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AXNT20 KNHC 211741
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT THU AUG 21 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 1715 UTC.


...SPECIAL FEATURES...

AN ELONGATED 1009 MB ATLANTIC OCEAN LOW PRESSURE CENTER IS LOCATED 310 NM SE OF GUADELOUPE NEAR 15N56W MOVING NW AT 20-25 KT. A TROPICAL WAVE PRESENTLY EXTENDS N FROM THE LOW CENTER. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 15N-20N BETWEEN 57W-63W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 8N-15N BETWEEN 54W-60W. GRADUAL DEVELOPMENT OF THIS FEATURE IS POSSIBLE DURING THE NEXT FEW DAYS ACROSS THE LEEWARD ISLANDS...PUERTO RICO...AND THE BAHAMAS. INTERESTS DOWNSTREAM OF THE LOW SHOULD MONITOR CLOSELY THE PROGRESS OF THIS SYSTEM. THE CHANCE FOR DEVELOPMENT INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS IS MEDIUM.


...TROPICAL WAVES...

A TROPICAL WAVE AXIS EXTENDS FROM 24N23W TO 13N25W MOVING W AT 5- 10 KT. THIS WAVE COINCIDES WITH 700 MB TROUGHING ALOFT AND SSMI TOTAL PRECIPITABLE WATER MAXIMUM. NO SIGNIFICANT CONVECTION IS RELATED TO THIS WAVE.

A TROPICAL WAVE AXIS EXTENDS FROM 23N56W TO 15N56W MOVING NW AT 20-25 KT. THIS WAVE IS EMBEDDED WITH THE SPECIAL FEATURE LOW DESCRIBED ABOVE. THIS WAVE COINCIDES WITH 700 MB TROUGHING ALOFT. SSMI TOTAL PRECIPITABLE WATER IMAGERY SHOWS VERY MOIST ENVIRONMENT SURROUNDING THIS WAVE...WITH MOISTURE MAXIMA S OF 20N BETWEEN 50W-65W.


...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 15N17W TO 10N30W TO 8N40W. AN ITCZ EXTENDS FROM 8N40W TO 8N47W TO 11N50W. BESIDES THE CONVECTION MENTIONED IN THE SPECIAL FEATURES SECTION
...WIDELY SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF WEST AFRICA FROM 5N-11N BETWEEN 11W-18W. ISOLATED MODERATE CONVECTION IS FROM 6N-11N BETWEEN 38W-47W.


...DISCUSSION...

GULF OF MEXICO...

A 1021 MB HIGH IS CENTERED OVER THE FLORIDA PANHANDLE NEAR 30N86W. 5-10 KT E TO SE WINDS ARE OVER THE GULF. SCATTERED SHOWERS AND THUNDERSTORMS ARE LOCATED ACROSS THE STRAITS OF FLORIDA AND SE GULF FROM 23N-26N BETWEEN 80W-86W. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED NEAR TAMPICO MEXICO AT 23N98W. SCATTERED MODERATE CONVECTION IS FROM 21N-24N BETWEEN 96W-99W. EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE NEXT 24 HRS ACROSS THE S GULF TO INCLUDE THE BAY OF CAMPECHE.

CARIBBEAN SEA...

A SURFACE LOW AND TROPICAL WAVE IS MOVING INTO THE LEEWARD ISLANDS. SEE THE SPECIAL FEATURE SECTION ABOVE. ELSEWHERE... 10- 20 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA...WITH STRONGEST WINDS ALONG THE COAST OF N COLOMBIA. MOSTLY FAIR WEATHER IS PREVAILING OVER THE CENTRAL CARIBBEAN. SCATTERED MODERATE CONVECTION IS ACROSS THE WEST COAST OF CUBA FROM 18N-20N BETWEEN 75W-79W. SCATTERED MODERATE SHOWERS ARE OVER THE NW CARIBBEAN AND YUCATAN CHANNEL FROM 19N-22N BETWEEN 83W-87W. FURTHER S... WIDELY SCATTERED MODERATE CONVECTION IS OVER THE PANAMA...COSTA RICA...AND THE SW CARIBBEAN FROM 8N-12N BETWEEN 77W-85W. IN THE UPPER LEVELS AN UPPER LEVEL LOW IS CENTERED S OF CUBA NEAR 20N81W. STRONG SUBSIDENCE PERSISTS MAINLY ACROSS HISPANIOLA AND PUERTO RICO...AHEAD OF THE TROPICAL WAVE DISCUSSED ABOVE. EXPECT ADDITIONAL CONVECTION OVER THE NEXT 24 HOURS OVER THE E CARIBBEAN E OF 70W. ALSO EXPECT CONTINUED CONVECTION OVER THE SW CARIBBEAN AND SOUTHERN CENTRAL AMERICA.


...HISPANIOLA...

FAIR WEATHER PREVAILING TODAY ACROSS THE ISLAND. EXPECT CONVECTION THIS AFTERNOON AND EVENING DUE TO DAYTIME HEATING AND INSTABILITY. ALSO EXPECT MORE CONVECTION TO ADVECT OVER THE DOMINICAN REPUBLIC IN 24 HOURS DUE TO THE SPECIAL FEATURE LOW AND TROPICAL WAVE.

ATLANTIC OCEAN...

A 1024 MB HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 32N46W WITH SURFACE RIDGING EXTENDING TO THE FLORIDA PANHANDLE. SCATTERED SHOWERS ARE OVER THE N BAHAMAS FROM 24-27N BETWEEN 77W- 80W. ANOTHER 1021 MB HIGH IS OVER THE E ATLANTIC NEAR 35N19W. IN THE UPPER LEVELS... AN UPPER LEVEL LOW IS CENTERED OVER THE W ATLANTIC NEAR 25N70W. SCATTERED SHOWERS ARE FROM 25N-27N BETWEEN 68W-71W. EXPECT OVER THE NEXT 24 HOURS FOR ADDITIONAL CONVECTION TO NE N OF THE LEEWARD ISLANDS S OF 23N BETWEEN 60W-72W.

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

$$ FORMOSA

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