Tropical Weather Discussion
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000
AXNT20 KNHC 052321
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE MAY 05 2015

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2245 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC
NEAR 11N15W ALONG 8N16W TO 5N20W WHERE THE ITCZ BEGINS AND
CONTINUES ALONG 3N24W 2N37W THEN S OF THE EQUATOR INTO BRAZIL
NEAR 43W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE
FROM 5N-8N BETWEEN 13W-21W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 1N TO INLAND OVER SW AFRICA BETWEEN 3W-12W
AND WITHIN 60 NM N OF THE ITCZ BETWEEN 23W-30W. ISOLATED
MODERATE CONVECTION IS FROM 1N-6N W OF 45W TO INLAND OVER SOUTH
AMERICA.

...DISCUSSION...

GULF OF MEXICO...
A SHARP UPPER TROUGH EXTENDS FROM THE FLORIDA PANHANDLE NEAR
PENSACOLA ACROSS THE E GULF INTO THE NW CARIBBEAN OVER W CUBA.
UPPER LEVEL DIFFLUENCE TO THE W OF THE UPPER TROUGH IS
GENERATING SCATTERED SHOWERS WITH POSSIBLE ISOLATED
THUNDERSTORMS E OF LINE FROM TAMPA BAY FLORIDA TO THE EXTREME W
TIP OF CUBA. A SURFACE RIDGE EXTENDS FROM THE W ATLC OVER THE SE
CONUS AND COVERS ALL BUT THE SW GULF OF MEXICO. THIS IS LEAVING
THE REMAINDER OF THE GULF UNDER FAIR SKIES THIS EVENING. HIGH
PRESSURE N OF THE AREA WILL MAINTAIN MODERATE TO FRESH E TO SE
WINDS ACROSS MAINLY THE CENTRAL AND W GULF THROUGH THU NIGHT
THEN A WEAK HIGH CENTER WILL DEVELOP OVER THE NE GULF FRI.

CARIBBEAN SEA...
AN UPPER TROUGH EXTENDS FROM THE E GULF OF MEXICO INTO THE NW
CARIBBEAN OVER THE EXTREME TIP OF W CUBA ALONG 16N80W THEN S TO
THE SW CARIBBEAN AND CENTRAL PANAMA. UPPER LEVEL DIFFLUENCE ON
THE E SIDE OF THE UPPER TROUGH IS GENERATING SCATTERED SHOWERS/
THUNDERSTORMS N OF 19N W OF 79W TO OVER CUBA AND THE YUCATAN
PENINSULA. SATELLITE WATER VAPOR IMAGERY SHOWS STRONG SUBSIDENCE
AND DRY STABLE AIR OVER THE E CARIBBEAN E OF 71W KEEPING THE
REMAINDER OF THE CARIBBEAN UNDER FAIR SKIES THIS EVENING.
SATELLITE IMAGERY SHOWS THE SAHARAN AIR LAYER EXTENDS INTO THE
CARIBBEAN TO NEAR 70W. FRESH TO STRONG TRADE WINDS ACROSS THE
CENTRAL CARIBBEAN THROUGH THE WEEK.

...HISPANIOLA...
MOSTLY FAIR SKIES ARE ACROSS THE ISLAND THIS EVENING WITH SOME
POSSIBLE ISOLATED LOW LEVEL SHOWERS ACROSS PORTIONS OF HAITI.
WATER VAPOR SATELLITE IMAGERY SHOWERS STRONG SUBSIDENCE AND DRY
STABLE AIR ALOFT THE ISLAND E OF 71W. SOUTHERLY FLOW ALOFT WITH
LIMITED MOISTURE WILL KEEP SKIES MOSTLY CLEAR ACROSS THE ISLAND
THROUGH LATE THU ALTHOUGH SOME ISOLATED SHOWERS LOW LEVEL
SHOWERS COULD DEVELOP OVER THE HIGHER TERRAIN ON HAITI THROUGH
THU. MOISTURE WILL BEGIN TO INCREASE LATE THU/EARLY FRI BRINGING
MORE SHOWERS FOR LATE IN THE WEEK.

ATLANTIC OCEAN...
THE UPPER TROUGH OVER THE GULF OF MEXICO AND THE NW CARIBBEAN IS
AMPLIFYING AN UPPER RIDGE AXIS OVER THE W ATLC THAT EXTENDS FROM
22N61W TO BEYOND 32N76W. A SURFACE TROUGH IS BENEATH THIS UPPER
RIDGE EXTENDING FROM 28N76W TO OVER CUBA TO NEAR 22N78W. UPPER
LEVEL DIFFLUENCE ON THE W SIDE OF THE UPPER RIDGE IS GENERATING
A BROAD AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS NW OF
LINE FROM CUBA NEAR 21N76W ALONG 25N71W TO 31N64W INCLUDING MOST
OF THE BAHAMA ISLANDS AND THE FLORIDA PENINSULA. AN UPPER TROUGH
OVER THE CENTRAL ATLC N OF 28N IS SUPPORTING A COLD FRONT THAT
ENTERS THE E/CENTRAL ATLC NEAR 32N28W EXTENDING ALONG 28N38W TO
25N51W WHERE IT DISSIPATES TO 25N60W. A SURFACE RIDGE COVERS THE
W INTO THE CENTRAL ATLC N AND W OF THIS FRONT AND IS ANCHORED BY
A 1030 MB HIGH NEAR 35N60W. A SECOND UPPER RIDGE AXIS EXTENDS
OVER THE E ATLC FROM 20N34W TO THE CANARY ISLANDS. A SURFACE LOW
IS EXPECTED TO FORM ALONG THE W ATLC SURFACE TROUGH OVER THE
NEXT COUPLE OF DAYS AS IT MOVES SLOWLY NORTHWARD TO JUST N OF
THE FORECAST WATERS BY EARLY THU...WHILE POSSIBLY STRENGTHENING.
THE 1030 MB HIGH IN THE W/CENTRAL ATLC WILL BUILD SW INTO THE
CENTRAL ATLC THROUGH FRI NIGHT.

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

$$
PAW


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