000
AXPZ20 KNHC 031709
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI DEC 03 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...

INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 07N78W TO LOW PRES 
NEAR 08N94W TO LOW PRES NEAR 09N108W TO 11N118W TO 08N140W. 
SCATTERED MODERATE CONVECTION IS FROM 09N TO 12N BETWEEN 115W 
AND 121W.

...DISCUSSION...

AN UPPER LEVEL SHORTWAVE TROUGH DIPS SOUTHWARD TO 15N WITH AXIS 
ALONG 135W AND SUPPORTS A 1011 MB LOW CENTERED NEAR 32N130W WITH 
ASSOCIATED COLD FRONT EXTENDING FROM THE LOW SW TO 20N140W. 
EARLIER MORNING ASCAT PASSES BETWEEN 03/0500-0700 UTC INDICATED 
WINDS OF 20 TO 25 KT WEST OF THE FRONT WITH SEAS RANGING FROM 9 
TO 14 FT. SOUTHERLY WINDS OF 20 KT WERE ARE ALSO NOTED WITHIN 
120 NM E OF THE FRONT N OF 27N. UPPER LEVEL SUPPORT FOR THIS 
FRONT IS EXPECTED TO REMAIN NEARLY STATIONARY OVER THE NEXT 24 
HOURS AND BECOME ABSORBED BY ANOTHER SHORTWAVE TROUGH DIVING 
INTO THE DISCUSSION AREA FROM THE NW. AS A RESULT...A 
REINFORCING COLD FRONT IS FORECAST TO IMPACT THE NW CORNER OF 
THE REGION MID-DAY SATURDAY AND INCREASE W TO NW WINDS TO 30 KT 
BY EARLY SUNDAY...WITH SEAS BUILDING TO A RANGE OF 9 TO 17 FT.  
EAST OF THE COLD FRONT...A PRE-FRONTAL TROUGH IS ANALYZED FROM 
25N130W TO 19N137W WITH SCATTERED SHOWERS AND ISOLATED TSTMS 
OCCURRING WITHIN 60 NM EITHER SIDE OF A LINE FROM 29N126W TO 
21N133W. ELSEWHERE...A 1021 MB HIGH IS CENTERED NEAR 23N118W AND 
IS EXPECTED TO WEAKEN OVER THE FORECAST PERIOD AS THE COLD FRONT 
MOVES EASTWARD AND GRADUALLY DISSIPATES.  

FURTHER SOUTH...A 1011 MB LOW PRES IS CENTERED NEAR 08N94W AND 
DRIFTING WESTWARD. A SMALL AREA OF 20 KT NE TO E WINDS AND SEAS 
TO 8 FT CAN BE FOUND WITHIN 90 NM OF THE LOW CENTER WITHIN THE N 
QUADRANT. A SURFACE TROUGH REMAINS EMBEDDED WITHIN THE ITCZ 
ANALYZED FROM 17N116W TO 09N118W 116W. GLOBAL MODELS SHOW THIS 
FEATURE PERSISTING WITHIN THE ITCZ THROUGH THE WEEKEND WHILE 
DRIFTING WESTWARD. 

GAP WINDS...
NORTHERLY WINDS ARE FORECAST TO DROP BELOW GALE FORCE LATER 
TODAY IN THE GULF OF TEHUANTEPEC. HOWEVER...WITH A HIGH PRESSURE 
RIDGE REMAINING OVER THE SW GULF OF MEXICO AND PORTIONS OF 
INTERIOR SOUTHERN MEXICO...RESIDUAL DRAINAGE FLOW WILL RESULT IN 
N TO NE WINDS IN THE RANGE OF 20 TO 30 KT THROUGH EARLY SUNDAY. 
LOOKING AHEAD...A STRONG ARCTIC HIGH PRES ACROSS THE CENTRAL 
U.S. PLAINS IS FORECAST INVADE THE WESTERN GULF OF MEXICO BY 
MONDAY AND POSSIBLY DELIVER ANOTHER ROUND OF GALE FORCE WINDS TO 
THE TEHUANTEPEC REGION LATE MONDAY.

GAP WIND THROUGH THE GULF OF PAPAGAYO IS EXPECTED TO CONTINUE 
OVER THE NEXT 48 HOURS WITH NE WINDS PULSING TO 20 KT AS HIGH 
PRES BUILDS OVER THE WESTERN CARIBBEAN. WINDS ARE NORMALLY 
GREATEST DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH THE 
ASSISTANCE OF THE NOCTURNAL DRAINAGE FLOW.

$$
HUFFMAN