Atlantic Tropical Weather Discussion

000
AXNT20 KNHC 180603
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT MAY 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...                                     

A TROPICAL WAVE IS ALONG 9N51W 6N52W 2N53W IN THE
SOUTHEASTERN CORNER OF FRENCH GUIANA. CONVECTIVE
PRECIPITATION...SCATTERED STRONG FROM 7N TO 9N
BETWEEN 47W AND 54W. 

...THE ITCZ/THE MONSOON TROUGH... 

THE MONSOON TROUGH PASSES THROUGH COASTAL GUINEA NEAR
11N15W TO 6N20W. THE ITCZ CONTINUES FROM 6N20W TO 2N33W
TO 2N44W AND 1N50W. CONVECTIVE PRECIPITATION...NUMEROUS
STRONG IN THE IVORY COAST FROM 4N TO 7N BETWEEN 5W AND 7W...
FROM 1N TO 3N BETWEEN 5W AND 8W...FROM 5N TO 6N BETWEEN
15W AND 16W. WIDELY SCATTERED TO SCATTERED MODERATE AND
ISOLATED STRONG ELSEWHERE TO THE SOUTH OF 10N TO THE EAST
OF 60W.

...DISCUSSION...

THE GULF OF MEXICO...

A MIDDLE LEVEL TO UPPER LEVEL RIDGE IS ALONG 20N98W IN
MEXICO BEYOND 28N100W INTO TEXAS. UPPER LEVEL WESTERLY
TO NORTHWESTERLY WIND FLOW MOVES ACROSS THE GULF OF
MEXICO. COMPARATIVELY DRIER AIR IS TO THE NORTH OF 23N
TO THE EAST OF 94W. 

A SURFACE RIDGE EXTENDS FROM AN ATLANTIC OCEAN 1023 MB
HIGH PRESSURE CENTER THAT IS NEAR 29N66W...CROSSING
THE NORTHERN BAHAMAS NEAR 26N77W...INTO THE CENTRAL
GULF OF MEXICO NEAR 26N90W...TO 21N97W IN THE
SOUTHWESTERN CORNER OF THE GULF OF MEXICO.

RAINSHOWERS ARE POSSIBLE TO THE SOUTH OF 26N
TO THE EAST OF 87W IN THE FLORIDA STRAITS.

LOW CLOUD CEILINGS COVER THE STATIONS THAT ARE CLOSER
TO THE COAST IN THE DEEP SOUTH OF TEXAS. FAIR SKIES/
CLEAR SKIES AT OR LOWER THAN 12000 FEET COVER THE REST
OF THE DEEP SOUTH OF TEXAS COMPARATIVELY MORE TO THE WEST.
LOW CLOUD CEILINGS ARE IN THE REST OF TEXAS...IN COASTAL
LOUISIANA...IN COASTAL MISSISSIPPI...AND IN THE FLORIDA
PANHANDLE TO THE WEST OF 86W. THE ST. PETERSBURG
FLORIDA AIRPORT IS REPORTING A LOW CLOUD CEILING. 
FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET ARE
ELSEWHERE IN FLORIDA.

FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE
TO THE NORTH OF 27N TO THE WEST OF 88W...

LOW CLOUD CEILINGS ARE BEING REPORTED AT THE FOLLOWING
ICAO STATIONS...KMZG...KGVX...KVBS...KCRH...AND KHQI.
FAIR SKIES/CLEAR SKIES AT OR LOWER THAN 12000 FEET
ARE REPORTED ELSEWHERE.

THE CARIBBEAN SEA...                                                

A MIDDLE LEVEL TO UPPER LEVEL RIDGE STARTS NEAR TRINIDAD
AND TOBAGO...CONTINUING ACROSS NORTHERN COASTAL SECTIONS
OF VENEZUELA AND COLOMBIA...TO 12N77W IN THE CARIBBEAN
SEA...TO 15N80W AND 16N82W. 

THE MONSOON TROUGH IS ALONG 8N74W IN COLOMBIA...TO 7N79W...
ACROSS SOUTHERN COASTAL PANAMA AND COASTAL COSTA RICA...
TO 10N86W...BEYOND 9N90W IN THE EASTERN PACIFIC OCEAN.
CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO
ISOLATED STRONG ELSEWHERE IN COLOMBIA TO THE NORTH OF 3N.

RAINSHOWERS ALSO ARE POSSIBLE TO THE NORTH OF 17N BETWEEN
JAMAICA AND 82W.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...
AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS
ABOUT THE NORTHEAST TO EAST 20 TO 25 KNOTS AND SEA HEIGHTS
REACHING 8 FEET FROM 11N TO 13N BETWEEN 72W AND 75W.

HISPANIOLA...                                                   

MIDDLE LEVEL TO UPPER LEVEL NORTHWESTERLY WIND FLOW PASSES
THROUGH THE FLORIDA STRAITS...ACROSS CUBA AND HISPANIOLA...
MERGING WITH THE MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC
WIND FLOW THAT IS RELATED TO THE TRINIDAD-TO-16N82W RIDGE.

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH THE 
ATLANTIC OCEAN NEAR 20N52W TO 17N60W...TO 17N67W TO THE
SOUTH OF THE MONA PASSAGE. THE SOUTHERNMOST POINT OF
AN ATLANTIC OCEAN STATIONARY FRONT IS NEAR 21N67W IN THE
ATLANTIC OCEAN. RAINSHOWERS ARE POSSIBLE FROM 16N TO 20N
BETWEEN 66W AND THE WINDWARD PASSAGE...INCLUDING IN
INTERIOR SECTIONS OF HISPANIOLA.

THE GFS MODEL GIVES A FORECAST OF A 250 MB TROUGH TO BE
ACROSS THE AREA DURING THE NEXT 48 HOURS OR SO. THE GFS MODEL
ALSO GIVES THE FORECAST OF A PERSISTENT RIDGE AT 500 MB
AND 700 MB...WITH NORTHWESTERLY WIND FLOW ALSO AT 500 MB...
DURING THE SAME TIME PERIOD. A WEAK SURFACE TROUGH MAY CONTINUE
FOR A BIT MORE TIME. THE GFS MODEL CUTS OUT THE SURFACE TROUGH
FROM ITS FORECAST. ENOUGH LOW LEVEL MOISTURE MAY CONTINUE TO BE
PRESENT IN ORDER TO HELP TO GIVE SOME PRECIPITATION TO THE AREA.

THE ATLANTIC OCEAN...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 32N43W
CYCLONIC CIRCULATION CENTER...TO 23N45W 20N52W 17N60W...
TO 17N67W TO THE SOUTH OF THE MONA PASSAGE. THE SOUTHERNMOST
POINT OF A STATIONARY FRONT IS NEAR 21N67W IN THE ATLANTIC
OCEAN. RAINSHOWERS ARE POSSIBLE FROM 16N TO 20N BETWEEN 66W
AND THE WINDWARD PASSAGE...INCLUDING IN INTERIOR SECTIONS
OF HISPANIOLA. A STATIONARY FRONT PASSES THROUGH 32N56W TO
28N60W 23N64W AND 21N67W. A SURFACE TROUGH IS ALONG 31N50W
TO 25N47W. RAINSHOWERS ARE POSSIBLE TO THE NORTHWEST AND 
NORTH OF THE LINE THAT PASSES THROUGH 32N52W 24N60W 20N67W...
INCLUDING ACROSS THE BAHAMAS AND THE ATLANTIC OCEAN TO THE
EAST OF FLORIDA.

A SURFACE RIDGE EXTENDS FROM AN ATLANTIC OCEAN 1023 MB
HIGH PRESSURE CENTER THAT IS NEAR 29N66W...CROSSING
THE NORTHERN BAHAMAS NEAR 26N77W...INTO THE CENTRAL
GULF OF MEXICO NEAR 26N90W...TO 21N97W IN THE
SOUTHWESTERN CORNER OF THE GULF OF MEXICO.

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH MOROCCO
TO 23N18W AND 18N19W. NO SIGNIFICANT DEEP CONVECTIVE 
PRECIPITATION APPEARS IN SATELLITE IMAGERY.

BROAD ATLANTIC OCEAN SURFACE ANTICYCLONIC WIND FLOW THAT IS
TO THE NORTH OF 14N TO THE EAST OF 52W IS INTERRUPTED BY THE
31N50W 25N47W SURFACE TROUGH.

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

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MT