[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 061037
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN MAY 06 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1030 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N13W 4N20W 1N30W EQ40W 1S50W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OVER AFRICA AND
ADJACENT ATLC WATERS FROM EQ-11N BETWEEN 7W-17W. NUMEROUS
MODERATE TO STRONG CONVECTION IS OFF THE COAST OF LIBERIA FROM
EQ-8N BETWEEN 9W-14W. ISOLATED MODERATE IS WITHIN 30NM EITHER
SIDE OF THE AXIS BETWEEN 17W-22W...AND WITHIN 150NM EITHER SIDE
BETWEEN 25W-36W. NUMEROUS MODERATE/ISOLATED STRONG IS OFF NE
SOUTH AMERICA FROM 4S-5N BETWEEN 35W-52W.

...DISCUSSION...

GULF OF MEXICO...
RETURN FLOW DOMINATING THE GULF REMAINS STRONGEST W OF 90W WHERE
A TIGHTER PRES GRADIENT EXISTS DUE TO LOWER PRESSURE OVER
MEXICO. THIS HAS ALLOWED SE WIND WAVES AND SWELL TO BUILD INTO
THE 6-9' RANGE FOR THE WRN GULF. ASIDE FROM A FEW ISOLATED CELLS
OF ELEVATED CONVECTION OFF OF NE MEXICO...DEEP CONVECTION
REMAINS AT A MINIMUM ACROSS THE GULF. ANTICYCLONIC FLOW AROUND
AN UPPER RIDGE BUILDING INTO THE WRN GULF IS SPREADING UPPER
MOISTURE EWD INTO THE GULF MAINLY W OF 90W. THIS IS OBSCURING
LOW CLOUDS TRAPPED UNDERNEATH A FAIRLY SIGNIFICANT LOW LEVEL
INVERSION. MOST ASOS STATIONS ALONG COASTAL TEXAS ARE REPORTING
CEILINGS BELOW 2000'. MOSTLY DRY MID TO UPPER AIR IS OVER THE
ERN PORTION WITH NW FLOW. SE WINDS AND SEAS REMAIN HIGHEST WRN
PORTION THROUGH SUN BEFORE RELAXING A TOUCH MON INTO TUE.
BACKDOOR FRONT ASSOCIATED WITH LOW PRESSURE DEVELOPING OFF THE
SOUTHEAST U.S. COAST WILL AFFECT THE MIDDLE AND ERN GULF LATE
TONIGHT INTO MON.

CARIBBEAN SEA...
TRADE FLOW REMAINS FAIRLY LIGHT OVERALL AS THE TYPICAL SYNOPTIC
PATTERN HAS BEEN DISRUPTED BY THE SFC TROUGHING IN THE SW NORTH
ATLC. UPPER SW FLOW DOMINATES THE BASIN BETWEEN AN UPPER HIGH
CENTERED OFF NE SOUTH AMERICA AND TROUGHING EXTENDING SSW FROM
OFF THE SE U.S. COAST INTO NW CARIB. THIS IS TRANSPORTING UPPER
MOISTURE NE THROUGH THE CENTRAL AND ERN CARIB. A CLUSTER OF
SCATTERED MODERATE CONVECTION ASSOCIATED WITH THE ITCZ IS
AFFECTING THE SW CARIB NEAR BOCAS DEL TORO PANAMA. FAIRLY WEAK
PRES GRADIENT WILL KEEP TRADES IN THE LIGHT TO MODERATE CATEGORY
OVER THE NEXT COUPLE OF DAYS.

ATLANTIC...
A SFC TROUGH ALONG 29N61W 19N66W HAS A 1012 MB LOW ATTACHED NEAR
26N62W. SATELLITE IMAGERY SHOWS A BROAD REGION OF LOW LEVEL
CYCLONIC TURNING WITH MORE THAN ONE CENTER POSSIBLE. HAVE GONE
WITH A MEAN CENTER OF THE OVERALL BROAD CIRCULATION. ASSOCIATED
BROKEN TO OVERCAST CLOUDINESS WITH EMBEDDED SHOWERS IS N OF 20N
BETWEEN 47W-64W. THE THICKEST CLOUDS/DEEPEST MOISTURE ARE E OF
THE SFC FEATURES WHERE MORE UPPER SUPPORT EXISTS...WITH
DIFFLUENCE BETWEEN THE TROUGHING IN THE WRN ATLC AND RIDGING IN
THE CENTRAL ATLC. ALTHOUGH THE FOCUS HAS BEEN ON THIS AREA THE
LAST FEW DAYS...THAT WILL CHANGE OVER THE NEXT 24-48 HOURS. THE
GLOBAL MODELS HAVE CONTINUED TO COME INTO BETTER AGREEMENT
REGARDING LOW PRES DEVELOPMENT OFF THE COAST OF THE SOUTHEAST
UNITED STATES LATER TODAY THROUGH TUESDAY. THIS IS EXPECTED TO
BRING SIGNIFICANT MARINE IMPACTS TO THE NW PORTION OF THE AREA
INTO EARLY NEXT WEEK...INCLUDING GALE FORCE WINDS AND LARGE NLY
SWELLS. SEE HIGH SEAS FORECAST UNDER AWIPS HEADER MIAHSFAT2 AND
STATEMENTS FROM LOCAL WEATHER SERVICE OFFICES FOR MORE DETAILS.

MUCH OF THE REMAINDER OF THE ATLC DISCUSSION AREA IS DOMINATED
BY THE SRN PERIPHERY OF A QUASI-STATIONARY 1032MB SFC HIGH E OF
THE AZORES NEAR 40N20W. THIS IS PRODUCING ABUNDANT MODERATE TO
FRESH TRADES AND FAIR WEATHER E OF 45W. THERE IS AN UPPER LOW
NEAR 28N27W BUT IT DOES NOT APPEAR TO BE GENERATING MUCH IN THE
WAY OF SENSIBLE WEATHER.

$$
WILLIS




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