[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 102356
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI APR 10 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.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N8W 1N20W CROSSING THE EQUATOR NEAR
24W AND EXTENDING TO 2S30W INTO NE BRAZIL NEAR 5S36W. SCATTERED
MODERATE CONVECTION IS FROM 1N-4N BETWEEN 15W-21W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS S OF 1N BETWEEN 28W-33W.

...DISCUSSION...

GULF OF MEXICO...
A VIGOROUS DEEP LAYERED TROUGH ACROSS THE OHIO RIVER VALLEY IS
SUPPORTING A COLD FRONT THAT EXTENDS ACROSS THE SE CONUS AND SW
LOUISIANA CONTINUING SW ALONG THE UPPER TEXAS GULF COAST. A PRE-
FRONTAL TROUGH IS ALSO ANALYZED ACROSS NE LOUISIANA ENTERING THE
GULF NEAR 29N91W TO 29N93W. WHILE A LACK OF PRECIPITATION IS
NOTED WITH THIS FRONT ACROSS THE NW GULF...IT WILL PROGRESS
SLOWLY EWD OVER THE NRN GULF WATERS DURING THE OVERNIGHT HOURS.
BY EARLY SATURDAY THE FRONT IS FORECAST TO EXTEND FROM THE
FLORIDA BIG BEND TO NE MEXICO AND BEGIN TO STALL. TO THE E OF
THE FRONT...SOUTHERLY RETURN FLOW IS OBSERVED ACROSS A MAJORITY
OF THE GULF WITH MOSTLY FAIR CONDITIONS SEEN ON VISIBLE
SATELLITE IMAGERY. AN UPPER LEVEL RIDGE WITH AXIS ALONG 95W IS
PROVIDING THE GULF WITH W-NW UPPER LEVEL FLOW. THIS FLOW IS
BRINGING HIGH CLOUDS SPILLING OVER THE APEX OF THE RIDGE ACROSS
THE NW WATERS N OF 25N W OF 93W.

CARIBBEAN SEA...
A WEAK INVERTED SURFACE TROUGH CONTINUES WWD NEAR 10 KT CENTERED
ALONG 72W ACROSS THE CENTRAL CARIBBEAN. LOW-MID LEVEL CLOUDINESS
AND EMBEDDED ISOLATED SHOWERS ARE WITHIN 150 NM EITHER OF THE
TROUGH AXIS. PATCHY CLOUDS AND EMBEDDED ISOLATED SHOWERS ARE
POSSIBLE ELSEWHERE. ALL OF THIS ACTIVITY IS SHALLOW IN NATURE
CAPPED BY STRONG SUBSIDENCE AND DRY AIR IN THE MID AND UPPER
LEVELS. E TO SE WINDS NEAR 15-20 KT ARE BLOWING OVER THE NW
CARIBBEAN DUE TO THE ENHANCED PRESSURE GRADIENT BETWEEN
TROUGHING OVER ERN MEXICO/BAY OF CAMPECHE AND HIGH PRESSURE OVER
THE W ATLC. SIMILAR MAGNITUDE E-NE WINDS ARE OCCURRING IN THE
USUAL ENHANCED ZONE NEAR THE COAST OF COLOMBIA. LITTLE CHANGE IS
EXPECTED IN THESE SURFACE WIND PATTERNS OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
A LARGE SCALE MID-UPPER TROUGH OVER THE W ATLC IS FLATTENING
PROVIDING LIMITED SUPPORT FOR A WEAKENING STATIONARY FRONT
EXTENDING FROM 31N55W TO 26N61W. ONLY BROKEN CLOUDINESS AND
ISOLATED SHOWERS ARE LINGERING WITHIN 60 NM OF THE FRONT. A 1027
MB HIGH PRESSURE IS CENTERED NEAR 29N67W W OF THE DISSIPATING
FRONT ACROSS THE REMAINDER OF THE W ATLC AND IS PROVIDING FAIR
WEATHER AND A FEW PASSING MID/HIGH LEVEL CLOUDS FROM 26N TO
BEYOND 32N BETWEEN 69W-75W. WINDS ARE GENERALLY LIGHT ACROSS THE
W ATLC BESIDES FOR SWLY WINDS OF UP TO 20 KT N OF 30N W OF 75W
ENHANCED BY THE LOW PRESSURE AREA OVER THE ERN CONUS. FARTHER
E...AN UPPER LOW CENTERED NEAR 25N31W IS PRODUCING MULTILAYER
CLOUDINESS AND EMBEDDED ISOLATED SHOWERS WITHIN 200 NM OF THE
CENTER. AT THE SURFACE ACROSS THE CENTRAL AND ERN ATLC...A 1031
MB HIGH CENTERED W OF THE AZORES IS PROVIDING NE TO ELY SURFACE
FLOW AND GENERALLY FAIR WEATHER.

$$
HUFFMAN



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