000
AXPZ20 KNHC 142157
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT NOV 14 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...
AXIS ALONG 09N84W TO 07N100W TO 11N113W TO 07N126W TO 09N135W.  
ISOLATED MODERATE CONVECTION WITHIN 90 NM OF AXIS E OF 94W.  
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM OF 
AXIS FROM 112W-116W.  SCATTERED MODERATE CONVECTION WITHIN 150 
NM OF AXIS W OF 130W. 

...DISCUSSION...
SHARPENING MID TO UPPER LEVEL TROUGH FROM 32N115W FORCED NE BY 
STRONG UPSTREAM RIDGE.  AIR MASS CONFLUENCE CAUSING MODERATE TO 
STRONG SUBSIDENCE/DRY AIR ALOFT WITHIN 240 NM W OF TROUGH AXIS. 
SUBTROPICAL JET TOPPING 145 KT EXTEND FROM BASE OF TROUGH NE 
THROUGH NRN BAJA CALIFORNIA TO SRN GREAT PLAINS ADVECTING 
ABUNDANT TROPICAL MOISTURE INTO DEVELOPING STORM SYSTEM OVER SRN 
GREAT PLAINS. 

AT THE SURFACE...TROUGH EMBEDDED WITHIN ITCZ EXTEND FROM 11N137W 
TO 09N140W.  BROAD AREA OF FRESH TO STRONG BREEZE FROM 10N TO 
25N W OF 125W ASSOCIATED WITH TIGHT PRES GRADIENT BETWEEN 1030 
MB SURFACE HIGH PRES CENTERED NEAR 35N142W AND TROUGH.  TRADES 
PRODUCING ADDING WIND WAVES TO PERSISTENT NW SWELL RESULTING IN 
COMBINED SEAS TO 12 FT RANGE.  PRES GRADIENT REMAIN TIGHT AS 
HIGH PRES SYSTEM MOVES E ALONG CALIFORNIA COAST FORCED BY STRONG 
COLD FRONT APPROACHING FAR NW CORNER OF BASIN.

WEAK LOW PRES CENTER 1010 MB AT 08N90W MOVE W CONTRIBUTE TO 
FRESH S CROSS EQUATORIAL BREEZE WITH ASSOCIATED S-SW SWELLS S OF 
10N E OF 115W. 

BUILDING HIGH PRES OVER ROCKIES EXPECTED TO FORCE NW NEAR GALE 
WINDS INTO NRN HALF OF GULF OF CALIFORNIA WITHIN NEXT 18 HRS.  
MODEL GUIDANCE APPEARS TO FALL SHORT IN WIND SPEEDS ALTHOUGH 
TIMING APPEARS TO BE REASONABLE.  NW WINDS EXPECTED TO BECOME 
LOCALLY GUSTY AS LOCAL TOPOGRAPHIC EFFECTS BECOME PREDOMINANT TO 
SYNOPTIC FEATURES.  EVENT EXPECTED TO BE SHORT-LIVED AS HIGH 
PRES MOVES RATHER QUICKLY E RELAXING PRES GRADIENT BY LATE MON. 

$$
WALLY BARNES