[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 292341
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST TUE JAN 29 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 06N11W TO
04N16W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
04N16W TO 01N30W TO 02N44W TO 01N51W. SCATTERED MODERATE
CONVECTION IS FROM 02N-03N BETWEEN 35W-39W.

...DISCUSSION...

GULF OF MEXICO...
MUCH OF THE GULF THIS EVENING IS UNDER THE INFLUENCE OF AN UPPER
LEVEL RIDGE WITH AXIS ALONG 86W. WATER VAPOR IMAGERY INDICATES
VERY DRY AIR AND SUBSIDENCE ALOFT WHICH IS PROVIDING OVERALL
CLEAR SKIES AND FAIR CONDITIONS AT THE SURFACE UNDER SOUTHERLY
WINDS IN THE RANGE OF 15 TO 25 KT. TO THE WEST OF THE UPPER
LEVEL RIDGE...A VIGOROUS MIDDLE TO UPPER LEVEL TROUGH IS
PROGRESSING OVER WESTERN TEXAS THIS EVENING AND CONTINUES TO
DEVELOP AN AREA OF SURFACE LOW PRESSURE OVER NORTH TEXAS AND
OKLAHOMA. THE ASSOCIATED COLD FRONT IS ANALYZED OVER THIS REGION
AND IS EXPECTED TO EMERGE INTO THE NW GULF WATERS BY EARLY
WEDNESDAY. IN THE MEANTIME...SOUTHERLY WINDS ARE EXPECTED TO
INCREASE AHEAD OF THE FRONT ACROSS THE BASIN THROUGH WEDNESDAY
AFTERNOON...WITH NORTHERLY WINDS USHERED IN WEST OF THE FRONT
SPREADING ACROSS THE ENTIRE BASIN BY EARLY THURSDAY. HIGH
PRESSURE WILL THEN BE IN CONTROL FRIDAY AND THROUGH THE WEEKEND.

CARIBBEAN SEA...
SOUTH-SOUTHWESTERLY FLOW ALOFT DOMINATES OVER THE CARIBBEAN SEA
THIS EVENING AS WATER VAPOR IMAGERY INDICATES A VERY DRY AND
SUBSIDENT ATMOSPHERE IS IN PLACE DUE TO A MID-LEVEL RIDGE
ANCHORED OVER THE BASIN NEAR 15N80W. WHILE THE MIDDLE TO UPPER
LEVELS ARE PROVIDING FAIRLY BENIGN WEATHER...AT THE SURFACE THE
TRADE WINDS REMAIN IN THE RANGE OF 15 TO 25 KT...WITH HIGHER
WINDS UP TO 30 KT POSSIBLE IN CLOSE PROXIMITY TO THE COAST OF
COLOMBIA...DUE TO A STRONG PRESSURE GRADIENT BETWEEN SURFACE
RIDGING OVER THE SW NORTH ATLC REGION AND LOWER PRESSURE LOCATED
OVER THE NORTHERN SOUTH AMERICAN CONTINENT. ISOLATED SHOWERS ARE
NOTED ON SATELLITE IMAGERY ACROSS THE BASIN THIS EVENING...WITH
THE MOST CONCENTRATED AREAS N OF 14N BETWEEN 63W-73W...INCLUDING
PUERTO RICO AND HISPANIOLA...AND ACROSS PORTIONS OF THE NW
CARIBBEAN FROM 14N-18N BETWEEN 80W-88W. OVERALL LITTLE CHANGE IS
EXPECTED SYNOPICALLY OVER THE NEXT 24 TO 36 HOURS. THEREAFTER...
A COLD FRONT IS EXPECTED TO ENTER THE NW CARIBBEAN WATERS ON
THURSDAY.

ATLANTIC OCEAN...
SURFACE HIGH PRESSURE IS CONTROLLING THE SW NORTH ATLC ANCHORED
BY A 1025 MB HIGH CENTERED NEAR 30N71W. THE HIGH IS SUPPORTED BY
A MIDDLE TO UPPER LEVEL RIDGE COVERING THE EASTERN CONUS AND
EASTERN U.S. SEABOARD. EAST OF THE RIDGING...BROAD UPPER LEVEL
TROUGHING IS NOTED ON WATER VAPOR IMAGERY N OF 26N BETWEEN
30W-60W THAT SUPPORTS A COLD FRONT ENTERING THE DISCUSSION AREA
IN THE CENTRAL ATLC NEAR 32N29W. THE FRONT CONTINUES SW ALONG
24N40W TO 20N55W THEN WESTWARD TO 21N70W AS A COLD FRONT THAT
CONTINUES TO DISSIPATE AND BECOME DIFFUSE. WIDELY SCATTERED
SHOWERS ARE OCCURRING WITHIN 150 NM EAST OF THE FRONT E OF 39W
AND WITHIN 210 NM W OF THE FRONT E OF 60W. THE REMAINDER OF THE
EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED
BY A 1030 MB HIGH CENTERED OVER THE IBERIAN PENINSULA NEAR
40N03W. THE RIDGE AXIS EXTENDS SW FROM THE HIGH TO 23N35W.

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

$$
HUFFMAN




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