000
AXPZ20 KNHC 270932
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JUL 27 2012

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 21N114W TO 14N115W MOVING W-NW AT 
10-15 KT. ISOLATED SHOWERS ARE ALONG THE WAVE N OF 17N. 

TROPICAL WAVE EXTENDS FROM 15N130W TO 09N135W. A 1009 MB LOW 
PRES IS ALONG THE WAVE NEAR 11N134W. CONVECTION WITH THE WAVE 
HAS DECREASED CONSIDERABLY COMPARED TO 24 HOURS AGO WITH ONLY A 
FEW SHOWERS WITHIN 60 NM EITHER SIDE OF WAVE. THE WAVE WILL 
CONTINUE TO MOVE WESTWARD AND IS EXPECTED TO CROSS OVER INTO THE 
CENTRAL PACIFIC OCEAN ON SAT.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH FROM 8N85W TO 10N90W. ITCZ FROM 10N90W TO 
8N100W 10N130W. NUMEROUS STRONG CONVECTION FROM 5N-8W E OF 81W. 
SCATTERED MODERATE TO STRONG CONVECTION WITHIN 300 NM S OF AXIS 
FROM FROM 106W-122W AND WITHIN 180 NM N OF AXIS FROM 122W-126W.

...DISCUSSION...
UPPER LEVEL RIDGE EXTENDS FROM AN ANTICYCLONIC CIRCULATION 
CENTERED NEAR 16N125W NW TO 32N138W. TO THE E OF THE RIDGE 
AXIS...THERE IS A TROUGH EXTENDING FROM 32N126W TO 21N120W. 
MODERATE TO STRONG SUBSIDENCE WITH DRY AND STABLE AIR MASS AT 
THE MIDDLE AND UPPER LEVELS DOMINATES MUCH OF THE NORTHERN 
PORTION OF THE DISCUSSION AREA N OF 20N W OF 115W. ANOTHER 
ANTICYCLONIC CIRCULATION IS CENTERED OVER NW MEXICO NEAR 30N108W 
WITH A RIDGE ALONG THE PACIFIC COAST OF MEXICO TO NEAR 12N99W. 
UPPER DIFFLUENCE ASSOCIATED WITH THIS SYSTEM IS ENHANCING 
SCATTERED TO NUMEROUS SHOWERS AND TSTMS OVER PARTS OF NORTHERN 
AND CENTRAL MEXICO. AN INVERTED TROUGH OVER THE SE PORTION OF 
THE GULF OF MEXICO EXTENDS ACROSS THE YUCATAN PENINSULA INTO THE 
EPAC THROUGH THE GULF OF TEHUANTEPEC.

SURFACE RIDGE EXTENDS FROM 32N140W TO 23N120W. THE PRES GRADIENT 
BETWEEN THE RIDGE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ 
IS MAINTAINING 20-25 KT TRADE WINDS FROM 11N TO 17N W OF 128W. 

ELY WINDS OF 20 KT ARE EXPECTED TO PERSIST OVER THE GULF OF 
PAPAGAYO THROUGH THE NEXT 48 HOURS.

$$
DGS