000
AXPZ20 KNHC 100921
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON JAN 10 2011

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 AXIS IS FROM A 1008 MB LOW 
NEAR 07N78W TO 05N95W TO A SECOND 1009 MB LOW NEAR 10N109W TO 
06N125W TO 07N140W. NO SIGNIFICANT CONVECTION IS NOTED.  

...DISCUSSION...

A SURFACE RIDGE DOMINATES THE REGION N OF 15N INCLUDING THE BAJA 
CALIFORNIA PENINSULA. PRES GRADIENT BETWEEN A GALE CENTER 
LOCATED WELL TO THE NW OF THE AREA AND THE RIDGE OVER FORECAST 
WATERS IS RESULTING IN SE TO S WINDS OF 20 TO 25 KT OVER THE 
AREA N OF 23N W OF 133W. THE 0532 ASCAT PASS VERIFIED THESE WIND 
SPEEDS. THESE WINDS ARE EXPECTED TO CONTINUE THROUGH THE NEXT 24 
HOURS...THEN DIMINISH TO ABOUT 20 KT BY 48 HOURS. SEAS OF 8 TO 
12 FT WILL PLAGUE THESE WATERS...THEN SUBSIDE TO 8 TO 11 FT IN 
24 HOURS AND TO 8 FT IN 48 HOURS. AN AREA OF FRESH TRADE WINDS 
CAN BE FOUND ON THE SOUTHERN PERIPHERY OF THE RIDGE FROM 07N TO 
18N BETWEEN 115W AND 137W. THE 0528 UTC ASCAT PASS CORROBORATED 
THE PRESENCE OF THESE WINDS. THIS WEATHER PATTERN WILL PERSIST 
OVER THE NEXT COUPLE OF DAYS AS THE RIDGE REMAINS IN PLACE.  

WINDS WILL INCREASE ALONG THE GULF OF CALIFORNIA IN ABOUT 24 TO 
30 HOURS AS PRES GRADIENT TIGHTENS OVER WESTERN MEXICO. 

A 1009 MB LOW PRES REMAINS EMBEDDED WITHIN THE ITCZ NEAR 10N109W.
THE ASCAT PASS MISSED THE SYSTEM TONIGHT. BASED ON THE COMPUTER 
MODELS...POSSIBLE 20 KT WINDS MAY EXIST WITHIN 150 NM SE 
QUADRANT AND 120 NM N SEMICIRCLE OF LOW CENTER. THE GLOBAL 
MODELS CONTINUE TO FORECAST THE LOW TO TRACK IN A GENERAL WNW 
DIRECTION OVER THE NEXT 48 HOURS WHILE REMAINING RATHER WEAK.  
HOWEVER...A TIGHT ENOUGH PRES GRADIENT N OF THE LOW WILL ALLOW 
FOR NE TO E WINDS OF 20 KT TO BLOW OVER THE AREA FROM 12N TO 16N 
BETWEEN 114W AND 120W BY 48 HOURS. SATELLITE DERIVED WINDS AND 
ANALYSIS FROM CIMSS ALONG WITH THE LATEST WATER VAPOR IMAGERY 
INDICATE THAT THE UPPER LEVEL ENVIRONMENT OVER THIS LOW HAS 
BECOME RATHER HOSTILE AS UPPER LEVEL SW-W WINDS CONTINUE TO 
INCREASE IN SPEEDS. SATELLITE IMAGERY SHOWS INTERMITTENT BURSTS 
OF MODERATE TO ISOLATED STRONG CONVECTION ASSOCIATED WITH THIS 
FEATURE. A SECOND 1008 MB LOW PRES IS ANALYZED NEAR 7N78W. THIS 
SYSTEM IS GENERATING SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION. 

LONG PERIOD NW SWELL CONTINUES TO PROPAGATE SE ACROSS THE 
REGIONAL WATERS COVERING MOST OF THE AREA W OF 100W. ANOTHER SET 
OF NW SWELL SHOULD REACH THE FAR NW PORTION TODAY. 

GAP WINDS...
A SURGE OF COLD DENSE AIR IS EXPECTED TO IMPACT THE WESTERN GULF 
OF MEXICO TUE THROUGH THU...AND COULD DELIVER A GALE FORCE WIND 
EVENT THROUGH THE GULF OF TEHUANTEPEC BY EARLY WED. BOTH...THE 
NAM AND THE GFS MODELS FORECAST NLY WINDS OF 30 TO 40 KT BY WED 
AT 0600 UTC WITH SEAS BUILDING QUICKLY UP TO 13 FT THERE. AS A 
RESULT...A GALE WARNING HAS BEEN ISSUED FOR THE GULF OF 
TEHUANTEPEC IN 48 HOURS. WINDS ARE ALSO EXPECTED TO INCREASE 
ACROSS THE GULF OF PAPAGAYO IN ABOUT 24 HOURS AS EASTERLY SURGES 
IN THE SW CARIBBEAN BLOWING THROUGH THE PASSES.

$$
GR