000 AXNT20 KNHC 181751 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU JUN 18 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... GALE-FORCE WINDS ARE FORECAST FOR THE CARIBBEAN SEA...FROM 11N TO 14N BETWEEN 70W AND 76W...INCLUDING IN THE GULF OF VENEZUELA. EXPECT SEA HEIGHTS IN THIS AREA TO RANGE FROM 10 FEET TO 14 FEET...EXCEPT REACHING TO 8 FEET IN THE GULF OF VENEZUELA. A STRONG SURFACE PRESSURE GRADIENT EXISTS BETWEEN AN ATLANTIC OCEAN 1021 MB HIGH PRESSURE CENTER THAT IS NEAR 28N76W...ABOUT 120 NM TO THE NORTHEAST OF THE ABACO ISLANDS IN THE BAHAMAS...AND COMPARATIVELY LOWER SURFACE PRESSURE IN COLOMBIA. THE FORECAST OF GALE-FORCE WIND CONDITIONS CONTINUES FOR THE NEXT 6 HOURS OR SO. PLEASE READ THE HIGH SEAS FORECAST...UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 15N33W 10N35W 5N37W E MOVING WESTWARD 15 TO 20 KT. THE WAVE COINCIDES WITH HIGHER MOISTURE VALUES ON TOTAL PRECIPITABLE WATER IMAGERY BETWEEN 26W AND 36W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 2N TO 11N BETWEEN 34W AND 42W. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 68W/69W FROM 16N SOUTHWARD MOVING WESTWARD 15 TO 20 KT. THE WAVE COINCIDES WITH A WEAK 700 MB TROUGH THAT IS BETWEEN 65W AND 72W. THE TROUGH IS EMBEDDED WITHIN A LENGTHY EASTERLY JET THAT STRETCHES FROM 12N37W TO 15N78W. NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS ASSOCIATED WITH THE WAVE AT THIS TIME. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 80W FROM 16N SOUTHWARD MOVING WESTWARD 10 KT. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THAT THE WAVE IS EMBEDDED WITHIN INCREASED VALUES OF DEEP MOISTURE ACROSS THE WESTERN CARIBBEAN SEA. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 9N TO 11N BETWEEN 81W IN THE COASTAL WATERS OF PANAMA AND COSTA RICA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL SECTIONS OF SIERRA LEONE NEAR 8N13W TO 8N19W. THE ITCZ CONTINUES FROM 8N19W TO 5N25W 8N32W 5N40W. CONVECTIVE PRECIPITATION...ISOLATED TO WIDELY SCATTERED MODERATE AND LOCALLY STRONG FROM 6N TO 11N FROM 34W EASTWARD. ...DISCUSSION... THE GULF OF MEXICO... LARGE-SCALE MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW COVERS THE GULF OF MEXICO. THE CYCLONIC WIND FLOW IS RELATED TO A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER THAT IS IN THE YUCATAN CHANNEL. COMPARATIVELY DRIER AIR IN SUBSIDENCE IS EVIDENT IN WATER VAPOR IMAGERY...EVERYWHERE FROM 93W EASTWARD...EXCEPT FOR THE SMALLER AREA THAT IS FROM 24N SOUTHWARD AND FROM 88W EASTWARD. A SURFACE RIDGE EXTENDS FROM A NORTHEASTERN GULF OF MEXICO 1020 MB HIGH PRESSURE CENTER THAT IS NEAR 29N87W...THROUGH COASTAL LOUISIANA...BEYOND EAST TEXAS. THE SURFACE RIDGE IS FORECAST TO REMAIN ALONG 28N FROM THE FLORIDA PENINSULA TO THE SOUTHEASTERN TEXAS COAST THROUGH FRIDAY...AND THEN SHIFT SLIGHTLY NORTHWARD TO 29N/30N BY SATURDAY. RAINSHOWERS ARE POSSIBLE FROM 22N NORTHWARD FROM 90W EASTWARD. THE CARIBBEAN SEA... A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN THE YUCATAN CHANNEL. CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG FROM 17N TO 18N BETWEEN 88W AND 90W IN PARTS OF BELIZE...THE YUCATAN PENINSULA...AND IN GUATEMALA... AND FROM NORTHEASTERN NICARAGUA INTO EASTERN HONDURAS. RAINSHOWERS ARE POSSIBLE ELSEWHERE IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA FROM 15N NORTHWARD FROM 78W WESTWARD. UPPER LEVEL CYCLONIC WIND FLOW COVERS THE CARIBBEAN SEA FROM 16N NORTHWARD FROM 71W EASTWARD. THIS CYCLONIC WIND FLOW IS ASSOCIATED WITH THE 26N59W ATLANTIC OCEAN CYCLONIC CIRCULATION CENTER. LOW LEVEL TO MIDDLE LEVEL NORTHEASTERLY WIND FLOW COVERS MUCH OF THE AREA THAT IS FROM 18N SOUTHWARD...EVEN INTO NICARAGUA AND HONDURAS. TWO TROPICAL WAVES ARE MOVING THROUGH THE CARIBBEAN SEA. PLEASE READ THE TROPICAL WAVES SECTION FOR DETAILS. ...HISPANIOLA... UPPER LEVEL NORTHWESTERLY WIND FLOW AND MIDDLE LEVEL NORTHEASTERLY WIND ARE MOVING ACROSS HISPANIOLA. CURRENT OBSERVATIONS...IN HAITI...FEW LOW LEVEL CLOUDS AND A MIDDLE LEVEL CLOUD CEILING ARE BEING REPORTED IN PORT-AU-PRINCE. IN THE DOMINICAN REPUBLIC...FEW LOW LEVEL CLOUDS AND SCATTERED MIDDLE LEVEL CLOUDS IN BARAHONA. FEW CUMULONIMBUS CLOUDS... SCATTERED LOW LEVEL CLOUDS AND A HIGH LEVEL CLOUD CEILING COVER SANTO DOMINGO. FEW CUMULONIMBUS CLOUDS AND SCATTERED LOW LEVEL CLOUDS COVER LA ROMANA. FEW CUMULONIMBUS CLOUDS AND MULTILAYERED CLOUD CEILINGS COVER PUNTA CANA. SCATTERED LOW LEVEL CLOUDS ARE IN SANTIAGO. FEW CUMULONIMBUS CLOUDS AND FEW LOW LEVEL CLOUDS ARE IN PUERTO PLATA. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 18N TO 21N BETWEEN 68W AND 74W. THIS PRECIPITATION IS OCCURRING IN THE CYCLONIC WIND FLOW THAT IS MOVING AROUND THE MIDDLE LEVEL TO UPPER LEVEL 26N59W ATLANTIC OCEAN CYCLONIC CIRCULATION CENTER. IT IS POSSIBLE THAT RAINSHOWERS MAY CONTINUE ACROSS HISPANIOLA FOR THE REST OF THE AFTERNOON/EARLY EVENING... GIVEN THE UPPER LEVEL CYCLONIC WIND FLOW...AND THE PEAK DAYTIME HEATING AND THE SURROUNDING ATMOSPHERIC INSTABILITY. THE ATLANTIC OCEAN... A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 31N18W CYCLONIC CIRCULATION CENTER...TO A 31N32W CYCLONIC CIRCULATION CENTER...TO A 24N44W CYCLONIC CIRCULATION CENTER...TO A 26N59W CYCLONIC CIRCULATION CENTER...TO 21N64W AND 21N69W. THE TROUGH EVENTUALLY EXTENDS TO THE ATLANTIC OCEAN COASTAL SIDE OF CENTRAL CUBA...TO A YUCATAN CHANNEL CYCLONIC CIRCULATION CENTER. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO STRONG WITHIN 60 NM ON EITHER SIDE OF 32N58W 27N67W. RAINSHOWERS ARE POSSIBLE ELSEWHERE FROM 21N NORTHWARD BETWEEN 57W AND 70W...AND BETWEEN 70W AND 80W. A SURFACE RIDGE PASSES THROUGH 32N33W TO 26N37W...24N49W... 27N66W...AND TO A 1021 MB HIGH PRESSURE CENTER THAT IS NEAR 28N76W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT