000 AXNT20 KNHC 141748 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN JUN 14 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 1715 UTC. ...SPECIAL FEATURES... A SHARP TROUGH OF SURFACE LOW PRESSURE ACROSS THE YUCATAN PENINSULA AND SOUTHERN GULF IN COMBINATION WITH AN UPPER-LEVEL LOW OVER THE GULF OF MEXICO...CONTINUES TO PRODUCE SHOWERS AND THUNDERSTORMS OVER PORTIONS OF GUATEMALA...BELIZE...THE YUCATAN...AND ADJACENT WATERS. UPPER LEVEL WINDS ARE EXPECTED TO BECOME MORE FAVORABLE FOR SOME DEVELOPMENT OVER THE NEXT DAY OR TWO AS THE SYSTEM MOVES NORTHWESTWARD INTO THE WESTERN GULF OF MEXICO. HEAVY RAINFALL IS EXPECTED TO CONTINUE OVER THESE AREAS TODAY...ALONG WITH WINDS TO NEAR GALE FORCE OVER PORTIONS OF THE NORTHWESTERN CARIBBEAN SEA AND THE SOUTHEASTERN GULF OF MEXICO. AN AIR FORCE RESERVE HURRICANE HUNTER IS SCHEDULED TO INVESTIGATE THE SYSTEM THIS AFTERNOON. ADDITIONAL INFORMATION ABOUT THIS FEATURE IS FOUND IN THE HIGH SEAS FORECAST UNDER WMO FZNT02 KNHC OR MIAHSFAT2. THE CHANCES OF THIS SYSTEM DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS IS MEDIUM. A TIGHT PRESSURE GRADIENT BETWEEN CENTRAL ATLC HIGH PRESSURE AND LOWER PRESSURES OVER S AMERICA SUPPORTS GALE FORCE WINDS S OF 12 N BETWEEN 70W AND 72W...INCLUDING THE GULF OF VENEZUELA. SEAS TO 8 FEET ARE POSSIBLE. WINDS ARE EXPECTED TO DROP BELOW GALE FORCE BY 1800 UTC TODAY. SEE THE LATEST HIGH SEAS FORECAST UNDER WMO FZNT02 KNHC OR MIAHSFAT2 FOR MORE DETAILS. ...TROPICAL WAVES... AN EASTERN ATLANTIC TROPICAL WAVE HAS EMERGED OFF THE AFRICAN COAST AND EXTENDS ALONG 16W/17W FROM 11N TO 5N MOVING WESTWARD AT AROUND 20 KT. SSMI TPW INDICATES A LARGE AREA OF DEEP MOISTURE IN THE WAVE ENVIRONMENT. SATELLITE ENHANCEMENTS SHOW A LARGE AREA OF SAHARAN DUST SURGING WESTWARD TO THE NORTH OF THE WAVE. SCATTERED MODERATE CONVECTION IS FROM 05N TO 13N BETWEEN 12W AND 25W. A CENTRAL ATLANTIC TROPICAL WAVE IS ALONG 41W/42W FROM 16N TO 06N...MOVING WESTWARD AT 15 TO 20 KT OVER THE PAST 24 HOURS. MODEL GUIDANCE DEPICTS A 700 MB TROUGH IN THE ENVIRONMENT OF THIS WAVE. TPW SSMI IMAGERY SHOWS THAT A DEEP MOIST ENVIRONMENT PREVAILS FROM 04N TO 15N. SAHARAN DUST IS NOTED N OF 15N. ISOLATED MODERATE CONVECTION IS FROM 08N TO 11N BETWEEN 42W AND 44W. A CENTRAL ATLANTIC TROPICAL WAVE IS ALONG 51W/52W FROM 14N TO 05N...MOVING WESTWARD AT 15 TO 20 KT OVER THE PAST 24 HOURS. SAHARAN DUST IS ALSO ALONG THE NORTHERN HALF OF THIS WAVE WHICH IS INHIBITING SIGNIFICANT CONVECTIVE PRECIPITATION OVER THIS AREA MAINLY TO THE NORTH OF 11N. SCATTERED MODERATE CONVECTION IS FROM 05N TO 11N BETWEEN 51W TO 61W. A CENTRAL CARIBBEAN SEA TROPICAL WAVE IS ALONG 74W/75W FROM HAITI NEAR 19N SOUTHWARD TO NORTHERN COLOMBIA. THE WAVE IS MOVING WESTWARD AT 15 TO 20 KT OVER THE PAST 24 HOURS. TOTAL PRECIPITABLE WATER IMAGERY SHOWS THAT THIS WAVE IS EMBEDDED IN RELATIVELY DRY AIR. THERE IS ALSO A BROAD SAHARAN AIRMASS PREVAILING ACROSS THE EASTERN CARIBBEAN INHIBITING ANY CONVECTION. NO DEEP CONVECTION IS NOTED WITH THIS WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH ENDS BEFORE CROSSING THE AFRICAN COAST AS A TROPICAL WAVE EXITS THE COASTAL REGIONS OF THE CONTINENT TODAY. THE ITCZ BEGINS NEAR 07N21W AND CONTINUES THROUGH 06N30W TO 08N41W...THEN CONTINUES WEST OF A TROPICAL WAVE FROM 08N44W TO 07N51W. OTHER THAN CONVECTION DISCUSSED IN THE TROPICAL WAVES SECTION...ISOLATED MODERATE CONVECTION IS WITHIN 100 NM OF THE ITCZ AXIS BETWEEN 24W AND 36W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 25N90W WITH CYCLONIC FLOW ALOFT OVER THE SOUTHERN GULF OF MEXICO. UPPER LEVEL RIDGING COVERS THE NORTHERN GULF. A SHARP TROUGH OF SURFACE LOW PRESSURE EXTENDS FROM 25N88W TO THE YUCATAN PENINSULA. GALE FORCE WINDS ARE OCCURRING OVER PORTIONS OF THE SOUTHEASTERN GULF ASSOCIATED WITH THIS FEATURE. SEE THE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS. THIS TROUGH IS INTERACTING WITH THE UPPER LEVEL LOW TO PRODUCE NUMEROUS MODERATE TO STRONG CONVECTION FROM 22N TO 25N BETWEEN 84W AND 89W. UPPER LEVEL DIFFLUENCE OVER THE NE GULF SUPPORTS SCATTERED THUNDERSTORMS FROM 25N TO THE NORTHERN GULF COAST BETWEEN 83W AND 91W. ASIDE FROM THE STRONGER WINDS NEAR THE SPECIAL FEATURE...SOUTHEASTERLY SURFACE WINDS OF 15 TO 20 KT DOMINATE THE BASIN. OVER THE NEXT 24 HOURS THE SPECIAL FEATURE WILL MOVE NORTHWESTWARD OVER THE CENTRAL GULF TOWARD THE NW GULF. EXPECT NUMEROUS AREAS OF CONVECTION TO SPREAD ACROSS THE CENTRAL GULF TO NW GULF THROUGH MONDAY...ALONG WITH AREAS OF GALE FORCE WINDS. THE CARIBBEAN SEA... CONVECTION AND GALE FORCE WINDS OVER THE EXTREME NORTHWESTERN PORTION OF THE CARIBBEAN IS ASSOCIATED WITH A SHARP TROUGH OF SURFACE LOW PRESSURE OVER THE YUCATAN PENINSULA AND GULF OF MEXICO. A STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE CENTRAL ATLC AND LOWER PRESSURE OVER S AMERICA IS SUPPORTING GALE FORCE WINDS OVER THE GULF OF VENEZUELA. PLEASE SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. SAHARAN DUST WITH RELATIVELY DRY AIR COVERS THE CENTRAL AND EASTERN CARIBBEAN EAST OF 82W. ASIDE FROM THE AREAS WITH GALE FORCE WINDS...15 TO 25 KT TRADE WINDS COVER MOST OF THE REMAINDER OF THE CARIBBEAN WITH AN AREA OF WINDS AROUND 30 KT FROM 11N TO 15N BETWEEN 70W AND 80W. OVER THE NEXT 24 HOURS CONVECTION AND WINDS WILL DECREASE OVER THE NORTHWESTERN CARIBBEAN AS THE SPECIAL FEATURE LIFTS NW ACROSS THE GULF OF MEXICO. A TROPICAL WAVE APPROACHING THE LESSER ANTILLES MAY BRING CONVECTION TO THE ISLANDS BY MONDAY NIGHT. ...HISPANIOLA... SAHARAN DUST IS BEING OBSERVED OVER THE ISLAND TODAY IN ADDITION TO RELATIVELY DRY AIR IN THE LOW LEVELS. THESE FACTORS ARE HELPING TO INHIBIT SHOWER AND THUNDERSTORM ACTIVITY OVER THE ISLAND TODAY. AN ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT THIS AFTERNOON AND MONDAY AFTERNOON. OTHERWISE...EXPECT GENERALLY FAIR CONDITIONS THROUGH MONDAY NIGHT. THE ATLANTIC OCEAN... A WEAK 1020 MB HIGH IS CENTERED NEAR 29N76W. UPPER LEVEL RIDGING JUST TO THE NORTH OF THIS SURFACE HIGH IS PRODUCING DIFFLUENCE WHICH SUPPORTS ISOLATED MODERATE CONVECTION FROM 30N TO 32N BETWEEN 74W AND 78W. AN UPPER LOW IS CENTERED NEAR 28N59W WITH A TROUGH AXIS EXTENDING SOUTHWESTWARD TO NEAR THE TURKS AND CAICOS. DYNAMIC LIFT ASSOCIATED WITH THE TROUGH SUPPORTS WIDELY SCATTERED MODERATE CONVECTION FROM 23N TO 26N BETWEEN 63W AND 73W. A NEARLY STATIONARY 1023 MB SURFACE HIGH IS CENTERED NEAR 28N53W. FARTHER EAST...A SURFACE TROUGH EXTENDS FROM 29N42W TO 24N44W. NO DEEP CONVECTION IS NOTED WITH THIS TROUGH. A 1026 MB HIGH CENTERED NEAR 31N33W DOMINATES THE EASTERN ATLC WITH ANTICYCLONIC FLOW AND GENERALLY FAIR WEATHER FROM 15N TO 32N EAST OF 55W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO