000
AXPZ20 KNHC 071527
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON MAY 07 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1445 UTC.

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

MONSOON TROUGH EXTENDS FROM 08N78W TO 06N85W TO 09N95W TO 
10N112W. ITCZ STRETCHES FROM O6N124W TO 04N132W TO 05N140W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED S OF 
THE MONSOON TROUGH TO 03N BETWEEN 97W AND 110W. SIMILAR 
CONVECTION IS ALSO SEEN FROM 09N TO 13N BETWEEN 109W AND 114W. 
SCATTERED MODERATE CONVECTION IS FROM 05N TO 07N BETWEEN 120W 
AND 125W...AND WITHIN 120 NM N OF THE ITCZ AXIS FROM 131W TO 
136W. A DIFFLUENT PATTERN ALOFT IS HELPING TO SUPPORT MOST OF 
THIS CONVECTIVE ACTIVITY.

...DISCUSSION...

ALOFT...AN UPPER LEVEL TROUGH IS OVER THE NORTHERN WATERS 
REACHING FROM SOUTHERN CALIFORNIA TO 30N120W TO 26N129W. SW 
FLOW...WITH WIND MAXIMA OF 70-90 KT...IS TRANSPORTING MID-UPPER 
LEVEL MOISTURE FROM THE TROPICS ALL THE WAY TO ACROSS THE 
SOUTHERN BAJA CALIFORNIA PENINSULA AND NORTHERN MEXICO INTO W 
TEXAS. OTHERWISE MAINLY BROAD ANTICYCLONIC FLOW DOMINATES THE 
REMAINDER OF THE DISCUSSION WATERS.

AT THE LOWER LEVELS...1030 MB HIGH PRES LOCATED N OF THE 
DISCUSSION AREA NEAR 34N137W EXTENDS A RIDGE INTO THE WATERS 
THROUGH NEAR THE REVILLAGIGEDO ISLANDS. THE PRES GRADIENT 
BETWEEN THIS RIDGING AND LOWER PRES ALONG CALIFORNIA AND 
NORTHERN BAJA CALIFORNIA IS RESULTING IN AN AREA OF 20-25 KT NLY 
WINDS N OF 27N BETWEEN 125W AND 135W. SCATTEROMETER DATA AND FEW 
SHIP OBSERVATIONS CONFIRMED THE PRESENCE OF THESE WIND SPEEDS. 
THIS WEATHER PATTERN WILL PERSIST THROUGH WED AS A STRONGER HIGH 
PRES MOVES TOWARD 40N140W IN THE WAKE OF A COLD FRONT FORECAST 
TO DISSIPATE BEFORE REACHING THE FAR NW CORNER OF THE REGION. 
MEANWHILE...A BELT OF FRESH NE TRADES PREVAILS ON THE SOUTHERN 
PERIPHERY OF THE RIDGE FROM 07N TO 20N W OF 130W. THESE 
CONDITIONS ARE FORECAST TO PERSIST THROUGH THE NEXT 24 HOURS 
WHILE SHIFTING WESTWARD...WITH WINDS GRADUALLY DIMINISHING A BIT 
TO 15-20 KT BY 48 HOURS.

THE MOST RECENT OSCAT SCATTEROMETER PASS ALONG WITH AN ASCAT 
PASS INDICATED THE WIND SHIFT ASSOCIATED WITH A TROUGH THAT 
EXTENDS FROM 12N116W TO 06N121W. SOME CONVECTIVE ACTIVITY IS 
NEAR THE TAIL END OF THE TROUGH AXIS WHICH IS FORECAST TO DRIFT 
WWD DURING THE NEXT FEW DAYS. THE LOW PRES PREVIOUSLY ASSOCIATED 
WITH THIS TROUGH HAS DISSIPATED. 

THE REMAINDER OF THE REGIONAL WATERS...PARTICULARLY E OF 110W 
ARE UNDER THE INFLUENCE OF MAINLY GENTLE TO MODERATE BREEZE AND 
SEAS OF 7 FT OR LESS. THESE MOSTLY FAIR WEATHER CONDITIONS WILL 
PERSIST THROUGH MIDWEEK.

$$
GR