Tropical Weather Discussion
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000
AXNT20 KNHC 041902 AAA
TWDAT

TROPICAL WEATHER DISCUSSION...UPDATE
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED MAY 04 2016

UPDATED FOR ITCZ/MONSOON TROUGH

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...

...GALE-FORCE WINDS ARE DEVELOPING IN THE ATLANTIC OCEAN...

THE 24-HOUR FORECAST CONSISTS OF A COLD FRONT FROM 31N75W TO
23N80W. EXPECT GALE-FORCE SOUTH-TO-SOUTHWEST WINDS AND SEA
HEIGHTS RANGING FROM 8 FEET TO 10 FEET TO THE NORTH OF 28N
WITHIN 300 NM TO THE EAST OF THE COLD FRONT. SCATTERED MODERATE
TO STRONG THUNDERSTORMS. PLEASE READ THE HIGH SEAS FORECAST...
MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE FORECAST...MIAOFFNT3/
FZNT23 KNHC...FOR MORE DETAILS.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH IS NOT PRESENT AT THIS TIME. A SURFACE TROUGH
IS ALONG 04N14W 03N18W 03N34W. THE ITCZ IS ALONG 03N14W 04N45W.
A NORTH-TO-SOUTH ORIENTED SURFACE TROUGH IS ALONG 06N45W 04N46W
01N46W. A SEPARATE SURFACE TROUGH IS ALONG 07N16W 09N18W 11N18W.
CONVECTIVE PRECIPITATION...SCATTERED STRONG FROM 03N TO 04N
BETWEEN 09W AND 11W. WIDELY SCATTERED MODERATE TO ISOLATED
STRONG FROM THE EQUATOR TO 05N BETWEEN 11W AND 30W...AND FROM
05N TO 10N BETWEEN 43W AND 52W. SCATTERED STRONG IN COASTAL
PLAINS OF BRAZIL FROM 01N TO 02N BETWEEN 50W AND 52W.

...DISCUSSION...

...THE GULF OF MEXICO...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH THAT IS MOVING THROUGH THE
SOUTHEASTERN U.S.A. AND THE EASTERN PART OF THE GULF OF MEXICO
IS SUPPORTING A COLD FRONT...THAT PASSES THROUGH NORTHEASTERN
FLORIDA...INTO THE CENTRAL GULF OF MEXICO...TO THE ISTHMUS OF
TEHUANTEPEC OF SOUTHERN MEXICO. THE FRONT BECOMES STATIONARY
NEAR 19N97W...AND IT RUNS NORTHWESTWARD...FROM 19N97W TO
23N101W...TO 26N101W...TO THE TEXAS BIG BEND...BEYOND 31N108W IN
NORTHEASTERN MEXICO. CONVECTIVE PRECIPITATION...NUMEROUS STRONG
FROM 23N TO 25N BETWEEN 82W AND 86W. SCATTERED TO NUMEROUS
STRONG COVERS FLORIDA AND COASTAL WATERS FROM 24N TO 28N BETWEEN
78W AND 82W. WIDELY SCATTERED MODERATE TO ISOLATED STRONG IS
WITHIN 180 NM TO THE WEST AND NORTHWEST OF THE LINE THAT PASSES
THROUGH 32N66W TO 30N67W 23N80W.

SURFACE HIGH PRESSURE HAS BEEN BUILDING FROM SOUTH TEXAS...ALONG
THE MEXICO COAST...INTO THE NORTHERN PART OF THE ISTHMUS OF
TEHUANTEPEC OF SOUTHERN MEXICO.

...THE CARIBBEAN SEA...

UPPER LEVEL CYCLONIC WIND FLOW IS TO THE EAST OF THE LINE THAT
PASSES THROUGH 22N86W 14N75W 12N73W. THE CYCLONIC WIND FLOW IS
RELATED TO THE ATLANTIC OCEAN-TO-NORTHEASTERN CARIBBEAN SEA
TROUGH. UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE REST OF
THE CARIBBEAN SEA AND CENTRAL AMERICA.

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 23N64W IN
THE ATLANTIC OCEAN...TO 18N62W IN THE NORTHEASTERN CORNER OF THE
CARIBBEAN SEA...TO 14N64W...AND 10N65W. CONVECTIVE
PRECIPITATION...RAINSHOWERS ARE FROM 16N TO 19N BETWEEN 63W AND
69W. THE PRECIPITATION IS OCCURRING IN THE WATERS THAT ARE TO
THE SOUTH OF PUERTO RICO...AND EVEN ACROSS PARTS OF PUERTO
RICO...ESPECIALLY IN THE NORTHWESTERN PART OF THE ISLAND.

24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT
03/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/ SXCA01 KNHC...ARE 0.12 IN SAN
JUAN IN PUERTO RICO...0.04 IN MONTEGO BAY IN JAMAICA...AND 0.01
IN GUADELOUPE.

...HISPANIOLA...

UPPER LEVEL NORTHWEST WIND FLOW IS MOVING ACROSS THE AREA.
HISPANIOLA IS ON THE WESTERN SIDE OF AN ATLANTIC OCEAN-TO-
NORTHEASTERN CARIBBEAN SEA UPPER LEVEL TROUGH.

THE SURFACE WIND FLOW IS FROM THE SOUTHEAST...PUSHING CLOUDS AND
POSSIBLE RAINSHOWERS ONSHORE AND ACROSS INTERIOR SECTIONS OF THE
DOMINICAN REPUBLIC.

SURFACE OBSERVATIONS...FOR PORT-AU-PRINCE IN HAITI...SCATTERED
CUMULONIMBUS CLOUDS WITH BASES AT 2600 FEET. FOR THE DOMINICAN
REPUBLIC...BARAHONA...FEW CUMULONIMBUS CLOUDS WITH BASES AT 1800
FEET. SANTO DOMINGO...A LOW CLOUD CEILING...MVFR. LA ROMANA...
RAIN IS NEARBY. PUNTA CANA...SCATTERED LOW LEVEL CLOUDS...VFR.
SANTIAGO...A LOW CLOUD CEILING...MVFR. PUERTO PLATA...SCATTERED
LOW LEVEL CLOUDS...VFR.

THE GFS MODEL FOR 250 MB SHOWS THAT THE FIRST 24 HOURS OF THE 48-
HOUR FORECAST PERIOD WILL CONSIST OF NORTHWEST WIND FLOW. DAY
TWO WILL CONSIST OF NORTHWEST AND WEST WIND FLOW. A TROUGH
STARTS TO WORK ITS WAY FROM THE BAHAMAS TO CUBA TO HISPANIOLA
DURING PARTS OF DAY TWO. THE GFS MODEL FOR 500 MB SHOWS THAT DAY
ONE WILL CONSIST OF NORTHWEST WIND FLOW FOR MOST OF THE
DAY...CHANGING TO WEST WIND FLOW AT THE END OF DAY ONE. DAY TWO
WILL CONSIST OF SOUTHWEST WIND FLOW...WITH A TROUGH IN THE
NORTHWESTERN PART OF THE CARIBBEAN SEA. THE GFS MODEL FORECAST
FOR 700 MB SHOWS THAT DAY ONE WILL START WITH SOUTHERLY WIND
FLOW WITH A RIDGE...AND CHANGE TO SOUTHERLY WIND FLOW WITH AN
APPROACHING TROUGH. DAY TWO WILL CONSIST OF MORE SOUTHERLY WIND
FLOW...AS THE TROUGH ORGANIZES ITSELF COMPARATIVELY MORE AND AS
THE TROUGH FROM THE WEST MOVES CLOSER TO HISPANIOLA.

...THE ATLANTIC OCEAN...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N66W TO
26N65W TO 23N64W IN THE ATLANTIC OCEAN...TO 18N62W IN THE
NORTHEASTERN CORNER OF THE CARIBBEAN SEA...TO 14N64W...AND
10N65W. CONVECTIVE PRECIPITATION...RAINSHOWERS ARE POSSIBLE FROM
19N NORTHWARD BETWEEN 60W AND 70W.

A SURFACE TROUGH IS ALONG 30N55W 26N59W 24N62W. RAINSHOWERS ARE
POSSIBLE WITHIN 60 NM TO 120 NM ON EITHER SIDE OF THE TROUGH.

A SECOND SURFACE TROUGH IS ALONG 30N48W 27N48W 24N49W.
RAINSHOWERS ARE POSSIBLE WITHIN 60 NM TO 120 NM ON EITHER SIDE
OF THE TROUGH.

A THIRD SURFACE TROUGH IS ALONG 23N40W 20N39W 17N38W.
RAINSHOWERS ARE POSSIBLE WITHIN 60 NM TO 120 NM ON EITHER SIDE
OF THE TROUGH.

FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE

$$
MT



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