[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 242356
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU DEC 24 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
2315 UTC.

...SPECIAL FEATURES...
A STRONG PRESSURE GRADIENT EXISTS BETWEEN LOWER PRESSURE ACROSS
NORTHWESTERN SOUTH AMERICA AND A 1032 MB HIGH CENTERED NEAR
BERMUDA INFLUENCING THE SW NORTH ATLC. NEAR GALE TO GALE FORCE
WINDS ACROSS THE SOUTH-CENTRAL AND SW CARIBBEAN ARE OCCURRING
FROM 11N-15N BETWEEN 73W-79W. THESE CONDITIONS ARE FORECAST TO
PERSIST THROUGH LATE SATURDAY. PLEASE SEE LATEST NWS HIGH SEAS
FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE
DETAILS.

...ITCZ/MONSOON TROUGH...
THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 02N AT THE
PRIME MERIDIAN TO 04N20W TO 02N35W TO 03N44W. SCATTERED MODERATE
CONVECTION IS FROM 01N-05N BETWEEN 17W-34W. A SURFACE TROUGH IS
ANALYZED TO THE WEST OF THE AXIS FROM 04N50W TO 10N48W
GENERATING ISOLATED MODERATE CONVECTION FROM 03N-08N BETWEEN 45W-
52W.

...DISCUSSION...

GULF OF MEXICO...
THE GULF BASIN REMAINS UNDER THE INFLUENCE OF GENERALLY
SOUTHWESTERLY FLOW ALOFT WITH AN EMBEDDED SHORTWAVE TROUGH NOTED
ON WATER VAPOR IMAGERY IN THE VICINITY OF 27N92W. THIS TROUGHING
IS GENERATING MIDDLE TO UPPER LEVEL DIFFLUENCE E OF 92W AND
POSSIBLE ISOLATED SHOWERS ACROSS PORTIONS OF THE CENTRAL GULF
THIS EVENING. STRONGER CONVECTIVE ACTIVITY IS OCCURRING ACROSS
THE COASTAL PLAIN AND INTERIOR AREAS OF THE SE CONUS AS THE
SHORTWAVE ENERGY ADVECTS NORTHEASTWARD. OTHERWISE...THE WESTERN
PERIPHERY OF A SURFACE RIDGE ANCHORED BY A 1032 MB HIGH ANCHORED
IN THE VICINITY OF BERMUDA CONTINUES TO PROVIDE MODERATE TO
OCCASIONAL FRESH E-SE WINDS THAT ARE EXPECTED TO PERSIST THROUGH
LATE SATURDAY. THEREAFTER...SOUTHERLY RETURN FLOW IS FORECAST TO
INCREASE W OF 90W AHEAD OF THE NEXT STRONG COLD FRONT TO EMERGE
OFF THE TEXAS COAST LATE SUNDAY INTO EARLY MONDAY.

CARIBBEAN SEA...
WATER VAPOR IMAGERY INDICATES MOSTLY DRY AIR AND SUBSIDENCE
ALOFT OVER A MAJORITY OF THE BASIN THIS EVENING RESULTING IN
MOSTLY CLEAR SKIES. THE PRIMARY MARINE IMPACT TO THE CARIBBEAN
IS THE STRONG TO OCCASIONAL NEAR GALE TRADES OCCURRING AT THIS
TIME DUE TO A STRENGTHENED PRESSURE GRADIENT BETWEEN LOWER
PRESSURE ACROSS NW SOUTH AMERICA AND A STRONG SURFACE RIDGE
ANCHORED IN THE VICINITY OF BERMUDA. GALE FORCE CONDITIONS ARE
EXPECTED TO PERSIST THROUGH SATURDAY WITHIN CLOSE PROXIMITY TO
THE COAST OF COLOMBIA AS MENTIONED ABOVE IN THE SPECIAL FEATURES
SECTION. OTHERWISE...BY EARLY NEXT WEEK...THE SW NORTH ATLC
RIDGING IS FORECAST TO WEAKEN AND SLIDE EASTWARD RELAXING THE
PRESSURE GRADIENT SOMEWHAT AND DECREASING THE TRADES INTO FRESH
TO STRONG LEVELS.

...HISPANIOLA...
DRY AIR AND STABILITY ALOFT ARE PROVIDING FOR OVERALL FAIR
CONDITIONS AND CLEAR SKIES ACROSS THE ISLAND THIS EVENING.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL RIDGE IS NOTED ON WATER VAPOR IMAGERY
ANCHORED NEAR 29N67W. THE RIDGING ALOFT SUPPORTS A STRONG 1032
MB HIGH CENTERED E OF BERMUDA NEAR 33N60W PROVIDING OVERALL FAIR
CONDITIONS FOR MUCH OF THE SW NORTH AND CENTRAL ATLC WATERS THIS
EVENING. THE PRIMARY IMPACT FROM THE ANTICYCLONE IS STRONG WINDS
WITHIN THE SOUTHERN PERIPHERY DUE TO A STRENGTHENED PRESSURE
GRADIENT BETWEEN THE HIGH AND LOWER PRESSURE ASSOCIATED WITH THE
INTERTROPICAL CONVERGENCE ZONE REGION ACROSS NORTHERN SOUTH
AMERICA. FRESH TO STRONG EASTERLY WINDS ARE FOUND GENERALLY FROM
15N-25N BETWEEN 53W-77W. OTHERWISE...MODERATE TO FRESH ANTI-
CYCLONIC FLOW PREVAILS N OF 25N W OF 50W. OTHERWISE...THE
EASTERN ATLC IS UNDER RELATIVELY QUIET CONDITIONS AS WELL...
HOWEVER A MID-LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR
IMAGERY NEAR 29N36W THAT IS SUPPORTIVE OF A FRONTAL TROUGH
EXTENDING FROM 32N30W TO 27N36W WITH POSSIBLE ISOLATED SHOWERS
OCCURRING WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS.

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

$$
HUFFMAN
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