000
AXPZ20 KNHC 251000
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED APR 25 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
NO MONSOON TROUGH EVIDENT. ITCZ AXIS FROM 04N87W TO 05N114W TO 
LOW PRES NEAR 02.5N128W. SCATTERED MODERATE TO STRONG CONVECTION 
NOTED WITHIN 180 NM N OF AXIS. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION NOTED WITHIN 90 NM N SEMICIRCLE OF LOW PRES 
NEAR 02.5N128W. 

...DISCUSSION...

AT UPPER LEVELS...RIDGE-TROUGH-RIDGE PATTERN CONTINUES N OF 10N 
BETWEEN 70W AND 140W. DEEP LAYERED LOW PRES FROM NEAR 29N130W 
WITH TROUGH SW TO 15N146W...WITH LOW DRIFTING SLOWLY E. RIDGE TO 
E AMPLIFYING...CURRENTLY CENTERED ALONG 110W N OF 14N...WITH 
DOWNSTREAM BROAD UPPER TROUGH COVERING ENTIRE GULF OF MEXICO. 
TROPICAL JET SEGMENT S OF UPPER TROUGH ACROSS W PORTIONS...FROM 
07N TO 11N BETWEEN 130W AND 150W...WITH CORE WIND SPEEDS 80-110 
KT. JET ENERGY RIDING NE AND OVER W SIDE OF RIDGE. DIFFLUENT 
UPPER FLOW N OF 10N BETWEEN 120W AND 130W CONTINUES TO AID IN 
ELEVATED CONVECTION THERE. ACTIVE CONVECTION ALONG ENTIRE LENGTH 
OF ITCZ CONTINUES TO PRODUCE A NARROW UPPER RIDGE OVERHEAD.

A WEAKENING 1012 MB SURFACE LOW NEAR 29.5N132W IS ASSOCIATED 
WITH THE DEEP LAYERED LOW ALOFT...WHILE AN ASSOCIATED COLD FRONT 
LIES TO THE E OF THIS LOW FROM 30N123W TO 20N130W. 20-25 KT 
WINDS WERE DEPICTED BY SEVERAL RECENT SCATTEROMETER PASSES 
ACROSS THE W SEMICIRCLE OF THE LOW...WHERE SEAS WERE RUNNING 9 
TO 15 FT IN NW SWELL. THE LOW WILL DRIFT E-SE AND CONTINUE TO 
WEAKEN DURING THE NEXT 24 HOURS AND GRADUALLY OPEN INTO A 
TROUGH. NW SWELL GENERATED FROM THIS SYSTEM HAS PEAKED OVERNIGHT 
AND WILL CONTINUE TO SPREAD SE ACROSS NW HALF OF BASIN THROUGH 
THU. MEANWHILE...THE ASSOCIATED FRONT HAS BECOME NEARLY 
STATIONARY OVERNIGHT...BUT WILL BEGIN TO MOVE E THIS AFTERNOON 
AND THEN ACCELERATE AND MOVE ACROSS NRN BAJA CALIFORNIA EARLY 
THU TO PRODUCE A BRIEF PERIOD OF WET WEATHER. NWLY WINDS TO 20 
KT WILL CONTINUE OFF THE W COAST OF THE BAJA PENINSULA S OF 28N 
FOR THE NEXT COUPLE OF DAYS. WINDS INSIDE THE GULF OF CALIFORNIA 
WILL INCREASE TO 20 KT ACROSS FAR N PORTIONS OF THE GULF THU 
AHEAD OF THE APPROACHING COLD FRONT...AND THEN FILL IN FROM THE 
NW TO N AT 20-25 KT ACROSS THE S HALF OF THE GULF THU NIGHT AND 
FRI MORNING.

GAP WINDS...
GULF OF TEHUANTEPEC...HIGH PRES CENTERED OVER THE N GULF OF 
MEXICO IS PRODUCING MODERATE ELY WINDS OVER THE BAY OF 
CAMPECHE...THAT ARE FUNNELING THROUGH THE CHIVELA PASS INTO THE 
GULF OF TEHUANTEPEC. ALTHOUGH WINDS HAVE DIMINISHED BELOW GALE 
FORCE THROUGH TEHUANTEPEC...OVERNIGHT DRAINAGE FLOW HAS 
INCREASED TO 25-30 KT EARLY THIS MORNING...BUT WILL INCREASE TO 
20-25 KT BY LATE MORNING. AS THE HIGH PRESSURE OVER THE GULF OF 
MEXICO SHIFTS EASTWARD TODAY...WINDS OVER THE SW GULF OF MEXICO 
WILL VEER SE. THIS WILL DECREASE WINDS FLOW INTO THE GULF OF 
TEHUANTEPEC WITH WINDS DIMINISHING BELOW 20 KT BY THU 
MORNING.

GULF OF PAPAGAYO...THE EASTERN MIGRATION OF THE HIGH PRES CENTER 
OVER GULF OF MEXICO HAS INCREASED THE PRESSURE GRADIENT OVER 
WESTERN CARIBBEAN AND CENTRAL AMERICA. THIS HAS INCREASED FLOW 
THROUGH THE GAP IN TOPOGRAPHY OVER NICARAGUA YIELDING FRESH TO 
STRONG E WINDS THROUGH GULF OF PAPAGAYO. THESE WINDS ARE 
EXPECTED TO CONTINUE THROUGH THU MORNING.

GULF OF PANAMA...PRESSURE GRADIENT MENTIONED ABOVE ALSO 
INCREASED NORTHERLY WINDS 20-25 KT THROUGH THE GULF OF 
PANAMA...AS DEPICTED BY A 0300 UTC ASCAT PASS. THESE WINDS WILL 
DIMINISH BELOW 20 KT BY THU AFTERNOON OR EVENING. 

$$
STRIPLING