[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 162348
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST MON FEB 16 2009

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N7W 1N14W 1N34W CROSSING THE
EQUATOR AT 37W...AND INTO NE BRAZIL NEAR 3S44W. SCATTERED
MODERATE CONVECTION IS S OF 5N BETWEEN 44W-52W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT IS ACROSS WRN CUBA AND EXTENDS
ACROSS THE YUCATAN CHANNEL. SATELLITE IMAGERY SHOWS A FEW
ISOLATED SHOWERS LINGERING ACROSS THE SE GULF AND YUCATAN
CHANNEL THIS EVENING. HIGH PRESSURE CURRENTLY OVER ARKANSAS IS
EXPECTED TO CONTINUE MOVING E-SE ACROSS THE SE CONUS AND PROVIDE
FAIR WEATHER FOR THE GULF THROUGH MIDWEEK. N TO NE WINDS OF 15
TO 20 KT ARE USHERING IN A RELATIVELY COOLER AND DRIER AIR MASS
WITH SCATTERED COLD AIR STRATOCUMULUS CLOUDS BEHIND THE FRONT
ACROSS PORTIONS OF THE CENTRAL GULF. THE HIGH PRESSURE SYSTEM
WILL SHIFT EAST BRINGING SOUTHERLY RETURN FLOW ACROSS THE WRN
GULF BY TUESDAY AS A SURFACE LOW PRESSURE DEVELOPS ACROSS THE
SRN U.S. PLAINS. IN THE UPPER LEVELS...THE ERN HALF OF A RIDGE
ANCHORED ON A HIGH OVER THE EPAC NEAR 10N96W DOMINATES THE GULF
PRODUCING STRONG W-NW FLOW AND ALSO MODERATE SUBSIDENCE S OF 26N
INCLUDING SE MEXICO AND THE YUCATAN PENINSULA.

CARIBBEAN SEA...
IN THE NW CARIBBEAN...A COLD FRONT IS ACROSS WRN CUBA EXTENDING
TO NEAR CANCUN MEXICO. NORTHERLY WINDS OF 10 TO 15 KT WITH A FEW
ISOLATED SHOWERS ARE OBSERVED ALONG AND BEHIND THE FRONT ACROSS
THE YUCATAN CHANNEL THIS EVENING. THE OTHER MAIN WEATHER FEATURE
ACROSS THE BASIN IS A SURFACE TROUGH ANALYZED FROM ANTIGUA S-SW
TO THE NRN VENEZUELA COAST NEAR 10N65W. SCATTERED SHOWERS ARE S
OF 17N BETWEEN 60W-70W. THIS ACTIVITY IS SUPPORTED BY A MID TO
UPPER LEVEL RIDGE AND THUS UPPER DIFFLUENCE OVER THE SE
CARIBBEAN. ELSEWHERE...PATCHES OF LOW LEVEL MOISTURE ARE BEING
USHERED IN ON MODERATE NE TRADES OVER THE CENTRAL AND WRN
CARIBBEAN...MOST CONCENTRATED IN A BAND EXTENDING FROM ERN CUBA
TO THE GULF OF HONDURAS AS WELL AS ERN HONDURAS. IN THE UPPER
LEVELS...A TROUGH IS OVER THE WRN CARIBBEAN W OF 75W WHILE THE
AFOREMENTIONED RIDGE COVERS THE ERN CARIBBEAN E OF 75W. STRONG
SUBSIDENCE IS NOTED N AND W OF A LINE FROM SAINT KITTS TO ARUBA.

ATLANTIC OCEAN...
A 1002 MB GALE FORCE LOW PRESSURE IS CENTERED IN THE W ATLC NEAR
31.5N69W. THE ATTENDANT COLD FRONT EXTENDS SW ACROSS THE NW
BAHAMAS TO WRN CUBA AND ACROSS THE YUCATAN CHANNEL. THIS LOW IS
FORECAST TO QUICKLY MOVE NEWD AS THE LOW RAPIDLY INTENSIFIES
OVER THE NEXT 24 HOURS TO A 998 MB STORM CENTER WITH POSSIBLE
HURRICANE FORCE WINDS OVER THE CENTRAL ATLC BY TUE AFTERNOON.
THE REMAINDER OF THE ATLC DISCUSSION AREA IS UNDER THE INFLUENCE
OF A RIDGE WITH AXIS ALONG 23N56W TO 26N33W AND BEYOND 32N26W.
THIS RIDGE IS GENERATING MOSTLY FAIR WEATHER...WITH A WIDESPREAD
SWATH OF 20 TO 25 KT E-NE WINDS OVER THE TROPICS...PARTICULARLY
BETWEEN 33W AND 47W. STRONG WESTERLY FLOW ALOFT IS NOTED OVER
THE NRN PORTION OF THE W ATLC W OF 45W DUE TO THE PRESENCE OF A
BRANCH OF JET-STREAM CORE WINDS WHICH ORIGINATE OVER THE CENTRAL
CONUS. AN UPPER-LEVEL TROUGH IS ACROSS THE ERN ATLC E OF 25W
WITH A CORE OF JET-STREAM WINDS UP TO 90 KT AROUND THE BASE OF
THE TROUGH CROSSING OVER AND SOUTH OF THE CAPE VERDE ISLANDS...
ENTERING W AFRICA THROUGH SENEGAL.

$$
HUFFMAN




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