000
AXPZ20 KNHC 062303 CCA
TWDEP 

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE DEC 06 2011

CORRECTED SUFACE ANALYSIS TIME

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... 

MONSOON TROUGH FROM LOW PRES NEAR 05N78W 1008 MB TO 08N86W TO 
05N98W TO 06N104W WHERE LOW LEVEL WINDS SUGGEST THAT THE ITCZ
THEN EXTENDS TO LOW PRES NEAR 08N117W 1011 MB TO 07N130W TO
07N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION EXISTS
WITHIN 60 NM S OF THE ITCZ BETWEEN 135W-139W.

...DISCUSSION...

A COUPLE OF UPPER LEVEL LOWS N OF THE AREA CAUGHT BLOCKED BETWEEN
LARGE HIGH PRES OVER THE NW U.S. AND HIGHLY AMPLIFIED HIGH PRES
RIDGING ALONG THE FAR WESTERN BOUNDARY OF THE REGION ARE SWINGING
A COUPLE OF SHORTWAVE TROUGHS THROUGH THE CENTRAL AND NW PORTIONS
OF THE AREA. A RATHER PRONOUNCED JET STREAM BRANCH ENTERS THE 
AREA THROUGH 14N140W...AND ROUNDS THE SOUTHERN PERIPHERIES OF 
THE TROUGHS AS IT STRETCHES NE TO 15N120W TO 19N110W AND TO 
ACROSS NRN MEXICO AND THE SE U.S. THE JET IS TAPPING ABUNDANT 
DEEP TROPICAL CENTRAL PACIFIC MOISTURE IN THE FORM OF BROKEN TO 
SCATTERED HIGH CLOUDS OBSERVED STREAMING NORTHEASTWARD TO ACROSS
BAJA CALIFORNIA...AND NORTHERN/CENTRAL MEXICO. 

A LARGE UPPER ANTICYCLONE IS ANCHORED JUST TO THE SW OF GUATEMALA
WITH A RIDGE W TO 14N105W. STABLE ATMOSPHERIC CONDITIONS PREVAIL
OVER THE REMAINDER OF THE AREA TO THE S AND SE OF THE JET RELATED
UPPER LEVEL MOISTURE WITH THE EXCEPTION OF THE FAR SE PORTION 
WHERE LOW LEVEL CONVERGENCE TO THE S OF THE MONSOON TROUGH IS 
NOTED AS ENHANCED TROPICAL MOISTURE PRODUCING SCATTERED SHOWERS 
AND ISOLATED TSTMS FROM 4N-6N E OF 89W. IN ADDITION A 1009 MB 
LOW IS ALONG THE MONSOON TROUGH NEAR 07N78W...JUST TO THE S OF 
THE TAIL END OF AN UPPER LEVEL TROUGH THAT EXTENDS INTO THE AREA 
FROM THE CARIBBEAN SEA. 

THE OVERALL BROAD SCALE PATTERN WILL CHANGE LITTLE OVER THE AREA
THROUGH THE NEXT 24-48 HRS AS A REX-TYPE OF PATTERN SETS UP N OF 
THE REGION TO THE W OF THE PACIFIC NW U.S. ALLOWING FOR BROAD 
RIDGING TO PREVAIL...FOR THE MOST PART...OVER THE DISCUSSION
AREA WITH NO FRONTS EXPECTED TO CROSS S OF 32N.

GULF OF TEHUANTEPEC...HIGH PRES BUILDING OVER THE CENTRAL PLAINS 
OF THE UNITED STATES HAS INCREASED THE PRES GRADIENT BETWEEN THE 
NORTHERN COAST OF THE ISTHMUS OF TEHUANTEPEC AND ITS SOUTHERN 
TERMINUS. SEA LEVEL PRES AT MINATITLAN ON THE NORTHERN COAST HAS 
RISEN TO 1023 MB COMPARED WITH 1012 MB AT IXTEPEC ON THE 
SOUTHERN END. MEANWHILE A STALLED COLD FRONT OVER THE SW GULF OF 
MEXICO WILL RECEIVE A REINFORCING SHOT OF COLD AIR TONIGHT INTO
WED MORNING...AND FUNNEL INTO THE GULF. THIS WILL ALLOW A SHARP 
INCREASE IN GAP FLOW THROUGH THIS EVENING...WITH WINDS LIKELY 
REACH STRONG GALE FORCE. LATEST MODEL WIND GUIDANCE HINTS AT 
WINDS PEAKING TO JUST BELOW STORM STRENGTH WED EVENING BEFORE 
GOING ON THE DECREASING TREND. GLOBAL MODELS SHOW A LARGE SWATH 
OF NE-E 20-30 KT REACHING AS FAR W AS 105W BY THU. SEAS ARE 
EXPECTED TO REACH A MAXIMUM OF 18 FT BY WED EVENING BEFORE 
SLOWLY SUBSIDING TO 15 FT THU AFTERNOON.

GULF OF CALIFORNIA...HIGH RESOLUTION ASCAT DATA FROM EARLY THIS
AFTERNOON REVEALED NW-N WINDS OF 20-30 KT SWEEPING THROUGH THE
GULF TO AS FAR S AS 22N E OF 110W WHERE THEY TURN MORE TO THE
N AND NE.  A ZONE OF NE-E WINDS IS ALREADY BEING FORCED ACROSS 
AND THROUGH PASSES IN THE BAJA CALIFORNIA PENINSULA AND INTO THE 
OPEN PACIFIC WATERS TO THE W OF THE PENINSULA WITH WINDS OF 
20-25 KT. AS THE GRADIENT SLACKENS OVER THE NEXT 24-48 
HRS...WINDS WILL RESPONSE BY DIMINISHING TO 20 KT AND LESS THAN 
20 KT AT 48 AROUND 48 HRS.

FURTHER SOUTH...A PERSISTENT 1010 MB LOW PRES SYSTEM CENTERED 
NEAR 09N117W IS MOVING WESTWARD AT 10 KT...WITHIN A TROUGH 
EXTENDING NE TO 13N113W. STRONG SW UPPER SHEAR HAS TOTALLY
DISSIPATED THE PREVIOUS LARGE CLUSTER OF STRONG CONVECTION 
NOTED TO THE E OF THE LOW. AS STATED IN PREVIOUS FORECASTS
...THE LOW WILL BE FORECAST TO CONTINUE ON A WESTWARD MOTION
TO NEAR 09N123W IN 24 HRS AND TO NEAR 09N128W BY 48 HRS. THE
PRES GRADIENT BETWEEN THE LOW AND HIGH PRES RIDGING TO ITS
N WILL ALLOW FOR WINDS 0F 20-25 KT IN THE 210 NM NE QUADRANT
...THEN 240 NM IN THE NW SEMICIRCLE IN 24 HRS AND 420 IN THE 
N AND NE QUADRANTS BY 48 HRS WITH SEAS OF 8-11 FT.

A MODERATE PRES GRADIENT IS OVER THE NW WATERS BETWEEN A STRONG 
1035 MB HIGH PRES WELL N OF THE AREA AT 45N178W AND LOWER PRES 
ASSOCIATED WITH THE ITCZ. NE TRADEWINDS ARE GENERALLY BELOW THE 
20 KT THRESHOLD...EXCEPT FOR SOME 20 KT WINDS BETWEEN 15N AND 
20N IN THE FAR WESTERN PORTION OF THE DISCUSSION AREA. SEAS 
THERE ARE RUNNING BETWEEN 8 AND 9 FT IN MIXED NE AND NW SWELL 
THAT COVERS MOST OF THE AREA W OF 110W.  THESE SWELL WILL 
GRADUALLY DIMINISH OVER TIME AND ARE RESTRICTED TO W OF 130W BY 
48 HOURS. THE NEXT LARGE SWELL EVENT SHOULD COMMENCE FRIDAY WITH 
LONG PERIOD NW SWELL REACHING THE NORTHWEST CORNER OF THE AREA.

GULF OF PAPAGAYO...WITH THE CURRENT TREND OF 20 KT WINDS 
CONTINUING TO PULSE UP AND DOWN IN AND DOWNWIND OF THE GULF OF 
PAPAGAYO THROUGH THE NEXT 48 HOURS...MAINLY DURING THE LATE 
NIGHT AND INTO THE EARLY MORNING HOURS DURING PEAK DRAINAGE FLOW 
OFF OF CENTRAL AMERICA THESE OCCURRENCES WILL NOT CONTINUE TO NOT
BE MENTIONED IN THE HIGH SEAS FORECAST.

$$
AGUIRRE