[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 011216
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED AUG 01 2007

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1030 UTC.

...SPECIAL FEATURES...

A 1010 MB LOW NEAR 12N55W IS ABOUT 325 NM E OF THE SOUTHERN
WINDWARD ISLANDS. A BAND OF SCATTERED MODERATE ISOLATED STRONG
CONVECTION HAS APPEARED INTERMITTENTLY WITHIN 90 NM OF THE LOW
LEVEL CENTER OVER THE PAST SEVERAL HOURS AND THE OVERALL
ORGANIZATION OF THE SYSTEM REMAINS INTACT. THE SYSTEM STILL HAS
THE POTENTIAL FOR FURTHER DEVELOPMENT AND COULD BECOME A
TROPICAL DEPRESSION OVER THE NEXT DAY OR SO. EVEN IF DEVELOPMENT
DOES NOT OCCUR...THE LOW WILL LIKELY BRING SQUALLS TO THE
WINDWARD ISLANDS DURING THE NEXT DAY OR SO.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 21W/22W FROM 5N TO 20N CONTINUES TO
PULL AWAY FROM THE AFRICAN COAST. A 1009 MB LOW WAS ALONG THE
WAVE AXIS NEAR 13N AND WAS SOMEWHAT SUPPORTED BY A 0732 UTC
QUIKSCAT PASS WHICH INDICATED BROAD TURNING IN THE WIND FIELD.
SATELLITE WISE THE WAVE CONSISTS OF A WELL DEFINED LOW AND MID
LEVEL CENTER WITH WIDELY SCATTERED SHOWERS AND A FEW
THUNDERSTORMS IN THE W SEMICIRCLE AND JUST E OF THE CAPE VERDE
ISLANDS. THE BULK OF THE DEEP CONVECTION IS ALONG THE
INTERSECTION OF THE WAVE AND THE ITCZ FROM 8N TO 11N BETWEEN 18W
AND 25W.

TROPICAL WAVE IS ALONG 38W/39W S OF 20N MOVING W 12 KT. WAVE
NOTED BY CYCLONIC TURNING IN STRATOCUMULUS FIELD. SCATTERED
MODERATE CONVECTION NOTED AT THE INTERSECTION OF THE WAVE AXIS
AND ITCZ BETWEEN 37W AND 43W.

TROPICAL WAVE IS OVER THE E CARIBBEAN ALONG 65W MOVING W 15-20
KT. 0000 UTC SOUNDING FROM GUADELOUPE INDICATED THE WAVE HAD
PASSED TO THE W OF THE SITE. WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS WERE NOTED WITHIN 180 NM EITHER SIDE OF THE WAVE
AXIS WITH MOST OF THE SHOWER AND THUNDERSTORM PASSING OVER THE
CARIBBEAN S OF PUERTO RICO AND EXTENDING SEWD TO THE SOUTHERN
WINDWARD ISLANDS.

TROPICAL WAVE IN THE CENTRAL CARIBBEAN AND SW ATLC IS BECOMING
FRACTURED WITH A TROUGH FROM 25N71W TO 23N74W WHILE THE WAVE
ITSELF EXTENDS FROM E CUBA ALONG 75W/76W TO THE COAST OF
COLOMBIA AND IS CONTINUING W AT 15-20 KT IN MODERATE
ELY FLOW OVER THE CARIBBEAN. THIS WAVE IS EMBEDDED WITHIN SOME
RATHER DRY STABLE AIR ESPECIALLY OVER THE CARIBBEAN...THUS ONLY
WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE BEING
GENERATED AT THE NORTHERN PORTION OF THE WAVE AND THE SURFACE
TROUGH OVER HAITI...E CUBA...THE WINDWARD PASSAGE AND THE
EXTREME SE BAHAMAS.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 14N17W 10N30W 9N37W 13N50W 11N57W
9N61W. EXCEPT AS NOTED IN ASSOCIATION WITH THE TROPICAL WAVES
ABOVE...ISOLATED MODERATE TO STRONG CONVECTION IS NOTED WITHIN
120 NM OF THE AXIS W OF 58W TOWARD TRINIDAD AND TOBAGO.

...DISCUSSION...
GULF OF MEXICO...
ANOMALOUSLY DEEP LAYERED TROUGH FOR EARLY AUGUST ALONG THE US
EASTERN SEABOARD IS BEGINNING TO EXERT MORE INFLUENCE ON THE NE
GULF AS THE MID TO UPPER LEVEL ANTICYCLONE OVER THE BIG BEND
AREA OF W TEXAS CONTINUES TO RETROGRADE AND THE ASSOCIATED RIDGE
AXIS ALONG 27N90W TO SOUTH FLORIDA SAGS SLOWLY SWD WITH TIME.
DESPITE THE PATTERN CHANGES ANTICYCLONIC FLOW STILL COVERS MOST
OF THE GULF WITH THE EXCEPTION OF THE FAR NE PORTION. THE FLOW
WAS BECOMING INCREASINGLY DIFLUENT OVER THE ERN THIRD OF THE
GULF WITH WIDELY SCATTERED SHOWERS AND TSTMS N OF 26N AND E OF
90W. ADDITIONAL THUNDERSTORM ACTIVITY IS ALONG THE WEST COAST OF
THE FLORIDA PENINSULA FROM EVERGLADES CITY NWD TO TARPON SPRINGS
MOVING EWD AT 15-20 KT. THIS PATTERN IS EXPECTED TO REMAIN IN
PLACE FOR THE NEXT FEW DAYS GENERATING ADDITIONAL TSTMS OVER THE
E GULF STATES AND FLORIDA AS A WEAK STATIONARY FRONT CURRENTLY
OVER THE FAR NE GULF REMAINS A FOCUS FOR THIS CONVECTIVE
ACTIVITY AND THE WEAK SURFACE RIDGE EXTENDING ACROSS THE CENTRAL
BAHAMAS...THE FLORIDA STRAITS TO THE CENTRAL GULF REMAINS IN
PLACE.

CARIBBEAN...
CONDITIONS ACROSS THE MAJORITY OF THE CARIBBEAN SEA ARE TRANQUIL
TONIGHT AS A RESULT OF A VAST AREA OF DRY STABLE AIR ALOFT.
NW-SE ORIENTED UPPER LEVEL INVERTED TROUGH EXTENDS ACROSS THE
CENTRAL CARIBBEAN FROM 19N85W SE TO THE N COAST OF COLOMBIA
NEAR 10N72W RESULTING IN SE FLOW ALOFT OVER THE E CARIBBEAN AND
N AND NWLY FLOW OVER THE W CARIBBEAN. WIDELY SCATTERED SHOWERS
AND THUNDERSTORMS ARE CONFINED TO THE E-CENTRAL CARIBBEAN E OF
70W IN ASSOCIATION WITH THE TROPICAL WAVE NOW ENTERING THE REGION
ALONG 65W. THIS COULD BE THE BEGINNING OF SEVERAL DAYS OF
UNSETTLED WEATHER OVER THE WINDWARD ISLANDS AND E CARIBBEAN AS
THE AREA OF LOW PRESSURE E OF THE ISLANDS APPROACHES AND THE
ASSOCIATED SHOWER AND THUNDERSTORM ACTIVITY SPREADS OVER THE
REGION.

ATLANTIC...
SEE SPECIAL FEATURES FOR INFORMATION ON THE 1010 MB LOW IN THE
W TROPICAL ATLC. ANOMALOUSLY DEEP LAYERED TROUGH ALONG THE US
EASTERN SEABOARD EXTENDS INTO THE W ATLC N OF 29N W OF 70W TO
OVER NE FLORIDA WITH AN ASSOCIATED WEAKENING COLD FRONT ENTERING
THE REGION NEAR 32N72W TO NE FLORIDA IN THE VICINITY OF CAPE
CANAVERAL. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 28N
AND WITHIN 360 NM E OF THE COLD FRONT. A NARROW EXTENSION OF THE
GULF RIDGE EXTENDS OVER SOUTH FLORIDA INTO THE W ATLC ALONG
27N70W TO BEYOND 32N63W. A SHARP NARROW SHEAR AXIS/TROUGH OVER
THE CENTRAL ATLANTIC EXTENDS FROM A CYCLONIC CIRCULATION NEAR
31N51W SWD TO 22N54W. THE REMAINDER OF THE ATLC IS DOMINATED BY
ANTICYCLONES NEAR 16N51W AND 26N30W WITH DEEP LAYERED EASTERLY
FLOW NOTED. UW CIMSS SAL ANALYSIS INDICATES A VAST AREA OF
AFRICAN DUST MAINLY N OF 15N AND E OF 45W WITH SOME OF DUST AND
STABLE AIR BEING ENTRAINED INTO THE TROPICAL WAVES ALONG 38W/39W
AND THE ONE EMERGING OFF THE W COAST OF AFRICA THEREBY LIMITING
CONVECTION TO THE ITCZ. AT THE SURFACE...HIGH PRESSURE RIDGE
CONTINUES TO DOMINATE THE ATLC ANCHORED BY A 1027 MB W OF THE
AZORES NEAR 35N39W.

$$
COBB







This weather bulletin was brought to you by:
www.nashvilleweather.net