000
AXPZ20 KNHC 222128
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN MAR 22 2009

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 05N77W 01N110W 02N140W. SCATTERED 
MODERATE CONVECTION IS FROM 04N-07N BETWEEN 83W-91W.

...DISCUSSION...

AN UPPER LOW CENTERED NEAR 22N140W IS THE MAIN WEATHER PRODUCING 
FEATURE. INSTABILITY AND DIFFLUENCE E OF THE LOW IS DRAWING 
WIDESPREAD MOISTURE AND EMBEDDED SCATTERED SHOWERS/ISOLATED 
TSTMS FROM 12N-27N W OF 120W. THE REMAINDER OF THE REGION IS 
DEVOID OF SIGNIFICANT PRECIP...BESIDES FOR A FEW CLUSTERS WITHIN 
THE ITCZ. 

AT THE SFC...THE PRESSURE GRADIENT BETWEEN A 1035 MB HIGH NEAR 
36N140W AND LOWER PRES ALONG THE ITCZ IS PRODUCING A LARGE SWATH 
OF 20-25 KT NE/E TRADES ACROSS MUCH OF THE REGION W OF 122W. 
SIMILAR MAGNITUDE NLY WINDS ARE BLOWING NEAR THE BAJA COAST. THE 
RIDGE IS EXPECTED TO BE QUASI-STATIONARY OVER THE NEXT COUPLE OF 
DAYS...SO LITTLE CHANGE IN WINDS IS FORECAST. NW SWELLS OF 12-14 
SECONDS HAVE JUST ENTERED THE NW CORNER. THIS SWELL TRAIN WILL 
HELP ELEVATE SEAS UP TO 14 FT OVER THE W PORTION OF THE AREA BY 
MON AND TUE. 

GAP WINDS...
GULF OF TEHUANTEPEC...A HI-RES QSCAT PASS AROUND 12 UTC THIS 
MORNING REVEALED MARGINAL NLY GALE CONDITIONS OVER THE GULF OF 
TEHUANTEPEC. SINCE THEN...ONLY SOURCE OF DATA IS A SHIP REPORT 
OF N 25 KT NEAR THE CORE OF THE GAP. GIVEN THAT THE SFC FLOW HAS 
SHIFTED ELY IN THE BAY OF CAMPECHE AND BECAUSE THE QSCAT PASS 
OCCURRED AT THE TIME WHERE DRAINAGE FLOW IS MAXIMIZED...ALLOWED 
THE GALE WARNING TO EXPIRE. WINDS SHOULD CONTINUE TO DIMINISH IN 
THIS REGION AND LIKELY BECOME LIGHT BY MON EVENING AS TROUGHING 
TAKES SHAPE OVER MEXICO AND THE SOUTHERN PLAINS OF THE U.S.

GULF OF PAPAGAYO...ASCAT AND A COUPLE OF SHIP REPORTS SHOW THAT 
THE GULF OF PAPAGAYO WINDS ARE STILL BLOWING NE 20-25 KT... 
EXTENDED THE SWATH W IN THE 18Z HSF INITIAL BASED ON THESE 
SOURCES. NWP MODELS ARE IN AGREEMENT IN FORECASTING THE EROSION 
OF THE WRN PERIPHERY OF THE ATLC SUBTROPICAL RIDGE. THIS WILL 
ALLOW THE WRN CARIBBEAN TRADES TO RELAX SLIGHTLY...LIMITING THE 
FUNNELING THROUGH THE GULF OF PAPAGAYO. BASED UPON A BLEND OF 
NWP GUIDANCE...WINDS ARE EXPECTED TO DIMINISH BELOW 20 KT IN 
ABOUT 48 HOURS. 

GULF OF PANAMA...HI-RES ASCAT DATA SHOWS PEAK WINDS OF ABOUT 
15-20 KT IN THE GULF OF PANAMA. FORECASTING LITTLE CHANGE OVER 
THE NEXT COUPLE OF DAYS AS THE PRES PATTERN BETWEEN THE 
SEMI-USUAL LOW OVER COLOMBIA AND SUBTROPICAL RIDGING REMAINS. 

GULF OF CALIFORNIA...WINDS ARE LIGHT AT THE MOMENT OVER THE GULF 
OF CALIFORNIA. HOWEVER...WITH SFC RIDGING BUILDING E OVER THE 
WRN U.S...NW TO N WINDS ARE EXPECTED TO INCREASE. SLP PATTERN 
DOES NOT SUGGEST GALE CONDITIONS AND AM FORECASTING 20-25 KT...A 
LITTLE HIGHER THAN MODEL OUTPUT. THIS FLOW SHOULD CONTINUE 
THROUGH TUE AS THE RIDGING HOLDS. 

$$
CANGIALOSI