Tropical Weather Discussion
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000
AXPZ20 KNHC 212141
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE OCT 21 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...

MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 09N81W TO LOW PRES
NEAR 08N87W 1008 MB TO LOW PRES NEAR 15N95W 1006 MB TO 16N100W
TO 11N110W TO 10N135W THEN TRANSITIONS TO ITCZ TO BEYOND
08N140W. SCATTERED MODERATE CONVECTION FROM 05N TO 08N BETWEEN
85W AND 95W. SCATTERED MODERATE CONVECTION WITHIN 240 NM N AND
120 NM S OF OF ITCZ AXIS W OF 130W.

...DISCUSSION...

A SMALL LOW PRES AREA IS EVIDENT JUST SOUTH OF THE GULF OF
TEHUANTEPEC...RELATED TO BETTER ORGANIZED LOW PRES TO THE NORTH
OVER THE SW GULF OF MEXICO. THE PACIFIC LOW PRES IS ALONG THE
MONSOON TROUGH...AND IS RESPONSIBLE FOR SCATTERED SHOWERS AND
THUNDERSTORMS ALONG THE COASTAL AREAS AND ADJACENT WATERS OF
GUATEMALA AND THE MEXICAN STATE OF CHIAPAS. WINDS REMAIN FAIRLY
LIGHT OUTSIDE OF ANY GUSTS RELATED TO THE SHOWERS AND
THUNDERSTORMS...DUE LARGE TO THE VERY WEAK PRES GRADIENT IN
PLACE BETWEEN THE TWO LOW PRES SYSTEMS ON EITHER SIDE OF THE
ISTHMUS OF TEHUANTEPEC. THIS WILL CHANGE BY LATE THU...AS THE
LOW IN THE GULF OF MEXICO DEEPENS AND SHIFTS EASTWARD AND HIGH
PRES BUILDS OVER THE FAR WESTERN GULF IN ITS WAKE. EXPECT STRONG
GAP WINDS INTO THE GULF OF TEHUANTEPEC THU INTO FRI MORNING AS A
RESULT.

CONVERGENCE OF 15 TO 20 KT SW FLOW INTO THE MONSOON TROUGH HAS
BEEN MAINTAINING AREAS OF SHOWERS AND THUNDERSTORMS IN AREA FROM
05N TO 08N BETWEEN 85W AND 95W...ALTHOUGH THIS APPEARS TO BE
WEAKENING. AN UPPER CYCLONE CENTERED NEAR 13N140W IS SUPPORTING
SCATTERED CONVECTION ALONG THE ITCZ FROM ROUGHLY 07N TO 15N W OF
130W. THIS AREA MAY PERSIST THROUGH THU...THEN DIMINISH AS THE
LOW PRES LIFTS NORTH.

ELSEWHERE...A 1024 MB RIDGE CENTERED NEAR 31N140W IS MAINTAINING
MODERATE TO FRESH TRADE WINDS SOUTH OF 20N W OF 120W. OTHERWISE
THE MAIN ISSUE IS NW SWELL OF 8 TO 13 FT NW OF A LINE FROM
29N115W TO 12N130W TO 10N140W. THE SWELL WILL EXPAND ACROSS MUCH
OF THE AREA W OF 110W OVER THE NEXT 24 TO 36 HOURS...BUT DECAY
BELOW 8 FT THROUGH 48 HOURS OVER MOST OF THE REGION. A SECOND
AREA OF NW SWELL IN EXCESS OF 8 FT WILL START TO MOVE SOUTH OF
30N BY LATE THU.

$$
CHRISTENSEN



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