000
AXPZ20 KNHC 301012
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE MAR 30 2010

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0930 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG 04N77W TO 
05N95W TO 05N105W TO 04N118W TO 03N130W TO 05N140W. SCATTERED 
MODERATE TO STRONG CONVECTION WITHIN 90 NM N AND 120 NM S OF 
AXIS BETWEEN 82W AND 92W. SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 150 NM N OF AXIS BETWEEN 116W AND 123W.

...DISCUSSION...

SUBTROPICS...
A NEW COLD FRONT CURRENTLY FOUND JUST ENTERING THE FAR NW 
PORTION OF THE AREA WILL GRADUALLY DISSIPATE AS IT SHIFTS SE 
ACROSS THE FORECAST WATERS TODAY THROUGH WED...BUT IS CURRENTLY 
NEAR THE LEADING EDGE OF A NEW PULSE OF LARGE LONG PERIOD NW 
SWELL...WITH SIGNIFICANT WAVE HEIGHTS TO 18 FT AND WAVE PERIODS 
REACHING 17-18 SECOND FORECAST AS THE SWELL PROPAGATES SE DURING 
THE NEXT 48 HOURS. 

THE PRES GRADIENT BETWEEN THE ITCZ AND 1032 MB HIGH PRES BEHIND 
THE COLD FRONT NEAR 33N155W WITH A RIDGE EXTENDING 
EAST-SOUTHEASTWARD TO SOCORRO ISLAND IS MAINTAINING A BROAD AREA 
OF FRESH TO STRONG TRADE WINDS FROM 06N TO 21N W OF 130W 
ACCORDING TO THE 0548 UTC ASCAT PASS. THE STRENGTH AND POSITION 
OF THIS HIGH PRES CENTER WILL VARY LITTLE OVER THE NEXT TWO DAYS 
BUT THE EASTWARD EXTENDING RIDGE AXIS WILL LIFT N AFTER THE COLD 
FRONT TO ITS N WEAKENS...AND THEN BE FORCED S ON WED AS A 
SECONDARY COLD FRONT DROPS S OFF THE CALIFORNIA COAST. THE AREA 
OF FRESH TO STRONG TRADE WINDS WILL CREEP NORTHWARD TODAY AND 
THEN BEGIN TO MERGE WITH THE NWLY WIND FIELD BEHIND THE 
SECONDARY FRONT WED AND WED NIGHT. THE PRES GRADIENT BETWEEN THE 
EASTERN EDGE OF THE SURFACE RIDGE AND A LEE SIDE TROUGH ALONG 
THE NW SLOPES OF THE SIERRA MADRE OCCIDENTAL HAS SLACKENED 
ENOUGH FOR WINDS IN THE CENTRAL GULF OF CALIFORNIA TO DROP BELOW 
20 KT BUT THE GRADIENT IS STILL GENERATING NW TO N WINDS TO 20 
KT ALONG THE W COAST OF BAJA CALIFORNIA. LITTLE CHANGE IS 
EXPECTED IN THESE CONDITIONS THROUGH TONIGHT. HOWEVER AS THE 
SECONDARY FRONT REACHES THE N WATERS WED EVENING LOOK FOR SW TO 
W WINDS AROUND 20 KT TO SPILL ACROSS FAR N PORTIONS OF THE GULF 
OF CALIFORNIA. 

TROPICS...
AN EQUATORIAL UPPER LOW LIES NEAR 01S126W AND AN ANTICYCLONE 
LIES TO ITS N NEAR 09N125W. A SURFACE TROUGH REFLECTION OF THE 
LOW ALOFT IS EMBEDDED IN THE ITCZ ALONG 125W. AN ELONGATED 
SHEARLINE/CONVERGENCE BOUNDARY EXTENDS W-SW TO E-NE JUST N OF 
THE ITCZ IN THIS REGION...WITH THE TRADES AND THE LLVL TROUGH 
HELPING TO MAINTAIN CONVERGENCE AND PULSING CONVECTION ALONG THE 
SHEARLINE.  STRONG CONVECTION HAS BECOME ACTIVE DURING THE PAST 
12 HOURS ALONG THE ITCZ E OF 92W WHERE HIGH PRECIPITABLE WATERS 
VALUES CONTINUE TO EMERGE OFF THE W COAST OF COLOMBIA AND MOVE W 
INTO THE TROPICAL EPAC. UPPER RIDGING AND DIFFLUENCE ACROSS THIS 
AREA HAS INCREASED OVERNIGHT IN RESPONSE TO THE INCREASED ITCZ 
CONVECTION. 

GAP WINDS...
A 0406 UTC ASCAT PASS REVEALED GALE FORCE WINDS CONTINUED ACROSS 
THE GULF OF TEHUANTEPEC...BUT SHOULD DIMINISH BELOW GALES ON OR 
VERY SHORTLY AFTER 1200 UTC. WIND THERE WILL GRADUALLY DIMINISH 
IN STRENGTH AND AREAL EXTENT AND DROP BELOW 20 KT BY 36 HOURS. 

CLOUD MOTION OFF THE W COAST OF NICARAGUA SUGGEST THAT WINDS  
HAVE ALREADY BEGUN TO FUNNEL THROUGH THE GULF OF PAPAGAYO AND 
HAVE REACHED 20 KT. WINDS HERE WILL INCREASE THIS MORNING AS NLY 
FLOW FUNNEL BEHIND THE NW CARIBBEAN COLD FRONT PASS...WITH THIS 
GAP FLOW PEAKING AT 20-25 KT TONIGHT AND WED MORNING AND THEN 
GRADUALLY DIMINISHING BY THU MORNING. 

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
STRIPLING