000
AXPZ20 KNHC 231549
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JAN 23 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 04N77W TO 06N85W TO 06N90W THE ITCZ 
AXIS CONTINUES FROM 06N90W TO 07N115W. NO SIGNIFICANT CONVECTION 
IS NOTED.

...DISCUSSION...
GAP WINDS CONTINUE TO BE THE MAIN ISSUE E OF 11OW. SCATTEROMETER 
DATA FROM AROUND 06 UTC LAST NIGHT INDICATED WINDS WERE REACHING 
MINIMAL GALE FORCE IN THE GULF OF TEHUANTEPEC...AND 20 TO 25 KT 
IN THE GULF OF PAPAGAYO. A SHIP REPORT INDICATED SIMILAR GAP 
FLOW THROUGH THE GULF OF PANAMA. THE IMPETUS FOR THE STRONG GAP 
WINDS IS HIGH PRES ANCHORED OVER THE GULF OF MEXICO. LITTLE 
CHANGE IS EXPECTED IN THE PATTERN THROUGH EARLY FRI. THE GAP 
WINDS MAINTAIN A DEFINITE DIURNAL TREND...WITH THE STRONGER 
WINDS OCCURRING IN THE EARLY MORNING HOURS. WINDS IN THE 
TEHUANTEPEC AREA WILL DIMINISH TO JUST BELOW GALE FORCE DURING 
THE DAY...THEN SURGE TO MINIMAL GALE FORCE LATE AT NIGHT INTO 
THE EARLY MORNING HOURS THU AND POSSIBLY FRI. WINDS WILL 
DIMINISH FRI INTO SAT AS THE HIGH PRES N OF THE AREA WEAKENS.

W OF 110W...A SHARP NEGATIVELY TILTED MID/UPPER LEVEL TROUGH 
EXTENDS FROM 48N135W TO A DEEP LAYER CYCLONE NEAR 26N130W. AT 
THE SURFACE...A PAIR OF LOW PRES SYSTEMS ARE NOTED NEAR 28N128W 
AND 24N128W. BOTH LOW PRES SYSTEMS HAVE AN ESTIMATED MSLP AROUND 
1008 MB. A WEAKENING COLD FRONT TRAILS FROM THE LOW NEAR 28N128W 
TO 15N125W THEN DISSIPATING TO 07N135W. SCATTEROMETER DATA FROM 
THE PAST 12 HOURS INDICATES GENERALLY 20 TO 25 KT N SURFACE FLOW 
WELL NW OF THE LOW COMPLEX...MAINLY N OF 22N W OF 130W...BETWEEN 
THE LOW PRES AND 1025 MB HIGH PRES AREA CENTERED NEAR 31N145W. 
OVERRUNNING OF SOMEWHAT MOIST SOUTHERLY FLOW ON THE EAST SIDE OF 
THE LOW PRES COMPLEX IS ALLOWING WHAT IS LIKELY AREAS OF LIGHT 
RAIN WITHIN 270 NM E OF THE FRONT N OF 23N. 

THROUGH THU...THE UPPER PORTION OF THE TROUGH SHIFT E INTO THE 
PACIFIC NW PORTION OF THE UNITED STATES...CUTTING OFF AND 
WEAKENING THE DEEP LAYER CYCLONE FARTHER SOUTH NEAR 28N128W. 
MODEL CONSENSUS SHOWS THE SURFACE LOW MERGING NEAR 27N128W AND 
FILLING BEFORE OPENING INTO A TROUGH ALONG 125W N OF 27N BY LATE 
THU. 

BY FRI...A SECOND MID/UPPER TROUGH DIGS ACROSS THE NE 
PACIFIC OCEAN N OF 35N...ALLOWING THE CYCLONE NEAR 28N128W TO 
OPEN AND SHIFT NE THROUGH NORTHERN BAJA AND SOUTHERN CALIFORNIA. 
MEANWHILE THE SURFACE HIGH PRES CENTERED NEAR 31N145W WILL DRIFT 
E...MAINTAINING THE FRESH TO STRONG N TO NE WINDS N OF 22N W OF 
127W THROUGH FRI EVEN AS THE LOW PRES WEAKENS. LOOKING AHEAD TO 
SAT...THE HIGH PRES BUILDS N OF THE AREA...BUT TRADE WINDS WILL 
DIMINISH TO 15 TO 20 KT W OF 130W AS THE TROUGH SHIFTS NE OF THE 
AREA.

$$
CHRISTENSEN