000
AXPZ20 KNHC 031527
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN JAN 03 2016

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1500 UTC.   

...SPECIAL FEATURES...

THE PRESSURE GRADIENT BETWEEN STRONG HIGH PRESSURE BEHIND A
STATIONARY FRONT OVER THE GULF OF MEXICO AND LOWER PRESSURE IN
THE VICINITY OF THE EASTERN NORTH PACIFIC ITCZ IS HELPING TO
FUNNEL GALE FORCE WINDS OVER THE GULF OF TEHUANTEPEC. WINDS ARE
FORECAST TO PULSE TO MINIMAL GALE FORCE INTO EARLY TUE MORNING.
AS A RESULT SEAS ARE FORECAST TO REMAIN IN THE 9 TO 12 FT RANGE.
SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS
MIAHSFEP2/FZPN03 KNHC FOR MORE DETAILS ON THE GALE AREA.

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

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N90W TO
04N105W TO 06N120W TO 05N130W TO 03N140W. SCATTERED MODERATE
CONVECTION IS FROM 06N TO 08N BETWEEN 110W AND 113W...FROM 03N
TO 08N BETWEEN 115W AND 133W...AND ALSO FROM 04N TO 07N W OF
135W.

A TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 06N75W TO 03N82W.
SCATTERED MODERATE CONVECTION IS WITHIN 90 NM N OF THE TROUGH.

...DISCUSSION...

N OF 15N E OF 120W...1018 MB HIGH PRES CENTERED NEAR 25N117W IS
SHIFTING S AND WEAKENING AHEAD OF A COLD FRONT APPROACHING FROM
THE W. THE NEGATIVELY TILTED UPPER TROUGH SUPPORTING THE FRONT
WILL LIFT TO THE NE THROUGH TONIGHT. THE COLD FRONT WILL LOSE
DEFINITION AS IT MOVES INTO BAJA CALIFORNIA NORTE BY TONIGHT...
WITH SW TO W WINDS OF 15 TO 20 KT PENETRATING GAPS INTO THE
NORTHERN GULF OF CALIFORNIA. THE MAIN IMPACT WILL BE THE
ACCOMPANYING SWELL...WITH SEAS 8 FT OR GREATER DUE TO NW SWELL
REACHING THE COAST OF BAJA CALIFORNIA NORTE BY LATE MON...BAJA
CALIFORNIA SUR AND THE REVILLAGIGEDO ISLANDS TUE...AND NEAR CABO
CORRIENTES AND THE ENTRANCE TO THE GULF OF CALIFORNIA THROUGH
MID WEEK. A SECOND COLD FRONT WILL REACH BAJA CALIFORNIA NORTE
TUE NIGHT...WITH A REINFORCING SHOT OF NW SWELL WITH SEAS TO 12
FT FOLLOWING THROUGH MID WEEK. 

S OF 15N E OF 110W...FRESH TO STRONG TRADE WINDS OVER THE
CARIBBEAN ARE FUNNELING THROUGH THE SAN JUAN RIVER VALLEY
BETWEEN COSTA RICA AND NICARAGUA AND EXITING AS GAP WINDS IN THE
GULF OF PAPAGAYO AND NEAR PUERTO SANDINO ON THE PACIFIC COAST OF
NICARAGUA. ENHANCED BY OVERNIGHT DRAINAGE EFFECTS...THE STRONG
GAP WIND PLUMES ARE REACHING 240 NM DOWNSTREAM WITH SEAS TO 8
FT. THE STRONG WINDS IN THE CARIBBEAN WILL ALSO INDUCE PULSES OF
MODERATE TO FRESH NORTHERLY GAP WINDS ACROSS THE ISTHMUS OF
PANAMA INTO THE GULF OF PANAMA THROUGH THE REMAINDER OF THIS
MORNING. THESE PLUMES WILL DIMINISH ALTOGETHER LATER TODAY...BUT
A WEAKER PULSE IS EXPECTED TONIGHT. WEAKENING HIGH PRES N OF THE
AREA WILL ALLOW FOR ONLY MARGINAL PULSES THEREAFTER THROUGH MID
WEEK. NE SWELL GENERATED FROM THE GAP WINDS WILL PROPAGATE
WESTWARD AND MERGE WITH NE SWELL GENERATED BY THE GULF OF
TEHUANTEPEC. 
 
ELSEWHERE...A COLD FRONT IS SWEEPING ACROSS THE NORTHERN
PORTIONS OF THE DISCUSSION AREA WHICH CURRENTLY EXTENDS FROM
30N125W TO 24N130W TO 20N136W. THE FRONT WILL MOVE E OF THE AREA
AND DISSIPATE BY LATE MON. DEEPENING LOW PRESSURE NORTH OF THE
AREA IS TIGHTENING THE PRESSURE GRADIENT ESPECIALLY N OF 24N W
OF THE FRONT. EARLIER SCATTEROMETER PASSES SHOWED NEAR GALE
FORCE WINDS THERE. THESE WINDS WILL GRADUALLY DIMINISH THROUGH
THIS EVENING AS THE FRONT CONTINUES E WHILE WEAKENING. THIS
SYSTEM IS ALSO USHERING IN A NEW SET OF NW SWELLS WITH COMBINED
SEAS REACHING CLOSE TO 20 FT OVER THE FAR NW PORTION. SEAS OF 12
TO 18 FT WILL SPREAD EASTWARD OVER THE WATERS N OF 20N THROUGH
LATE SUN.

THE PASSAGE OF SUCH SUCCESSIVE COLD FRONTS HAS WEAKENED THE
GRADIENT ENOUGH TO MAINTAIN GENERALLY MODERATE TRADE WIND FLOW
ACROSS THE DEEP TROPICS S OF 20N W OF 120W. A WEAK UPPER TROUGH
BETWEEN 118W AND 124W IS SUPPORTING MODEST CONVECTION ALONG THE
ITCZ. NW SWELL WITH COMBINED SEA HEIGHTS 8 TO 11 FT WILL BUILD
ACROSS THE WATERS S OF 20N W OF 115W THROUGH TUE. LOOKING
AHEAD...THE HIGH PRES WILL BUILD NORTH OF THE AREA STARTING MID
WEEK... ALLOWING A GRADUAL INCREASE IN TRADE WIND FLOW. SEAS
WILL BUILD TO 12 FT IN MIXED NW SWELL AND NE WIND WAVES.

$$
LEWITSKY