000
AXPZ20 KNHC 262205
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON APR 26 2010

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 
2115 UTC.

...ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS WAS ANALYZED ALONG 07N80W TO 
09N87W TO 06N106W TO 08N123W TO 04N140W. SCATTERED TO LOCALLY 
NUMEROUS MODERATE TO STRONG CONVECTION WAS FROM 02N TO 11N 
BETWEEN 79W AND 96W. SCATTERED MODERATE TO STRONG CONVECTION WAS 
WITHIN 180 NM S AND 120 NM N OF AXIS BETWEEN 96W AND 121W. 
SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 120 NM OF 
AXIS W OF 121W. 

...DISCUSSION...
A SURFACE RIDGE AXIS EXTENDS FROM A 1025 MB HIGH CENTERED NEAR 
25N144W SW TO NEAR 16N120W. THIS HIGH PRESSURE SYSTEM CONTINUES 
TO WEAKEN AS AN ELONGATED MID/UPPER LEVEL TROUGH SLICES THE NW 
PORTION OF THE DISCUSSION AREA FROM A SLOW MOVING TROUGH ACROSS 
SRN CALIFORNIA ACROSS 30N120W TO AND EMBEDDED MID LEVEL VORT 
CENTER NEAR 22N127W TRAILING W-SW TO BEYOND 16N145W. A S/W UPPER 
RIDGE WAS DAMMED AGAINST THE NW FLANKS OF THIS 
TROUGH...EXTENDING SW TO NE ACROSS THE FAR NW CORNER OF THE 
AREA. A WEAK COLD FRONT IS POISED TO BEGIN IMPACTING THESE 
NORTHWESTERN WATERS OVERNIGHT INTO EARLY TUESDAY...SUPPORTED BY 
A LARGE UPPER LOW OVER THE NE PACIFIC. AS THIS FRONT SKIRTS THE 
NORTHERN WATERS AND WEAKENS CONSIDERABLY BY WEDNESDAY...THE 
REMAINS OF THE HIGH ARE FORECAST TO MERGE WITH STRONGER HIGH 
PRESSURE TO THE W. AFTERNOON ASCAT PASSES SUGGEST THE AREA OF 
FRESH NELY TRADES CONTINUE TO ENVELOPE A SMALL AREA FROM ROUGHLY 
17N S TO THE ITCZ AND WERE W OF 132W. THIS AREA OF FRESH TRADES 
IS EXPECTED TO SHRINK THROUGH THE FORECAST PERIOD. MEANWHILE...A 
90-140 KT SOUTHWESTERLY UPPER LEVEL JET IS ON THE LEADING EDGE 
OF THE TROUGH...FROM NEAR 15N138W TO THE S HALF OF BAJA 
CALIFORNIA WHERE IT BECOMES MODESTLY DIFFLUENT AS IT VEERS ELY 
AND MOVES OVER THE TOP OF AN UPPER RIDGE AND ACROSS NRN MEXICO.  
THIS JET IS TRANSPORTING UPPER LEVEL MOISTURE MANIFESTED AS 
CIRRUS NORTHEASTWARD FROM THE ITCZ W OF 115W. FINALLY...WITH THE 
COLD FRONT EXPECTED BY EARLY TUESDAY...THE PRIMARY IMPACT WILL 
BE A SURGE IN NW SWELL WITH SIGNIFICANT WAVE HEIGHTS RISING TO 9 
FT W OF THE FRONT TUESDAY AFTERNOON.

ALOFT...THE REMAINDER OF THE DISCUSSION AREA IS UNDER THE 
INFLUENCE OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED 
NEAR 14N104W THAT IS EXPECTED TO SLOWLY SLIDE EASTWARD AS THE 
AFOREMENTIONED UPPER LEVEL TROUGH TO THE NW MOVES THROUGH THE 
NORTHERN WATERS. 

E OF THE SURFACE RIDGE NUDGED SE INTO THE AREA...A BROAD LOW 
LEVEL CYCLONIC GYRE PERSISTS BETWEEN 120W AND THE COAST OF 
COLOMBIA S OF 14N. ABUNDANT TROPICAL MOISTURE CONTINUES TO DRIFT 
SLOWLY W OFF OF S AMERICA AND CONVERGE ACROSS THIS 
AREA...LEADING TO SCATTERED TO NUMEROUS MODERATE TO STRONG 
CONVECTION. GLOBAL MODELS ARE BEGINNING TO KEY ON ANOTHER AREA 
OF MIDDLE TO LOW LEVEL CYCLONIC FLOW CURRENTLY LOCATED OVER THE 
SW CARIBBEAN MOVING WESTWARD. THE ENERGY ASSOCIATED WITH THESE 
GYRES ARE FORECAST TO MERGE OVER THE SE WATERS AND BRING 
POTENTIALLY HEAVY RAINFALL ACROSS PORTIONS OF SOUTHERN CENTRAL 
AMERICA THE NEXT SEVERAL DAYS. TOTAL PRECIPITABLE WATER IMAGERY 
AND GFS MODEL FORECAST SOUNDINGS INDICATE VALUES OF PRECIPITABLE 
WATER AT OR ABOVE 2.4 INCHES OVER MUCH OF THE AREA E OF 
95W...WHICH WILL ALLOW FOR PLENTY OF LOW LEVEL MOISTURE TO 
CONVERGE ALONG AND NORTH OF THE ITCZ. STRONG CONVECTION WILL 
LIKELY BE ENHANCED E OF 90W AS CONDITIONS ALOFT ARE FORECAST TO 
REMAIN WITHIN A FAIRLY DIFFLUENT PATTERN. A PORTION OF THE UPPER 
LEVEL ANTICYCLONE CENTERED NEAR 13N105W WILL DRIFT EASTWARD 
ACROSS SOUTHERN MEXICO AND LOCATE ITSELF OVER THE WESTERN 
CARIBBEAN AND CENTRAL AMERICA BY EARLY TUESDAY.

FINALLY...LARGE LONG PERIOD NW SWELLS WILL CONTINUE TO PROPAGATE 
THROUGH THE BASIN AND MERGE WITH CROSS-EQUATORIAL SW SWELL 
ACROSS THE TROPICS THROUGH WEDNESDAY.

$$
STRIPLING