000
AXPZ20 KNHC 222204
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE JAN 22 2013

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 
2145 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 02N78W TO 07N87W TO 07N95W THEN 
TRANSITIONS TO THE ITCZ AXIS TO 06N102W TO 08N113W. SCATTERED 
MODERATE CONVECTION EXISTS FROM 10N-12N BETWEEN 114W-116W.

...DISCUSSION...

A RATHER SHARP DEEP LAYER TROUGH EXTENDS FROM WELL NW OF THE 
AREA SEWD THROUGH 32N137W AND SE TO A NEARLY STATIONARY UPPER 
LEVEL LOW AT 27N133W. THE TROUGH CONTINUES SEWD TO 17N128W TO 
14N120W AND TO NEAR 08N111W. THE UPPER LEVEL LOW IS ALIGNED 
VERTICALLY WITH A SURFACE LOW THAT MARKS THE TRIPLE POINT 
OF AN UNUSUALLY SRN LATITUDE COMPLEX OCCLUDED/COLD FRONTAL
SYSTEM. THE SURFACE LOW PRES IS 1008 MB WITH THE SAME POSITION
AS THE UPPER LOW. THE MEAN SURFACE LOW ASSOCIATED WITH THIS 
COMPLEX FRONTAL SYSTEM HAS MOVED SE TO A POSITION AT 21N134W
WITH PRES 1006 MB. THE OCCLUDED FRONT EXTENDS FROM IT TO 
22N131.5W TO 15N135W TO JUST W OF THE AREA AT 20N141W...THEN 
WRAPS BACK INTO THE AREA THROUGH 26N140W AND INTO THE 1008 MB 
LOW AT 27N133W. A COLD FRONT EXTENDS FROM THE 1008 MB LOW SSE TO 
24N129W TO 16N128W...AND SW TO W OF THE AREA AT 07N140W. UPPER 
LEVEL DIVERGENCE ALOFT RESULTING FROM THE INTERACTION BETWEEN 
THE UPPER LEVEL LOW AND A HIGHLY AMPLIFIED DOWNSTREAM RIDGE THAT 
COVERS THE ERN PORTION OF THE AREA N OF 11N E OF ABOUT 127W 
SUPPORTS EXTENSIVE AREAS OF RAIN WITH EMBEDDED SCATTERED TO 
NUMEROUS SHOWERS WITHIN 480 NM E OF THE COLD FRONT N OF ABOUT 
20N. E TO SE WINDS ARE PRESENT WITHIN 240 NM E OF THE COLD FRONT 
FROM 20N TO 26N. SEAS THERE ARE IN THE 9-12 FT RANGE.

THE DEEP LAYER TROUGH WILL SHIFT EWD OVER THE NEXT 48 
HOURS...WHILE THE SURFACE LOW BEGINS TO TRACK MORE TO THE 
ENE WEAKENING. AREA OF RAIN WITH EMBEDDED SCATTERED TO NUMEROUS
SHOWERS WILL PERSIST E OF THE COLD FRONT AND LOW THROUGH THE
NEXT 48 HRS. A GALE WARNING REMAINS IN EFFECT IN THE HIGH SEAS 
FORECAST BEGINNING EARLY TONIGHT FOR N TO NE WINDS OF 30 TO 35 
KT TO BEGIN THIS EVENING FOR N WINDS OF 30-35 KT IN A TIGHTENING
PRES GRADIENT NW OF THE SURFACE LOW AND FRONTS TO THE NW OF A 
LINE FROM 30N134W TO 22N140W WITH SEAS THERE IN THE 10-15 FT. 
HOWEVER...THESE GALE CONDITIONS ARE EXPECTED TO DIMINISH WED 
AFTERNOON. HIGH SEA STATE IN THE RANGE OF 10-15 FT WILL BE 
EVIDENT IN THE FAR W AND IN THE NW PORTIONS OF THE AREA THROUGH 
THU 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 OVER MEXICO FROM
ITS ERN SECTIONS SSW TO THE GULF OF TEHUANTEPEC TO 10N98W TO 
AND SE TO NEAR 05N86W. SATELLITE WATER VAPOR IMAGERY SHOWS 
MODERATE SUBSIDENCE KEEPING A STABLE AIR MASS IN PLACE W OF 
THE TROUGH TO NEAR 105W.

W OF THE DEEP LAYER TROUGH DESCRIBED ABOVE...SATELLITE WATER 
VAPOR IMAGERY SHOWS MOSTLY MODERATE TO STRONG SUBSIDENCE IN 
CONFLUENT FLOW INTO THE LONGWAVE TROUGH. COLD AIR STRATOCUMULUS 
CLOUDS WITH POSSIBLE 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 W OF 113W IS NO LONGER 
IDENTIFIABLE AS IT HAS LIFTED N AND BECOME ABSORBED BY THE 
ABUNDANT DEEP ATMOSPHERIC MOISTURE AHEAD OF THE TROUGH AND 
SURFACE COLD FRONT. SCATTERED SHOWERS AND ISOLATED TSTMS ARE 
NOTED FROM 26N TO 30N BETWEEN 126W-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 THU...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. NLY WINDS WILL DIMINISH TO
20 KT OR LESS THROUGH THE GULF OF PANAMA AND DOWNSTREAM FROM THAT
GULF IN ABOUT 48 HRS WITH SEAS THERE LOWERING TO LESS THAN 8 FT. 
EXPECT SEAS TO LOWER ONLY SLIGHTLY IN AND DOWNSTREAM THE GULF OF 
PAPAGAYO THROUGH THU.

$$
AGUIRRE