[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 080604
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE MAY 08 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0545 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N13W 5N20W 2N30W 1N40W 2N51W.
NUMEROUS MODERATE CONVECTION WITH EMBEDDED ISOLATED STRONG
ACTIVITY IS WITHIN 60NM N AND 150NM S OF THE AXIS BETWEEN
11W-27W. ISOLATED MODERATE TO STRONG CONVECTION IS WITHIN 150NM
EITHER SIDE OF THE AXIS BETWEEN 28W-43W.

...SPECIAL FEATURE...

AN OCCLUDED 1001 MB SFC LOW WAS LOCATED NEAR 30.5N 75.0W AS OF
08/0300 UTC...OR ABOUT 300NM E OF THE FLORIDA/GEORGIA BORDER. A
STORM WARNING ASSOCIATED WITH THIS SYSTEM IS IN AFFECT FOR THE
OFFSHORE AREA N OF 28N W OF 74W BUT IS EXPECTED TO RELAX TO GALE
CONDITIONS THROUGH MORNING. THIS WAS VERIFIED BY THE 0000 UTC
QUIKSCAT PASS WHICH SHOWED 50-60 KT WINDS OFF THE SOUTHEAST
COAST. THESE WINDS ARE CONTINUING TO PRODUCE A SIGNIFICANT SWELL
EVENT FOR THE SOUTHEAST U.S. COAST AND THE BAHAMAS. BUOY 41010
RECENTLY REPORTED 25 FT SEAS AT 16 SEC...WITH BOTH THE PERIOD
AND HEIGHT SLIGHTLY UNDERDONE BY THE REGIONAL WW3. LIGHTNING
DATA HAS BEEN DEPICTING SCATTERED TSTMS ESPECIALLY N AND E OF
THE CENTER OVER THE LAST FEW HOURS FROM 29N-33N BETWEEN 75W-79W.
THE MAIN THREAT...HOWEVER...WILL CONTINUE TO BE THE HIGH WINDS
AND WAVES ASSOCIATED WITH THE SYSTEM. THE MODEL CONSENSUS IS TO
MOVE THE LOW WEST TOWARDS NORTH FLORIDA/GEORGIA OVER THE NEXT 36
HOURS WHILE SLOWLY WEAKENING. PLEASE REFER TO THE HIGH SEAS
FORECASTS AND STATEMENTS FROM LOCAL WEATHER FORECAST OFFICES FOR
MORE DETAILS REGARDING EXPECTED OFFSHORE AND COASTAL IMPACTS.

...DISCUSSION...

GULF OF MEXICO...
A BACKDOOR COLD FRONT ASSOCIATED WITH THE LARGE OCCLUDED LOW
PRES SYSTEM IN THE W ATLC CONTINUES TO SLOWLY PUSH SW IN THE
GULF ANALYZED FROM WRN CUBA TO SRN LOUISIANA...MARKED BY PATCHES
OF LOW TO MID CLOUDS. BEHIND THE FRONT...15-20 KT E/NE WINDS ARE
USHERING IN FAIRLY COMFORTABLE TEMPS AND A NOTICEABLE DROP IN
HUMIDITY. WINDS AND SEAS WILL DIMINISH THROUGH WED AS HIGH
PRES BUILDS OVER THE GULF BEHIND THE FRONT. ABUNDANT SUBSIDENCE
IS KEEPING SKIES FAIR TO MAINLY CLEAR IN THIS REGION. W OF THE
FRONT...THE AIRMASS IS MORE HUMID BUT OTHERWISE THE WEATHER
CONDITIONS ARE SIMILAR WITH FAIR SKIES AND BRISK E TO SE WINDS.
MORE ACTIVE WEATHER IS OCCURRING OVER NRN MEXICO AND S TEXAS...S
OF A STALLED FRONT AND ALSO AIDED BY A DIFFLUENT PATTERN ALOFT.
UPPER MOISTURE OVER THIS CONVECTION IS SPREADING EWD INTO THE
WRN GULF AROUND AND UPPER RIDGE.

CARIBBEAN SEA...
THE LARGE LOW PRES SYSTEM IN THE WRN ATLC IS RESULTING IN A WEAK
PRESSURE PATTERN ACROSS THE CARIB WHICH IS KEEPING E/NE TRADES
FAIRLY LIGHT...MOSTLY IN THE 5-15 KT RANGE EXCEPT TO 20 KT IN
THE SE PORTION. THIS IS GENERALLY EXPECTED TO PERSIST OVER THE
NEXT DAY OR SO. THE BACK DOOR COLD FRONT ASSOCIATED WITH THE
LARGE WRN ATLC LOW IS PUSHING SLOWLY SWD THROUGH CUBA. THERE ARE
POSSIBLE ISOLATED SHOWERS ALONG THIS BOUNDARY. MORE IMPRESSIVE
ACTIVITY ASSOCIATED WITH THE ITCZ IS OVER COLOMBIA AND COSTA
RICA. SIMILAR SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS
ALSO AFFECTING THE SW CARIBBEAN S OF 12N E OF 79W.   DEBRIS
MID-HIGH LEVEL CLOUDS ARE BEING TRANSPORTED NE FROM THIS
CONVECTIVE AREA TO THE LEEWARD ISLANDS BY STRONG WSW UPPER FLOW.

WESTERN ATLANTIC...
THE HIGHLIGHT CONTINUES TO BE A LARGE OCCLUDED LOW PRES SYSTEM
CENTERED OFF THE SE U.S...SEE SPECIAL FEATURE SECTION ABOVE FOR
MORE DETAILS. A TRAILING/BACK DOOR COLD FRONT EXTENDS FROM A
TRIPLE POINT NEAR 32N68W ACROSS THE SOUTHEAST BAHAMAS. A
STATIONARY FRONT RUNS FROM THE TRIPLE POINT TO 51W ALONG 32N
WHERE A WEAK FRONTAL WAVE EXISTS. SCATTERED SHOWERS POSSIBLE
WITHIN 120NM OF THE FRONT. PREFRONTAL TROUGHING S OF BERMUDA
ALONG WITH A DIFFLUENT PATTERN ALOFT ARE SUPPORTING SCATTERED
TSTMS FROM 26N-29N BETWEEN 62W-67W. SIMILAR ACTIVITY IS NOTED
JUST NE OF HISPANIOLA.

CENTRAL AND EASTERN ATLANTIC...
A PERSISTENT 1033 MB AZORES HIGH IS IN CONTROL OF THE PATTERN
ACROSS THE ATLC E OF 50W. THIS HIGH IS PRODUCING A LARGE AREA OF
MODERATE TO FRESH TRADES...STRONGEST E OF 25W WHERE THE PRES
GRADIENT IS TIGHTENED DUE TO LOWER PRES OVER AFRICA. SCATTERED
STRATOCUMULUS COVER MUCH OF THE REGION...EXCEPT S OF 20N E OF
35W WHERE THIS LOW-LEVEL CLOUD DECK IS ERODED BY SAHARAN DUST.
AN UPPER LOW IS NW OF THE CANARY ISLANDS NEAR 31N22W THAT HAS
ASSOCIATED TROUGHING STRETCHING SWD ALONG 25W. THIS UPPER SYSTEM
IS ONLY GENERATING SCATTERED PATCHES OF CIRRUS.

$$
WILLIS




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