000
AXPZ20 KNHC 091003
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI MAR 09 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 0945 UTC.

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

THE ITCZ IS JUST S OF THE EQUATOR BETWEEN 95W-107W AND S OF THE
EQUATOR ELSEWHERE. A SMALL MONSOON TROUGH SEGMENT IS JUST S OF 
THE EQUATOR E OF 89W TO EQUATOR AT 80W. NO SIGNIFICANT
CONVECTION IS NOTED. 

...DISCUSSION...

MID/UPPER LEVEL RIDGING COVERS JUST ABOUT THE ENTIRE AREA EXCEPT
FOR THE NE PORTION WHERE THE TAIL END OF AN UPPER TROUGH OVER 
THE SW U.S. STRETCHES SW TO 29N121W AND TO 24N126W. SATELLITE 
WATER VAPOR IMAGERY SHOWS MOSTLY MODERATE SUBSIDENCE MAINTAINING
RATHER DRY AND STABLE ATMOSPHERIC CONDITIONS THROUGHOUT N OF 
ABOUT 20N. HOWEVER...OVER THE FAR WRN PORTION DEEP LAYER MOISTURE
IS NOTED STREAMING NEWD IN ADVANCE OF A NARROW UPPER TROUGH THAT 
EXTENDS SW TO A CUT-OFF UPPER LEVEL LOW LOCATED TO THE NW OF THE 
HAWAIIAN ISLANDS. A JET STREAM BRANCH S OF THE UPPER LOW EXTENDS 
EWD TO ACROSS THE DISCUSSION AREA AT 15N140W...THEN TURNS NE TO 
16N130W TO 20N120W AND TO ACROSS N CENTRAL MEXICO. TO THE SE OF 
THE JET STREAM...BROAD MID/UPPER LEVEL RIDGING IS IN PLACE WITH
A CREST TILTING NEWD TO THE FAR NW GULF OF MEXICO. AT THE 
SURFACE...A 1028 MB HIGH CENTER JUST N OF THE AREA AT 34N127W 
EXTENDS A RIDGE SE TO 25N118W TO 16N109W. A COLD FRONT 
ASSOCIATED WITH THE UPPER TROUGH IS JUST CROSSING INTO THE FAR 
NW CORNER OF THE AREA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE
WITHIN 60 NM SE OF THE FRONT. 

THE NARROW UPPER TROUGH WILL BROADEN OUT AS IT MOVES ACROSS THE 
FAR NRN PORTION DURING THE NEXT 48 HRS AND WILL FOLLOW IN BEHIND 
THE TROUGH CURRENTLY OVER THE NE PORTION AS THAT ONE PULLS OFF
TO THE E AS WELL. THIS WILL MEAN THAT THE UPPER FLOW BECOMES MORE
ZONAL INTO THE NEXT 48 HRS. THE COLD FRONT ENTERING THE FAR 
NW CORNER OF THE AREA LOSES ITS UPPER SUPPORT AND WEAKENS AS THE
UPPER TROUGH QUICKLY SLIDES EASTWARD LEAVING STRONGER SURFACE 
HIGH PRES TO BUILD EASTWARD ACROSS THE NRN AND CENTRAL PORTIONS 
OF THE AREA THROUGH SUN. LARGE NW SWELLS RESULTING IN POSSIBLE
SEAS OF 11 OR 12 FT WILL SPREAD ACROSS THE NW WATERS SAT AND 
SUN.

GAP WINDS... 
THE GULF OF CALIFORNIA...A TIGHT SURFACE PRESSURE BETWEEN HIGH 
PRES OVER THE N CENTRAL WATERS AND LOWER PRES OVER NW MEXICO IS 
RESULTING IN TIGHT PRES GRADIENT OVER THE GULF OF CALIFORNIA. 
THIS GRADIENT IS BRINGING NW WINDS OF 20-30 KT NW OVER THE 
ENTIRE GULF. NW WINDS OF 20 KT ARE OCCURRING N OF 26N AND E OF 
116W TO THE COAST OF BAJA CALIFORNIA. AS THE PRES GRADIENT 
SLACKENS DURING THE NEXT 48 HRS WINDS WILL DIMINISH TO 20 KT 
FROM 23N-28N AT THAT TIME.

THE GULF OF TEHUANTEPEC...20 KT NE WINDS WILL BEGIN OVER THE 
GULF OF TEHUANTEPEC IN ABOUT 18 HRS FOLLOWED SHORTLY IN 24 
HOURS WITH N-NE GALE FORCE WINDS OF 35 KT. THESE GALE FORCE
WINDS SHOULD BE SHORT-LIVED LASTING TILL SAT EVENING BEFORE
DIMINISHING.

THE GULF OF PAPAGAYO...A 2342 UTC WINDSAT PASS FROM LAST NIGHT
SHOWED 20 KT GAP WIND FLOW IN NORTHWESTERN COSTA RICA AND THE 
COAST OF NICARAGUA...REACHING AS FAR WEST INTO THE PACIFIC AS 
92W. A LARGE AREA OF NORTHEASTERLY SWELL HAS BEEN ESTABLISHED IN 
THE TROPICAL NORTH PACIFIC OCEAN TO THE EAST OF 110W DUE TO THE 
COMBINED INFLUENCE OF THE EARLIER TEHUANTEPEC AND PAPAGAYO GAP 
WINDS EVENTS. HIGH PRESSURE THAT IS BUILDING TO THE N OF THE 
CARIBBEAN SEA WILL MAINTAIN STRONG TRADE WINDS THAT WILL
WILL FUNNEL ACROSS AND THROUGH THE GULF AS NE-E 20-25 KT
DURING THE NEXT 48 HRS. IT WILL ALSO MAINTAIN THE NE-E SWELL IN 
THE DOWNSTREAM PLUME.

THE GULF OF PANAMA...STRONG TRADE WINDS IN THE SOUTHWESTERN 
CARIBBEAN SEA WILL MAINTAIN SPURTS OF FRESH NORTHERLY FLOW 
ACROSS THE PANAMA ISTHMUS AND INTO THE BAY OF PANAMA THROUGH THE 
NEXT 48 HRS.

$$
AGUIRRE