000
AXPZ20 KNHC 240931
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON DEC 24 2012

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH IS ALONG 07N78W TO 07N90W. THE INTERTROPICAL 
CONVERGENCE ZONE AXIS EXTENDS FROM 07N90W TO 05N97W TO 08N118W 
TO 08N140W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF 
03N82W...WITHIN 30 NM EITHER SIDE OF THE ITCZ BETWEEN 93W AND 
97W...WITHIN 60 NM N OF A LINE FROM 07N99W TO 06N106W...WITHIN 
60 NM N OF THE ITCZ BETWEEN 112W AND 116W...AND ALSO FROM 08N TO 
11N BETWEEN 117W AND 121W.

...DISCUSSION...

A LARGE MID TO UPPER LEVEL ANTICYCLONE CENTERED NEAR THE COAST 
OF MEXICO AT 15N100W DOMINATES THE FLOW OVER THE EAST PACIFIC E 
OF 125W. AN UPPER LEVEL TROUGH/SHEAR AXIS EXTENDS FROM THE 
NORTHERN PORTION OF THE BAJA CALIFORNIA PENINSULA W/SW THROUGH 
25N127W TO 16N138W TO 10N138W...THEN SE TO THE EQUATOR NEAR 
130W. STRONG W/SW FLOW BETWEEN THESE TWO FEATURES ALOFT WITHIN 
THE AXIS OF A VERY STRONG SUBTROPICAL JETSTREAM CONTINUES TO 
TRANSPORT COPIOUS AMOUNTS OF MID TO UPPER LEVEL MOISTURE NE 
ACROSS BAJA CALIFORNIA AND NORTHERN MEXICO INTO THE SOUTHERN 
GREAT PLAINS OF THE U.S. THE CORE OF THE JETSTREAM HAS WINDS IN 
EXCESS OF 150 KT AS INDICATED BY SATELLITE DERIVED WINDS. THESE 
WINDS EXTEND FROM THE BASE OF THE AFOREMENTIONED TROUGH NEAR 
16N135W NORTHEASTWARD TO ACROSS NORTH-CENTRAL TEXAS.  

AT THE SURFACE...1025 MB HIGH PRES IS POSITIONED NEAR 27N132W 
WITH A RIDGE AXIS EXTENDING WESTWARD ALONG 27N...AND TO THE SE 
WITH A TERMINUS NEAR 14N98W. A 0558 UTC ASCAT SCATTEROMETER PASS 
SHOWED A LARGE AREA OF 20-25 KT NE TRADE WINDS S OF THE RIDGE... 
WITH THE HIGHEST WINDS AND SEAS FROM 08N TO 19N W OF 117W. LARGE 
HIGH ENERGY LONG PERIOD NW SWELL OF UP TO 18-20 SECONDS 
CONTINUES TO SWEEP SOUTHWARD OVER THE DISCUSSION AREA WITH SEAS 
OF 8 FT OR GREATER NOW EXTENDING INTO THE SOUTHERN HEMISPHERE. 
COMBINED SEAS ARE UP TO 14 FT WITHIN THE AREA OF ENHANCED TRADES 
MENTIONED ABOVE. EAST OF 110W...MERGING NE SWELL GENERATED BY 
HIGH WINDS NEAR THE GULF OF PAPAGAYO AND PREVIOUS HIGH WINDS IN 
THE GULF OF TEHUANTEPEC ARE CREATING AN ADDITIONAL AREA OF 8-13 
FT SEAS S OF 14N E OF 110W.

THE RIDGE WILL REMAIN ANCHORED ALONG 27N THROUGH TUE NIGHT WHILE 
A WEAKENING COLD FRONT MOVES EASTWARD JUST N OF 30N. THE 
TRAILING EDGE OF THE FRONT WILL AFFECT THE FAR NE PORTION OF THE 
AREA WED INTO WED NIGHT. STRONGER WINDS N OF THE AREA WILL 
RESULT IN A NEW SET OF NW SWELL UP TO 10-11 FT WHICH WILL PUSH 
INTO THE NW CORNER OF THE AREA BEGINNING WED MORNING. STRONG 
HIGH PRES THAT DEVELOPS BEHIND THE FRONT NEAR 35N140W WED SHIFTS 
SLOWLY SE THROUGH FRI AS ANOTHER CENTRAL PACIFIC COLD FRONT 
PUSHES EASTWARD N OF 30N. THE ITCZ WILL REMAIN SITUATED ALONG 
08N/09N THROUGH FRI...SUPPORTING MODERATE TO FRESH NE TRADE 
WINDS S OF THE SUBTROPICAL RIDGE FROM 10N TO 20N W OF 125W EARLY 
WED...RETREATING FURTHER TO THE W WED NIGHT THROUGH FRI AS THE 
RIDGE WEAKENS.

MEANWHILE...A TIGHTENING PRES GRADIENT EXISTS OVER FAR NW MEXICO 
BETWEEN THE RIDGING AND WEAK TROUGHING ALONG THE WESTERN COAST 
OF MEXICO. A 0420 UTC ASCAT PASS INDICATED FRESH TO STRONG NW-N 
WINDS N OF 24N W OF THE BAJA CALIFORNIA PENINSULA ALONG WITH 
FRESH WINDS IN THE GULF OF CALIFORNIA. THESE WINDS WILL DIMINISH 
TO 20 KT OR LESS BY 48 HOURS AS THE AFOREMENTIONED RIDGING 
WEAKENS.

GAP WINDS...
A 0416 UTC ASCAT PASS CLIPPED THE WESTERN EDGE OF THE GULF OF 
TEHUANTEPEC AREA CAPTURING ONLY LIGHT TO MODERATE WINDS NEAR AND 
SW OF THE GULF. A SHIP DID REPORT LINGERING SEAS TO 9 FT NEAR 
13N95W GENERATED BY THE RATHER IMPRESSIVE STORM/GALE FORCE WIND 
EVENT THAT ENDED IN THE GULF ON SUN. EXPECT THE REMNANT SEAS TO 
SUBSIDE TO LESS THAN 8 FT LATER THIS MORNING. LOOKING AHEAD...A 
WEAKER COLD FRONT IS FORECAST TO MOVE THROUGH THE SW GULF OF 
MEXICO WED WITH NORTHERLY WINDS SURGING THROUGH THE CHIVELA PASS 
BEHIND IT. MODEL GUIDANCE CONTINUES TO INDICATE THE POTENTIAL 
FOR A MINIMAL GALE FORCE WIND EVENT OF 6-12 HOURS COMMENCING 
AROUND 00 UTC THU.

TO THE SE...A 0546 UTC OCEANSAT SCATTEROMETER PASS SHOWED NE 
15-20 KT WINDS IN THE GULF OF PAPAGAYO. WINDS ARE STILL FORECAST 
TO INCREASE THERE TO 20-25 KT WITH ENHANCED DRAINAGE FLOW DURING 
THESE LATE NIGHT/EARLY MORNING HOURS. SUBSEQUENT OVERNIGHT 
DRAINAGE FLOW EVENTS SHOULD REMAIN WEAKER...20 KT OR LESS... 
DURING THE NEXT FEW DAYS.

$$
LEWITSKY