000
AXPZ20 KNHC 042200
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN JAN 04 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 
2145 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...05N77W TO 
05N100W TO 10N124W TO 07N140W. SCATTERED MODERATE FROM 10N TO 
14N BETWEEN 121W AND 125W.   

...DISCUSSION...

AMPLIFYING DEEP LAYERED SHORTWAVE TROUGH EXTENDS FROM A CUT-OFF
LOW NEAR 30N117W SWWD TO A BASE NEAR 16N130W. THE TROUGH IS 
SWINGING EWD AT 15-20 KT AND IS FORECAST TO TO MOVE ACROSS NRN 
MEXICO THROUGH 48 HOURS. LARGE DEEP LAYERED ANTICYCLONE WELL NW 
OF THE AREA NEAR 33N143W DOMINATES THE REGION W OF THE TROUGH 
NOTED ABOVE WITH MODERATE TO STRONG UPPER LEVEL NLY FLOW 
SWEEPING INTO THE AREA ADVECTING HIGH LEVEL MOISTURE. 
AREA OF STRONG SUBSIDENCE/DRY AIR ALOFT WAS NOTED WITHIN 240 NM 
EITHER SIDE OF A LINE FROM 20N123W THROUGH 19N140W. 

AT THE SURFACE...A 1032 MB HIGH IS CENTERED JUST OUT OF THE AREA 
NEAR 32N144W. A RIDGE EXTENDS SE FROM THE HIGH TO 20N112W. FRESH 
TRADE WINDS WERE INDICATED S OF THE RIDGE TO 12N AND GENERALLY W 
OF 125W. QUIKSCAT DATA INDICATED STEADY 25 KT WINDS IN THE 
AREA.  

OVER THE TROPICS...WEAK UPPER LEVEL ANTICYCLONIC FLOW PREVAILED 
E OF 115W. SOME UPPER DIFFLUENCE IS OCCURRING N OF THE ITCZ TO 
25N AND E OF THE DIGGING TROUGH NOTED ABOVE. STRONG UPPER LEVEL 
SW WINDS WERE ADVECTING MULTI-LEVEL MOISTURE NORTHEASTWARD OVER 
SOUTHERN BAJA CALIFORNIA AND CENTRAL MEXICO. THE CLOUDS ARE 
DISSIPATING ON THE WINDWARD SLOPES OF THE SIERRA MADRE 
OCCIDENTAL.

LATEST QUIKSCAT PASS INDICATED GAP WINDS OF 20 TO 25 KT 
CONTINUING IN THE GULF OF PAPAGAYO REGION. THE WINDS ARE 
FORECAST TO BE INTERMITTENT WITH THE STRONGEST WINDS DURING THE 
NIGHTTIME HOURS. THE SEAS MAY REACH 8 FT DUE TO THE INTERMITTENT 
NATURE OF THE WINDS AND THE LIMITED FETCH.

NORTHERLY GAP WINDS ALSO CONTINUE IN THE GULF OF PANAMA REGION 
WITH WINDS APPROACHING 20 KT AND SEAS LESS THAN 8 FT. THESE 
WINDS ARE FORECAST TO DIMINISH TO LESS THAN 20 KT LATER TONIGHT.

LATEST QUIKSCAT PASS ALSO INDICATED WINDS OF 20 TO 25 KT OVER 
THE NORTHERN GULF OF CALIFORNIA N OF 29N. SEAS ARE EXPECTED TO 
BE LESS THAN 8 FT. THESE WINDS AND SEAS ARE FORECAST TO PERSIST 
FOR THE NEXT 48 HOURS.   

$$
FORMOSA