000
AXPZ20 KNHC 170250
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI SEP 17 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...ITCZ...

AXIS ALONG 16N97W 13N107W 14N115W 08N128W 11N140W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION WITHIN 60 NM N OF THE AXIS 
BETWEEN 102W AND 107W.

...DISCUSSION...
ALOFT...
AN ANTICYCLONE OVER CENTRAL MEXICO EXTENDS A RIDGE WNW TO ANOTHER
ANTICYCLONE CENTERED NEAR 23N115W. A RIDGE EXTENDS SW FROM THIS
ANTICYCLONE TO A COL REGION AT 19N128W. W TO SW FLOW ASSOCIATED 
WITH THE SOUTHERN EDGE OF THE SUBTROPICAL JET PREVAILS N OF 27N 
TO THE WEST COAST OF MEXICO. STRONG EASTERLY FLOW AND HIGH 
VERTICAL SHEARING EFFECTS ARE FOUND S OF 8N ACROSS THE ENTIRE 
BASIN. A BROAD AREA OF LIGHTER E WINDS IS LOCATED N OF 8N AND S 
OF THE RIDGE AXIS THAT APPEARS SOMEWHAT FAVORABLE FOR TROPICAL 
CYCLONE DEVELOPMENT FOR ANY CIRCULATIONS EMBEDDED IN THE ITCZ. 
CURRENTLY SEVERAL WEAK LOWS ARE EMBEDDED ALONG A MORE ACTIVE 
ITCZ AXIS IN ENHANCED SW MONSOON FLOW S OF 11N.

SURFACE...
1022 MB HIGH PRES AT 29N133W EXTENDS RIDGE E TO NEAR 21N115W.  
LAST VISIBLE SATELLITE IMAGERY SHOWED A DEVELOPING 1007 MB LOW 
CENTER WITH ASSOCIATED EXPOSED LOW CLOUD LINES E OF THE LOW 
CENTERED NEAR 14N113W. THE LOW IS FORECAST TO DRIFT NW OVER THE 
NEXT 24 HOURS...THEN BECOME NEARLY STATIONARY BEFORE TURNING ENE 
WITHIN THE NEXT 36-48 HOURS. RECENT RUNS OF THE GFS ARE HAVE 
TONED DOWN POSSIBLE DEVELOPMENT WITH THIS LOW OVER THE NEXT 48 
HOURS...SIMILAR TO THE OTHER GLOBAL MODELS WHERE THE LOW BECOMES 
ABSORBED INTO A BROAD AREA OF LOW PRES IN THE EASTERN PORTION OF 
THE AREA. WHETHER THE LOW INTENSIFIES OR NOT...INCREASING SW TO 
W WINDS OF 20-25 KT CAN BE EXPECTED MAINLY IN THE SOUTHERN 
SEMICIRCLE OF THE LOW WITH A POSSIBILITY OF WINDS INCREASING TO 
30 KT NEAR 48 HOURS. 

MARINE...
SEAS ASSOCIATED WITH THE LOW MENTIONED ABOVE ARE EXPECTED BY THE
NOAA WAVEWATCH MODEL TO BUILD TO AROUND 13-14 FT THROUGH THE 
NEXT 48 HOURS AS SW MONSOON WINDS INTENSIFY AND LONG PERIOD SW
SWELLS PROPAGATE NE THROUGH MUCH OF THE CENTRAL WATERS. LONG 
PERIOD NW SWELLS OF UP TO 8 FT ARE EXPECTED TO BEGIN FILTERING 
INTO THE NE PORTION ABOUT 36 HOURS...THEN EXIST WITHIN 120 NM OF 
THE BAJA CALIFORNIA COAST N OF 27N IN ABOUT 48 HOURS UNDER NW 
WINDS OF 20 KT AS A WEAK COLD FRONT NW OF AREA MOVES INTO THE 
FAR NORTHERN WATERS AND PRESSES THE ASSOCIATED RIDGE WITH THE 
1022 MB HIGH TOWARDS THE BAJA CALIFORNIA COAST. 

$$
AGUIRRE