000
AXPZ20 KNHC 192203
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE JUN 19 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...SPECIAL FEATURES...
VISIBLE SATELLITE IMAGERY FROM THROUGHOUT THE DAY SHOW THAT THE
LOW LEVEL CIRCULATION ASSOCIATED WITH THE LOW PRES NEAR 18N107W 
REMAINS TOTALLY EXPOSED DUE TO MODERATE NE WIND VERTICAL SHEAR
ALOFT. SCATTERED STRONG CONVECTION IS WITHIN 150 NM OF THE LOW
IN THE SW QUADRANT. THE LOW REMAINS EMBEDDED IN THE NE PORTION 
OF THE MONSOON TROUGH...WITH STRONG SW TO S WINDS CONTINUING 
ACROSS A BROAD AREA SE OF THE LOW AND THE MONSOON TROUGH. 
UPPER-LEVEL WINDS REMAIN MARGINALLY CONDUCIVE FOR DEVELOPMENT
...AND ONLY A SMALL INCREASE IN ORGANIZATION WOULD RESULT IN THE 
FORMATION OF A TROPICAL DEPRESSION DURING THE NEXT DAY OR SO. 
THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE 
DURING THE NEXT 48 HOURS AS IT REMAINS NEARLY STATIONARY. 
INTERESTS ALONG THE SOUTHWESTERN COAST OF MEXICO SHOULD MONITOR 
THE PROGRESS OF THIS SYSTEM. REGARDLESS OF DEVELOPMENT...THE 
COMBINATION OF MONSOON DEEP MOISTURE AND THAT ASSOCIATED WITH 
THE LOW SHOULD MAINTAIN LOCALLY HEAVY RAINFALL ALONG THE 
SOUTHERN COAST OF MEXICO DURING THE NEXT 48 HRS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...MONSOON 
TROUGH EXTENDS FROM 15N105W TO THE 1005 MB LOW AT 18N107W...AND
SW TO 10N121W TO 08N130W. THE ITCZ AXIS EXTENDS FROM 08N130W
TO BEYOND 04N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION 
IS WITHIN 75 NM OF LINE FROM 15N105W TO 13N108W TO 12N111W. 
SIMILAR ACTIVITY EXISTS FROM 11N TO 13N BETWEEN 111W AND 116W.

...DISCUSSION...
A MID TO UPPER LEVEL CUT OFF LOW MOVING NW IS NEAR 27N135W. AN 
INVERTED TROUGH...REFLECTION OF THIS LOW...IS ANALYZED AT THE 
SURFACE EXTENDING FROM 30N131W TO 20N140W. UPPER RIDGING 
GENERALLY PREVAILS BETWEEN THIS LOW AND NW MEXICO...INCLUDING 
THE BAJA CALIFORNIA PENINSULA. THE RIDGE IS ANCHORED ON AN  
ANTICYCLONIC CIRCULATION LOCATED NEAR 24N118W. UPPER DIFFLUENCE 
ON THE SE AND S PARTS OF THIS SYSTEM IS CONTINUING TO INDUCE 
CONVECTION NEAR THE LOW PRES AT 18N107W AND ALONG THE MONSOON 
TROUGH. THE RIDGE ALSO EXTENDS SE ALONG THE MEXICAN COAST. UPPER 
LEVEL NE WINDS PREVAIL E OF 100W. WATER VAPOR IMAGERY SHOWS 
ABUNDANT SUBSIDENCE MAINTAIN RATHER DRY AND STABLE ATMOSPHERIC 
CONDITIONS OVER MUCH OF THE AREA TO THE NW OF MONSOON TROUGH 
ASSOCIATED MOISTURE AND CONVECTION DESCRIBED ABOVE.

ELSEWHERE AT THE SURFACE...A RIDGE EXTENDS INTO THE AREA TO THE 
E OF THE ABOVE SURFACE TROUGH FROM 32N133W AND TO NEAR 24N122W. 
A VERY TIGHT PRES GRADIENT CONTINUES BETWEEN THE SURFACE TROUGH 
MENTIONED ABOVE AND THE RIDGE ALLOWING FOR FRESH TO STRONG NELY 
WINDS ACROSS THE NW PORTION OF THE DISCUSSION AREA REA...MAINLY
N OF 25N TO THE NW OF THE TROUGH AXIS WITH SEAS OF 8 TO 11 FT. 
GLOBAL MODELS INDICATE THAT THE TROUGH WILL DRIFT WWD AND 
GRADUALLY WEAKEN AS THE RIDGE STRENGTHENS...RESULTING IN A 
GRADUAL DECREASE IN WINDS AND SEAS ACROSS THE NW WATERS OVER THE 
NEXT 48 HOURS.

AS MENTIONED ABOVE...SW WINDS OF 20 TO 25 KT ARE NOTED IN A 
LARGE AREA SE OF LOW PRES CENTER NEAR 18N107W...AND ALONG AND SE 
OF THE MONSOON TROUGH THERE...COVERING ROUGHLY FROM 14N TO 17N 
BETWEEN 102W AND 110W. THE SW FLOW EXTENDS FARTHER E AND BECOMES 
WLY ALONG THE PACIFIC COAST OF MEXICO TO OFFSHORE OF THE GULF OF 
TEHUANTEPEC. THIS FLOW IS CONTINUES TO PUMP ABUNDANT TROPICAL 
MOISTURE ACROSS THESE AREAS...RESULTING IN SCATTERED TO NUMEROUS 
SHOWERS AND TSTMS WITH PERIODS OF LOCALLY HEAVY RAINFALL AS 
WELL. THIS PATTERN IS EXPECTED TO REMAIN IN PLACE FOR THE NEXT 
FEW DAYS AND WILL MAINTAIN A WET WEATHER PATTERN ACROSS CENTRAL 
AMERICA AND SOUTHERN MEXICO.

$$
AGUIRRE