000
AXPZ20 KNHC 172205
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN JAN 17 2010

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 
2115 UTC.

...ITCZ...

AXIS WAS ANALYZED ALONG 4N77W TO 5N90W TO 6N100W 6N112W 6N123W
6N140W. SCATTERED MODERATE CONVECTION IS WITHIN 30 NM OF AXIS 
BETWEEN 81W-85W.

...DISCUSSION...

W OF 105W...

THE PREVAILING UPPER PATTERN IS OBSERVED TO CONSIST OF STRONG DEEP 
WESTERLY FLOW PRIMARILY TO THE N OF 25N OVER THE THE NORTHERN 
PERIPHERY OF LARGE SCALE RIDGING CENTERED WELL W OF THE AREA TO 
THE SW OF THE HAWAIIAN ISLANDS. A SERIES OF SHORTWAVE TROUGHS 
EMBEDDED WITHIN THE WESTERLY FLOW ARE QUICKLY MOVING EASTWARD
TOWARDS THE WESTERN U.S. AND NORTHERN BAJA CALIFORNIA REGIONS.
THE EASTERN MOST TROUGH EXTENDS FROM THE FOUR CORNERS AREA OF
THE U.S. SSW TO THE SOUTHERN GULF OF CALIFORNIA...THEN SW TO 
16N118W TO 13N124W TO 10N130W WHERE IT IS BEST DESCRIBED AS A
SHEAR AXIS SW TO W OF THE REGION AT 7N140W. THE BULK OF DEEP
LEVEL MOISTURE ASSOCIATED WITH THE TROUGHS IS NOTED N OF THE AREA
...BUT A BATCH HAS MADE IT INTO THEN PORTION OF THE AREA N OF 23N
AND IS SPREADING E TOWARDS SOUTHERN CALIFORNIA AND THE BAJA
PENINSULA. MID/UPPER LEVEL FORCING DUE TO THE TROUGHS WILL
RESULT IN ABUNDANT PRECIPITATION SKIRTING THE AREA OVER THE NE
PORTION AND AFFECT THE WESTERN U.S OVER THE NEXT 48 HRS. WATER
VAPOR IMAGERY SHOWED ABUNDANT MODERATE SUBSIDENCE WITH ASSOCIATED
STABLE ENVIRONMENT CONDITIONS COVERING THE JUST ABOUT THE ENTIRE
AREA SW OF A LINE FROM 32N140W TO 26N130W TO 23N119W. A SURFACE
COLD FRONT RELATED TO ONE OF THE TROUGHS PASSING NW OF THE AREA 
NEAR 141W EXTENDS FROM 32N138W SW TO 30N145W. SW TO W WINDS OF
20 TO 25 KT ARE OCCURRING AHEAD OF THE FRONT N OF 28N AND 130W.
ALTHOUGH UPPER LEVEL IMPULSES WILL MAINLY STAY TO THE N INTO
MON...ENOUGH OF THAT ENERGY WILL MAKE IT JUST S OF 32N TO 
PROVIDE ENOUGH IMPETUS TO W T NW FLOW BEHIND THE FRONT ON MON
SUPPORTING WINDS OF 25 TO 30 KT WITH POSSIBLE HIGHER GUSTS LATER 
INTO TUE AS A SECOND AND STRONGER COLD FRONT FOLLOWS IN BEHIND 
THIS INITIAL FRONT. HOWEVER...THE MAIN ISSUE WITH BE MARINE RELATED
WITH SURGES OF VERY LARGE LONG PERIOD NW SWELLS MIGRATING INTO MUCH
OF THE WESTERN AND CENTRAL PORTIONS OF THE AREA THROUGH TUE WITH
SEAS POSSIBLY BUILDING TO AS HIGH AS 25 FT OVER THE FAR NORTHERN 
WATERS W OF THE SECOND COLD FRONT.

THE PRES DIFFERENCE BETWEEN WEAK HIGH PRES AND LOWER PRES NEAR 
THE ITCZ SHOULD MAINTAIN AN AREA OF NE TO E 20 TO 25 KT TRADES
FROM 7N TO 16N W OF 120W THROUGH TUE WITH SEAS UP 11 FT IN NW
SWELL TO POSSIBLY 13 FT BY TUE AFTERNOON.

SOUTHWESTERLY WINDS ALOFT ARE LOCATED OVER THE TROPICS IN A 7 TO 
8 DEGREE WIDE BAND CENTERED FROM 15N105W TO 07N120W. A SURFACE 
TROUGH IS LOCATED FROM NEAR 15N105W TO 07N108W. ALSO AT THE 
SURFACE A WEAK STATIONARY FRONT IS LOCATED THROUGH 32N120W TO 
NEAR 25N124W. A STRONG COLD FRONT IS APPROACHING THE NW CORNER 
OF THE DISCUSSION AREA. IN THE AREA FROM N OF 28N W OF 130W 
WINDS ARE SW TO W 20 TO 25 KT WITH SEAS 8 TO 12 FT. ALSO FROM 
07N TO 16N W OF 125W WINDS ARE NE TO E 20 TO 25 KT WITH SEAS 9 
TO 12 FT IN PRIMARILY NW SWELL. ELSEWHERE IN THE AREA BOUNDED BY 
30N118W TO 20N110W TO 00N85W TO 00N140W TO 30N140W TO 30N118W 
WINDS ARE LESS THAN 20 KT WITH SEAS 8 TO 11 FT IN PRIMARILY NW 
SWELL. THE NW SWELLS ARE EXPECTED TO BUILD AS HIGH AS 24 FEET N 
OF 26N W OF 128W IN 48 HOURS.

E OF 105W...
STRONG SUBSIDENCE IS LOCATED OVER THE AREA E OF 105W AS 
INDICATED BY WATER VAPOR IMAGERY. WINDS ALOFT ARE GENERALLY 
LIGHT EXCEPT FOR MODERATE SW WINDS ALONG THE MEXICAN COAST. A 
MINIMAL GALE IS LOCATED OVER THE GULF OF TEHUANTEPEC. GULF OF 
PAPAGAYO AND GULF OF PANAMA WINDS ARE AS HIGH AS 25 KNOTS.

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

$$
CAB/AGUIRRE