[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 060527
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT MON APR 06 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 0515 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N10W 4N16W CROSSING THE EQUATOR
NEAR 21W AND EXTENDING TO 2S30W INTO NE BRAZIL NEAR 6N38W.
SCATTERED MODERATE CONVECTION IS FROM 1N-4N BETWEEN 1W-14W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS S OF 2N BETWEEN
19W AND 24W.

...DISCUSSION...

THE GULF OF MEXICO...
A STRONG FRONT FOR THIS TIME OF YEAR IS ON THE MOVE EXTENDING
FROM SRN MISSISSIPPI TO 22N98W. STRONG N WINDS FOLLOW THE FRONT
DUE TO THE TIGHT PRES GRADIENT BETWEEN IT AND A 1039 MB HIGH
BUILDING S FROM CANADA. WINDS ARE EXPECTED TO REACH GALE FORCE
BEHIND THE FRONT OVER THE SW WATERS THIS MORNING...WHERE LOCAL
TOPOGRAPHY PROVIDES AN ENHANCEMENT. A PRE-FRONTAL TROUGH LIES
ABOUT 120-180 NM AHEAD OF THE FRONT...DEPICTING A SLY-WLY WIND
SHIFT WITH OVERALL LIGHT TO MODERATE MAGNITUDES ON BOTH SIDES.
BOTH OF THESE SFC FEATURES ARE PRODUCING LITTLE SIGNIFICANT
MOISTURE...IN PART CAPPED BY WIDESPREAD STABILITY IN THE
MID-LEVELS. THE FRONT IS EXPECTED TO CLEAR THE ENTIRE AREA BY
THIS EVENING BRINGING COOLER AND DRIER CONDITIONS TO THE REGION
IN ITS WAKE.

THE CARIBBEAN SEA...
A WEAK SFC TROUGH IS MOVING SLOWLY W CENTERED ALONG 67W N OF
14N. SATELLITE IMAGERY AND SAN JUAN DOPPLER RADAR SHOW AN AREA
OF LOW-MID LEVEL CLOUDINESS WITH EMBEDDED SCATTERED SHOWERS AND
ISOLATED TSTMS N OF 14N BETWEEN 63W-68W. FAIR WEATHER DOMINATES
THE REMAINDER OF THE REGION ENHANCED BY A STRONGLY SUBSIDENT
ENVIRONMENT BETWEEN AMPLIFIED UPPER RIDGING OVER THE TROPICAL
EPAC AND TROUGHING OVER THE CENTRAL ATLC. RECENT QSCAT DATA AND
SFC OBS DEPICT LIGHT TO MODERATE TRADES...EXCEPT FOR THE GULF OF
HONDURAS AND NEAR THE COAST OF COLOMBIA. LOOKING AHEAD...THE
WEAK TROUGH MENTIONED IS EXPECTED TO CONTINUE W-NW MOVING OVER
HISPANIOLA LATER TODAY. MEANWHILE...A STRONG FRONT FOR THIS TIME
OF YEAR IS EXPECTED TO MOVE INTO THE NW CARIBBEAN TONIGHT.

THE ATLANTIC OCEAN...
IR IMAGERY AND LIGHTNING DATA DEPICT AN AREA OF SCATTERED
SHOWERS AND TSTMS BETWEEN THE SE CONUS AND BERMUDA N OF 29N
BETWEEN 72W-78W. THIS ACTIVITY IS BEING TRIGGERED BY A MID-LEVEL
VORTICITY MAXIMUM THAT IS DIVING SE INTO A TROUGH OVER THE
CENTRAL ATLC. THAT TROUGH IS PROVIDING SUPPORT FOR A COLD FRONT
THAT EXTENDS FROM 32N59W TO 25N70W THEN STATIONARY AND
DISSIPATING TOWARD THE NW BAHAMAS. LOW-LEVEL CONVERGENCE AND
UPPER DIFFLUENCE E OF THE TROUGH AXIS IS PRODUCING SCATTERED
SHOWERS AND TSTMS N OF 24N BETWEEN 59W-64W. FARTHER E...AN
ELONGATED UPPER TROUGH EXTENDS ALONG 29N/30N E OF 40W PROVIDING
LIMITED SUPPORT FOR A WEAK SFC LOW CENTERED NEAR 29N43W...
ANALYZED 1018 MB. THIS FEATURE WILL LIKELY DISSIPATE LATER
TODAY. OVER THE DEEP TROPICS...THE MAIN FEATURE IS A LARGE UPPER
HIGH CENTERED NEAR 11N17W. ONLY ASSOCIATED EFFECTS EXIST ON ITS
WRN PERIPHERY WHERE UPPER SLY FLOW AND AN OVERALL DIFFLUENT
PATTERN IS GENERATING AND SPREADING MOISTURE N FROM THE ITCZ S
OF 10N BETWEEN 40W-55W.

$$
CANGIALOSI





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