000
AXPZ20 KNHC 131530
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI MAY 13 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
THE ITCZ AXIS IS ANALYZED ALONG 10N103W TO 08N108W TO 09N114W TO 
06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 
NM OF AXIS BETWEEN 108W AND 119W...AND FROM 04N TO 06N E OF 90W.

...DISCUSSION...
UPPER LEVEL TROUGHING DOMINATES THE NW PORTION OF THE FORECAST 
AREA WHILE BROAD UPPER LEVEL DIVERGENCE AND ANTICYCLONIC FLOW 
PREVAILS OVER THE SE PORTION. MODERATE TO STRONG ITCZ CONVECTIVE 
ACTIVITY IS BEING ENHANCED ALONG THE SW PERIPHERY OF THE UPPER 
RIDGE AXIS ALONG 08N BETWEEN 107W AND 122W.

AT THE SURFACE...WEAK HIGH PRES IS ANALYZED N OF 30N WITH A RIDGE
EXTENDING E-SE TO AROUND 18N110W. PRES GRADIENT ASSOCIATED WITH A
TROUGH IN NW MEXICO ALONG THE SONORAN COAST IS PRODUCING MODERATE
TO FRESH NW WINDS WITHIN 120 NM W OF BAJA CALIFORNIA. WINDS WILL
AGAIN INCREASE TO AROUND 20 KT THIS WEEKEND AS THE PRES GRADIENT 
TIGHTENS NEAR THE GULF OF CALIFORNIA. A SMALL AREA OF MODERATE TO
FRESH TRADE WINDS AND 7-8 FT SEAS IS EVIDENT FROM SCATTEROMETER 
DATA W OF 130W BETWEEN 07N AND 20N. LITTLE CHANGE IS EXPECTED IN 
THE TRADE WIND FLOW OVER THE NEXT FEW DAYS. A MONSOON TROUGH IS 
ANALYZED FROM THE GULF OF PANAMA TO 10N102W. SOUTHERLY FLOW S OF 
THE TROUGH IS EXPECTED TO INCREASE TO 20 KT BY SAT NIGHT...WITH 
SEAS BUILDING TO 8 FT IN THE VICINITY OF 05N85W. MODEL GUIDANCE 
SHOWS THE MONSOON TROUGH REMAINING A SEMI-PERMANENT FEATURE FOR
SEVERAL DAYS E OF 100W THROUGH THE MIDDLE OF NEXT WEEK.

$$
MUNDELL