[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 260543
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU MAR 26 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
0530 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N9W 2N20W CROSSING THE EQUATOR NEAR
32W AND INTO NE BRAZIL NEAR 2S45W. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS N OF 3N TO INLAND OVER W AFRICA BETWEEN
4W-9W. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM S OF THE
AXIS BETWEEN 17W-23W.

...DISCUSSION...

GULF OF MEXICO...
SOUTHERLY RETURN FLOW OF 20-25 KT COVER THE MIDDLE AND EAST GULF
ON THE WRN PERIPHERY OF A SURFACE RIDGE OVER THE W ATLC. A 1006
MB LOW IS CENTERED OVER NW LOUISIANA WITH A STATIONARY FRONT
EXTENDING SW ALONG THE SE TEXAS GULF COAST. A DOPPLER RADAR
MOSAIC SHOWS A STRONG LINE OF TSTMS ASSOCIATED WITH THIS
BOUNDARY PROGRESSING EWD EXTENDING FROM NRN MISSISSIPPI TO NEAR
GALVESTON TEXAS. HOWEVER...WHILE THESE STORMS ARE MOSTLY OVER
THE SE CONUS...SCATTERED TSTMS WILL REMAIN POSSIBLE ALONG THE
IMMEDIATE GULF COAST AS THE LINE MOVES EWD ACROSS THE EXTREME
NRN GULF WATERS OVERNIGHT N OF 28N. ELSEWHERE...SCATTERED CLOUDS
WITH POSSIBLE ISOLATED SHOWERS ARE OVER THE ERN GULF WHILE THE
WRN GULF AND BAY OF CAMPECHE REMAIN MOSTLY CLEAR UNDER MODERATE
SUBSIDENCE AND DRY AIR ALOFT.

CARIBBEAN SEA...
HIGH PRESSURE OVER THE W ATLC IS MAINTAINING FRESH TO STRONG
TRADE WINDS ACROSS THE CARIBBEAN. THE STRONGEST WINDS...25-30
KT...ARE OBSERVED ALONG THE COAST OF COLOMBIA. LOW-LEVEL WIND
SPEED CONVERGENCE IS GENERATING ISOLATED TRADE WIND SHOWERS
ACROSS THE ERN CARIBBEAN E OF 72W. ALOFT...A TROUGH EXTENDS FROM
THE W ATLC ACROSS HISPANIOLA TO COSTA RICA...AND INTO THE E
PACIFIC. STRONG SUBSIDENCE AT THE BASE OF THIS TROUGH IS
CREATING A DRY AND STABLE ENVIRONMENT ACROSS THE CARIBBEAN NW OF
A LINE FROM PUERTO RICO TO PANAMA. E OF THE TROUGH AXIS...STRONG
SWLY UPPER WINDS ARE TRANSPORTING UPPER LEVEL MOISTURE AND
MIDDLE TO HIGH CLOUDS ACROSS THE ERN CARIBBEAN AND LESSER
ANTILLES.

ATLANTIC OCEAN...
A DEEP-LAYERED LOW PRESSURE SYSTEM IS OVER THE W ATLC WITH THE
OCCLUDED SURFACE LOW CENTERED WELL NORTH OF THE AREA NEAR
40N57W. A COLD FRONT EXTENDS INTO THE DISCUSSION AREA NEAR
32N45W THEN CONTINUES ALONG 30N46W 25N50W TO 18N58W. SCATTERED
SHOWERS ARE WITHIN 200 NM E OF THE FRONTAL BOUNDARY. WEST OF THE
FRONT...A SURFACE TROUGH ENTERS THE REGION NEAR 32N53W AND
CONTINUES ALONG 30N54W 27N60W TO 28N71W. SCATTERED SHOWERS ARE
WITHIN 90 NM EITHER SIDE OF THE TROUGH. SCATTERED COLD-AIR
STRATOCUMULUS CLOUDS HAVE FILTERED IN ACROSS THE W ATLC BEHIND
THE MAIN COLD FRONT. A SECOND 1009 MB LOW PRESSURE SYSTEM IS
SPINNING OVER THE E ATLC NEAR 33N21W...HOWEVER LITTLE CONVECTION
IS ASSOCIATED WITH THIS FEATURE DUE TO MID TO UPPER LEVEL DRY
AIR. BETWEEN THESE TWO LOW PRESSURE SYSTEMS...A NARROW SURFACE
RIDGE COVERS THE CENTRAL ATLC BETWEEN 27W-42W. IN THE TROPICS...
DIVERGENCE AROUND AN UPPER-LEVEL ANTICYCLONE NEAR 4N35W IS
ENHANCING THE ISOLATED CONVECTION ALONG THE ITCZ.

$$
HUFFMAN





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