000
AXPZ20 KNHC 190255
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT MAR 19 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0230 UTC.              
 
...SPECIAL FEATURE...

GALE WARNING FOR GULF OF TEHUANTEPEC...A GALE WARNING HAS BEEN
POSTED FOR THE GULF OF TEHUANTEPEC BEGINNING SUN AFTERNOON. A
RELATIVELY STRONG COLD FRONT IS FORECAST TO MOVE SE ACROSS THE
GULF OF MEXICO AND REACH THE CHIVELA PASS ON SUN. THE BUILDING
HIGH PRES BEHIND THE FRONT WILL INDUCE A GULF OF TEHUANTEPEC GAP
WIND EVENT. GFS MODEL GUIDANCE SUGGESTS THAT N WINDS OF 20-30 KT
WILL BEGIN EARLY ON SUN WITHIN 45 NM EITHER SIDE OF A LINE FROM
16N95W TO 15N95W...THEN INCREASE TO GALE FORCE RANGE OF 30-35 KT
WITH SEAS IN THE RANGE OF 8 TO 10 FT DURING SUN. THESE
CONDITIONS INCREASE SUN NIGHT WITH MAX WINDS REACHING 40 KT AND
SEAS BUILDING TO THE RANGE OF 9-13 FT EARLY SUN NIGHT...AND TO
14-18 FT LATE SUN NIGHT. ON MON...THE MAX WINDS MAY REACH 45 KT
WITH SEAS BUILDING FURTHER TO AROUND 19 FT. ALSO ON MON...NE
WINDS OF 25-30 KT ARE FORECAST ELSEWHERE WITHIN 90 NM OF A LINE
FROM 16N95W 12.5N96W TO 11N97W. SEAS OF 9-14 FT ARE FORECAST TO
SPREAD SW FROM THE GULF TO NEAR 10N100W BY LATE MON.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...         
THE ITCZ AXIS EXTENDS FROM 06N97W TO 06N108W TO 03N121W TO 04N130W
TO BEYOND 03N140W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM
OF AXIS BETWEEN 132W-136W...AND WITHIN 30 NM OF THE AXIS BETWEEN
95W-97W.

...DISCUSSION...                                              
A BROAD AND NEARLY STATIONARY UPPER LEVEL TROUGH PREVAILS ACROSS
MOST OF THE WESTERN U.S. THIS EVENING WITH A TROUGH AXIS
EXTENDING SW TO EXTREME NW MEXICO AND BAJA CALIFORNIA NORTE. A
PAIR OF MID TO UPPER LEVEL SHORTWAVE TROUGHS ARE SWINGING
EASTWARD THROUGH THE SW PORTION OF THE UPPER TROUGH...THE FIRST
EXITING BAJA CALIFORNIA SUR AND MOVING INTO WRN MEXICO...AND A
SECOND ACROSS BAJA CALIFORNIA NORTE. THIS IS SUPPORTING
ELONGATED TROUGHING AT THE SURFACE ALONG THE LENGTH OF THE BAJA
PENINSULA...WITH MODERATE NW WINDS ACROSS THE PACIFIC WATERS OUT
TO NEAR 125W...AND LIGHT SW TO S WINDS INSIDE THE GULF OF
CALIFORNIA. SEAS ACROSS THE PACIFIC WATERS OF BAJA ARE IN THE
RANGE OF 4-6 FT IN NW SWELL. 

FARTHER W...A DEEP LAYERED UPPER LEVEL CYCLONE IS CENTERED WELL
N OF THE HAWAIIAN ISLANDS NEAR 46N153W...AND SUPPORTS A
WEAKENING STATIONARY FRONT ACROSS THE NW PORTION OF THE
DISCUSSION AREA ALONG A POSITION FROM 32N131W TO 26N140W. AN
ASCAT PASS FROM 1812 UTC FRI AFTERNOON HIGHLIGHTED MAINLY GENTLE
TO MODERATE S-SW WINDS WITHIN ABOUT 90 NM E OF THE FRONT...AND
MODERATE NE WINDS BEHIND THE FRONT. SEAS W OF THE FRONT CONTINUE
TO RANGE FROM 8 FT ALONG THE FRONT TO 12-13 FT NW OF A LINE FROM
32N126W TO 27N140W. THE FRONT IS FORECAST TO DRIFT BACK TO THE
NW THROUGH THE NEXT 18 HOURS. THE NW SWELL WILL CONTINUE TO
PROPAGATE SE AND SPREAD ACROSS THE NWRN WATERS THROUGH SAT AND
EVENTUALLY IMPACT THE W-CENTRAL WATERS SAT NIGHT INTO SUN AS
SEAS OVERALL BEGIN TO GRADUALLY SUBSIDE. AFTER 18 HOURS...THE
FRONT WILL BEGIN TO MOVE BACK TO THE E AS A WEAK COLD FRONT...
AND WHILE A NEW COLD FRONT APPROACHES THE FAR NW CORNER OF THE
AREA. S-SW WINDS OF 20-25 KT ARE EXPECTED WITHIN 180 NM E OF THE
TROUGH N OF 29N WITH SEAS OF 10-11 FT. BY LATE SAT NIGHT...THE
NEW COLD FRONT WILL MERGE WITH THE WEAKENING COLD FRONT ALONG A
POSITION FROM 32N133W TO 26N138W...AND BECOME STATIONARY TO
24N140W. THE NW SWELL WILL PRODUCE SEAS OF 8-10 FT AT THAT TIME
NW OF A LINE FROM 32N118W TO 05N140W WITH HIGHER SEAS OF 10-12
FT IN THE FAR NW PART.

THE COLD FRONT WILL THEN BEGIN TO RAPIDLY LOSE ITS IDENTITY LIKE
THE AFOREMENTIONED ONE AS IT REACHES FROM NEAR 32N128W TO
27N135W AND STATIONARY TO 24N140W BY EARLY SUN EVENING 
...HOWEVER...YET ANOTHER SURGE OF LARGE LONG PERIOD NW
WILL BEGIN TO INVADE THE NW PORTION WITH HIGH SEAS IN THE 12-16
FT RANGE. SEAS OF 8-9 FT ARE FORECAST AT THAT TIME TO SPREAD
SEWD TO A LINE FROM 32N116W TO 15N124W TO 10N126W TO 04N140W
WITH SEAS OF 9-10 FT IN MIXED NW AND NE SWELL FROM 09N-15N W OF
136W.

ELSEWHERE AT THE SURFACE...A 1020 MB HIGH IS CENTERED E OF THE
STATIONARY FRONT NEAR 27N130W WITH A RIDGE AXIS EXTENDING SE TO
NEAR 18N119. THE OVERALL PRESSURE GRADIENT BETWEEN THE RIDGE AND
LOWER PRES TO THE S WITHIN THE ITCZ REGION IS SUPPORTING
MODERATE TO OCCASIONAL FRESH NE TRADES S OF 18N AND W OF
116W...WITH SEAS RANGING 5-8 FT.

BEYOND 48 HOURS...A GULF OF PAPAGAYO GAP WIND EVENT WITH 20-25
KT NE WINDS IS SUGGESTED BY MODEL GUIDANCE TO BRIEFLY TAKE PLACE
MON MORNING AND LIKELY PULSE EACH MORNING THROUGH WED.

$$
AGUIRRE