[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 051739
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SAT JAN 05 2013

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1700 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 04N08W TO
01N13W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
01N13W THEN ALONG THE EQUATOR TO 30W. ISOLATED MODERATE
CONVECTION IS FROM THE EQUATOR TO 06N BETWEEN 23W-32W.

...DISCUSSION...

GULF OF MEXICO...
AT 1500 UTC...A SHARP SURFACE TROUGH IS IN THE WESTERN GULF FROM
19N92W TO 27N96W. SCATTERED MODERATE CONVECTION EXISTS NORTH OF
22N BETWEEN 88W AND THE TROUGH AXIS. NW TO N WINDS OF 20-30
KT EXIST TO THE WEST OF THE TROUGH AND NE TO E WINDS OF 15-25 KT
ARE OCCURRING OVER THE REMAINDER OF THE GULF.  THESE NORTHERLY
WINDS WEST OF THE TROUGH ARE FUNNELING SUBSTANTIAL AMOUNTS OF
COOL AND DRY AIR EQUATORWARD ALONG THE TEXAS AND MEXICAN
COASTLINES.  THE CONVECTION IS BEING AIDED BY A BROAD UPPER
TROUGH OVER NORTHERN MEXICO AND THE SOUTH CENTRAL UNITED STATES.
A STATIONARY FRONTAL BOUNDARY CONTINUES IN THE SE GULF EXTENDING
FROM THE FLORIDA KEYS TO NEAR 24N85W. ONLY WIDELY SCATTERED
SHOWERS ARE ASSOCIATED WITH THIS FRONTAL BOUNDARY.  DURING THE
NEXT DAY...THE TROUGH WILL REMAIN IN PLACE BUT THE FRONTAL
BOUNDARY MAY PUSH POLEWARD AS A WARM FRONT IN THE EASTERN GULF.

CARIBBEAN SEA...
A MODERATE NORTH-SOUTH PRESSURE GRADIENT IS INDUCING NE TO E
TRADEWINDS OF 20 TO 30 KT ACROSS THE CARIBBEAN WITH WINDS UP TO
MINIMAL GALE FORCE JUST NORTH OF COLUMBIA. NO SUBSTANTIAL DEEP
CONVECTION IS OCCURRING OVER THE CARIBBEAN...AS TYPICAL
SUBSIDENT RIDGING IS APPARENT IN THE WATER VAPOR IMAGERY TODAY.
SOME LOW-TOPPED SHOWERS ARE OCCURRING ALONG THE UPSLOPE EASTERN
PORTIONS OF THE GREATER AND LESSER ANTILLES AS WELL AS CENTRAL
AMERICA.  LITTLE CHANGE IS ANTICIPATED DURING THE NEXT DAY OR
SO.  GALE CONDITIONS NEAR COLUMBIA WILL LIKELY DIMINISH BY LATE
SUNDAY.

ATLANTIC OCEAN...
AN ELONGATED FRONTAL BOUNDARY EXTENDS FROM SOUTH FLORIDA
NORTHEASTWARD UP TO 29N70W TO 31N48W.  WEST OF ABOUT 68W...THE
FRONT IS STATIONARY.  EAST OF ABOUT 55W THE FRONT IS A
PROGRESSIVE COLD FRONT.  IN BETWEEN...THE FRONT IS A DISSIPATING
STATIONARY BOUNDARY.  ISOLATED SHOWERS ARE OCCURRING WITHIN
ABOUT 120 NM OF THE EXTENDED FRONTAL BOUNDARIES.  JUST NORTH OF
OUR AREA BETWEEN 65W AND 73W...A NEW APPROACHING COLD FRONT WILL
LIKELY MERGE WITH THE EXISTING WESTERNMOST STATIONARY FRONTAL
BOUNDARY IN THE NEXT DAY OR SO.  THE EASTERN COLD FRONT WILL
CONTINUE MOVING EASTWARD IN THE EASTERN ATLANTIC DURING THE NEXT
DAY WITH LITTLE CHANGE.  NONE OF THE FRONTAL BOUNDARIES ARE
ASSOCIATED WITH WINDS HIGHER THAN 25 KT.  SOUTH OF THE
FRONTS...AN EAST-WEST ORIENTED SURFACE RIDGE ALONG 26N DOMINATES
THE REMAINDER OF THE TROPICAL ATLANTIC.  EQUATORWARD OF THE
RIDGE...THE NE TRADEWINDS ARE TYPICALLY 20 KT OR LESS. THE
AFOREMENTIONED CONVECTION AS WELL AS NUMEROUS UPPER LEVEL
CLOUDINESS IN THE EASTERNMOST ATLANTIC IS LIKELY ENHANCED BY AN
UPPER LEVEL TROUGH AXIS EXTENDING FROM THE WEST COAST OF AFRICA
NEAR 21N16W TO TO A BASE NEAR 03N30W.  LITTLE CHANGE TO THE
SYNOPTIC SITUATION IS ANTICIPATED DURING THE NEXT DAY OR SO
ASIDE FROM THE GRADUAL DEVELOPMENT OF A HIGH PRESSURE CENTER
ALONG THE RIDGE AXIS NEAR 25N45W ON SUNDAY.

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

$$
LANDSEA



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