Tropical Weather Discussion
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000
AXPZ20 KNHC 210231
TWDEP

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

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

AN ILL-DEFINED MONSOON TROUGH EXTENDS W FROM THE COAST OF
COLOMBIA AT 04N77W TO 04.5N80W THEN TURNS NW TO 06N91W WHERE
SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ AXIS. THE
ITCZ AXIS CONTINUES W TO 06N107W THEN WSW TO 04.5N120W...THEN
WNW TO BEYOND 07N140W.

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED OVER AND
TO THE S OF OF THE MONSOON TROUGH AND ITCZ WITHIN 180 NM EITHER
SIDE OF A LINE FROM 03N86W TO 07N100W...AND ALONG THE WESTERN
SEGMENT OF THE MONSOON TROUGH WITHIN 90 NM EITHER SIDE OF A LINE
FROM 11N118W TO 06N133W TO 06N140W. SCATTERED MODERATE CONVECTION
IS OBSERVED ALONG THE ITCZ WITHIN 120 NM OF 04N117W.

...DISCUSSION...

AN UPPER CYCLONE IS OVER THE OKLAHOMA PANHANDLE WITH A MID TO
UPPER TROUGH EXTENDING SW ACROSS NORTHERN OLD MEXICO AND THE
BAJA CALIFORNIA PENINSULA TO A BASE OVER THE TROPICAL EPAC NEAR
10N126W. A 180 NM WIDE BAND OF UPPER DEBRIS MOISTURE CONTINUES E
OF THIS TROUGH AXIS. THE MOISTURE ORIGINATES IN THE DEEP TROPICS
NEAR 10N116W...AND SPREADS NE ACROSS THE PACIFIC COAST OF MEXICO
AT 19N106W...THEN ACROSS THE CENTRAL GULF OF MEXICO. ANOTHER MID-
UPPER SHORTWAVE TROUGH IS APPROACHING THE FAR NW PORTION OF THE
DISCUSSION AREA...AND IS PRECEDED BY A LARGE AREA OF UPPER
MOISTURE OBSERVED TO THE N OF 28N AND W OF 126W...WITH THE
EASTERN EDGE OF THIS MOISTURE THINNING AS IT SPREADS E ACROSS
THE CALIFORNIA COAST NEAR 34N. OTHERWISE...DRY UPPER AIR IS
NOTED ACROSS THE DISCUSSION AREA BETWEEN THESE UPPER TROUGHS...
ROUGHLY WITHIN 540 NM EITHER SIDE OF A LINE FROM 30N108W TO
18N131W.

AN UPPER ANTICYCLONE IS NOTED JUST W OF THE AREA AT 07N146W WITH
A RIDGE EXTENDING E INTO THE DISCUSSION AND OVER THE WESTERN
SEGMENT OF THE MONSOON TROUGH...AND ENHANCING THE PREVIOUSLY
DESCRIBED CONVECTION ALONG THE ITCZ TO THE W OF 125W. AN ILL-
DEFINED LOW-MID LEVEL TROUGH IS NOTED FROM 19N109W TO 10N125W
WITH CONVECTION FLARING SE OF THE TROUGH AS PREVIOUSLY
MENTIONED. THE DEBRIS MOISTURE FROM THIS CONVECTION CONCENTRATES
INTO THE TROPICAL PLUME ALSO ALREADY MENTIONED. JUST TO E IS
ANOTHER UPPER ANTICYCLONE IS CENTERED AT 07N105W WITH AN UPPER
RIDGE EXTENDING NE TO A CREST AT 14N96W. UPPER DIFFLUENCE
ENHANCED SCATTERED MODERATE ISOLATED STRONG CONVECTION EARLIER
ALONG THE TROUGH...BUT THE CONVECTION IS CURRENTLY ONLY ISOLATED
AT BEST.

A WEAK UPPER TROUGH EXTENDS SW FROM OVER HONDURAS TO A BASE OVER
THE DEEP TROPICS AT 07N96W. THIS TROUGH EFFECTIVELY SEPARATES
THE UPPER ANTICYCLONIC FLOW JUST DESCRIBED FROM THE FLOW
ASSOCIATED WITH ANOTHER E TO W UPPER RIDGE EXTENDING W OFF THE
COAST OF COLOMBIA ALONG 05N TO A CREST NEAR 05N92W. WEAK
DIFFLUENCE ALONG THIS EASTERN RIDGE IS SUPPORTING THE PREVIOUSLY
DESCRIBED CONVECTION ALONG THE MONSOON TROUGH AND ITCZ BETWEEN
85-98W. DEBRIS MOISTURE FROM CONVECTION OVER PANAMA AND COSTA
RICA IS STREAMING NE ACROSS THE SW AND CENTRAL CARIBBEAN.

A SURFACE RIDGE EXTENDS FROM 34N132W TO NEAR 14N102W. NE TRADES
ARE ENHANCED TO 15-20 KT BETWEEN THE RIDGE AND 06N TO THE W OF
115W...WITH SEAS OF 7-10 FT IN MIXED LONG PERIOD NW AND LONG
PERIOD CROSS-EQUATORIAL S SWELL. THIS AREA OF ENHANCED SEAS WILL
BE REINFORCED ON MON BY A NEW BATCH OF NW SWELL THAT HAS MOVED
INTO THE DISCUSSION WATERS NW OF A LINE FROM 32N120W TO 21N140W.
THE NW SWELL WILL CONTINUE TO PROPAGATE E REACHING THE NW COAST
OF THE BAJA PENINSULA IN THE FORM OF COMBINED SEAS OF 6-9 FT ON
MON...THEN GRADUALLY SUBSIDING ACROSS THE DISCUSSION WATERS N OF
20N THROUGH TUE. THE PRESSURE GRADIENT WILL TIGHTEN ON TUE NIGHT
WITH NW WINDS INCREASING TO 15-25 KT ACROSS THE WATERS N OF 25N
E OF 122W TO BAJA PENINSULA ON WED. THESE WINDS WILL DIMINISH
AND THE SEAS WILL SUBSIDE ON THU.

$$
NELSON


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