000 AXNT20 KNHC 221049 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 22 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...SPECIAL FEATURES... A 1010 MB LOW IS LOCATED 200 NM MILES EAST OF PUERTO RICO NEAR 18N62W...MOVING W AT 15-20 KT. A TROPICAL WAVE EXTENDS N FROM THE LOW CENTER TO 26N62W. SCATTERED SHOWERS AND THUNDERSTORMS REMAIN W FROM THE LOW FROM 14N-22N BETWEEN 65W-70W. ON THURSDAY AFTERNOON...HURRICANE HUNTER AIRCRAFT FOUND GALE FORCE WINDS IN THE NORTHERN SEMICIRCLE OF THE LOW PRESSURE CENTER. A GALE WARNING IS ACTIVE FOR THIS AREA FOR THE NEXT 18 HOURS. GRADUAL DEVELOPMENT OF THE LOW IS STILL EXPECTED DURING THE NEXT FEW DAYS AS IT MOVES ACROSS THE GREATER ANTILLES. INTERESTS DOWNSTREAM OF THE LOW SHOULD MONITOR CLOSELY THE PROGRESS OF THIS SYSTEM. CHANCES FOR DEVELOPMENT INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS IS HIGH. ...TROPICAL WAVES... A TROPICAL WAVE IS WEST OF THE CAPE VERDE ISLANDS WITH AXIS EXTENDING FROM 23N29W TO 11N28W MOVING W AT 5-10 KT. NO SIGNIFICANT CONVECTION IS OCCURRING AT THIS TIME AS DRY SAHARAN AIR AND DUST ARE IN ITS ENVIRONMENT. A TROPICAL WAVE IS EAST OF THE LEEWARD ISLANDS WITH AXIS EXTENDING FROM 26N63W TO THE CENTER OF A LOW PRESSURE SYSTEM NEAR 18N62W. SEE SPECIAL FEATURES SECTION FOR MORE INFORMATION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N17W AND CONTINUES ALONG 12N28W TO 11N28W TO 08N40W. AN ITCZ EXTENDS FROM 08N40W TO 09N53W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 07N-14N E OF 22W AND WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE FROM 06N-09N BETWEEN 41W-55W. ...DISCUSSION... GULF OF MEXICO... A 1020 MB HIGH PRESSURE SYSTEM IS CENTERED ON THE N GULF NEAR 29N90W. LATEST SURFACE OBSERVATIONS ALONG WITH A SCATTEROMETER PASS SHOW ANTICYCLONIC WINDS MAINLY BETWEEN 5-10 KT WINDS UP TO 15 KT W OF 90W. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE MOVING ACROSS THE SE PORTION OF THE BASIN MAINLY TO THE NORTHWEST OF CUBA SUPPORTED BY UPPER LEVEL DIFFLUENCE AND LOW LEVEL MOISTURE S OF 25N E OF 83W. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS MAINLY OVER THE SOUTHERN HALF OF THE BASIN DURING THE NEXT 24 HOURS. CARIBBEAN SEA... AN AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE IS NW OF BARBUDA...WITH LOW PRESSURE CENTER LOCATED NEAR 18N62W. MID- LEVEL DIVERGENCE ALONG WITH DEEP LAYER MOISTURE ASSOCIATED WITH THIS SYSTEM IS SUPPORTING THE CONVECTION DESCRIBED IN THE SPECIAL FEATURES SECTION...FOR MORE INFORMATION PLEASE SEE ABOVE. AN ELONGATED UPPER LEVEL LOW EXTENDS ACROSS THE SW CARIBBEAN ENHANCING SHOWERS AND THUNDERSTORMS ON WESTERN CUBA AND EAST OF THE YUCATAN PENINSULA. THIS LOW ACCOMPANIED BY UPPER LEVEL DIFFLUENCE ACROSS THE NW BASIN IS ENHANCING SHOWERS AND THUNDERSTORMS ON WESTERN CUBA AND THE ADJACENT WATERS. FAIR WEATHER IS PREVAILING ELSEWHERE ACROSS THE BASIN BEING SUPPORTED BY DEEP LAYER DRY AIR AND/OR STRONG ENVIRONMENTAL SHEAR ACROSS CENTER CARIBBEAN. TRADE WINDS OF 10-15 KT ARE ACROSS THE REGION...EXCEPT ALONG THE WATERS CLOSE TO COLOMBIA...WHERE WINDS INCREASE UP TO 20 KT. SHOWERS ASSOCIATED WITH THE SYSTEM ON THE SPECIAL FEATURES WILL BE AFFECTING THE GREATER ANTILLES OVER THE WEEKEND. ...HISPANIOLA... HIGH MOISTURE CONTENT AND INSTABILITY IS PRESENT ACROSS THE EASTERN DOMINICAN REPUBLIC AND THE ADJACENT WATERS AND WILL CONTINUE ON THE INCREASE AS THE LOW PRESSURE AND ASSOCIATED TROPICAL WAVE DISCUSSED IN THE SPECIAL FEATURES SECTION APPROACH THE ISLAND. SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER THE WEEKEND...PEAKING BY SATURDAY MORNING AS THE SYSTEM MOVES ACROSS THE ISLAND. ATLANTIC OCEAN... MID/UPPER LEVEL RIDGING PREVAILS ACROSS THE BASIN N OF 25N WHICH IS SUPPORTING SURFACE RIDGING. GALE FORCE WINDS ARE CLOSE TO THE LEEWARD ISLANDS ASSOCIATED WITH THE SYSTEM IN THE SPECIAL FEATURES. FOR MORE INFORMATION...SEE ABOVE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RIVERA