000
AXPZ20 KNHC 110248
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI MAY 11 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0200 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 07N84W TO 06N94W TO 09N100W TO 
08N105W TO 09N112W TO 07N117W TO 07N124W WHERE IT TRANSITIONS TO 
ITCZ...CONTINUING ON TO 07N130W TO BEYOND 05.5N140W.  SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 150 NM N AND 210 NM S 
OF TROUGH BETWEEN 87W AND 98W. SCATTERED TO LOCALLY NUMEROUS 
MODERATE TO STRONG CONVECTION WITHIN 180 NM N AND 210 NM S OF 
TROUGH BETWEEN 99W AND 118W.

...DISCUSSION...
MIDDLE TO UPPER CYCLONE NEAR 27N145W IS APPROACHING W BOUNDARY 
OF BASIN AND CONTINUES TO NUDGE DOWNSTREAM BROAD UPPER LEVEL 
RIDGE EASTWARD...PRESENTLY CENTERED ALONG 125-130W AND N OF 
21N.  CYCLONE FORECAST TO LIFT NE NEXT FEW DAYS AND CONTINUE TO 
NUDGE RIDGE EWD AND WEAKEN IT...WITH RIDGE REACHING ALONG 120W 
BY SUN MORNING. DOWNSTREAM OF RIDGE...VIGOROUS CUT OFF LOW 
CONTINUES TO DRIFT E ACROSS FAR W TEXAS...IGNITING SCATTERED 
DEEP CONVECTION WELL TO THE E ACROSS CENTRAL AND S TEXAS. LOW 
FORECAST TO CONTINUE DRIFTING E THROUGH FRI BEFORE EJECTING NE 
AND WEAKENING OVER THE WEEKEND. TWO BROAD TROPICAL RIDGES 
PREVAIL ACROSS THE AREA S OF THESE FEATURES... ONE ALONG 
135-140W AND S OF 18N...WITH A SECOND BROAD RIDGE ANCHORED ON AN 
UPPER ANTICYCLONE NEAR 13N93W WITH RIDGE EXTENDING E INTO 
EXTREME SW CARIB. WIDESPREAD ACTIVE CONVECTION NEAR THE MONSOON 
TROUGH E OF 118W CONTINUES TO PRODUCE DIVERGENT FLOW DIRECTLY 
OVERHEAD OF THE CONVECTION...AND IS AIDING IN MAINTAINING THE 
UPPER RIDGING ACROSS THIS REGION. THE SOUTHERN TAIL OF A 
SHORTWAVE TROUGH WILL SWEEP EWD ACROSS W PORTIONS DURING THE 
NEXT FEW DAYS AND ERODE W PORTIONS OF THIS RIDGE...LEADING 
RIDGING WELL ESTABLISHED E OF 105-110W THROUGH THE WEEKEND.

...ELSEWHERE AT THE LOWER LEVELS...
A 1033 MB HIGH PRES CENTER WELL N OF AREA NEAR 45N131W CONTINUES 
TO SHIFT NE AND AWAY FROM THE AREA...LEAVING A GRADUALLY 
RELAXING PRES GRADIENT ACROSS N PORTIONS OF THE AREA. HOWEVER 
STRONG TO GALE FORCE WINDS PREVAILING OFFSHORE OF CALIFORNIA 
HAVE PRODUCE N AND NW SWELL THAT CONTINUES TO INTRUDE INTO N 
PORTIONS OF THE AREA...WITH SEAS TO 11 FT ALONG THE N BORDER 
NEAR 130W THIS EVENING. THIS SWELL WILL CONTINUE TO PROPAGATE 
SWD AND DECAY NEXT FEW DAYS...WITH SEAS LESS THAN 8 FT BY LATE 
FRI EVENING. OTHERWISE...NE WINDS AROUND 20 KT ARE FOUND ACROSS 
THE FAR NW CORNER OF THE AREA NW OF A LINE FROM 30N135W TO 
28.5N140W. LIGHT TO MODERATE NE TRADES ARE FOUND S OF THE RIDGE 
ACROSS THE TROPICS...WHILE LIGHT TO MODERATE MONSOONAL FLOW 
GENERALLY PREVAILS S OF THE MONSOON TROUGH E OF 120W. MODERATE 
TO STRONG CONVECTION HAS INCREASED SURROUNDING THE MONSOON 
TROUGH BETWEEN 98W AND 116W LATE THIS AFTERNOON AND EVENING... 
AND TWO DISTINCT LOW LEVEL CYCLONIC CIRCULATIONS HAVE BEGUN TO 
EMERGE...ONE IN THE VICINITY OF 08N112W AND A SECOND IN THE 
VICINITY OF 08N102W. GLOBAL MODELS ARE NOT IN AGREEMENT WITH THE 
EVOLUTION OF THESE FEATURES AND IT IS LIKELY THAT THEY WILL 
DRIFT NW AND CONTINUE TO PULSE CONVECTIVELY FOR A FEW DAYS  
BEFORE WEAKENING. AFTERNOON SCATTEROMETER PASSES SUGGESTED SW TO 
W WINDS NEAR 20 KT FLOWING INTO THIS CONVECTION...AND THESE 
FRESH WINDS WILL LIKELY PULSE WITH CONVECTIVE GROWTH OVER THE 
NEXT FEW DAYS.  

$$
STRIPLING