[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 091739
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN MAR 09 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
SECTIONS OF SOUTH AMERICA...AND THE 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 1715 UTC.

...THE ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N10W 3N21W CROSSING THE EQUATOR
NEAR 34W TO 2S45W. SCATTERED MODERATE CONVECTION IS WITHIN 210
NM N OF THE AXIS BETWEEN 28W-33W. ISOLATED MODERATE IS FROM THE
EQUATOR TO 8N W OF 40W.

...DISCUSSION...

THE GULF OF MEXICO...

A 1026 MB SFC HIGH IS CENTERED IN THE MID-GULF NEAR 26N88W
PROVIDING MAINLY LIGHT TO MODERATE WINDS...EXCEPT FOR THE FAR W
GULF WHERE QSCAT IS DEPICTING 15-20 KT SLY RETURN FLOW. THIS
MOIST LOW-LEVEL FLOW IS PRODUCING SHALLOW CLOUDINESS AND
POSSIBLE EMBEDDED LIGHT SHOWERS W OF 95W. IN THE MID AND UPPER
LEVELS...WIDESPREAD SWLY FLOW EXISTS BETWEEN A PRONOUNCED TROUGH
OVER THE SW CONUS/MEXICO AND STRONG RIDGING IN THE CARIBBEAN AND
THE SW ATLC. THIS FLOW IS NOT TAPPING MUCH MOISTURE AT THE
MOMENT AS WV IMAGES SHOW A MODESTLY DRY ENVIRONMENT. LOOKING
AHEAD A DAY OR SO...MOISTURE MAY INCREASE SLIGHTLY OVER THE
YUCATAN PENINSULA AND S GULF AS THE WEAKENING FRONT IN THE CARIB
DRIFTS BACK W AS IT DISSIPATES.

THE CARIBBEAN SEA...

THE TAIL END OF A STALLED FRONT EXTENDS FROM CENTRAL CUBA TO
HONDURAS ALONG 22N78W 16N87W. DENSE LOW TO MID LEVEL CLOUD
COVER WITH EMBEDDED SCATTERED SHOWERS ARE WITHIN 180 NM W OF THE
FRONT. THE PRESSURE GRADIENT BETWEEN THE FRONT AND HIGH PRES IN
THE GULF OF MEX IS PRODUCING NE WINDS IN THE 20-25 KT RANGE.
ELSEWHERE...TYPICAL PATCHES OF LOW-LEVEL CLOUDS ARE BEING DRIVEN
FROM NE-SW BY THE TRADE WIND FLOW. ALOFT...A WELL DEFINED UPPER
HIGH IS LOCATED NEAR 14N79W AND STRONG TROUGHING EXTENDS ACROSS
THE LESSER ANTILLES FROM 17N59W TO VENEZUELA. WIDESPREAD
SUBSIDENCE IS ASSOCIATED WITH THESE FEATURES...STRONGEST BETWEEN
THE RIDGE AND TROUGH AXIS WHERE THE UPPER FLOW IS CONFLUENT.
THIS VERY STABLE ENVIRONMENT IS SUPPRESSING THE DEVELOPMENT OF
ANY DEEP MOISTURE.

THE ATLANTIC OCEAN...

A COLD FRONT ENTERS THE AREA NEAR 32N69W AND EXTENDS TO 27N73W
THEN STATIONARY TO CENTRAL CUBA. DENSE LOW TO MID LEVEL CLOUDS
AND EMBEDDED SCATTERED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF
THE COLD FRONT AND 120 NM W OF THE STATIONARY PORTION. MUCH
COOLER AND DRIER AIR HAS BUILT IN BEHIND THE FRONT...NOTED BY A
SCATTERED STRATOCUMULUS DECK EVIDENT ON SAT IMAGERY. THE ONLY
OTHER AREA OF LOW PRES IS A WEAKENING 1016 MB LOW NEAR 26N40W.
THIS LOW HAS GREATLY WEAKENED OVER THE PAST COUPLE OF DAYS NOW
ONLY CONSISTING OF A SWIRL OF LOW CLOUDS. HOWEVER...THE TIGHT
PRES GRADIENT ON THE N SIDE OF THE SYSTEM IS STILL PRODUCING
STRONG NE WINDS AS REVEALED BY A QSCAT AND ASCAT PASS THIS
MORNING. THIS WEAK SFC LOW IS EMBEDDED IN AN HIGHLY ELONGATED
MID TO UPPER TROUGH. EXTENSIVE SWLY FLOW ON THE E SIDE OF THE
TROUGH IS DRAWING MID TO HIGH LEVEL CLOUDS ACROSS THE TROPICAL E
ATLC AND ENHANCING CONVECTION IN THE ITCZ NEAR THE SOUTH
AMERICAN COAST.  THE REMAINDER OF THE ATLC DISCUSSION ZONE IS
TRANQUIL ON THE S SIDE OF STRONG SFC RIDGING ALONG 38N.

$$
CANGIALOSI


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