Tropical Weather Discussion
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000
AXPZ20 KNHC 281526
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAR 28 2015

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1500 UTC.

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...HIGH PRES ACROSS THE WESTERN
GULF OF MEXICO EXTENDS A RIDGE ACROSS THE ISTHMUS OF TEHUANTEPEC
TIGHTENING THE PRESSURE GRADIENT THERE. AS A RESULT...GALE
FORCE WINDS CONTINUE TO BLOW ACROSS THE GULF OF TEHUANTEPEC AND
DOWNWIND TO NEAR 13N96W BASED ON THE MOST RECENT SCATTEROMETER
PASS. FIRST VISIBLE IMAGERY OF THE DAY REVEALS A WELL DEFINED
ROPE CLOUD MOVING DOWNSTREAM OF THE GULF WHICH LIKELY DELINEATES
THE LEADING EDGE OF THE CURRENT GAP WIND EVENT. WINDS WILL
LIKELY REMAIN NEAR MINIMAL GALE FORCE TONIGHT BEFORE SLOWLY
DIMINISHING TO 30 KT LATE SUNDAY MORNING. THEN...WINDS WILL
CONTINUE PULSE TO 25-30 KT SUN NIGHT INTO EARLY MON MORNING...
AND TO 20-25 KT MON NIGHT INTO EARLY TUE MORNING WITH THE
ASSISTANCE OF THE NOCTURNAL DRAINAGE FLOW. SWELL ASSOCIATED WITH
THIS GAP WIND EVENT WILL SPREAD SOUTHWARD COVERING THE WATERS
FROM 08N TO 13N BETWEEN 94W AND 102W BY SUN MORNING WITH SEAS TO
AROUND 9 FT.

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

VERY WEAK MONSOON TROUGH EXTENDS FROM 08N82W TO 05N103W TO
04N120W. THE ITCZ CONTINUES FROM 04N120W TO 08N130W THEN RESUMES
AT 06N135W TO BEYOND 04N140W. SCATTERED MODERATE ISOLATED STRONG
CONVECTION IS NOTED FROM 02N TO 07N BETWEEN 101W AND 110W.

...DISCUSSION...

A 1032 MB HIGH PRES LOCATED N OF AREA NEAR 35N136W EXTENDS A
RIDGE ACROSS THE FORECAST WATERS TO NEAR 20N115W. SOUTH OF THE
RIDGE...THE PRES GRADIENT BETWEEN THE HIGH AND LOWER PRES ALONG
THE ITCZ IS RESULTING IN FRESH TO STRONG NE TRADEWINDS FROM 12N
TO 24N W OF 130W...WHERE SEAS ARE 8-11 FT IN MIXED NE WIND WAVES
AND LONG PERIOD CROSS EQUATORIAL SOUTHERLY SWELLS. AN ALTIMETER
PASS PROVIDED OBSERVATIONS OF THESE SEA HEIGHTS. THE AERIAL
EXTENT OF THE TRADES WILL DECREASE ON SUN AS HIGH PRES MOVES NE
AND SLIGHTLY WEAKENS.

A SURFACE TROUGH IS ANALYZED ON THE 1200 UTC SURFACE MAP FROM
FROM 12N131W TO 06N132W. THIS TROUGH IS EMBEDDED WITHIN THE
ITCZ. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS
OBSERVED WITHIN 120 NM E OF TROUGH AXIS FROM 07N TO 12N. THIS
FEATURE WILL DRIFT WESTWARD OVER THE NEXT 24-48 HOURS. BROAD AND
WEAK MONSOONAL FLOW IS NOTED E OF THE TROUGH AXIS MAINLY BETWEEN
103W AND 120W AS MENTIONED ABOVE.

LONG PERIOD SOUTHERLY SWELL CONTINUES TO DOMINATE MUCH OF THE
FORECAST WATERS REACHING THE CENTRAL AMERICAN AND MEXICAN
COASTLINES THROUGH BAJA CALIFORNIA. THIS SWELL EVENT IS LIKELY
GENERATING VERY LARGE AND POWERFUL WAVES...AND DANGEROUS
CONDITIONS WITHIN THE SURF ZONE.

GAP WINDS...

GULF OF PAPAGAYO...EXPECT INCREASING WINDS ACROSS THIS GAP WIND
REGION BY EARLY SUN MORNING AS HIGH PRES BUILDS ACROSS THE NW
CARIBBEAN AND NORTHERN CENTRAL AMERICA IN THE WAKE OF A COLD
FRONT THAT CURRENTLY EXTENDS FROM CENTRAL CUBA TO THE GULF OF
HONDURAS. WINDS WILL PULSE AGAIN ACROSS THIS AREA EARLY MON
MORNING.

$$
GR



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