Tropical Weather Discussion
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000
AXPZ20 KNHC 192153
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT APR 19 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 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 SOUTHERN ARIZONA WITH A MID TO UPPER
TROUGH EXTENDING SW TO A BASE NEAR 13N127W. A 360 NM WIDE BAND
OF UPPER DEBRIS MOISTURE CONTINUES E OF THIS TROUGH AXIS FROM
THE TROPICS AT 13N120W TO ACROSS THE PACIFIC COAST OF MEXICO AT
22N105W...THEN TURNS N ACROSS NE MEXICO EVENTUALLY FANNING OUT
OVER CENTRAL TEXAS. ANOTHER BAND OVER UPPER MOISTURE IS
STREAMING E ACROSS THE NORTHERN PORTION OF THE DISCUSSION AREA
WITHIN 150 NM OF A LINE FROM 31N140W TO 31N124W TO ACROSS
SOUTHERN CALIFORNIA. 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 05N W OF 105W AND IS SUPPORTING THE PREVIOUSLY DESCRIBED
ITCZ CONVECTION. SOME OF THE RESULTANT DEBRIS MOISTURE IS
ADVECTED NE INTO THE TROPICAL MOISTURE PLUME ALREADY MENTIONED.

ANOTHER E TO W UPPER RIDGE EXTENDS W OFF THE COAST OF COLOMBIA
ALONG 07N TO A CREST NEAR 07N103W. WEAK DIFFLUENCE ALONG THIS
RIDGE IS SUPPORTING THE PREVIOUSLY DESCRIBED CONVECTION ALONG
THE MONSOON TROUGH AND ITCZ TO THE E OF 103W. DEBRIS MOISTURE
FROM EARLIER ITCZ CONVECTION 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 6-8 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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