000
AXPZ20 KNHC 061002
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE OCT 06 2009

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 
0845 UTC.

...ITCZ...

THE ITCZ AXIS WAS ALONG 10N85W TO 07N95W TO 12N110W TO 07N123W 
TO 13N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS 
FROM 05N NORTHWARD TO THE COASTLINES BETWEEN 85W AND 100W. 
ELSEWHERE ISOLATED MODERATE CONVECTION WAS WITHIN 210 NM MAINLY 
S OF THE AXIS. 

...DISCUSSION...

ALOFT...A BROAD ANTICYCLONIC CIRCULATION CENTERED OVER CENTRAL 
MEXICO DOMINATES MUCH OF THE FORECAST AREA...WITH THE RIDGE AXIS 
EXTENDING SW TO 14N130W...AND E ACROSS THE ENTIRE GULF OF 
MEXICO. THIS RIDGE HAS BEEN QUASISTATIONARY FOR DAYS NOW...BUT 
IS EXPECTED TO SHIFT EAST AND WEAKEN DURING THE NEXT FEW DAYS AS 
A MID TO UPPER LEVEL TROUGH CURRENTLY FROM CENTRAL CALIFORNIA TO 
25N130W TO 16N136W...DIGS SE THROUGH CALIFORNIA AND SWEEPS E 
ACROSS THE DESERT SW OF THE U.S. BY EARLY SATURDAY. A SWLY JET 
WAS READILY DETECTED IN WATER VAPOR IMAGERY BETWEEN THE RIDGE 
AND THE UPPER TROUGH...WITH CORE WINDS OF 80-110 KT MOVING INTO 
NRN BAJA CALIFORNIA AND SRN CALIFORNIA ACCELERATING TO 135 KT 
ACROSS ARIZONA AND INTO THE FOUR CORNERS REGION. 

SE OF THE RIDGE...A TUTT AXIS EXTENDED FROM THE CENTRAL ATLANTIC 
THROUGH THE WINDWARD PASSAGE...ACROSS CENTRAL AMERICA ALONG THE 
HONDURAS-NICARAGUA BORDER AND INTO THE TROPICAL EPAC ALONG 94W. 
SPEED DIVERGENCE ALOFT ACROSS THE EPAC E OF 100W WAS COMBINING 
WITH A VERY MOIST AND UNSTABLE ENVIRONMENT TO MAINTAIN SCATTERED 
TO NUMEROUS CONVECTION ACROSS THE REGION. A TROPICAL WAVE ALONG 
86/87W WAS ALSO CONTRIBUTING TO MOISTURE AND INSTABILITY ACROSS 
THIS AREA. 

AT THE SURFACE...A 1033 MB HIGH IS OVER THE NE PACIFIC NEAR 
47N142W...WITH RIDGE AXIS EXTENDING SE TO NEAR 18N112W. THIS 
SYSTEM IS PRODUCING FRESH NW FLOW OFFSHORE OF CALIFORNIA 
EXTENDING S TO THE PACIFIC COASTAL WATERS ALONG THE BAJA 
PENINSULA. FRESH NELY TRADE WINDS WERE ALSO OCCURRING ON THE S 
SIDE OF THIS RIDGE BETWEEN 13N AND 20N AND W OF 135W PER AN 
EVENING QUIKSCAT PASS. OVERNIGHT SATELLITE PICTURES AND 
SCATTEROMETER PASSES REVEALED A COUPLE OF LOW PRES CENTERS 
EMBEDDED WITHIN THE ITCZ. THE EASTERN ONE IS NEAR 
10N111.5W...WITH 20-25 KT WINDS WITHIN 180 NM OF THE SE 
SEMICIRCLE. ALSO...A PAIR OF LOWS WITH SCATTERED MODERATE TO 
STRONG CONVECTION WERE NOTED EXITING THE AREA TO THE W...ALONG 
15N141W...AND ANOTHER WELL ORGANIZED LOW NEAR 14N148W. 

REGIONAL SEAS ARE IN THE 8 TO 10 FT RANGE W OF 115W IN MIXED 
MODERATE PERIOD N TO NE SWELL...AND LONGER PERIOD SW AND SE 
SWELL. S OF 10N AND BETWEEN 115W AND 100W SEAS WERE NEAR 8 FT IN 
MIXED SE AND SW SWELL. WAVEWATCH SHOWS THESE AREAS OF SWELL 
DECAYING...WITH COMBINED SEAS FALLING BELOW 8 FT OVER THE NEXT 
COUPLE OF DAYS BEFORE THE TRADES INCREASE AGAIN IN THE WAKE OF A 
TROUGH PASSAGE.

$$
STRIPLING