[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 270534
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT JUN 27 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0530 UTC.

...SPECIAL FEATURES...

...GALE WARNING CONTINUES IN THE CARIBBEAN SEA...

A GALE WARNING FOR MINIMAL GALE FORCE WINDS REMAINS IN EFFECT
FOR THE SW CARIBBEAN FROM 11N-17N BETWEEN 72W-81W THROUGH THE
EARLY MORNING HOURS. THESE CONDITIONS WILL PULSE EVERY EVENING
OVER THE NEXT 48 HOURS. THESE WINDS ARE BEING GENERATED DUE TO A
TIGHT PRESSURE GRADIENT CREATED BETWEEN PERSISTENT STRONG HIGH
PRESSURE OVER THE WESTERN ATLANTIC AND THE LOWER PRESSURES OVER
SOUTH AMERICA AND THE SW CARIBBEAN SEA. SEE THE LATEST NWS HIGH
SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC AND
THE OFFSHORE FORECAST...MIAOFFNT3/ FZNT23 FOR MORE DETAILS.

...TROPICAL WAVES...

A TROPICAL WAVE IS OVER THE FAR EASTERN TROPICAL ATLANTIC WITH
AXIS EXTENDING FROM 13N27W TO 04N27W...MOVING W AT 10-15 KT.
DESPITE THE FACT THAT THE SSMI TOTAL PRECIPITABLE WATER IMAGERY
SHOWS THE WAVE EMBEDDED IN LOW-LEVEL MOISTURE FROM 05N-10N...NO
CONVECTION IS OBSERVED IN THE VICINITY OF THIS WAVE AS A BROAD
SAHARAN AIRMASS PREVAILS ACROSS THE TROPICAL ATLANTIC INHIBITING
CONVECTION.

A TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLANTIC WITH AXIS
EXTENDING FROM 14N47W TO 04N47W...MOVING W AT 10-15 KT UNDER THE
SOUTHERN PERIPHERY OF A STRONG ATLANTIC HIGH PRESSURE. THE SSMI
TOTAL PRECIPITABLE WATER IMAGERY ALSO SHOWS THIS WAVE EMBEDDED
IN DEEP LOW-LEVEL MOISTURE AND WITH THE SAHARAN DUST SURGE TO
THE N OF 12N...ISOLATED CONVECTION IS OBSERVED E OF THE WAVE
AXIS BETWEEN 09N-11N AND ALONG 45W. THIS WAVE IS LIKELY TO
AMPLIFY SOME IN LONGITUDINAL SIZE AS IT MOVES FARTHER W DURING
THE NEXT 24-48 HOURS.

A TROPICAL WAVE CURRENTLY MOVING OVER THE WINDWARD ISLANDS WITH
AXIS EXTENDING FROM 19N61W TO 09N61W...MOVING W AT 10-15 KT.
LATEST SATELLITE IMAGERY CONTINUES TO SHOW AN INVERTED-V SHAPE
LOW-LEVEL CLOUD PATTERN WITH THIS WAVE ALTHOUGH LESS DEFINED
THAT EARLIER TODAY.  THE SSMI TOTAL PRECIPITABLE WATER IMAGERY
SHOWS THIS WAVE EMBEDDED IN AN AREA OF HIGH LOW-LEVEL MOISTURE
CONTENT BUT ONCE AGAIN THE SAHARAN AIRMASS IS MORE POWERFUL AND
CONTINUES INHIBITING ANY SIGNIFICANT CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA REACHING THE TROPICAL
ATLANTIC NEAR 11N16W THROUGH 08N25W. THE ITCZ BEGINS FROM THIS
LAST POINT TO 08N27W THEN RESUMES W OF A TROPICAL WAVE NEAR
08N28W TO 07N46W. THE ITCZ BEGINS AGAIN W OF ANOTHER TROPICAL
WAVE NEAR 06N47W TO 04N51W. SCATTERED MODERATE CONVECTION IS
OBSERVED FROM 06N-09N BETWEEN 32W-40W.

...DISCUSSION...

GULF OF MEXICO...

AN UPPER-LEVEL LOW IS CENTERED OVER THE NW GULF NEAR 25N96W AND
EXTENDING E OVER MOST OF THE BASIN MAINLY W OF 85W. AN UPPER-
LEVEL HIGH IS CURRENTLY OVER THE FLORIDA PENINSULA NEAR 28N82W
AND PREVAILING ACROSS THE E GULF E OF 85W. UPPER-LEVEL
DIFFLUENCE PREVAILS OVER THE SOUTHERN PORTION OF THE BASIN
SUPPORTING ISOLATED CONVECTION N OF THE YUCATAN PENINSULA FROM
21N-25N BETWEEN 89W-92W. AT THE SURFACE...A 1018 MB HIGH
PRESSURE IS CENTERED NEAR 26N89W SUPPORTING A LIGHT TO GENTLE
ANTICYCLONIC FLOW ACROSS THE BASIN AND FAIR WEATHER. AN AREA OF
GENTLE TO MODERATE WINDS IS DEPICTED IN SCATTEROMETER DATA OVER
THE BAY OF CAMPECHE MAINLY S OF 21N BETWEEN 91W-94W. A SIMILAR
WEATHER PATTERN IS EXPECTED OVER THE NEXT 24 HOURS.

CARIBBEAN SEA...

A NARROW UPPER-LEVEL RIDGE IS CENTERED OVER THE YUCATAN CHANNEL
WHILE AN UPPER-LEVEL LOW EXTENDS ITS TROUGH FROM THE SW ATLANTIC
OVER E CUBA AND INTO THE N CARIBBEAN. THIS PATTERN IS SUPPORTING
ISOLATED CONVECTION ACROSS CUBA WHILE THE REMAINDER OF THE BASIN
CONTINUES WITH FAIR WEATHER AS A BROAD AREA OF SAHARAN DUST
PREVAILS INHIBITING CONVECTION. A GALE WARNING CONTINUES IN
EFFECT FOR THE WATERS N OF COLOMBIA. FOR MORE
INFORMATION...PLEASE REFER TO THE SECTION ABOVE. GENTLE TO
MODERATE TRADES ARE DEPICTED IN SCATTEROMETER DATA ACROSS THE
REMAINDER OF THE BASIN. A TROPICAL WAVE IS CURRENTLY OVER THE
WINDWARD ISLANDS WITH NO SIGNIFICANT CONVECTION ASSOCIATED TO
IT. FOR MORE INFORMATION PLEASE SEE THE SECTION ABOVE. OVER THE
NEXT 24 HOURS...EXPECT FOR THE TROPICAL WAVE TO MOVE W ACROSS
THE E CARIBBEAN INCREASING THE LOW-LEVEL MOISTURE AND HENCE
SUPPORTING ISOLATED CONVECTION ACROSS THE GREATER ANTILLES.

...HISPANIOLA...

FAIR WEATHER PREVAILS ACROSS THE AREA TONIGHT. A TROPICAL WAVE
CURRENTLY JUST OVER THE WINDWARD ISLANDS SHOULD APPROACH
HISPANIOLA OVER THE NEXT 24 HOURS INCREASING THE LOW-LEVEL
MOISTURE AND HENCE SUPPORTING ISOLATED CONVECTION IN THE
AFTERNOON HOURS DUE TO DAYTIME HEATING AND OROGRAPHIC LIFTING.

ATLANTIC OCEAN...

THE BASIN IS UNDER THE INFLUENCE OF A BROAD 1030 MB SURFACE HIGH
CENTERED NEAR 29N49W. AT UPPER-LEVELS...A PAIR OF UPPER-LEVEL
LOWS CENTERED NEAR 21N75W AND 26N69W ARE SUPPORTING ISOLATED
CONVECTION N OF 22N AND W OF 75W AFFECTING THE BAHAMAS AND
PORTIONS OF CUBA. FAIR WEATHER PREVAILS ACROSS THE REMAINDER OF
THE BASIN AS A BROAD SAHARAN AIRMASS CONTINUES ACROSS THE
TROPICAL ATLANTIC AS DEPICTED BY THE NOAA/NESDIS AEROSOL PRODUCT
AND LATEST VISIBLE SATELLITE IMAGERY. THREE TROPICAL WAVES WERE
ANALYZED ACROSS THE BASIN...PLEASE REFER TO THE SECTION ABOVE
FOR MORE INFORMATION. OVER THE NEXT 24 HOURS...EXPECT FOR THE
SURFACE HIGH AND SAHARAN DUST TO PREVAIL ACROSS THE BASIN
WITH FAIR WEATHER.

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

$$

ERA
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