106
AXNT20 KNHC 191205
TWDAT
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED SEP 19 2018
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
1115 UTC.
..TROPICAL WAVES
AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 18W FROM 20N SOUTHWARD,
MOVING W AT 10 KT. THIS WAVE IS ASSOCIATED WITH A DISTINCT 700 MB
TROUGH. SCATTERED MODERATE CONVECTION IS OVER AFRICA FROM 14N-18N
BETWEEN 12W-17W. WIDELY SCATTERED MODERATE CONVECTION IS OVER THE
SOUTHERN PORTION OF THE WAVE OVER THE ATLANTIC FROM 05N-08N
BETWEEN 10W-21W.
A SURFACE TROUGH IS OVER THE ATLANTIC ALONG 45W FROM 12N
SOUTHWARD, MOVING W AT 10-15 KT. THIS TROUGH MAY BE DEVELOPING A
SURFACE LOW. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS
FROM 04N-14N BETWEEN 40W-50W.
A CARIBBEAN TROPICAL WAVE IS ALONG 62W FROM 19N SOUTHWARD, MOVING
W AT 10-15 KT. ISOLATED MODERATE CONVECTION IS FROM 10N-17N
BETWEEN 58W-64W, MOST CONCENTRATED NEAR BARBADOS.
..MONSOON TROUGH/ITCZ
THE MONSOON TROUGH PASSES THROUGH THE COASTAL AREAS OF GUINEA
NEAR 11N14W, TO 09N18W. THE ITCZ CONTINUES FROM 09N18W TO 07N25W,
AND TO 08N40W. SCATTERED MODERATE TO ISOLATED STRONG RAINSHOWERS
ARE WITHIN 190 NM ON EITHER SIDE OF THE LINE THAT RUNS FROM
09N14W 07N19W, 06N27W, 06N38W, TO 11N51W.
..DISCUSSION
GULF OF MEXICO...
A SURFACE RIDGE EXTENDS FROM THE FLORIDA PANHANDLE, ACROSS THE N
CENTRAL GULF OF MEXICO, TO THE DEEP SOUTH OF TEXAS NEAR 27N97W.
ISOLATED MODERATE RAINSHOWERS ARE IN THE COASTAL WATERS/COASTAL
PLAINS OF SE LOUISIANA.
WEAK HIGH PRESSURE EXTENDS ACROSS THE NORTHERN GULF OF MEXICO,
SUPPORTING LIGHT BREEZES AND MINIMAL SEAS. A SURFACE TROUGH, THAT
IS IN THE NW CORNER OF THE CARIBBEAN SEA, WILL MOVE ACROSS THE
YUCATAN CHANNEL THROUGH WED, INTO THE SOUTHWEST GULF OF MEXICO ON
THURSDAY AND FRIDAY, AND THEN DISSIPATE ON SATURDAY.
CARIBBEAN SEA...
A SURFACE TROUGH IS IN THE NW CORNER OF THE CARIBBEAN SEA, FROM NW
CUBA TO E SECTIONS OF HONDURAS. WIDELY SCATTERED MODERATE
CONVECTION IS FROM 17N TO CUBA BETWEEN 79W-87W.
SCATTERED MODERATE TO STRONG CONVECTION IS OVER THE SW CARIBBEAN
FROM 15N SOUTHWARD BETWEEN 77W-84W. THE MONSOON TROUGH IS ALONG
09N OVER COSTA RICA AND PANAMA.
A SURFACE TROUGH OVER THE NW CARIBBEAN SEA WILL CONTINUE MOVING
WESTWARD OVERNIGHT AND EXIT THE AREA ON WEDNESDAY, ACCOMPANIED BY
ACTIVE WEATHER. A TROPICAL WAVE, THAT IS MOVING ACROSS THE LESSER
ANTILLES WILL MOVE THROUGH THE CENTRAL CARIBBEAN SEA FROM
THURSDAY INTO FRIDAY, AND PASS TO THE WEST OF THE AREA THROUGH
LATE SATURDAY INTO SUNDAY. HIGH PRESSURE, THAT IS BUILDING FROM
THE CENTRAL ATLANTIC OCEAN INTO THE CENTRAL BAHAMAS, WILL SUPPORT
MODERATE TO FRESH TRADE WINDS AND BUILDING SEAS ACROSS THE ENTIRE
BASIN FROM LATE WEDNESDAY THROUGH FRIDAY.
ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION CENTER,
THAT IS ABOUT 160 NM TO THE SSW OF BERMUDA, TO THE SOUTHERN HALF
OF THE BAHAMAS. A SURFACE TROUGH PASSES THROUGH 32N64W, TO 28N66W,
AND TO 23N70W. ISOLATED MODERATE TO LOCALLY STRONG RAINSHOWERS
COVER THE AREA THAT RUNS FROM 20N NORTHWARD BETWEEN 47W AND THE
WINDWARD PASSAGE.
A SURFACE TROUGH, REACHING FROM BERMUDA TO THE SOUTHERN BAHAMAS,
WILL SHIFT NW SLOWLY AND WEAKEN THROUGH EARLY WEDNESDAY, AS THE
CENTRAL ATLANTIC OCEAN RIDGE BUILDS INTO THE CENTRAL BAHAMAS. LOW
PRESSURE MOVING OFF THE CAROLINAS WILL DRAG AN ATTENDANT FRONTAL
TROUGH ACROSS THE WATERS NORTH OF 27N ON THURSDAY AND FRIDAY. THE
LOW WILL MOVE TO NEAR 31N67W ON FRIDAY EVENING, AND THEN DRIFT W
AND WEAKEN SLOWLY ON SATURDAY AND SUNDAY.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE
FORMOSA
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