000
AXPZ20 KNHC 090348
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT JAN 09 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 3N78W TO 4N90W
5N100W 8N110W 8N120W 7N130W 6N140W. SCATTERED MODERATE CONVECTION IS 
WITHIN 120 NM N OF THE AXIS W OF 135W...AND WITHIN 30 NM N OF THE 
AXIS BETWEEN 125W-130W.

...DISCUSSION...

A RATHER AMPLIFIED UPPER TROUGH EXTENDS FROM NORTHERN MEXICO SW TO 
19N110W TO NEAR 9N114W. THE TROUGH WILL CONTINUE TO PROGRESS 
EASTWARD AS IT BECOMES ABSORBED IN THE LONGWAVE BROAD TROUGH 
CENTERED OVER THE CENTRAL U.S. AS THE TROUGH MOVES FURTHER
E OF THE AREA OVER THE NEXT TWO DAYS...A PLUME OF MID TO UPPER LEVEL 
TROPICAL MOISTURE ASSOCIATED WITH THE LEADING EDGE OF THE UPPER 
TROUGH SHOULD SHIFT FROM CENTRAL MEXICO TO SOUTHERN MEXICO.

UPPER LEVEL RIDGING IS NOTED OVER THE SOUTHERN PORTION OF THE AREA
SE OF THE TROUGH WITH AMPLE MODERATE SUBSIDENCE AND STABLE 
CONDITIONS. EXTENSIVE UPPER LEVEL MOISTURE PLUME BETWEEN THE TROUGH
AND RIDGE IS STREAMING NE TOWARDS MEXICO AND THE GULF OF MEXICO.

AT THE SURFACE...A 1020 MB HIGH IS CENTERED NEAR 30N126W WITH A 
RIDGE TO NEAR 23N137W. THE HIGH IS FORECAST TO REMAIN STATIONARY 
OVER THE NEXT 24-48 HOURS. THIS RIDGE WILL INHIBIT THE EASTWARD 
PROGRESS OF THE COLD FRONT CURRENTLY OVER THE NW PORTION FROM 
30N136W TO 26N140W. THE FRONT IS EXPECTED TO DISSIPATE WITHIN THE 
NEXT 24 HRS. HOWEVER...NW SWELL FROM THIS SYSTEM HAS ALREADY BROUGHT 
SIGNIFICANT WAVE HEIGHTS TO 18 FT IN FAR NW WATERS. THIS SWELL WILL 
CONTINUE TO PROPAGATE SE OVER THE NEXT TWO DAYS AND WILL REMAIN 
HIGHEST...IN THE 15 TO 20 FT RANGE...OVER NW WATERS THROUGH SAT. TO 
THE S OF THE RIDGE AXIS...SCATTEROMETER DATA FROM FRI AFTERNOON 
SHOWED NE TO E WINDS OF 20 TO 25 KT S OF THE RIDGE AXIS AND W OF A 
SURFACE TROUGH EMBEDDED IN THE ITCZ FROM NEAR 8N119W TO 15N116W. THE 
LARGEST AREA OF DEEP CONVECTION OVER FORECAST WATERS IS ASSOCIATED 
WITH THIS TROUGH. THIS SYSTEM CURRENTLY LIES UNDER AN UPPER RIDGE. 
THIS CONVECTIVE ACTIVITY IS EXPECTED TO WANE SAT WHEN THE FLOW ALOFT 
BECOMES MORE CONFLUENT AS THE NEXT UPPER TROUGH PUSHES INTO WESTERN 
WATERS...INCREASING THE SOUTHWESTERLY SHEAR OVER THE SYSTEM. THIS 
SHOULD WEAKEN THE SURFACE TROUGH AND BRING THE TRADE WINDS DOWN TO 
20 KT.

GAP WINDS...
GULF OF TEHUANTEPEC...ANOTHER STRONG COLD FRONT IS PUSHING THROUGH 
THE ISTHMUS OF TEHUANTEPEC FOLLOWED BY STRONG HIGH PRES AND 
ASSOCIATED TIGHT PRES GRADIENT DIGGING SOUTHWARD ACROSS EASTERN AND 
SOUTHERN MEXICO. AS A RESULT...GALE FORCE WINDS THROUGH THE 
GULF ARE JUST ABOUT TO INCREASE TO STORM CRITERIA. THESE WINDS ARE
EXPECTED TO REACH UP TO 55 KT SUN AFTERNOON OR EVENING PER LATEST
10M NAM AND 925 MB GFS MODEL GUIDANCE WITH SEAS BUILDING TO POSSIBLY 
UP TO 19 FT.

GULFS OF PAPAGAYO AND FONSECA...STRONG TRADE WINDS IN THE CARIBBEAN 
SHOULD CONTINUE TO BLEED THROUGH CENTRAL AMERICA AND BE SEEN AS NE 
TO E 20 TO 30 KT WINDS FUNNELING THROUGH THESE GULF. BY SUN...THE 
COLD FRONT GENERATING STORM FORCE WINDS IN THE GULF OF TEHUANTEPEC 
SHOULD MAKE ITS WAY SOUTH...INCREASING WINDS ABOVE 20 KT IN THE GULF 
OF FONSECA AS WELL. 

GULF OF PANAMA...N TO NE WINDS OF 20 KT ARE EXPECTED TO CONTINUE
THROUGH SAT NIGHT AS N TO NE TRADES IN THE FAR SW CARIBBEAN WEAKEN.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
AGUIRRE