000 AXNT20 KNHC 180604 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU JUL 18 2013 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 20N26W 15N28W 9N28W...MOVING WESTWARD 15 TO 20 KNOTS. CONVECTIVE PRECIPITATION...SCATTERED MODERATE IN THE ITCZ FROM 7N TO 10N BETWEEN 27W AND 30W. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 20N62W 16N64W 12N64W...MOVING WESTWARD 20 TO 25 KNOTS. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 15N TO 21N BETWEEN 59W AND 71W. SOME OF THE PRECIPITATION THAT IS IN THE COMPARATIVELY MORE WESTERN PART OF THE AREA MAY NOT BE RELATED TO THE WAVE. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 17N76W 14N77W 11N77W...MOVING WESTWARD 20 KNOTS. BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW IS MOVING ACROSS THE AREA OF THE WAVE. CONVECTIVE PRECIPITATION... ISOLATED MODERATE IN THE WATERS THAT ARE BETWEEN 65W AND 70W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL MAURITANIA NEAR 18N16W TO 17N18W. THE ITCZ STARTS NEAR 8N30W... TO 8N38W 5N47W...TO 5N53W AT THE COAST OF FRENCH GUIANA. CONVECTIVE PRECIPITATION...NUMEROUS STRONG FROM 7N TO 9N BETWEEN 30W AND 35W...AND FROM 5N TO 8N BETWEEN 43W AND 53W. SCATTERED MODERATE TO ISOLATED STRONG FROM 3N TO 8N BETWEEN 35W AND 43W. ...DISCUSSION... FROM THE ATLANTIC OCEAN...INTO THE CARIBBEAN SEA... TO THE NORTH OF 15N BETWEEN 59W AND 71W... A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC ENVELOPE COVERS THE AREA. MULTIPLE CYCLONIC CIRCULATION CENTERS ARE PRESENT IN THE AREA...IN THE ATLANTIC OCEAN. ONE IS NEAR 29N63W. A SECOND CENTER IS NEAR 28N71W. AN ATLANTIC OCEAN SURFACE TROUGH IS ALONG 31N72W 27N74W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE BETWEEN 57W AND 72W TO THE NORTH OF 20N. MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW FROM A 20N74W 30N80W RIDGE COVERS THE ATLANTIC OCEAN THAT IS BETWEEN 71W AND 80W. WARMING CLOUD TOP TEMPERATURES AND WEAKENING CONVECTIVE PRECIPITATION ARE UNDER THE RIDGE. THE GULF OF MEXICO... ONE MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 28N85W OFF THE COAST OF FLORIDA. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG TO THE SOUTH OF 26N TO THE EAST OF 86W IN THE SOUTHEASTERN CORNER OF THE GULF OF MEXICO. EARLIER STRONG CONVECTIVE PRECIPITATION WAS IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...IN AN AREA OF DIFFLUENT WIND FLOW...TO THE NORTH OF 18N TO THE WEST OF 80W. WIDELY SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION REMAINS THERE. A SECOND CYCLONIC CIRCULATION CENTER APPEARS TO BE WEAKENING AS ITS CYCLONIC WIND FLOW COVERS THE YUCATAN PENINSULA. BROAD MULTILAYERED NORTHERLY-TO- NORTHWESTERLY WIND FLOW COVERS THE REST OF THE GULF OF MEXICO. OVERCAST HIGH CLOUDS ARE IN THE NEW ORLEANS LOUISIANA METROPOLITAN AREA...AND IN THE TAMPA METROPOLITAN AREA. ELSEWHERE IN FLORIDA...LOW LEVEL AND HIGH LEVEL CLOUD CEILINGS STRETCH FROM MILTON TO CRESTVIEW. LIGHT DRIZZLE IS IN PANAMA CITY. A LOW CLOUD/MIDDLE CLOUD CEILING COVERS TALLAHASSEE...AND MARATHON KEY. FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ELSEWHERE. FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N TO THE WEST OF 88W... A LOW CLOUD CEILING IS REPORTED AT THE ICAO STATIONS KMZG...KEIR...AND KDLP. A MIDDLE LEVEL CLOUD CEILING IS AT THE ICAO STATION KEMK. FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE BEING REPORTED ELSEWHERE. THE CARIBBEAN SEA... EARLIER STRONG CONVECTIVE PRECIPITATION WAS IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...IN AN AREA OF DIFFLUENT WIND FLOW...TO THE NORTH OF 18N TO THE WEST OF 80W. WIDELY SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION REMAINS THERE. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 67W TO THE SOUTH OF 20N...MOVING WESTWARD 15 TO 20 KNOTS. BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW IS MOVING ACROSS THE AREA OF THE WAVE. CONVECTIVE PRECIPITATION... ISOLATED MODERATE IN THE WATERS THAT ARE BETWEEN 65W AND 70W. THE MONSOON TROUGH IS ALONG 10N74W 10N82W...ACROSS COSTA RICA...AND BEYOND 9N86W IN THE EASTERN PACIFIC OCEAN. CONVECTIVE PRECIPITATION...NUMEROUS STRONG ON THE EASTERN PACIFIC OCEAN SIDE OF CENTRAL AMERICA FROM 6N TO 10N BETWEEN 83W AND 87W. NUMEROUS STRONG ALSO IS ALONG THE COAST OF NICARAGUA FROM 11N TO 12N BETWEEN 82W AND 84W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2... AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE 20 TO 25 KNOT NORTHEAST TO EAST WINDS AND 8 TO 11 FOOT SEA HEIGHTS FROM 11N TO 18N BETWEEN 70W AND 82W. HISPANIOLA... A CARIBBEAN SEA TROPICAL WAVE IS ALONG 20N62W 16N64W 12N64W...MOVING WESTWARD 20 TO 25 KNOTS. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 15N TO 21N BETWEEN 59W AND 71W. SOME OF THE PRECIPITATION THAT IS IN THE COMPARATIVELY MORE WESTERN PART OF THE AREA MAY NOT BE RELATED TO THE WAVE. THE WAVE SHOULD AFFECT HISPANIOLA LATER TODAY. THE GFS FORECAST FOR 700 MB SHOWS EASTERLY WIND FLOW ACROSS THE AREA FOR THE FIRST 30 HOURS OR SO... FOLLOWED BY SOUTHEASTERLY WIND FLOW ACROSS THE AREA. THE GFS FORECAST FOR 500 MB STARTS WITH HISPANIOLA IN A RIDGE FOR MOST OF THE FIRST 24 HOURS...FOLLOWED BY AN INVERTED TROUGH MOVING WESTWARD ACROSS THE AREA. THE 250 MB GFS SHOWS THAT A TROUGH WILL START ON TOP OF THE AREA...FOLLOWED BY THE TRANSITION TO NORTHERLY WIND FLOW...FOLLOWED BY AN INVERTED TROUGH ACROSS THE AREA FOR THE REST OF THE 48 HOURS. THE REST OF THE ATLANTIC OCEAN... A SURFACE RIDGE EXTENDS FROM A 1026 MB HIGH PRESSURE CENTER THAT IS NEAR 33N23W TO 29N30W 27N39W...TO A 1025 MB HIGH PRESSURE CENTER THAT IS NEAR 28N49W...TO 29N70W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR MORE DETAILS ABOUT 20 KNOT WINDS OR LESS AND 9 FOOT SEA HEIGHTS TO THE NORTH OF THE LINE 21N35W 17N50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT