[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202351
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SUN DEC 20 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...SPECIAL FEATURE...

A PRESSURE GRADIENT GENERATED BY THE INTERACTION OF A HIGH
PRESSURE OVER THE ATLANTIC AND LOWER PRESSURES OVER SOUTH
AMERICA CONTINUE TO SUPPORT GALE FORCE WINDS ACROSS THE S-
CENTRAL CARIBBEAN FROM 10.5N-13N BETWEEN 73W-78W WITH SEAS
RANGING FROM 10-14 FT. THESE CONDITION S ARE EXPECTED TO
CONTINUE THROUGH THE NEXT 48 HOURS. FOR MORE INFORMATION PLEASE
REFER TO THE HIGH SEAS FORECAST PRODUCT UNDER AWIPS/WMO HEADER
MIAHSFAT2/FZNT02 KNHC.

...ITCZ/MONSOON TROUGH...

THE ITCZ EXTENDS FROM 04N08W TO 05N36W TO 05N52W. SCATTERED
LIGHT TO MODERATE CONVECTION IS ALONG THE AXIS FROM 03N-05N
BETWEEN 19W-40W.

...DISCUSSION...

GULF OF MEXICO...

A BROAD SURFACE RIDGE ANCHORED BY A 1033 MB HIGH CENTERED OVER E
GEORGIA EXTENDS SW ACROSS THE BASIN. WITH THIS...A MODERATE TO
FRESH ANTICYCLONIC FLOW PREVAILS ACROSS MOST OF THE AREA. THE
ONLY EXCEPTION IS ACROSS THE FLORIDA STRAITS WHERE THE TIGHT
PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRESSURES TO THE S
ARE SUPPORTING FRESH TO STRONG NE WINDS BETWEEN 80W-85W. THE
TAIL OF A WEAK STATIONARY FRONT EXTENDS FROM NORTHERN YUCATAN
NEAR 22N89W TO W CUBA NEAR 22N84W. ISOLATED CONVECTION IS
OBSERVED ALONG THIS BOUNDARY. WESTERN CUBA TO THE NORTHERN
YUCATAN PENINSULA. OVER THE NEXT 24 HOURS...EXPECT FOR THE
FRONTAL BOUNDARY ALONG THE SOUTHER PORTION OF THE BASIN TO
DISSIPATE. WINDS WILL WEAKEN AS THE SURFACE RIDGE DRIFTS E.

CARIBBEAN SEA...

THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE CURRENTLY OVER THE
ATLANTIC AND LOWER PRESSURES OVER THE NORTHERN PORTION OF SOUTH
AMERICA CONTINUE TO SUPPORT GALE FORCE WINDS ACROSS THE S-
CENTRAL CARIBBEAN WHILE MODERATE TO FRESH TRADES PREVAIL ACROSS
THE REMAINDER OF THE BASIN. PLEASE REFER TO THE SPECIAL FEATURES
SECTION FOR MORE DETAILS ABOUT THE GALE CONDITIONS. AN UPPER-
LEVEL TROUGH ALONG THE W ATLANTIC SUPPORTS A WEAK STATIONARY
FRONT THAT EXTENDS ACROSS THE YUCATAN CHANNEL AND W CUBA. WITH
ISOLATED CONVECTION. SHALLOW MOISTURE TRANSPORTED BY THE TRADES
ARE ENHANCING ISOLATED CONVECTION ACROSS THE BASIN. EXPECT
A SIMILAR WEATHER PATTERN TO PREVAIL OVER THE NEXT 24 HOURS.

...HISPANIOLA...

SHALLOW MOISTURE AND A DIFFLUENT ENVIRONMENT ALOFT ARE
GENERATING ISOLATED MODERATE CONVECTION ACROSS THE
NORTHERN PORTION OF THE ISLAND AT THIS TIME. THIS ACTIVITY WILL
CONTINUE OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...

AN UPPER-LEVEL TROUGH EXTENDS ALONG THE W ATLANTIC SUPPORTING A
STATIONARY FRONT ANALYZED FROM 23N79W TO 30N57W. THE BOUNDARY
THEN BECOMES A COLD FRONT AND EXTENDS NE ACROSS THE W AND
CENTRAL ATLANTIC. SCATTERED MODERATE CONVECTION IS OBSERVED
WITHIN 150 NM OF THE STATIONARY FRONT AFFECTING THE BAHAMAS AND
ADJACENT WATERS. TO THE E...A BROAD SURFACE RIDGE EXTENDS ACROSS
THE CENTRAL AND E ATLANTIC ANCHORED BY A 1030 MB HIGH CENTERED
NEAR 33N30W. A WEAK STATIONARY FRONT WAS ANALYZED S OF THIS HIGH
ACROSS THE E ATLANTIC FROM 20N41W TO 28N13W. EXPECT OVER THE
NEXT 24 HOURS FOR THE FRONTAL BOUNDARIES TO CONTINUE WEAKENING
AND DISSIPATE. HIGH PRESSURE WILL PREVAIL ACROSS MOST OF THE
BASIN.

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

$$

ERA
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