT 15 KT. 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM OF THE WAVE AXIS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 07N80W TO 09N95W TO 
08N107W. ITCZ AXIS EXTENDS FROM 08N107W TO 09N112W TO 05N130W TO 
07N136W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS N 
OF 02N E OF 84W...FROM 07N TO 13N BETWEEN 85W AND 90W...FROM 13N 
TO 16N BETWEEN 92W AND 97W...AND FROM 05N TO 09N BETWEEN 93W AND 
96W. SCATTERED MODERATE CONVECTION IS FROM 05N TO 09N BETWEEN 
103W AND 117W.

...DISCUSSION...

HURRICANE HILDA CONTINUES TO MOVE W AWAY FROM THE DISCUSSION 
AREA. THERE IS NO SIGNIFICANT DEEP CONVECTION OVER THE FORECAST 
AREA ASSOCIATED WITH HILDA. WINDS HAVE ALSO DIMINISHED BELOW THE 
ADVISORY CRITERIA OF 20-25 KT WHILE SEAS REMAIN 7-9 FT FROM 16N-
20N W OF 137. SEAS ARE EXPECTED TO SUBSIDE BELOW 8 FT OVER THE 
FORECAST AREA BY THIS EVENING. REFER TO THE LATEST HIGH SEAS 
FORECAST ISSUED BY WFO HONOLULU UNDER AWIPS/WMO HEADERS HFOHSFNP 
AND FZPN40 FOR MORE DETAILS ON HILDA. 

A BROAD CYCLONIC CIRCULATION DEPICTED ON THE SURFACE ANALYSIS AS 
A 1009 MB LOW PRESSURE NEAR 16N124W SHOWS SOME SIGNS OF 
ORGANIZATION IN INFRARED SATELLITE IMAGERY. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS FROM 13N TO 16N BETWEEN 123W AND 
125W. SCATTERED MODERATE CONVECTION IS ALSO NE OF CENTER FROM 
18N TO 18N BETWEEN 118W AND 120W. THIS SYSTEM CURRENTLY LIES 
UNDER A COL AREA ALOFT BETWEEN UPPER-LEVEL ANTICYCLONES CENTERED 
NEAR 17N136W AND 11N113W. IN ADDITION...AN UPPER LOW NEAR 
21N115W IS PROPELLING DRIER AIR IN THE MID- AND UPPER-LEVELS 
TOWARD THE SYSTEM. THIS SYSTEM IS EXPECTED TO MOVE W WITH SLOW 
DEVELOPMENT POSSIBLE IN THE NEXT DAY OR TWO BEFORE DRIER AIR AND 
INCREASED NORTHERLY SHEAR INHIBIT DEVELOPMENT.

A SURFACE RIDGE EXTENDS FROM A 1029 MB HIGH AT 39N161W TO 
30N140W TO 17N111W. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND 
TROUGHING IN THE VICINITY OF THE GULF OF CALIFORNIA IS 
SUPPORTING A MODERATE TO FRESH BREEZE ON THE PACIFIC COAST OF 
THE BAJA CALIFORNIA PENINSULA. 
 
CROSS-EQUATORIAL SW SWELL WILL INCREASE SEAS TO 8 FT ACROSS S 
CENTRAL WATERS TODAY. THIS SWELL WILL CONTINUE TO PUSH 
NORTHEASTWARD INTO THE AREA...WITH THE LEADING EDGE REACHING THE 
COAST OF SOUTHERN MEXICO AND CENTRAL AMERICA WITH 15-17 SECOND 
PERIODS MON AFTERNOON INTO MON EVENING. COMBINED SEAS ARE 
EXPECTED TO BE IN THE 8-10 FT RANGE IN MIXED SE AND SW SWELL 
ACROSS THE AREA W OF 80W S OF A LINE FROM 06N80W TO 06N110W TO 
00N140W BY EARLY TUE MORNING. 

$$
FORMOSA