[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 121126
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT DEC 12 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...SPECIAL FEATURE...

A 1000 MB SURFACE LOW IS LOCATED ACROSS THE CENTRAL ATLANTIC
NEAR 33N50W. A COLD FRONT EXTENDS SW FROM THE LOW TO 27N54W TO
26N64W. THE FRONT THEN BECOMES STATIONARY TO 26N74W. STRONG TO
GALE FORCE WINDS ARE NOTED IN SCATTEROMETER DATA SW OF THE LOW
AND BEHIND THE COLD FRONT N OF 29N BETWEEN 47W-54W...WITH SEAS
RANGING FROM 14-20 FT. EXPECT THESE CONDITIONS TO PREVAIL OVER
THE NEXT 18 HOURS. FOR MORE DETAILS PLEASE REFER TO THE HIGH
SEAS FORECAST PRODUCT UNDER THE AWIPS/WMO HEADERS
MIAHSFAT2/FZNT02.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA NEAR 10N14W TO
08N17W. THE ITCZ BEGINS FROM 08N17W TO 02N31W TO 02N47W.
SCATTERED MODERATE CONVECTION PREVAILS FROM 00N-08N AND E OF 35W.

...DISCUSSION...

GULF OF MEXICO...

AN UPPER-LEVEL RIDGE EXTENDS FROM THE E PACIFIC ACROSS MEXICO
AND THE W GULF TO OVER THE SE CONUS SUPPORTING A SURFACE RIDGE
THAT DOMINATES THE GULF. TO THE E...AN UPPER-LEVEL TROUGH OVER
THE W ATLANTIC CLIPS THE STRAITS OF FLORIDA NEAR 23N78W THEN
EXTENDS ACROSS CENTRAL CUBA INTO THE NW CARIBBEAN. WITH THESE
FEATURES...A STRONG SUBSIDENCE AND A DRY AIRMASS COVERS THE GULF
SUPPORTING FAIR WEATHER ACROSS THE AREA. SCATTEROMETER DATA
DEPICTS A GENTLE TO MODERATE ANTICYCLONIC FLOW ACROSS THE BASIN.
EXPECT OVER THE NEXT 24-48 HOURS FOR A PRESSURE GRADIENT TO
TIGHTEN ACROSS THE BASIN AS A DEEPENING LOW PRESSURE WITH ITS
ASSOCIATED COLD FRONT APPROACHES THE NW GULF.

CARIBBEAN SEA...

AN UPPER-LEVEL TROUGH EXTENDS FROM THE W ATLANTIC ACROSS THE
STRAITS OF FLORIDA AND CENTRAL CUBA FROM 23N78W TO 16N80W.
ISOLATED CONVECTION PREVAILS E OF THIS UPPER TROUGH ALONG A LINE
FROM 15N84W TO 19N76W. TO THE E...A DIFFLUENT FLOW ALOFT
CONTINUES TO ENHANCE CLOUDINESS AND CONVECTION ACROSS HISPANIOLA
AND ADJACENT WATERS MAINLY N OF 18N BETWEEN 69W-73W. SHALLOW
MOISTURE IS TRANSPORTED BY THE MODERATE TO FRESH TRADES
ENHANCING ISOLATED CONVECTION ACROSS THE REMAINDER OF THE BASIN.
EXPECT A SIMILAR WEATHER REGIME TO PREVAIL OVER THE NEXT 24
HOURS.

...HISPANIOLA...

A SURFACE TROUGH WAS ANALYZED ACROSS NW HISPANIOLA AND THE SW
ATLANTIC FROM 23N70W TO 20N73W. A DIFFLUENT FLOW ALOFT SUPPORTS
THIS TROUGH AND ENHANCES CLOUDINESS AND CONVECTION ACROSS THE
ISLAND MAINLY BETWEEN 69W-73W. THE UPPER-LEVEL TROUGH IS
EXPECTED TO MOVE E AND DEVELOP A LOW N OF THE ISLAND IN 24
HOURS. THIS WILL KEEP MOISTURE HIGH THROUGH THE WEEKEND ACROSS
THE ISLAND AND CONVECTION WILL BE POSSIBLE.

ATLANTIC OCEAN...

AN UPPER-LEVEL TROUGH EXTENDS ACROSS THE W ATLANTIC AND THE NW
CARIBBEAN. AT THE SURFACE...A TROUGH WAS ANALYZED FROM 29N73W TO
25N76W. TO THE E OF THE SURFACE TROUGH...A DIFFLUENT FLOW ALOFT
SUPPORTS SCATTERED LIGHT TO MODERATE CONVECTION BETWEEN 63W-73W.
A FRONTAL SYSTEM EXTENDS ACROSS THE W-CENTRAL ATLANTIC. IT
BEGINS AS A STATIONARY FRONT FROM 26N73W TO 26N64W. THE FRONT
TRANSITIONS TO A COLD FRONT FROM 26N64W TO 27N56W TO 31N49W.
ISOLATED MODERATE CONVECTION IS OBSERVED WITHIN 100 NM OF THE
FRONT BETWEEN 48W-55W. A GALE WARNING IS IN EFFECT FOR THE AREA
BEHIND THE FRONT. PLEASE REFER TO THE SPECIAL FEATURES SECTION
ABOVE FOR DETAILS. A SURFACE RIDGE PREVAILS ACROSS THE CENTRAL
AND E ATLANTIC ANCHORED BY A 1021 MB HIGH NEAR 25N43W AND
ANOTHER 1021 MB HIGH NEAR 24N33W. N OF THIS RIDGE...A COLD FRONT
ENTERS THE AREA FROM 27N37W TO 31N29W. EXPECT OVER THE NEXT 24
HOURS FOR THE COLD FRONT ACROSS THE W-CENTRAL ATLANTIC TO
CONTINUE MOVING E WITH CONVECTION. THE COLD FRONT ACROSS THE E-
CENTRAL ATLANTIC IS EXPECTED TO WEAKEN.

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

$$

ERA
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