000
AXPZ20 KNHC 131001
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU MAR 12 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 
09300 UTC.

...ITCZ...
AXIS ALONG 08N83W TO 01N100W TO 05N127W TO 05N140W.  SCATTERED 
MODERATE CONVECTION WAS WITHIN 45 NM OF AXIS BETWEEN 83W AND 
94W. ISOLATED MODERATE WAS WITHIN 30 NM OF AXIS FROM W OF 125W.

...DISCUSSION...
A LARGE AND VIGOROUS DEEP LAYERED LOW WAS CENTERED ALONG 29-30N 
AND N OF THE HAWAIIAN ISLANDS...RETROGRADING SLOWLY SW. 
DOWNSTREAM OF THIS LOW WAS A S/W RIDGE N OF 28N AND BETWEEN 140W 
AND 130W...WITH L/W UPPER TROF FURTHER DOWNSTREAM...EXTENDING 
FROM CENTRAL CANADA...SW TO A VORTEX ACROSS THE S HALF OF AZ. A 
S/W HAS ROTATED AROUND THE BASE OF THIS UPPER TROF ACROSS CA AND 
THE 4 CORNERS REGION...AND WAS MOVING ACROSS EXTREME SW NEW 
MEXICO...INDUCING NEGATIVE TILT TO THE UPPER VORTEX...AND GOOD 
UPPER DIVERGENCE ACROSS EXTREME W TEXAS AND ADJACENT MEXICO. S 
OF THESE FEATURES...A 10 DEG WIDE MOIST PLUME OF UPPER MOISTURE 
SPREAD FROM THE EQUATORIAL CENTRAL PAC ENE TO 135W...WHERE THIS 
WSW UPPER FLOW THEN BECAME DIFFLUENT AND MILDLY ANTICYCLONIC... 
SPREADING INTO THE BAJA AND NORTHERN MEXICO. THIS WAS ACTING TO 
VENT SCATTERED MODERATE TO DEEP CONVECTION ACROSS THE 
SUBTROPICAL PAC BETWEEN 135W AND 125W ALONG A STRONG CONVERGENCE 
ZONE DISCUSSED BELOW. STLT DERIVED WINDS INDICATED AN UPPER JET 
OF 110-125 KT PASSING WITHIN 5 DEG OF THE BIG ISLAND OF HAWAII. 

A 1000 MB LOW WAS REFLECTED AT THE SURFACE...N OF THE HAWAIIAN 
ISLANDS...WITH A LARGE AND BROAD ZONE OF STORM FORCE WINDS IN 
THE WRN SEMICIRCLE OF THIS LOW. NE OF THIS LOW...HIGH PRES WAS 
CENTERED NEAR 40N 134W AND RIDGED SSE TO OFFSHORE OF BAJA 
CALIFORNIA. SW OF THE RIDGE AND TO THE SE OF THE DEEP LAYERED 
LOW LIES A NEARLY W TO E ALIGNED LLVL TROUGH WITH POSSIBLE WEAK 
LOW NEAR 18N 133W. S OF THE TROUGH IS WEAK ANTICYCLONIC 
FLOW...WHILE ALONG AND TO 30N ARE FRESH E TO NE WINDS OF 20 TO 
30 KT...YIELDING A BROAD CONVERGENCE ZONE AND THE SCATTERED 
MODERATE TO STRONG CONVECTION MENTIONED ABOVE. THIS ZONE OF 
FRESH WINDS...BROAD CONVERGENCE...AND ACTIVE CONVECTION IS 
EXPECTED TO CONTINUE FOR ANOTHER 24 HOURS. 

VERY ROUGH AND CONFUSED SEAS ARE OCCURRING INVOF THIS 
CONVERGENCE ZONE AS LONG PERIOD NWLY SWELLS GENERATED FROM THE 
HAWAIIAN LOW ARE MOVING INTO THE AREA...AND MERGING WITH LONG 
PERIOD SRN HEMI SWELL AFFECTING THE ENTIRE REGION...ALL MIXING 
WITH BUILDING E TO NE WIND WAVES ACROSS THE REGION. MAX SEAS IN 
THIS ZONE WERE INDICATED 12 TO 14 FT BY WWIII AND WILL GRADUALLY 
SUBSIDE DURING THE NEXT 48 HOURS. 

GAP WINDS ACROSS GULFS OF PAPAGAYO AND PANAMA CONTINUE TO 
DIMINISH AS LOW PRES 1008 MB OVER COLOMBIA WEAKENS WITHIN NEXT 
TWO DAYS.

$$
STRIPLING