000
AXPZ20 KNHC 092205
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN JAN 09 2011

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 
2130 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 6N77W
6N90W 8N96W TO A 1008 MB LOW NEAR 9N108W TO 5N123W TO 7N133W 
7N140W. NO SIGNIFICANT CONVECTION IS NOTED.

...DISCUSSION...

A SURFACE RIDGE EXTENDS SE INTO THE AREA THROUGH 32N129W TO
24N120W TO 20N110W. WELL TO THE NW OF THE AREA A 999 MB GALE 
CENTER IS NEAR 38N148W. ITS ASSOCIATED WEAKENING COLD FRONT
EXTENDS FROM THE LOW SE TO 29N141W...THEN BECOMES STATIONARY 
S TO NEAR 20N143W AND TO SW OF THE HAWAIIAN ISLANDS. THE PRES
PRES GRADIENT BETWEEN THIS SYSTEM AND THE RIDGE IS RESULTING IN
SE TO S WINDS OF 20 TO 30 KT OVER THE AREA N OF 23N W OF 133W.
THESE WINDS ARE EXPECTED TO CONTINUE THROUGH THE NEXT 24 HOURS
...THEN DIMINISH TO ABOUT 20 KT BY 48 HOURS. SEAS OF 9 TO 13 FT
WILL PLAGUE THESE WATERS...THEN SUBSIDE TO 9 FT IN NW IN 48 
HOURS.

ELSEWHERE WINDS ARE ON THE RATHER LIGHT SIDE...WITH THE EXCEPTION
OF THE SOUTHERN PERIPHERY OF THE RIDGE FROM 6N TO 18N BETWEEN 
115W AND 137W WHERE THE GRADIENT SUPPORTS NE TO E WINDS OF 20 KT 
WITH SEAS UP TO 9 FT. AN ASCAT PASS FROM 1822 UTC DEPICTED THESE
WIND SPEEDS. ELSEWHERE FROM 5N TO 20N W OF 110W AND S OF 5N W OF 
130W WINDS ARE LESS THAN 20 KT WITH SEAS TO 9 FT IN NW SWELLS.

SATELLITE WATER VAPOR IS SHOWING A HIGHLY AMPLIFIED MID/UPPER 
LEVEL RIDGE EXTENDING FROM 32N131W S TO 24N132W TO 17N132W. TO 
ITS W...A VERY PRONOUNCED LARGE DEEP LAYER TROUGH IS JUST W OF 
THE REGION WITH SEVERAL SHORTWAVES ROTATING THROUGH IT. THIS 
ENTIRE SYSTEM IS SUPPORTING THE ABOVE MENTIONED GALE CENTER AND 
FRONTAL SYSTEM. EXTENSIVE MOISTURE IS BEING CHANNELED FROM THE 
CENTRAL PACIFIC AHEAD OF THE TROUGH INTO THE FAR WESTERN SECTION 
OF THE AREA. SCATTERED SHOWERS AND TSTMS WITH POSSIBLE STRONG 
GUSTY WINDS ARE JUST CROSSING 140W FROM 19N TO 24N. THE UPPER 
LEVEL MOISTURE FIELD SPREADS EASTWARD UP AND OVER THE MID/UPPER 
LEVEL RIDGE WITH A TRAJECTORY EASTWARD TOWARDS W CENTRAL MEXICO.

A SHORTWAVE TROUGH HAS JUST MOVED INLAND THE SW U.S. AND NORTHERN
MEXICO. MODERATE SUBSIDENCE AND ASSOCIATED DRY AIR IN ITS WAKE
EXTENDS FROM 21N TO 30N E OF 130W.
 
SATELLITE IMAGERY IS ALSO SHOWING SCATTERED MODERATE/ISOLATED
STRONG CONVECTION E OF THE LOW FROM 10 TO 14N BETWEEN 105W AND 
108W. WINDS TO 20 KT ARE WITHIN 150 NM IN THE E SEMICIRCLE OF
THE LOW. THE GLOBAL MODELS CONTINUE TO FORECAST THE LOW TO TRACK 
IN A GENERAL WNW DIRECTION OVER THE NEXT 48 HOURS WHILE 
REMAINING RATHER. 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 WLY WINDS CONTINUE TO INCREASE IN SPEEDS. 
THESE WINDS WILL CONTINUE TO IMPINGE ON THE CURRENT CONVECTION 
BEING OBSERVED BY WEAKENING IT FURTHER. HOWEVER...A TIGHT ENOUGH
PRES GRADIENT N OF THE LOW WILL ALLOW FOR NE TO E 20 KT N OF THE
LOW OVER THE AREA FROM 11N TO 14N BETWEEN 111W AND 115W BY 48 
HOURS.

GAP WINDS...A SURGE OF COLD DENSE AIR IS EXPECTED TO MOVE INTO 
THE WESTERN GULF OF MEXICO TUESDAY THROUGH THURSDAY. IT IS 
POSSIBLE THAT THE SURGE OF COLD AIR MAY LEAD TO AN ONSET OF
GALE FORCE WINDS  THROUGH THE GULF OF TEHUANTEPEC BEGINNING 
LATE TUE NIGHT INTO WEDNESDAY. GULF OF PAPAGAYO NE TO E 20 KT
WINDS SHOULD BEGIN IN ABOUT 36 HOURS.

$$
AGUIRRE