000
AXPZ20 KNHC 232227 RRA
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                          
2205 UTC THU JAN 23 2014

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 
2100 UTC.                              

...SPECIAL FEATURES...                                           

GULF OF TEHUANTEPEC GALE WARNING...A 1536 UTC ASCAT 
SCATTEROMETER PASS SHOWED ONLY 15-20 KT WINDS IN THE GULF OF 
TEHUANTEPEC. RESIDUAL NE SWELL CONTINUES TO MIX WITH LONGER 
PERIOD NW SWELL TO THE S AND SW OF THE IMMEDIATE GULF AREA... 
WITH COMBINED SEAS AT 8-11 FT FROM 03N TO 13N BETWEEN 90W AND 
100W. ANOTHER COLD FRONT WILL APPROACH THE AREA FROM THE NW-N 
MOVING THROUGH THE GULF OF MEXICO TONIGHT THROUGH FRI. STRONG 
1043 MB HIGH PRESSURE WILL BE POSITIONED OVER TEXAS WITH SHARP 
RIDGING EXTENDING WELL TO THE SE-S ALONG THE EASTERN SLOPES OF 
MEXICO TOWARD THE TEHUANTEPEC AREA EVEN JUST OUT AHEAD OF THE 
FRONT. THIS SET UP WILL RAPIDLY INDUCE ANOTHER ROUND OF GALE 
FORCE WINDS IN THE GULF OF TEHUANTEPEC WHERE A GALE WARNING 
COMMENCES AT 12 UTC FRI AND WILL PERSIST THROUGH AT LEAST 18 UTC 
SAT. WINDS WILL PEAK AT 40-45 KT OVERNIGHT FRI...ALTHOUGH 
MINIMAL STORM FORCE CANNOT BE ENTIRELY RULED OUT AND CONDITIONS 
WILL NEED TO BE MONITORED IN CASE THE WARNING NEEDS TO BE 
UPGRADED. IT SHOULD BE NOTED THAT PLENTIFUL UPWELLING OCCURRED 
WITH THE PREVIOUS GALE EVENT...AND ASSUMING THAT SSTS ARE NOT 
ABLE TO RECOVER ENOUGH IN TIME FOR THE NEXT ROUND WINDS WILL 
LIKELY NOT REACH STORM FORCE.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 01N82W. THE ITCZ 
AXIS EXTENDS FROM 06N88W TO 03N100W TO 05N11W...THEN RESUMES 
FROM 10N126W TO 06N140W. SCATTERED MODERATE CONVECTION IS WITHIN 
90 NM N OF THE ITCZ BETWEEN 91W AND 93W.

...DISCUSSION...

AN UPPER LEVEL TROUGH IS SEEN ON WATER VAPOR IMAGERY EXTENDING 
FROM AN ELONGATED UPPER LOW AT 31N127W SSE THROUGH 20N126W TO A 
SHARP BASE NEAR 10N121W. THE ASSOCIATED SURFACE TROUGH IS 
ANALYZED FROM 16N121W TO 08N125W. SCATTERED MODERATE CONVECTION 
IS OCCURRING WITHIN 120 NM N OF A LINE FROM 07N116W TO 09N121W 
...WITH SCATTERED MODERATE AND ISOLATED STRONG CONVECTION FROM 
12N TO 21N BETWEEN 116W AND 123W. MID/UPPER LEVEL RIDGING IS 
PRESENT E OF THE UPPER TROUGH...WHILE A SHARP RIDGE IS TO THE W 
OF THE UPPER TROUGH ROUGHLY ALONG 135W N OF 19N. THE UPPER 
TROUGH WILL LIFT NE AND DAMPEN OUT OVER THE NEXT 24 HOURS AS 
ANOTHER UPPER TROUGH CURRENTLY W OF 140W MOVES INTO THE FAR 
WESTERN PORTION OF THE DISCUSSION AREA. MEANWHILE THE SURFACE 
TROUGH WILL TRACK NW THROUGH EARLY FRI...THEN TO THE NNE INTO 
SAT AHEAD OF THE APPROACHING UPPER TROUGH AND AN ASSOCIATED 
SURFACE COLD FRONT THAT IS CURRENTLY JUST W OF THE AREA.

THAT SURFACE COLD FRONT IS FORECAST TO WEAKEN AS IT EXTENDS FROM 
A POSITION FROM 30N136W TO 21N140W BY EARLY FRI...THEN WILL 
FURTHER WEAKEN TO A REMNANT TROUGH AS IT EXTENDS FROM 30N134W TO 
23N134W TO 16N138W BY LATE SAT MORNING. PRECEDING FRESH TO 
STRONG SE-S WINDS IN THE NW CORNER WILL DIMINISH AS THE FRONT 
FINALLY ARRIVES WHILE WEAKENING. ASSOCIATED LARGE LONG-PERIOD NW 
SWELL WITH PERIODS OF GREATER THAN 20 SECONDS CONTINUE TO SPREAD 
TO THE SE OVER THE NW PORTION OF THE AREA WITH SIGNIFICANT WAVE 
HEIGHTS UP TO 20 FT NEAR 30N140W...AND THE SWELL OF 8 FT OR 
GREATER COVERING THE ENTIRE WATERS W OF 110W. PEAK WAVE HEIGHTS 
WILL SUBSIDE TO 18 FT BY EARLY FRI...THEN TO 16 FT BY LATE SAT 
MORNING WHILE SEAS OF 8 FT OR GREATER CONTINUE TO COVER THE 
WATERS W OF 110W.

GAP WINDS...                                                 
GULF OF PAPAGAYO...THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE 
RIDGING ALONG THE SPINE OF CENTRAL AMERICA AND LOWER PRESSURE 
ASSOCIATED WITH THE MONSOON TROUGH WILL CONTINUE TO PRODUCE 
DIURNAL PULSES OF 20-25 KT NE-E WINDS IN AND DOWNWIND FROM 
PAPAGAYO TO NEAR 90W DURING THE NEXT 48 HOURS. WIND-DRIVEN SEAS 
WILL BUILD TO UP TO 8-10 FT DURING THE PEAK WINDS...BRIEFLY 
SUBSIDING TO 6-7 FT IN THE IMMEDIATE GULF BETWEEN WIND SURGES.

GULF OF PANAMA...A TIMELY 1714 UTC OSCAT SCATTEROMETER PASS 
INDICATED FRESH TO STRONG N-NE WINDS IN THE GULF SPREADING 
DOWNWIND TO 05N AS THE SAME HIGH PRESSURE RIDGING SUPPORTING THE 
PAPAGAYO WIND EVENTS ALSO CONTINUES TO SUPPORT SIMILAR 
CONDITIONS IN THE GULF OF PANAMA. WINDS ARE FORECAST TO DIMINISH 
SLIGHTLY TO 20 KT OR LESS BY THIS TIME SAT.

$$
LEWITSKY