000
AXPZ20 KNHC 182203
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI MAR 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2145 UTC.              
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE ITCZ AXIS EXTENDS FROM 07N96W TO 05N110W TO 05N125W TO
05N132W TO BEYOND 03N140W. SCATTERED MODERATE CONVECTION IS
WITHIN 60 NM OF AXIS BETWEEN 132W-139W...AND WITHIN 30 NM OF THE
AXIS BETWEEN 115W-119W.

...DISCUSSION...                                              
A BROAD AND NEARLY STATIONARY UPPER LEVEL TROUGH PREVAILS ACROSS
MOST OF THE WESTERN U.S. THIS AFTERNOON 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 46N154W...AND SUPPORTS A
WEAKENING COLD FRONT ACROSS THE NW PORTION OF THE DISCUSSION
AREA ALONG A POSITION FROM 32N130W TO 26N140W WHERE IT BECOMES
STATIONARY SW OF THE AREA TO NEAR 22N145W. AN ASCAT PASS FROM 
1812 UTC THIS 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. AS THE FRONT WEAKENS AND BECOMES STATIONARY DURING
THE NEXT 24 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. A PRE-FRONTAL TROUGH WILL MERGE WITH
THE WEAKENING STATIONARY FRONT SAT AFTERNOON AS 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 TROUGH ALONG A POSITION FROM 32N132W 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 LIKE THE AFOREMENTIONED
ONE AS IT REACHES FROM NEAR 32N129W TO 27N136W AND STATIONARY TO
24N140W BY SUN AFTERNOON...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 1021 MB HIGH IS CENTERED E OF THE
COLD 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 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. CURRENTLY...GALE CONDITIONS ARE
FORECAST TO BEGIN SUN AFTERNOON AND CONTINUE THROUGH TUE
MORNING...WITH PEAK SUSTAINED WINDS FORECAST TO REACH 40 KT WITH
POSSIBLE HIGHER GUSTS DURING THIS EVENT. LATEST WAVEWATCH
GUIDANCE INDICATES THAT WAVE HEIGHTS MAY REACH A RANGE OF ABOUT
14-19 FT SUN NIGHT INTO MON AFTERNOON IN THE GULF REGION WITH
SEAS OF 9-14 FT SPREADING DOWNWIND FROM THE GULF TO NEAR
10N100W.

IN ADDITION...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