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004
AXPZ20 KNHC 200231
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN APR 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0215 UTC.

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

THE EPAC MONSOON TROUGH EXTENDS NW FROM THE COAST OF COLOMBIA AT
03N77W TO 06N88W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION
TO AN ITCZ AXIS. THE ITCZ TURNS SW FROM 06N88W TO 04N110W...
THEN WNW TO 05N123W...THEN WSW TO BEYOND 04N140W.

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED ALONG
THE MONSOON TROUGH AND ITCZ WITHIN 150 NM EITHER SIDE OF LINES
FROM 03N77W TO 05N110W AND FROM 05N116W TO 09N127W. SIMILAR
CONVECTION IS NOTED ALONG A LOW TO MID LEVEL TROUGH WITHIN 90 NM
EITHER SIDE OF A LINE FROM 15N108W TO 10N120W.

...DISCUSSION...

AN UPPER CYCLONE IS OVER SE ARIZONA WITH A MID TO UPPER TROUGH
EXTENDING SW TO A BASE NEAR 12N129W. A 420 NM WIDE BAND OF UPPER
DEBRIS MOISTURE CONTINUES E OF THIS TROUGH AXIS FROM THE TROPICS
AT 12N120W TO ACROSS THE PACIFIC COAST OF MEXICO AT 21N105W...
THEN CONTINUES ACROSS NE MEXICO EVENTUALLY FANNING OUT OVER
EASTERN TEXAS. ANOTHER BAND OVER UPPER MOISTURE IS STREAMING E
ACROSS THE NORTHERN PORTION OF THE DISCUSSION AREA WITHIN 120 NM
EITHER SIDE OF A LINE FROM 31N140W TO 30N124W TO ACROSS SOUTHERN
CALIFORNIA AND NORTHERN BAJA. OTHERWISE DRY UPPER AIR IS NOTED
ACROSS THE DISCUSSION AREA W OF THE UPPER TROUGH AXIS.

AN E TO W UPPER RIDGE CONTINUES ACROSS THE DEEP TROPICS ALONG
ABOUT 04N W OF 133W AND IS SUPPORTING THE PREVIOUSLY DESCRIBED
CONVECTION ALONG TE WESTERN SEGMENT OF THE ITCZ.

ANOTHER E TO W UPPER RIDGE EXTENDS W OFF THE COAST OF COLOMBIA
ALONG 07N AND HAS AMPLIFIED W TO A GENTLE CREST NEAR 07N128W.
WEAK DIFFLUENCE ALONG THIS RIDGE IS SUPPORTING THE PREVIOUSLY
DESCRIBED CONVECTION ALONG THE MONSOON TROUGH AND ITCZ TO THE E
OF 103W. THE RESULTANT DEBRIS MOISTURE FROM CONVECTION BETWEEN
113-129W IS ADVECTED NE MERGING INTO THE TROPICAL MOISTURE PLUME
ALREADY MENTIONED. DEBRIS MOISTURE FROM EARLIER ITCZ CONVECTION
ALONG THE EASTERN SEGMENT OF THE ITCZ IS STREAMING NE ACROSS
CENTRAL AMERICA AND THE CENTRAL CARIBBEAN.

A SURFACE RIDGE EXTENDS FROM 31N140W TO NEAR 10N110W. NE TRADES
ARE ENHANCED TO 15-20 KT BETWEEN THE RIDGE AND 07N TO THE W OF
125W...WITH SEAS OF 6-9 FT IN MIXED LONG PERIOD NW AND LONG
PERIOD CROSS-EQUATORIAL SE SWELL. THIS AFFECTED AREA S OF THE
RIDGE WILL PERSIST THROUGH THE WEEKEND. NW 10-15 KT WINDS WILL
CONTINUE THROUGH SUN NIGHT TO NE OF THE RIDGE ALONG THE PACIFIC
COAST OF THE BAJA CALIFORNIA PENINSULA WITH SEAS OF 4-5 FT. A
NEW BATCH OF NW SWELL WILL ARRIVE OVER THE FAR NW PORTION NEAR
30N140W TONIGHT...AND CONTINUE TO PROPAGATE E REACHING THE NW
COAST OF THE BAJA PENINSULA IN THE FORM OF COMBINED SEAS OF 6-9
FT ON MON. SEAS OF 8-9 FT WILL GRADUALLY SUBSIDE ACROSS THE
DISCUSSION WATERS N OF 20N BETWEEN 112W-135W THROUGH LATE MON.
THE PRESSURE GRADIENT WILL TIGHTEN ON TUE AND TUE NIGHT WITH NW
WINDS INCREASING TO 20-25 KT ACROSS THE WATERS N OF 25N E OF
122W TO BAJA PENINSULA ON WED.

NORTHERLY FLOW HAS DIMINISHED TO 20-25 KT IN AND JUST DOWNSTREAM
OF THE GULF OF TEHUANTEPEC. LITTLE CHANGE EXPECTED THROUGH SUN
AFTERNOON WHEN THE GRADIENT QUICKLY RELAXES SUPPORTING NOCTURNAL
MAXIMUM DRAINAGE OF 10-15 KT EACH NIGHT FROM SUN NIGHT THROUGH
TUE NIGHT. ONLY LIGHT NORTHERLY WINDS EXPECTED ON WED NIGHT AND
THU NIGHT.

$$
NELSON




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