[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 081751
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE AUG 08 2006

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...WEATHER OBSERVATIONS...RADAR...
AND METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURE...
A 1009 MB ATLANTIC OCEAN LOW PRESSURE CENTER IS NEAR 12N47W...OR
ABOUT 725 NM EAST OF WINDWARD ISLANDS...MOVING WEST NEAR 15 KT.
ALTHOUGH THUNDERSTORM ACTIVITY IS MINIMAL AND UPPER-LEVEL WINDS
ARE ONLY MARGINALLY CONDUCIVE FOR DEVELOPMENT...THIS SYSTEM
STILL HAS SOME POTENTIAL TO BECOME A TROPICAL DEPRESSION DURING
THE NEXT DAY OR SO.

...TROPICAL WAVES...

AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 30W SOUTH OF
18N MOVING WEST 10 TO 15 KT. CYCLONIC CURVATURE IS MUCH MORE
EVIDENT IN TODAYS LOW CLOUD MOTIONS...AS THE MONSOON TROUGH THAT
WAS SUPERIMPOSED YESTERDAY IS NOW LESS ACTIVE. MINIMAL SHOWER
ACTIVITY IS NOTED IN THE VICINITY OF THE NORTHERN PORTION OF THE
WAVE N OF 11N. ISOLATED SHOWERS/TSTMS LIE WITHIN 300NM OF EITHER
SIDE OF THE WAVE S OF 11N.

A CENTRAL CARIBBEAN SEA TROPICAL WAVE IS ALONG 75W/76W SOUTH OF
24N MOVING WEST 15 TO 20 KT. THIS WAVE IS INTERACTING WITH AN
ELONGATED UPPER LOW OVER THE BAHAMAS TO PRODUCE CLOUDINESS AND
SCATTERED SHOWERS AND TSTMS NORTH OF CUBA THROUGH THE BAHAMAS
AND THE ADJACENT WATERS. ONLY ISOLATED SHOWERS AND TSTMS ARE
NOTED IN THE VICINITY OF THE CARIBBEAN PORTION OF THIS
WAVE...LIKELY BEGIN SUPPRESSED BY THE EXTENSIVE DRY AIR AND
SAHARAN DUST IN THE VICINITY. UPPER LEVEL WINDS ARE UNFAVORABLE
FOR ANY SIGNIFICANT DEVELOPMENT OF THIS WAVE. HOWEVER...
ASSOCIATED SHOWERS AND TSTMS WILL CONTINUE AFFECTING THE
BAHAMAS...CUBA...AND SOUTHERN FLORIDA THROUGH LATER TODAY AND
TOMORROW.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 14N17W 13N29W 13N32W 12N43W 11N51W
TO INLAND THROUGH SOUTH AMERICAN TO NEAR 9N68W. CONVECTION ALONG
THE ITCZ IS LESS PROMINENT THAN IT HAS BEEN OVER THE LAST COUPLE
OF DAYS. THE CLUSTER OF MODERATE TO STRONG CONVECTION THAT
PUSHED OFF OF SENEGAL LAST NIGHT HAS WEAKENED SUBSTANTIALLY.
ISOLATED MODERATE CONVECTION IS NOW NOTED OFF THE W COAST OF
AFRICA FROM 6N-16N BETWEEN 13W-21W. ASIDE FROM THE SPECIAL
FEATURE AND THE TROPICAL WAVE ALONG 30W...ONLY ISOLATED SHOWERS
AND TSTMS ARE NOTED IN THE VICINITY OF THE ITCZ AXIS WEST OF 35W
THROUGH THE S AMERICAN COAST. A CLUSTER OF MODERATE CONVECTION
LIES NORTH OF THE EPAC PORTION OF THE ITCZ AXIS AFFECTING THE S
CARIBBEAN N OF PANAMA.

...DISCUSSION...
THE GULF OF MEXICO...
WV IMAGERY SHOWS BROAD EASTERLY FLOW BLANKETING MUCH OF THE GULF
THIS AFTERNOON...ON THE SOUTH SIDE OF THE UPPER HIGH EXTENDING S
FROM THE SE US. THE EASTERLY FLOW IS PUSHING THE ISOLATED
SHOWERS/TSTMS ACROSS THE GULF QUICKLY TO THE W. THE GREATEST
CONCENTRATION OF THESE WITH EMBEDDED MODERATE CONVECTION IS
MOVING ONSHORE MEXICO AND TEXAS. THESE SHOWERS/TSTMS ARE
ASSOCIATED WITH WEAK UPPER DIFFLUENCE/SFC TROUGHING. SCATTERED
SHOWERS/TSTMS ARE ALSO BEGINNING TO MOVE INTO THE FLORIDA
STRAITS AND SE GULF NEAR THE BASE OF THE UPPER TROF OVER THE
BAHAMAS...AND AHEAD OF THE TROPICAL WAVE EXTENDING THROUGH THE
CENTRAL CARIBBEAN. DOPPLER RADAR SHOWS SEVERAL SHOWERS AND TSTMS
MOVING THROUGH THE FLORIDA STRAITS AND INTO SE FL. SURFACE WINDS
ACROSS THE GULF ARE GENERALLY E 5 TO 15 KT ON THE SOUTH SIDE OF
A 1022MB HIGH ANALYZED NEAR JACKSON MISSISSIPPI. SIMILAR LIGHT
E/SE FLOW IS EXPECTED THROUGH TOMORROW...THOUGH SHOWERS AND
TSTMS ASSOCIATED WITH THE TROPICAL WAVE AND ITS INTERACTION WITH
THE UPPER LOW NEAR THE BAHAMAS WILL CONTINUE SPREADING INTO THE
ERN GULF.

THE CARIBBEAN SEA...
A TROPICAL WAVE IS MOVING THROUGH THE CENTRAL CARIBBEAN BUT MOST
OF THE ASSOCIATED CONVECTION LIES N OF THE CARIBBEAN...ASIDE
FROM A NARROW PATCH OF MODERATE CONVECTION BETWEEN JAMAICA AND
ERN CUBA. ISOLATED MODERATE CONVECTION IS AGAIN AFFECTING THE NW
CARIBBEAN THIS AFTERNOON WEST OF JAMAICA TO THE YUCATAN
PENINSULA...ASSOCIATED WITH UPPER DIFFLUENT AIR BETWEEN THE
UPPER LOW NEAR THE NW BAHAMAS AND THE EASTERLY FLOW ON THE S
PORTION OF THE UPPER HIGH OVER THE SE US. MID TO UPPER LEVEL
E/SE FLOW IS AFFECTING MUCH OF THE CENTRAL AND ERN
CARIBBEAN...ON THE SW SIDE OF AN UPPER HIGH CENTERED IN THE SW
ATLANTIC NEAR 24N67W. AT THE SURFACE...15 TO 25 KT TRADE FLOW
DOMINATES ON THE S/SW PORTION OF THE ATLANTIC HIGH. THIS
MORNINGS QUIKSCAT PASS CONTINUED TO SHOW SLIGHTLY STRONGER 30 KT
ENE WINDS JUST OFF THE COLOMBIAN COAST AS THE HIGH INTERACTS
WITH THE COLOMBIAN LOW. THIS IS EXPECTED TO PERSIST OVER THE
NEXT COUPLE OF DAYS...THOUGH THE FEW SHOWERS/TSTMS ASSOCIATED
WITH THE TROPICAL WAVE ALONG 76W WILL MOVE INTO THE WRN
CARIBBEAN TOMORROW.

THE ATLANTIC OCEAN...
UPPER LEVEL NE/ENE FLOW IS HOVERING OVER FLORIDA AND THE
ADJACENT ATLC WATERS THIS AFTERNOON BETWEEN THE UPPER HIGH OVER
THE SE US AND THE UPPER LOW MOVING THROUGH THE NW BAHAMAS. THE
NRN PORTION OF THE TROPICAL WAVE EXTENDING THROUGH ERN CUBA AND
THE SE BAHAMAS IS INTERACTING WITH THIS UPPER LOW TO PRODUCE
SCATTERED MODERATE CONVECTION EXTENDING NORTH OF CUBA...THROUGH
THE BAHAMAS...AND THE ADJACENT WATERS. AN UPPER ANTICYCLONE
CENTERED NEAR 24N66W IS PRODUCING CLOCKWISE FLOW IN THE ATLC
WATERS BETWEEN 60W AND 75W. A SMALL...WEAK UPPER LOW IS SEEN
SPINNING NEAR 21N58W. MID TO UPPER LEVEL ANTICYCLONIC FLOW
DOMINATES MUCH OF THE E AND CENTRAL ATLC FROM THE AFRICAN COAST
TO 50W...WITH THE RIDGE AXIS GENERALLY EXTENDING E TO W ALONG
20N FROM THE AFRICAN COAST TO 50W. ASIDE FROM THE TROPICAL WAVE
ALONG 30W AND THE SPECIAL FEATURE...SURFACE HIGH PRESSURE
DOMINATES MUCH OF THE AREA WITH 1021MB HIGH CENTERS ANALYZED
NEAR 30N74W AND 29N65W. THE S PORTION OF A 1031MB HIGH NORTH OF
THE AZORES IS ALSO AFFECTING THE EASTERN ATLC. A NEARLY
STATIONARY LOW PRESSURE SYSTEM IS LOCATED ABOUT 650NM SOUTHWEST
OF THE AZORES.  SHOWER ACTIVITY NEAR THIS LOW IS MINIMAL AND
FURTHER DEVELOPMENT IS NOT ANTICIPATED.

$$
WILLIS


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