Tropical Weather Discussion
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000
AXPZ20 KNHC 202145
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT DEC 20 2014

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 MONSOON TROUGH EXTENDS W FROM THE PACIFIC COAST OF COLOMBIA
AT 07N78W TO 06N92W WHERE SCATTEROMETER WINDS INDICATE A
TRANSITION TO AN ITCZ WHICH CONTINUES WNW TO A 1011 MB EMBEDDED
LOW PRESSURE AT 08N101W TO 05N140W...THEN CONTINUES WSW TO
BEYOND 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION
OBSERVED ALONG THE MONSOON TROUGH WITHIN 90 NM OF 05N80W.
SCATTERED MODERATE ISOLATED STRONG OBSERVED NEAR THE EMBEDDED
LOW PRESSURE WITHIN 90 NM EITHER SIDE OF A LINE FROM 07N97W TO
09N101W TO 05N113W. SCATTERED MODERATE WITHIN 30 NM EITHER SIDE
OF A LINE OF LINE FROM 07N123W TO 07N130W.

...DISCUSSION...

AN UPPER LEVEL TROUGH EXTENDS FROM 32N106W TO 16N125W. DENSE
UPPER MOISTURE IS SPREADING SE ACROSS THE DISCUSSION AREA TO THE
N OF 27N BETWEEN 110-124W. A PLUME OF UPPER MOISTURE...
ORIGINATING FROM ITCZ CONVECTION BETWEEN 138-160W...CONTINUES TO
STREAM NE ACROSS THE DISCUSSION AREA WITHIN 300 NM EITHER SIDE
OF A LINE FROM 10N120W TO OVER THE PACIFIC COAST OF MEXICO AT
10N105W...THEN NARROWS AS IT CONTINUES NE ACROSS CENTRAL
MEXICO...TURNING ENE ACROSS THE GULF OF MEXICO AND ACROSS
CENTRAL FLORIDA.

AT THE LOW LEVELS...LONG PERIOD NW SWELL CONTINUES PROPAGATE E
ACROSS THE ENTIRE OPEN WATERS WATERS N OF THE ITCZ W OF ABOUT
115W...RESULTING IN COMBINED SEAS OF 8-16 FT...WITH THE HIGHEST
SEAS NEAR 30N125W. THIS LONG PERIOD NW SWELL WILL ARRIVE ALONG
THE PACIFIC COAST OF THE NORTHERN BAJA PENINSULA IN THE FORM OF
8-13 FT SEAS TONIGHT THEN DIMINISH SOME...WITH 7-10 FT SEAS
EXPECTED ALONG THE ENTIRE PACIFIC COAST OF THE BAJA PENINSULA ON
SUN. THE SWELLS WILL SUBSIDE WITH 6-8 FT CONDITIONS EXPECTED
ALONG THE ENTIRE PACIFIC COAST OF THE BAJA PENINSULA ON MON AND
MON NIGHT...THEN SUBSIDE TO 4-7 FT ON TUE ACROSS THE COASTAL
WATERS S OF 28N. GUIDANCE IS SUGGESTING THE NORTHERLY FLOW WILL
INCREASE TO 20-25 KT...SEAS 8-11 FT...ACROSS THE DISCUSSION
WATERS N OF 28N BETWEEN 120-128W ON MON NIGHT...THEN DIMINISH TO
15-20 KT ON TUE. GUIDANCE IS ALSO SUGGESTING NE WINDS WILL
INCREASE TO 20-25 KT ALONG THE PACIFIC COAST OF THE BAJA
PENINSULA AT 29N ON TUE...THEN SPREAD SW TO NE 27N117W ON TUE
NIGHT BEFORE DIMINISHING ON WED.

A SURFACE RIDGE EXTENDS FROM 31N136W TO 15N105W. NE 15-20 KT
TRADES ARE OBSERVED ACROSS THE TROPICS BETWEEN THE ITCZ AND THE
RIDGE WITH AN AREA OF EMBEDDED 20-25 KT NE WINDS ACROSS THE
WATERS FROM 07-22N W OF 120W. THE GRADIENT SHOULD BEGIN TO
WEAKEN ON MON WITH THE AREA OF 20-25 KT CONDITIONS SHRINKING
THROUGH MON...AND DIMINISHED BELOW 20 KT ACROSS THE DISCUSSION
WATERS ON TUE. THE COMBINED SEAS WILL CONTINUE TO SUBSIDE TO THE
7-9 FT RANGE ACROSS THE PACIFIC WATERS W OF 115W ON THU.

GULF OF TEHUANTEPEC...EXPECTING A MAX OF 15-20 KT NOCTURNAL
DRAINAGE FLOW ACROSS THE GULF OF TEHUANTEPEC TONIGHT AND 10-15
KT ON SUN NIGHT. MODEL GUIDANCE SUGGESTS THE DRAINAGE FLOW WILL
INCREASE TO 20-25 KT LATE TUE NIGHT...THEN RAPIDLY INCREASE TO
GALE FORCE WED AFTERNOON...AND FURTHER INCREASE TO NEAR STORM
STRENGTH LATE WED NIGHT. EXPECT THE GALE EVENT TO END ON THU
NIGHT.

GULF OF PAPAGAYO...NE 15-20 KT NOCTURNAL PULSES EXPECTED THROUGH
EARLY MON...THEN ONLY 10-15 KT DRAINAGE FLOW MON AND TUE NIGHTS.
GUIDANCE SUGGESTS 20-25 KT CONDITIONS WILL BEGIN LATE WED
NIGHT...WITH A SIGNIFICANT EVENT OF 20-30 KT WINDS LATE THU
NIGHT.

GULF OF CALIFORNIA...15-20 KT NW WINDS ARE EXPECTED THROUGH SUN
NIGHT THEN DIMINISH TO 10-15 KT ON MON AND MON NIGHT. THE
GRADIENT WILL TIGHTEN EARLY TUE WITH THE NW FLOW INCREASING TO
20-25 KT ACROSS THE NORTHERN GULF WATERS EARLY TUE...WITH THESE
CONDITIONS SPREADING S ACROSS THE ENTIRE GULF OF CALIFORNIA BY
TUE EVENING. THE GRADIENT SHOULD RELAX ON WED.

$$
NELSON


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