000
AXPZ20 KNHC 212239 CCA
TWDEP 

TROPICAL WEATHER DISCUSSION...CORRECTED 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON JAN 21 2013

CORRECTED LOCATION OF SOME FEATURES

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2215 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 06N77W TO 07N88W TO 06N93W THEN 
TRANSITIONS TO ITCZ TO 07N106W TO 08N115W TO 10N126W. SCATTERED 
MODERATE CONVECTION EXISTS FROM 08N TO 11N BETWEEN 121W-125W.

...DISCUSSION...

A LONGWAVE TROUGH EXTENDS FROM WELL NW OF THE AREA SE THROUGH 
32N137W TO A RATHER VIGOROUS NEARLY STATIONARY VORTEX AT 26N136W
TO 18N133W TO NEAR 11N129W. AT THE SURFACE...A LOW PRES CENTER 
IS ANALYZED AT 27N137W 1006 MB WITH A COLD FRONT TO 28N135W TO 
24N134W TO 20N135W TO 16N140W. A STATIONARY FRONT IS AHEAD OF 
THE COLD FRONT ALONG 30N138W TO 27N131W TO 24N127W TO 15N133W. 
UPPER LEVEL DIVERGENCE E OF THE MID/UPPER TROUGH SUPPORTS 
EXTENSIVE AREAS OF RAIN WITH EMBEDDED SCATTERED MODERATE 
CONVECTION ALONG AND WITHIN 300 NM E OF THE STATIONARY FRONT N 
OF 15N. SE TO S WINDS OF 20 TO 25 KT ARE N OF 19N BETWEEN THE 
FRONT AND 128W AS WAS SUGGESTED BY AN ASCAT PASS FROM 1848 
UTC THIS AFTERNOON. HIGHER WINDS OF 25 TO 30 KT ARE POSSIBLE
N OF 27N BETWEEN THE FRONT AND 128W. SEAS ARE 10 TO 13 FT IN NW 
SWELLS AHEAD OF THE FRONT TO 128W...EXCEPT HIGHER SEAS OF 11 TO 
16 FT N OF 27N.

THE LONGWAVE TROUGH AND ATTENDANT SURFACE LOW WILL MOVE E THROUGH
THE NEXT 48 HOURS AND REMAIN NEGATIVELY TILTED WITH RAIN AND 
SCATTERED MODERATE CONVECTION WITHIN ABOUT 360 NM TO ITS E.
A GALE WARNING IN THE HIGH SEAS FORECAST HAS BEEN ISSUED FOR N 
TO NE WINDS OF 30 TO 40 KT TO BEGIN TUE EVENING BETWEEN 360 NM 
AND 480 NM IN THE NW QUADRANT OF THE LOW WITH SEAS OF 14 TO 18 
FT DUE TO THE FORECAST TIGHT PRES GRADIENT EXPECTED NW OF THE 
LOW AS HIGH PRES TO ITS N BUILDS EASTWARD. HIGH SEA STATE IN 
THE RANGE OF 12-18 FT WILL BE EVIDENT IN THE FAR W AND IN 
THE NW PORTIONS OF THE AREA THROUGH WED AS GENERATED BY THE 
AREA OF FORECAST GALE WINDS IN COMBINATION WITH LARGE NW 
SWELLS PROPAGATING INTO THE NW AND N SECTIONS.
 
A MID/UPPER LEVEL TROUGH IS JUST E OF THE AREA FROM NW MEXICO
TO 21N104W TO 15N107W TO 10N103W AND SE TO NEAR 05N96W. SATELLITE
WATER VAPOR IMAGERY SHOWS MODERATE SUBSIDENCE AND ASSOCIATED
DRY AIR BETWEEN THE TROUGH AND ABOUT 115W.

W OF THE TROUGH OVER THE WRN PORTION OF THE AREA...SATELLITE
WATER VAPOR IMAGERY SHOWS MOSTLY MODERATE TO STRONG SUBSIDENCE 
IN CONFLUENT FLOW INTO THE LONGWAVE TROUGH. COLD AIR 
STRATOCUMULUS CLOUDS WITH ISOLATED SHOWERS MOVING SE ARE NOTED 
TO THE NW OF THE AFOREMENTIONED COLD FRONT. WITH THE COLD FRONT 
HAVING PUSHED SO FAR TO THE SE...THE ITCZ SEGMENT BETWEEN 120W 
AND 126W HAS RESPONDED BY LIFTING NWD. SCATTERED SHOWERS AND 
ISOLATED TSTMS ARE NOTED FROM 15N TO 20N BETWEEN 123W-129W.

VERY LONG PERIOD NW SWELLS ARE CURRENTLY MOVING THROUGH WESTERN
AND CENTRAL SECTIONS OF THE DISCUSSION AREA. THESE SWELLS ARE
IMPACTING MOST OF THE NRN AND CENTRAL PORTIONS OF BAJA 
CALIFORNIA. BUOY DATA NETWORK N OF THE AREA ARE REPORTING LARGE 
NW SWELLS GREATER THAN 9 FT W OF 120W WITH PERIODS IN EXCESS OF 
18 SECONDS. EXPOSED COASTS WITH NW EXPOSURE ARE LIKELY TO BE
IMPACTED BY STRONG AND POWERFUL SURF...AND POSSIBLE COASTAL 
EROSION DURING HIGH TIDES OVER THE NEXT 48 HRS. THE SUBSIDING 
SWELL TRAIN...THAT CURRENTLY IS NEAR 9 FEET...CROSSES THE 
EQUATOR AFFECTING THE SOUTH PACIFIC OCEAN TO THE WEST OF 105W.

GAP WINDS...
N TO NE GALE FORCE WINDS OF 30 TO 35 KT THROUGH THE GULF OF 
TEHUANTEPEC ARE EXPECTED TO LINGER THROUGH WED...HOWEVER
THESE WINDS WILL DIMINISH AT TIMES TO JUST BELOW 35 KT THROUGH
THIS PERIOD.

N TO NE WINDS CONTINUE TO FUNNEL THROUGH THE GULFS OF PAPAGAYO 
AND PANAMA WITH SEAS OF 8 TO 10 FT DOWNSTREAM THE GULF OF 
PAPAGAYO...AND SEAS TO 8 FT N OF 05N BETWEEN 79W AND 
81W...INCLUDING THE GULF OF PANAMA. EXPECT SEAS TO LOWER SOME IN 
AND DOWNSTREAM THE GULF OF PAPAGAYO THROUGH WED...AND TO CHANGE 
LITTLE IN AND NEAR THE GULF OF PANAMA ALSO THROUGH WED.

$$
AGUIRRE