000
AXPZ20 KNHC 181526
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JUL 18 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURES... 
POST-TROPICAL CYCLONE FABIO AT 1500 UTC JUL 18 IS NEAR 25.7N 
120.8W OR ABOUT 425 MI...685 KM SW OF PUNTA BAJA MEXICO OR ABOUT 
535 MI...855 KM SSW OF SAN DIEGO CALIFORNIA MOVING N OR 360 DEG 
AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. MAXIMUM 
SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. SCATTERED 
MODERATE CONVECTION LIES WELL N OF THE CENTER FROM 28N TO 30N 
BETWEEN 120W AND 122W. SEE THE LAST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS FROM 07N77W TO 08N97W TO 12N107W TO 1007 MB 
LOW PRES NEAR 08N114W TO 05N120W TO 08N126W. ITCZ AXIS FROM 
08N126W TO 10N130W TO 10N140W. SCATTERED MODERATE CONVECTION IS 
FROM 5N TO 10N BETWEEN 77W AND 106W...AND FROM 05N TO 12N 
BETWEEN 112W AND 123W. 

...DISCUSSION...
A 1036 MB SUBTROPICAL HIGH IS CENTERED WELL NW OF THE FORECAST 
AREA NEAR 43N151W WITH A RIDGE AXIS EXTENDING NW OF FABIO TO 
30N130W. POST-TROPICAL FABIO REMAINS THE ONLY FEATURE WITH WINDS 
ABOVE 20 KT AND SEAS GREATER THAN 8 FT. THESE WINDS AND SEAS 
WILL ONLY LAST ANOTHER 24 HOURS. ELSEWHERE...BY EARLY THU 
SOUTHERN HEMISPHERIC SOUTHWESTERLY SWELL WILL BUILD SEAS TO 8 FT 
GENERALLY S OF 04N BETWEEN 108W AND 120W. IN THE TROPICS...THE 
MONSOON TROUGH AND ITCZ IS ACTIVE. SEE ABOVE. A BROAD 1007 MB 
LOW IS ALONG THE MONSOON TROUGH AXIS NEAR 08N114W AND IS 
EXPECTED TO DRIFT SLOWLY WESTWARD OVER THE FEW DAYS. THERE IS 
ONLY A LOW RISK OF THIS SYSTEM BECOMING A TROPICAL CYCLONE IN 
THE NEXT 48 HOURS. IN ADDITION...SCATTERED MODERATE TO STRONG 
CONVECTION IS OVER THE GULF OF TEHUANTEPEC FROM 13N TO 17N 
BETWEEN 92W AND 96W.

A BROAD ANTICYCLONIC CIRCULATION ALOFT SPANS MUCH OF THE REGION 
FROM 02N TO 22N BETWEEN 100W AND 130W. DIFFLUENCE ON THE 
SOUTHERN PERIPHERY OF THE ANTICYCLONE AND IS ENHANCING 
CONVECTION ALONG THE MONSOON TROUGH. THE UPPER LEVEL ANTICYCLONE 
WILL SHRINK 10 DEGREES ON ITS EASTERN EDGE TODAY INTO EARLY 
THURSDAY AS AN INVERTED UPPER LEVEL TROUGH CURRENTLY E OF 100W 
MOVES WESTWARD. THE ANTICYCLONE SHOULD WEAKEN FURTHER BY EARLY 
FRI. 

GAP WINDS...NE TO E WINDS HAVE BEEN PULSING TO AS HIGH AS A 
STRONG BREEZE DURING THE MORNING HOURS DOWNWIND OF THE GULF OF 
TEHAUNTEPEC THE LAST FEW DAYS. WIND ARE EXPECTED TO BECOME MORE 
CONSISTENTLY FRESH TO STRONG BY 0600 UTC THU AFTER A TROPICAL 
WAVE MOVES THROUGH MUCH OF CENTRAL AMERICA. THESE WINDS WILL 
LAST FOR AT LEAST 24 MORE HOURS. 

$$
FORMOSA