[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191804
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN JUL 19 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AXIS NEAR
38W...MOVING W AT 15-20 KT. ENHANCEMENTS OF METEOSAT SATELLITE
IMAGERY INDICATE THE WAVE IS BEING ENGULFED BY SAHARAN DRY AIR
AND DUST...WHICH IS SUPPORTING LACK OF CONVECTION.

A TROPICAL WAVE IS AROUND 500 NM E OF THE LESSER ANTILLES WITH
AXIS ALONG 51W...MOVING W AT 15 KT. SSMI TPW IMAGERY INDICATE
THE WAVE IS EMBEDDED IN A MODERATE MOIST ENVIRONMENT WITH A
MAXIMUM IN MOISTURE SW OF THE AXIS THAT ENHANCES SCATTERED
MODERATE CONVECTION FROM 09N TO 13N BETWEEN 52W AND 55W. SAHARAN
DRY AIR AND DUST IS OVER THE REMAINING WAVE ENVIRONMENT...THUS
HINDERING CONVECTION.

A TROPICAL WAVE IS AROUND 100 NM E OF THE LESSER ANTILLES WITH
AXIS NEAR 59W...MOVING W AT 15 KT. SAHARAN DRY AIR AND DUST ARE
IN THE ENVIRONMENT OF THE WAVE ALONG WITH STRONG DEEP LAYER WIND
SHEAR...WHICH IS INHIBITING CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 10N14W TO
07N25W WHERE THE INTERTROPICAL CONVERGENCE ZONE AXIS BEGINS AND
CONTINUES TO 07N35W...RESUMING W OF A TROPICAL WAVE NEAR 07N40W TO
THE NORTHERN COAST OF S AMERICA NEAR 05N53W. A CLUSTER OF
MODERATE CONVECTION IS WEST OF THE AFRICAN COAST FROM 06N TO 13N
E OF 24W ASSOCIATED WITH THE NEXT TROPICAL WAVE TO COME OFF THE
COAST. OTHERWISE...SCATTERED MODERATE CONVECTION IS FROM 01N TO
08N BETWEEN 38W AND 50W.

...DISCUSSION...

GULF OF MEXICO...

A BROAD MIDDLE TO UPPER LEVEL ANTICYCLONE CENTERED OVER NORTHERN
LOUISIANA COVERS THE BASIN EXCEPT THE FAR SE GULF WHERE AN
INVERTED TROUGH IS OBSERVED. AT THE SURFACE...A BROAD RIDGE
COVERING GREAT PORTIONS OF THE ATLC EXTENDS AN AXIS ACROSS THE
FLORIDA PENINSULA AND THE GULF AND PROVIDES VARIABLE WIND FLOW
OF LESS THAN 10 KT. A WEAKNESS WITHIN THE RIDGE IS ANALYZED AS A
SURFACE TROUGH FROM 28N82W TO 28N92W THAT ENHANCES SCATTERED
SHOWERS AND TSTMS FROM 26N TO 29N BETWEEN 87W AND 93W AND FROM
24N TO 29N E OF 85W. FAIR WEATHER IS ELSEWHERE. SURFACE RIDGING
WILL BE THE DOMINANT FEATURE DURING THE NEXT TWO DAYS.

CARIBBEAN SEA...

EXCEPT THE NW AND SW BASIN...SSMI TPW IMAGERY SHOW MOSTLY DRY
AIR ACROSS THE BASIN THAT ALONG WITH STRONG DEEP LAYER WIND
SHEAR SUPPORT FAIR WEATHER OVER THE EASTERN CARIBBEAN. AN UPPER
LEVEL ELONGATED LOW OVER THE NW CARIBBEAN SUPPORT A SURFACE
TROUGH FROM 21N82W TO 15N83W WHERE A MODERATE MOIST ENVIRONMENT
ENHANCES ISOLATED SHOWERS AND TSTMS...INCLUDING WESTERN AND
CENTRAL CUBA. OVER THE SW BASIN...LOW PRESSURE OVER THE NORTHERN
COLOMBIA AND DEEP MOISTURE SUPPORT SCATTERED MODERATE CONVECTION
AND TSTMS S OF 13N W OF 76W. A TROPICAL WAVE WILL BE ENTERING THE E
CARIBBEAN LATE TODAY...A SECOND TROPICAL WAVE ENTERS THE BASIN
TUESDAY.

...HISPANIOLA...

DRY AIR IN PLACE IS EXPECTED TO INHIBIT SHOWER AND THUNDERSTORMS
OVER THE ISLAND TODAY...EXCEPT FOR ISOLATED SHOWERS IN SHALLOW
MOISTURE IN THE TRADE WIND FLOW. SIMILAR CONDITIONS WILL OCCUR
ON MONDAY.

ATLANTIC OCEAN...

THE SE PERIPHERY OF A MIDDLE TO UPPER LEVEL ANTICYCLONE CENTERED
OVER NORTHERN LOUISIANA COVERS THE SW N ATLC W OF 70W. SCATTERED
MODERATE CONVECTION AND TSTMS ARE FROM 27N TO 31N BETWEEN 70W
AND 77W BEING SUPPORTED BY MODERATE MOISTURE AND DIFFLUENT WIND
FLOW GENERATED BY AN UPPER LOW CENTERED NEAR 29N55W. SIMILAR
CONVECTION IS BETWEEN NORTHERN-CENTRAL CUBA AND ANDROS ISLAND.
FARTHER EAST...THE AFOREMENTIONED LOW SUPPORT ISOLATED SHOWERS
AND TSTMS FROM 27N TO 32N BETWEEN 54W AND 60W. THE REMAINDER
BASIN IS DOMINATED BY HIGH PRESSURE AND SURFACE RIDGING. FOR
TROPICAL WAVES INFORMATION PLEASE REFER TO SECTION ABOVE.

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

$$
NR
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