000
AXPZ20 KNHC 220923
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT MAY 22 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 
0700 UTC.

..TROPICAL WAVES...
TROPICAL WAVE FROM 03N81W TO 08N80W THROUGH CENTRAL PANAMA INTO 
SW CARIBBEAN MOVING W-NW AT 5-10 KT. THIS WAVE LIES UNDER 20 TO 
25 KT OF E-NE SHEAR OVER FORECAST WATERS S OF 06N AND THERE IS 
NO SIGNIFICANT CONVECTION ASSOCIATED WITH IT AT THIS TIME.  

TROPICAL WAVE FROM 04N91W TO 13N87W INTO FAR SW HONDURAS MOVING 
NW AT 10 KT. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION 
LIES WITHIN 300 NM E AND 90 NM W OF THE WAVE N OF 
06N...INCLUDING ALONG THE COAST FROM NORTHERN COSTA RICA TO 
EASTERN EL SALVADOR.

TROPICAL WAVE FROM 05N116W TO 11N110W MOVING W-NW 10 KT. 
SCATTERED MODERATE CONVECTION LIES WITHIN 330 NM E AND 60 NM W 
OF THE WAVE FROM 08N TO 10N.   

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 08N78W TO 
11N92W TO 09N110W TO 07N120W TO 07N140W. SCATTERED MODERATE 
CONVECTION LIES WITHIN 120 NM S OF THE ITCZ AXIS BETWEEN 101W 
AND 105W AS WELL AS WITHIN 90 NM S OF THE ITCZ AXIS BETWEEN 119W 
AND 122W.

...DISCUSSION...
THE RIDGE EXTENDING FROM A 1033 MB HIGH PRES CENTER NEAR 35N146W 
TO 15N110W DOMINATES THE SURFACE PATTERN OVER THE FORECAST AREA 
W OF 110W. THERE IS A TIGHT PRES GRADIENT IN PLACE BETWEEN THIS 
RIDGE AND TROUGHING IN THE U.S. GREAT BASIN. NW TO N WINDS ALONG 
THE W COAST OF BAJA CALIFORNIA ARE IN THE 20-25 KT RANGE 
ACCORDING TO THE 0412 UTC ASCAT PASS AND EXTEND W TO 127W 
ACCORDING TO THE 0554 UTC PASS WITH DRIFTING BUOY 46589 NEAR 
26N114W REPORTING 15 FT SEAS AT 0600 UTC. THE STRONG PRES 
GRADIENT OVER NE WATERS WILL BE MAINTAINED THE NEXT FEW DAYS 
WITH THE MAIN PATTERN CHANGE BEING A SHIFT SE IN THE PRES 
GRADIENT...ALLOWING THE 20-25 KT WINDS TO CONTRACT E AND PUSH S 
ALONG THE BAJA CALIFORNIA COAST BEGINNING SUN. THE EASTWARD 
SHIFTING GRADIENT SHOULD ALSO INCREASE THE NW TO N WINDS IN THE 
GULF OF CALIFORNIA TO 20 KT MON. LOOK FOR NE TRADE WINDS BETWEEN 
THE RIDGE AND THE ITCZ...CURRENTLY IN THE 20-25 KT RANGE 
ACCORDING TO THE 0552 UTC ASCAT PASS...TO REMAIN IN PLACE 
GENERALLY W OF 127W THROUGH MON MORNING.

AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE GULF OF 
TEHUANTEPEC WITH A RIDGE AXIS EXTENDING SE THROUGH NICARAGUA 
INTO EASTERN PANAMA. THE DIFFLUENT CONDITIONS INDUCED BY THE 
RIDGE ALOFT IS ENHANCING THE CONVECTION ASSOCIATED WITH THE 
TROPICAL WAVE CENTERED NEAR 90W. THE RIDGE ALSO EXTENDS W OF 
THE ANTICYCLONE CENTER TO 05N115W...OVER THE TROPICAL WAVE 
CENTERED NEAR 113W. MEANWHILE...A 40-60 KT W-SW UPPER JET 
PARALLELS THE RIDGE AXIS WITH ITS JET CORE APPROXIMATELY 710 NM 
N OF THIS RIDGE. SOME CONVECTIVE BLOW OFF FROM THE ITCZ IS BEING 
TRANSPORTED NE TOWARD SW MEXICO BY THIS JET. FARTHER W...A 1010 
MB LOW PRES CENTER IS EMBEDDED IN THE ITCZ NEAR 07N133W. 
SCATTERED MODERATE CONVECTION WAS WITHIN 45 NM N AND 120 NM S 
SEMICIRCLE OF THE LOW. THIS LOW LIES UNDER INCREASING SOUTHERLY 
SHEAR AND IS EXPECTED TO DIMINISH TO A TROUGH LATER TODAY.

LARGE CROSS-EQUATORIAL LONG PERIOD SW SWELL HAS REACHED MUCH OF  
THE PACIFIC COASTLINE WITHIN THE FORECAST AREA WITH WAVE HEIGHTS 
IN THE 8-10 FT RANGE WITH 18-20 SECOND PERIODS. THE EXCEPTION TO 
THIS BEING THE W COAST OF BAJA CALIFORNIA WHERE NW WIND WAVES 
HAVE DRIVEN SEAS UP TO 15 FT. THIS VERY LARGE AND POWERFUL SURF 
FOUND ALONG THE COASTLINES...REEFS...AND SHOALS FROM BAJA 
CALIFORNIA TO PERU IS EXTREMELY DANGEROUS. THESE SWELLS WILL 
BEGIN TO FADE BY SUNDAY NIGHT. 

$$
SCHAUER