000
AXPZ20 KNHC 290915
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE DEC 29 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 
0900 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...05N77W TO 
06N110W TO 07N140W. SCATTERED MODERATE WITH ISOLATED STRONG 
CONVECTION IS WITHIN THE AREA FROM 06N TO 08N WEST OF 133W.
 
...DISCUSSION...

MODERATE DEEP LAYER WESTERLIES ARE NORTH OF 15N. A STRONG 
SHORTWAVE IS WITHIN THESE WESTERLIES AND IS OVER BAJA CALIFORNIA 
AND NORTHWEST MEXICO. DEEP LAYER MOISTURE IS PRESENT EAST OF THE 
SHORTWAVE OVER MEXICO WEST OF 100W. BROKEN TO OVERCAST MIDDLE 
AND UPPER LEVELS CLOUDS ARE ASSOCIATED WITH THE MOISTURE AREA. 
THE SHORTWAVE IS FORECAST TO MOVE EAST ABOUT 30 KNOTS AND REACH 
TEXAS LATE TODAY. AREAS OF RAIN AND SOME EMBEDDED CONVECTION IS 
NOTED NEAR AND WITHIN ABOUT 300 NM EAST OF THE SHORTWAVE. THE 
OVERALL DEEP LAYER WESTERLIES ARE FORECAST TO WEAKEN THROUGH THE 
NEXT COUPLE OF DAYS WITH A TROUGH PERSISTING OVER THE PACIFIC 
OCEAN AREA TO THE WEST OF MEXICO.

DIFFLUENT UPPER FLOW OVER THE ITCZ WEST OF 125W IS SPREADING 
MOISTURE FROM ITCZ CONVECTION OVER THE AREA FROM ABOUT 04N TO 
14N. ITCZ CONVECTION IS SLIGHTLY ENHANCED BY THE DIFFLUENCE 
ALOFT.

EXCEPT FOR THE ABOVE TWO AREAS OF MOISTURE THE AREA WEST OF 90W 
IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS. DEEP LAYER 
MOISTURE IS PRESENT EAST OF 90W NORTH OF THE ITCZ.

HIGH PRESSURE IS CENTERED NEAR 29N134W WITH A CENTRAL PRESSURE 
OF 1023 MB. ASSOCIATED MODERATE SURFACE RIDGE IS NORTH OF 12N 
WEST OF 110W. WEST OF 120W THE ITCZ SURFACE PRESSURE IS LOWER 
DUE TO THE DIFFLUENCE ALOFT AND ASSOCIATED CONVECTIVE HEATING. 
THIS LOWER PRESSURE IS CAUSING THE TRADES NORTH OF THE ITCZ TO 
BE IN THE 20 TO 25 KT RANGE FROM NEAR THE ITCZ TO 20N WEST OF 
128W. ELSEWHERE A BROAD TROUGH CENTERED ON THE ITCZ IS ANALYZED 
AT THE SURFACE.

GAP WINDS...
GULF OF TEHUANTEPEC...N WINDS OF GALE FORCE ARE FORECAST TO 
DIMINISH TO 20 TO 25 KT DURING TODAY AND DIMINISH FURTHER TO  20 
KT WEDNESDAY.

GULF OF PAPAGAYO...E WINDS OF 20 TO 25 KT AND OCCASIONALLY TO 30 
KT ARE EXPECTED TO CONTINUE THROUGH WEDNESDAY NIGHT.

SEAS CONDITIONS ARE DOMINATED BY LONG PERIOD NW SWELL (WAVE 
PERIODS OF UP TO 16 SECONDS) WITH SIGNIFICANT WAVE HEIGHTS AS 
HIGH AS 12 FT. NOAA WAVE WATCH III GUIDANCE SUGGESTS THAT 
THIS SWELL EVENT WILL CONTINUE TO SPREAD SE REACHING NEAR 90W IN 
ABOUT 48 HOURS.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE
  
$$
LL