000
AXPZ20 KNHC 180905
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT AUG 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0645 UTC.

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

THE MONSOON TROUGH AXIS WAS ANALYZED FROM 10N85W TO 13N99W TO 
09N108W TO 13N120W TO 10N140W. SCATTERED MODERATE TO STRONG 
CONVECTION WAS WITHIN 150 NM N OF THE AXIS BETWEEN 88W AND 91W 
AND WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 102W AND 104W. 
SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS S OF THE 
AXIS TO 04N BETWEEN 93W AND 97W AND FROM 04N TO 07N BETWEEN 90W 
AND 93W. SCATTERED MODERATE CONVECTION WAS WITHIN 60 NM N AND 90 
NM S OF THE AXIS BETWEEN 126W AND 134W.

...DISCUSSION...

STRONG UPPER LEVEL WINDS CAN BE FOUND OVER MUCH OF THE FORECAST 
AREA THIS MORNING. AN UPPER LEVEL CYCLONE IS N OF AREA AT 
41N133W AND HAS A TROUGH EXTENDING S TO A COL NEAR 23N137W. 
30-40 KT WESTERLIES LIE TO THE W OF THE UPPER TROUGH AXIS WITH 
40-60 KT SOUTHWESTERLIES BETWEEN THE TROUGH AND THE COAST OF 
CENTRAL CALIFORNIA. ANTICYCLONES ALOFT NEAR 20N149W AND OVER THE 
NORTHERN GULF OF CALIFORNIA NEAR 30N113W EXTEND A RIDGE BETWEEN 
THEM THROUGH THE AFOREMENTIONED COL. WATER VAPOR IMAGERY SHOWS 
STRONG SUBSIDENCE N OF 14N W OF 130W. THE ANTICYCLONE OVER THE 
GULF OF CALIFORNIA IS PROPELLING MID TO UPPER LEVEL MOISTURE 
NORTHWARD TO THE EAST OF 130W. DIFFLUENCE ASSOCIATED WITH THIS 
ANTICYCLONE IS ENHANCING CONVECTION OVER THE GULF OF CALIFORNIA 
FROM 27N TO 30N. 30-40 KT EASTERLIES LIE S OF THE EASTERN 
ANTICYCLONE...PRIMARILY ALONG 20N E OF 130W. FARTHER S...30-40 
KT EASTERLIES DOMINATE THE REGION S OF 05N W OF 90W. THESE 
STRONG UPPER WINDS ARE INHIBITING THE DEVELOPMENT OF DEEP 
CONVECTION.

THE GOES-R PROVING GROUND TROPICAL OVERSHOOTING TOPS PRODUCT AND 
LIGHTNING DATA SHOW MOST OF THE ACTIVE CONVECTION IN THE 
FORECAST AREA LIES ALONG AND S OF THE DIFFLUENT UPPER RIDGE AXIS 
THAT EXTENDS FROM 13N110W TO AN ANTICYCLONE NEAR 10N110W. LOW 
LEVEL CONFLUENCE NEAR THE MONSOON TROUGH AXIS AND SPEED 
CONVERGENCE S OF THE AXIS ALONG 06N BETWEEN 90W AND 96W IS 
POOLING THE LOW LEVEL MOISTURE. THIS MOSITURE IS BEING LIFTED BY 
THE DIFFLUENCE ALOFT WHICH IS ENHANCING CONVECTION. THIS 
CONVECTION IS DESCRIBED IN THE SECTION ABOVE.
 
1018 MB HIGH PRES CENTERED NEAR 31N131W IS PRESENTING AN 
OBSTACLE FOR THE NW MOTION OF THE REMAINS OF HECTOR. THIS LOW 
PRES CENTER WAS NEAR 23N117W 1009 MB AT 0600 UTC. THE HIGH IS 
EXPECTED TO LINGER NEAR 30N130W THE NEXT FEW DAYS. THE REMNANTS 
ARE EXPECTED TO DRIFT FURTHER N BEFORE DISSIPATING ON SUN. THE 
HIGHEST PRECIPITABLE WATER VALUES IN THE FORECAST AREA LIE 
BETWEEN THE HECTOR REMNANTS AND THE NORTHERN GULF OF 
CALIFORNIA...WITH A SURGE OF LOW LEVEL MOSITURE CURRENTLY MOVING 
NORTHWARD THROUGH THE GULF.

SHIPS VQKR7 AND H9UY ALONG WITH THE ASCAT PASS FROM 1616 UTC AND 
THE OSCAT PASS FROM 1856 UTC SHOW FRESH TO STRONG NW WINDS ALONG 
THE COAST OF CABO CORRIENTES MEXICO DRIVEN BY THE PRES GRADIENT 
BETWEEN LOWER PRES OVER THE CENTRAL MEXICO AND RIDGING IN THE 
PACIFIC. THESE WINDS ARE FORECAST TO DIMINISH TO A FRESH BREEZE 
OR LESS BY AFTERNOON WHEN THE PRES GRADIENT RELAXES. 

$$
SCHAUER