[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201743
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT SEP 20 2014

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
1730 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE CONTINUES E OF THE CAPE VERDE ISLANDS WITH AXIS
EXTENDING FROM 20N21W TO THE MONSOON TROUGH NEAR 13N22W.  THE
WAVE IS MOVING SLOWLY AT AROUND 5 KT. METEOSAT SAL IMAGERY SHOWS
BOTH DUST AND DRY AIR IN THE ENVIRONMENT OF THIS WAVE SUPPRESSING
CONVECTION TO THE AREA NEAR THE MONSOON TROUGH MAINLY S OF 16N
BETWEEN 18W-24W.

A TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLANTIC WITH AXIS
EXTENDING FROM 21N52W TO 10N53W...MOVING W AT 15 KT. TOTAL
PRECIPITABLE WATER IMAGERY SHOWS A MOIST ENVIRONMENT IN THE
VICINITY OF THIS WAVE. SCATTERED MODERATE CONVECTION IS FROM 09N-
19N BETWEEN 49W-53W. ELSEWHERE... ISOLATED SHOWERS ARE WITHIN
300 NM OF THE WAVE AXIS.

A TROPICAL WAVE IS OVER WESTERN HISPANIOLA WITH AXIS EXTENDING
FROM 21N73W TO 12N74W...MOVING W AT 10-15 KT. ALTHOUGH MODERATE
DEEP LAYER MOISTURE IS IN THE ENVIRONMENT OF THIS WAVE...NO
CONVECTION IS PRESENT DUE TO DEEP LAYER WIND SHEAR.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 15N18W TO
09N39W. THE ITCZ AXIS EXTENDS FROM 09N39W TO 10N49W. OTHER THAN
THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION...ISOLATED
MODERATE CONVECTION IS FROM 08N-13N BETWEEN 26W-31W.

...DISCUSSION...

GULF OF MEXICO...

AN UPPER-LEVEL TROUGH CONTINUES ACROSS EASTERN US EXTENDING TO
THE ATLANTIC AND EASTERN GULF. TO THE WEST...AN UPPER-LEVEL HIGH
CONTINUES ACROSS NORTHERN MEXICO AND EXTENDING TO THE WESTERN
GULF WATERS. THESE FEATURES ARE KEEPING A DIFFLUENT FLOW ACROSS
MOST OF THE BASIN. AT LOW LEVELS...A STATIONARY FRONT REMAINS
OVER THE NORTHERN GULF WATERS. A SURFACE TROUGH EXTENDS FROM THE
ATLANTIC TO THE GULF NEAR 26N95W. SCATTERED MODERATE CONVECTION
REMAINS S OF THE TROUGH BETWEEN 97W-82W. EXPECT IN 24 HOURS FOR
A 1012MB SURFACE LOW TO DEVELOP OVER THE W ATLANTIC NEAR 30N80W
BRINGING ITS FRONTAL BOUNDARY TO THE EASTERN GULF ENHANCING
CONVECTION.

CARIBBEAN SEA...

UPPER-LEVEL DIFFLUENCE PERSISTS ACROSS THE NORTH-WESTERN HALF OF
THE CARIBBEAN AS AN UPPER-LEVEL HIGH CENTERED NEAR 11N77W N OF
PANAMA INTERACTS WITH AN UPPER-LEVEL LOW S OF CUBA NEAR 18N82W.
DESPITE THIS...FAIR WEATHER PREVAILS ACROSS MOST OF THE BASIN
DUE TO DEEP LAYER WIND SHEAR. FOR INFORMATION ABOUT THE TROPICAL
WAVE OVER WESTERN HISPANIOLA...REFER TO THE SECTION ABOVE.
ABUNDANT MOISTURE IS PRESENT ALONG THE MONSOON TROUGH N OF
PANAMA SUPPORTING CLUSTERS OF SCATTERED MODERATE CONVECTION S OF
11N BETWEEN 76W-82W. EXPECT THE SAME WEATHER PATTERN OVER THE
NEXT 24 HOURS OVER THE W CARIBBEAN...WHILE ADDITIONAL CONVECTION
ADVECTS OVER THE CENTRAL AND EASTERN CARIBBEAN DUE TO THE
NEXT TROPICAL WAVE APPROACHING.

...HISPANIOLA...

A TROPICAL WAVE IS MOVING ACROSS W HAITI WITH NO SIGNIFICANT
CONVECTION ACROSS THE ISLAND. EXPECT CONVECTION TO DEVELOP LATER
TODAY AND OVER THE WEEKEND DUE TO OROGRAPHIC LIFTING AND DAYTIME
HEATING.

ATLANTIC OCEAN...

FOR INFORMATION ABOUT THE TROPICAL WAVES...REFER TO THE SECTION
ABOVE. AN UPPER-LEVEL HIGH IS CENTERED NEAR 33N42W PAIRED WITH
AN UPPER-LEVEL LOW NEAR 24N51W KEEPING A DIFFLUENT FLOW ACROSS
THE W ATLANTIC. AT THE SURFACE...A FRONTAL BOUNDARY EXTENDS FROM
THE COAST OF LOUISIANA ACROSS THE FLORIDA PENINSULA INTO THE NW
ATLANTIC. A SURFACE TROUGH IS PRECEDING THIS FRONTAL BOUNDARY
EXTENDING FROM THE E GULF WATERS TO 28N73W. SCATTERED MODERATE
CONVECTION IS FROM 26N-36N W OF 68W. A 1021 MB SURFACE HIGH IS
CENTERED OVER THE CENTRAL ATLANTIC NEAR 29N36W PRODUCING FAIR
WEATHER. EXPECT IN 24 HOURS FOR A 1012 MB SURFACE LOW TO DEVELOP
OVER THE W ATLANTIC NEAR 30N80W BRINGING ITS FRONTAL BOUNDARY TO
THE WESTERN ATLANTIC ENHANCING CONVECTION.

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

$$
ERA


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