[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 121759
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE AUG 12 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
1745 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE HAS COME OFF THE WEST AFRICAN COAST EARLIER THIS
MORNING AND ITS AXIS CURRENTLY EXTENDS FROM 17N18W TO 9N18W.
DEEP LAYER MOISTURE IS ASSOCIATED WITH THIS WAVE WHICH ALONG
UPPER-LEVEL DIFFLUENCE SUPPORT SCATTERED MODERATE CONVECTION AND
ISOLATED TSTMS FROM 9N-15N BETWEEN 17W-24W.

A TROPICAL WAVE IS ON THE CENTRAL ATLC WITH AXIS EXTENDING FROM
18N33W TO A 1012 MB LOW NEAR 13N33W TO 9N34W...MOVING W AT 15
KT. SSMI TPW AND METEOSAT SAL TRACKING IMAGERY INDICATE SAHARA
DRY AIR IS ENTRAINING THE WAVE ENVIRONMENT N OF 11N WHICH IS
SUPPRESSING THE DEVELOPMENT OF CONVECTION IN THE NORTHERN AND
CENTRAL PORTIONS OF THE WAVE. SCATTERED MODERATE CONVECTION IS
OCCURRING SW OF THE LOW CENTER FROM 8N-11N BETWEEN 33W-38W BEING
ENHANCED BY UPPER LEVEL DIFFLUENCE.

A TROPICAL WAVE CONTINUES NEAR HISPANIOLA. ITS AXIS EXTENDS FROM
11N75W TO 20N74W AND MOVES WEST AT 15-20 KT. THE WAVE IS
ASSOCIATED WITH MODERATE MOISTURE AT LOW LEVELS...HOWEVER DRY
AIR SUBSIDENCE FROM ALOFT IS HINDERING THE DEVELOPMENT OF DEEP
CONVECTION.

A TROPICAL WAVE IS MOVING ACROSS SOUTHERN MEXICO WITH AXIS
EXTENDING FROM THE BAY OF CAMPECHE NEAR 20N95W TO THE E PAC
WATERS NEAR 11N95W MOVING WEST AT 20 KT. IN THE SW GULF...THE
WAVE IS ASSOCIATED WITH MODERATE DEEP LAYER MOISTURE WHICH ALONG
UPPER LEVEL DIVERGENCE SUPPORT SCATTERED HEAVY SHOWERS AND TSTMS
SOUTH OF 20N WEST OF 92W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST NEAR
12N16W TO 13N28W TO A 1012 MB LOW NEAR 13N34W TO 9N40W 8N46W.
THE INTERTROPICAL CONVERGENCE ZONE AXIS BEGINS NEAR 8N47W TO
10N57W. BESIDES THE CONVECTION ASSOCIATED WITH THE TROPICAL
WAVES...SCATTERED MODERATE CONVECTION IS FROM 7N-11N BETWEEN 47W-
54W.

...DISCUSSION...

GULF OF MEXICO...

A MIDDLE-LEVEL TROUGH IS ACROSS THE EASTERN CONUS WITH BASE
EXTENDING INTO THE N-NE GULF N OF 27N. THIS TROUGH ALOFT
SUPPORTS A SURFACE PRE-FRONTAL TROUGH EXTENDING FROM THE SW N
ATLC NEAR 30N80W...ACROSS NORTHERN FLORIDA TO 29N83W 28N87W TO
26N91W WHICH IS ENHANCING SCATTERED HEAVY SHOWERS AND TSTMS N OF
26N E OF 93W. A TROPICAL WAVE IS MOVING ACROSS SOUTHERN MEXICO
WITH AXIS EXTENDING FROM THE BAY OF CAMPECHE TO THE E PAC
WATERS. SEE THE TROPICAL WAVES SECTION ABOVE FOR MORE DETAILS. WEAK
SURFACE RIDGING DOMINATES ELSEWHERE ACROSS THE BASIN AND
PROVIDES VARIABLE WINDS OF 5-10 KT. A WEAK COLD FRONT IS
EXPECTED TO ENTER THE NORTHERN BASIN BY WED MORNING WHICH IS
EXPECTED TO DISSIPATE THU MORNING. SURFACE RIDGING WILL DOMINATE
ELSEWHERE ACROSS THE GULF DURING THIS PERIOD.

CARIBBEAN SEA...

A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL CARIBBEAN BEING
SUPPORTED BY AN UPPER LEVEL INVERTED TROUGH. DRY AIR SUBSIDENCE
FROM ALOFT ACROSS THIS REGION OF THE BASIN IS DEHUMIDIFYING THE
WAVE ENVIRONMENT AT THE LOWER LEVEL...THUS SUPPRESSING
CONVECTION. MODERATE DEEP LAYER MOISTURE IS ACROSS THE REMAINDER
BASIN WHICH ALONG REGIONS OF UPPER LEVEL DIFFLUENCE SUPPORT
ISOLATED HEAVY SHOWERS AND TSTMS ON THE NW CARIBBEAN N OF 18N W
OF 80W AND N OF 13N BETWEEN 65W-70W...INCLUDING PUERTO RICO.
TRADES OF 15-20 KT ARE ACROSS THE CENTRAL AND EASTERN BASIN
ASSOCIATED WITH THE PASSAGE OF THE TROPICAL WAVE AND A TIGHTER
PRESSURE GRADIENT. ELSEWHERE...TRADES OF 5-10 KT DOMINATE. THE
TROPICAL WAVE IS FORECAST TO MOVE INTO CENTRAL AMERICA BY THU
MORNING.

HISPANIOLA...

MOSTLY DEEP LAYER DRY AIR IS ACROSS THE ISLAND WHICH IS
PROVIDING AN OVERALL STABLE ENVIRONMENT. HOWEVER...SOME
CLOUDINESS ARE ACROSS THE WESTERN AND EASTERN COASTS ASSOCIATED
WITH PATCHES OF MODERATE LOW-LEVEL MOISTURE.
HOWEVER...RAINSHOWERS ARE EXPECTED TO DEVELOP LATER THIS
AFTERNOON THROUGH EARLY WED MORNING ASSOCIATED WITH A MOIST
AIRMASS CURRENTLY MOVING ACROSS PUERTO RICO AND THE EASTERN
CARIBBEAN.

ATLANTIC OCEAN...

A MIDDLE-LEVEL TROUGH IS ACROSS THE EASTERN CONUS WITH BASE
EXTENDING INTO THE N-NE GULF N OF 27N. THIS TROUGH ALOFT
SUPPORTS A SURFACE PRE-FRONTAL TROUGH EXTENDING FROM THE SW N
ATLC NEAR 30N80W...ACROSS NORTHERN FLORIDA AND NORTHERN GULF.
LOW-LEVEL MOISTURE CONVERGENCE ALONG WITH UPPER LEVEL DIFFLUENCE
W OF 60W SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED
TSTMS N OF 28N W OF 62W. SIMILAR CONVECTION IS FARTHER EAST N OF
28N BETWEEN 47W-56W AHEAD OF A COLD FRONT N OF THE AREA OF
DISCUSSION. FINALLY...THE CENTRAL AND EASTERN ATLC ARE UNDER THE
INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1028 MB HIGH CENTERED
SW OF THE AZORES NEAR 35N29W.

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

$$
NR/ER


This weather bulletin was brought to you by:
www.nashvilleweather.net