[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 192352
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST TUE JAN 19 2010

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 4N05W 4N20W 2N37W CROSSING THE
EQUATOR NEAR 43W THEN TO THE NE BRAZIL COAST NEAR 1S46W.
ISOLATED MODERATE CONVECTION IS FROM 2N-4N BETWEEN 3W-7W AND
FROM 1N-4N BETWEEN 24W-30W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE EXTENDS ACROSS THE ENTIRE GULF OF MEXICO
ANCHORED BY A 1021 MB HIGH CENTERED IN THE NE GULF NEAR 27N86W
THAT CONTINUES TO PROVIDE GENERALLY FAIR WEATHER THIS EVENING.
LIGHT ANTICYCLONIC SURFACE FLOW IS NOTED WITH THE RIDGE AS SE
WINDS REACH 15 KT ACROSS PORTIONS OF THE WESTERN GULF. ALOFT...
ZONAL WESTERLY UPPER LEVEL FLOW EXISTS ACROSS THE GULF WITH
WATER VAPOR IMAGERY INDICATING DRY AIR AND RELATIVELY STRONG
SUBSIDENCE IN THE MIDDLE TO UPPER LEVELS OF THE ATMOSPHERE. AS
THE SURFACE RIDGE SHIFTS EAST INTO THE W ATLC BY LATE
WEDNESDAY...SOUTHERLY RETURN FLOW IS FORECAST TO INCREASE ACROSS
THE WESTERN AND CENTRAL GULF AHEAD OF THE NEXT COLD FRONT
EXPECTED TO ENTER THE NW GULF WATERS EARLY THURSDAY.

CARIBBEAN SEA...
THE TAIL END OF A SURFACE TROUGH EXTENDS ACROSS HISPANIOLA FROM
THE W ATLC AND CONTINUES TO PROVIDE A LOW-LEVEL FOCUS FOR
ISOLATED SHOWERS ACROSS THE ISLAND OF HISPANIOLA AND THE
ADJACENT COASTAL WATERS. ANOTHER PAIR OF WEAK SURFACE TROUGHS
ARE LOCATED EAST OF THE LESSER ANTILLES...ONE ANALYZED FROM
17N57W TO 12N60W. POSSIBLE ISOLATED SHOWERS ARE WITHIN 120 NM W
OF THE SURFACE TROUGH...INCLUDING MANY OF THE WINDWARD ISLANDS
AND SOUTHERN LEEWARD ISLANDS THIS EVENING. FARTHER NORTH...THE
SECOND SURFACE TROUGH IS ANALYZED FROM 20N58W TO 18N61W WITH
MUCH OF THE ASSOCIATED SHOWER ACTIVITY REMAINING OVER THE
TROPICAL NORTH ATLC WATERS WITHIN 120 NM W OF THE SURFACE
TROUGH. THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING GENERALLY
FAIR WEATHER UNDER THE INFLUENCE OF DRY AIR AND SUBSIDENCE
AROUND AN UPPER LEVEL RIDGE COVERING THE BASIN WITH AXIS ALONG
66W. FRESH TO STRONG TRADEWINDS ARE OVER MUCH OF THE BASIN WITH
THE STRONGEST WINDS OFF THE COAST OF COLOMBIA...REACHING GALE
FORCE FROM 11N-15N BETWEEN 72W-77W.

ATLANTIC OCEAN...
A COLD FRONT EXTENDS ACROSS THE W ATLC FROM A 986 MB LOW NEAR
41N49W ENTERING THE DISCUSSION AREA NEAR 32N51W CONTINUING SW
ALONG 27N60W TO WESTERN HISPANIOLA NEAR 20N72W. ISOLATED SHOWERS
ARE WITHIN 90 NM EITHER SIDE OF THE FRONT N OF 26N. A PRE-
FRONTAL SURFACE TROUGH IS E OF THE COLD FRONT ANALYZED FROM
26N61W TO EASTERN PORTIONS OF HISPANIOLA NEAR 18N70W. ISOLATED
SHOWERS ARE WITHIN 75 NM OF THE TROUGH AXIS. A SECONDARY COLD
FRONT IS ANALYZED FROM 31N59W TO 28N69W. ISOLATED SHOWERS ARE
POSSIBLE ALONG THIS FRONT N OF 28N BETWEEN 59W-70W. MOST OF THE
UPPER LEVEL SUPPORT FOR THIS COLD FRONT REMAINS N OF THE
DISCUSSION AREA AS AN UPPER LEVEL RIDGE AXIS STEMMING FROM THE
NE CARIBBEAN NEAR PUERTO RICO AMPLIFIES OVER THE CENTRAL ATLC
BETWEEN 50W-70W. ACROSS THE EASTERN ATLC...A SURFACE RIDGE IS IN
PLACE ANCHORED BY A 1027 MB HIGH CENTERED NEAR 33N21W. THE
SURFACE RIDGE AXIS EXTENDS FROM THE HIGH CENTER TO THE SW ALONG
26N40W TO 22N54W.

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

$$
HUFFMAN



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