[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 120555
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST THU FEB 12 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...THE ITCZ...

ITCZ IS CENTERED ALONG 6N9W 1N30W CROSSING THE EQUATOR NEAR
35W...AND INTO NE BRAZIL NEAR 2S46W. SCATTERED MODERATE TO
STRONG CONVECTION IS S OF 2N BETWEEN 22W-29W.

...DISCUSSION...

GULF OF MEXICO...
STRONG WESTERLY FLOW ALOFT IS PRESENT ACROSS THE N GULF IN THE
BASE OF A VIGOROUS DEEP LAYER TROUGH MOVING EWD ACROSS THE ERN
CONUS. A SURFACE COLD FRONT ASSOCIATED WITH THIS TROUGH CROSSES
THE FLORIDA PANHANDLE AND INTO THE GULF NEAR PANAMA CITY
EXTENDING SW TO NEAR 26N90W TO 22N95W TO 19N96W. NLY WINDS AND A
RELATIVELY COOLER AND DRIER AIRMASS ARE OBSERVED N OF THIS
FRONT. LOW-LEVEL CONVERGENCE IS SUPPORTING SCATTERED SHOWERS
WITHIN 90 NM EITHER SIDE OF THE COLD FRONT. THIS ACTIVITY IS
BEING ENHANCED BY UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE
AFOREMENTIONED VIGOROUS DEEP LAYER TROUGH. ELSEWHERE...A SURFACE
RIDGE EXTENDS FROM A 1028 MB HIGH ANCHORED IN THE W ATLC ACROSS
SRN FLORIDA AND THE SE GULF. SUBSIDENCE ASSOCIATED WITH THIS
RIDGE IS COMBINING WITH DRY AIR AND A STABLE ATMOSPHERE ALOFT TO
INHIBIT DEEP CONVECTION.

CARIBBEAN SEA...
GENERALLY FAIR WEATHER IS PRESENT ACROSS THE WRN CARIBBEAN...
WHERE DEEP LAYER DRY AIR AND CONFLUENT WESTERLY FLOW ARE
OBSERVED. UPPER LEVEL MOISTURE CONTINUES TO BE ADVECTED NEWD
INTO THE ERN CARIBBEAN...WITH SCATTERED SHOWERS E OF 70W. STRONG
TRADE WINDS S OF A 1028 MB SURFACE HIGH IN THE W ATLC NEAR
29N61W ARE OCCURRING AND ARE FORECAST TO CONTINUE ACROSS MUCH OF
THE CARIBBEAN THROUGH THURSDAY.

ATLANTIC OCEAN...
STRONG SOUTHWESTERLY FLOW ALOFT CONTINUES ACROSS THE SW NORTH
ATLC AS THE VIGOROUS DEEP LAYER TROUGH OVER THE ERN CONUS MOVES
EWD. A SURFACE COLD FRONT ASSOCIATED WITH THIS TROUGH IS
FORECAST TO ENTER THE SW NORTH ATLC DURING THE NEXT DAY...
FOLLOWED BY W TO NW WINDS AND RELATIVELY COOLER AND DRIER
CONDITIONS. FARTHER TO THE E...DEEP LAYER DRY AIR AND SUBSIDENCE
ARE PRESENT IN THE VICINITY OF A 1028 MB SURFACE HIGH NEAR
29N61W. ACROSS THE CENTRAL ATLC...A DEEP LAYER TROUGH IS PRESENT
WITH AN ASSOCIATED WEAKENING SURFACE COLD FRONT EXTENDING FROM
25N41W TO BEYOND 32N33W. A PRE-FRONTAL SURFACE TROUGH IS ALSO
ANALYZED FROM 27N36W TO 21N42W SE OF THE COLD FRONT. LOW-LEVEL
CONVERGENCE IN THE VICINITY OF THESE BOUNDARIES IS SUPPORTING
SCATTERED SHOWERS N OF 20N BETWEEN 33W-43W. IN THE ERN ATLC...
FAIR WEATHER CONDITIONS ARE OBSERVED...WHERE SUBSIDENCE
ASSOCIATED WITH A SURFACE RIDGE IS PRESENT. ACROSS THE TROPICAL
ATLC...AN UPPER HIGH IS PRESENT NEAR 5N42W. UPPER LEVEL
DIVERGENCE ASSOCIATED WITH THIS HIGH IS ENHANCING THE CONVECTION
ASSOCIATED WITH THE ITCZ.

$$
HUFFMAN


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