[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202345
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST FRI JAN 20 2012

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.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO
04N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
04N19W TO 02N38W TO THE EQUATOR NEAR 50W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM THE EQUATOR TO 06N BETWEEN 25W-39W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES THAT WESTERLY UPPER LEVEL FLOW IS
DOMINANT ALOFT ACROSS THE GULF THIS EVENING ON THE NORTHERN
PERIPHERY OF A BROAD UPPER LEVEL RIDGE STRETCHING FROM WESTERN
MEXICO TO THE FLORIDA PENINSULA. THIS UPPER LEVEL FEATURE IS
SUPPORTIVE OF A SURFACE RIDGE EXTENDING ACROSS THE GULF FROM THE
SW NORTH ATLC AND FLORIDA PENINSULA SW TO SOUTHERN MEXICO NEAR
21N97W. SOUTHERLY RETURN FLOW IS EXPECTED TO PERSIST THROUGH
THIS EVENING INTO THE OVERNIGHT HOURS WITH A WEAK FRONT EXPECTED
TO ENTER THE NW GULF BRIEFLY SATURDAY MORNING THEN LIFT
NORTHWARD BY LATE SATURDAY. ANOTHER AREA OF SURFACE LOW PRESSURE
IS FORECAST TO DEVELOP OVER THE CENTRAL PLAINS AND INTRODUCE A
STRONGER COLD FRONT INTO THE NW GULF LATE SUNDAY INTO EARLY
MORNING WHICH WILL PROVIDE NORTHERLY WINDS TO PORTIONS OF THE
WESTERN GULF ON MONDAY.

CARIBBEAN SEA...
NORTHWEST TO WESTERLY UPPER LEVEL FLOW IS OVER THE CARIBBEAN
BASIN THIS EVENING WHICH IS PROVIDING AN OVERALL DRY AND STABLE
ATMOSPHERE ALOFT LIMITING ANY SIGNIFICANT AREAS OF DEEP
CONVECTION. FRESH TO STRONG EASTERLY TRADES ARE FORECAST TO
PERSIST THROUGH THE UPCOMING WEEKEND WITH NO MAJOR CHANGES
EXPECTED TO MODIFY THE CURRENT WEATHER PATTERN.

ATLANTIC OCEAN...
MOST OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE
RIDGE ANCHORED BY A 1024 MB HIGH CENTERED NEAR 31N73W WITH AXIS
EXTENDING SW ACROSS THE FLORIDA PENINSULA INTO THE GULF OF
MEXICO. MOSTLY CLEAR SKIES AND FAIR WEATHER ARE OCCURRING ACROSS
THE BAHAMAS AND THE FLORIDA PENINSULA THIS EVENING. AN UPPER
LEVEL TROUGH IS OVER THE WESTERN NORTH ATLC WATERS WITH AXIS
ALONG 60W THAT SUPPORTS A WEAKENING COLD FRONT ANALYZED FROM
32N58W TO 24N68W. LOW-LEVEL MOISTURE IN THE VICINITY OF THE
FRONT S OF 30N REMAINS LIMITED...HOWEVER SCATTERED SHOWERS AND
ISOLATED TSTMS ARE OCCURRING N OF 27N BETWEEN 53W-58W EAST OF
THE FRONT WHERE LOW-LEVEL MOISTURE CONVERGENCE AND UPPER LEVEL
DIFFLUENCE ARE MAXIMIZED. AS THIS COLD FRONT IS FORECAST TO
CONTINUE MOVING OFF TO THE NE...A MIDDLE TO UPPER LEVEL LOW
CENTERED NEAR 28N44W SUPPORTS A 1014 MB SURFACE LOW CENTERED
NEAR 27N44W THAT IS EXPECTED TO DRIFT NORTHWARD AND BECOMING
ABSORBED INTO THE FRONTAL BOUNDARY BY EARLY SUNDAY. CURRENTLY A
WARM FRONT EXTENDS FROM THE LOW CENTER TO 30N45W TO 32N44W. A
STATIONARY FRONT ALSO EXTENDS FROM THE LOW CENTER ALONG 25N42W
TO 20N43W TO 15N50W. THE SYSTEM EXHIBITS A CLASSIC COMMA CLOUD
SATELLITE PRESENTATION WITH SCATTERED SHOWERS AND POSSIBLE
ISOLATED TSTMS OCCURRING WITHIN THE NORTHEAST SEMICIRCLE AT A
RANGE OF 360 NM FROM THE LOW CENTER. ADDITIONAL ISOLATED SHOWERS
ARE OCCURRING WITHIN 90 NM EAST OF THE STATIONARY FRONT FROM
21N-24N. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE
INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1038 MB HIGH CENTERED
WEST OF THE IBERIAN PENINSULA NEAR 42N16W.

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

$$
HUFFMAN




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