[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 052347
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN AUG 05 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...
HIGH AMPLITUDE TROPICAL WAVE IS ALONG 33W SOUTH OF 22N MOVING
WEST 15 TO 20 KT.  THIS WAVE SHOWS A LARGE WELL DEFINED AREA OF
CYCLONIC TURNING IN THE LOW AND MIDDLE LEVEL CLOUDS.  MOST OF
THE PRECIPITATION IS ON THE ITCZ.

TROPICAL WAVE IS ALONG 47W SOUTH OF 20N MOVING WEST 10 TO 15 KT.
THIS WEAK WAVE REMAINS DIFFICULT TO LOCATE AND IS MOVED BY
CONTINUITY. PRECIPITATION IS CONFINED TO THE ITCZ.

HIGH AMPLITUDE TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN
ALONG 65W SOUTH OF 22N MOVING WEST 15 TO 20 KT. THIS WAVE SHOWS
UP WELL ON SATELLITE IMAGERY AND IS INTERACTING WITH AN UPPER
LOW LOCATED NE OF PUERTO RICO NEAR 20N62W. BOTH FEATURES ARE
GENERATING SCATTERED TO NUMEROUS SHOWERS WITH EMBEDDED TSTMS
OVER THE NORTHERN LEEWARD ISLANDS AND THE UK/VIRGIN ISLANDS AS
WELL AS ACROSS EASTERN PUERTO RICO. ACCORDING TO THE GFS
MODEL...THE UPPER LOW SHOULD REMAIN NEARLY STATIONARY THROUGH
THE NEXT 24 HOURS. AS A RESULT...THE ENVIRONMENT WILL CONTINUE
HUMID AND UNSTABLE OVER THE NE CARIBBEAN INCLUDING PUERTO
RICO...THE UK/VIRGIN ISLANDS AND THE REGIONAL COASTAL WATERS.
THE TROPICAL WAVE IS FORECAST TO MOVE ACROSS DOMINICAN REPUBLIC
AND HAITI TOMORROW INCREASING THE CHANCE OF RAIN. ST. THOMAS
REPORTED HEAVY RAIN DURING THE PAST SEVERAL HOURS.

THE FIRST STRONG TROPICAL WAVE OF THE SEASON IS OVER THE YUCATAN
PENINSULA AND GUATEMALA ALONG 91W MOVING WEST NEAR 15 KT.
SATELLITE IMAGERY SHOWS APPARENT BANDING FEATURES ASSOCIATED
WITH THE WAVE OVER THE EASTERN BAY OF CAMPECHE AND OVER MUCH OF
CENTRAL AMERICA N OF COSTA RICA. THESE BANDING FEATURES CONSIST
OF CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION. THE
STRONGEST ONES ARE OVER THE YUCATAN PENINSULA AND NICARAGUA.
LOCALLY HEAVY RAIN AND GUSTY WINDS ARE STILL POSSIBLE OVER THE
AREA TONIGHT. AN UPPER LEVEL HIGH IS ABOVE THIS WAVE ENHANCING
THE SHOWER AND TSTM ACTIVITY. MOISTURE FROM THIS WAVE IS ALREADY
SPREADING OVER THE BAY OF CAMPECHE AND SOUTHERN MEXICO. MERIDA
REPORTED HEAVY RAIN AND SUSTAINED WINDS OF 30 KT JUST BEHIND THE
WAVE AXIS. THIS WAVE WILL MOVE ACROSS THE BAY OF CAMPECHE
TOMORROW AND WILL EXIT THE SW GULF MON NIGHT.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N16W 11N32W 9N40W 9N50W 11N62W.
CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE
NEAR 10N21W AND 12N29W. WIDELY SCATTERED MODERATE CONVECTION
FROM 10N-13N BETWEEN 27W AND 33W...AND FROM 7N-12N BETWEEN
40W-48W. AN IMPRESSIVE CLUSTER OF STRONG CONVECTION IS INLAND
OVER W AFRICA ASSOCIATED WITH A 1003 MB SFC LOW NEAR 17N7W.

DISCUSSION...
THE GULF OF MEXICO...
AS OF 2100 UTC...A COUPLE OF WEAK 1018 MB HIGHS ARE OVER THE
NORTHERN GULF WATERS NEAR 28N87W AND 28N93W. LIGHT WINDS AND
FAIR WEATHER ARE FOUND UNDER THE INFLUENCE OF THIS SYSTEM. A
TROPICAL WAVE IS OVER THE YUCATAN PENINSULA. FOR DETAILS REFER
TO THE TROPICAL WAVES SECTION ABOVE. ALOFT...AN UPPER LEVEL HIGH
IS CENTERED NEAR 23N86W. MID TO UPPER DEBRIS MOISTURE FROM THE
CONVECTION OVER THE YUCATAN PENINSULA IS SPREADING N OVER THE
GULF REACHING 26N. STRONG SUBSIDENCE DOMINATES THE REMAINDER OF
THE AREA AND THE STATE OF FLORIDA.

THE CARIBBEAN SEA...
A TROPICAL WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN. SEE
ABOVE. IN ADDITION...AFTERNOON HEAT INDUCED SHOWERS ARE OVER
HISPANIOLA...EASTERN CUBA AND JAMAICA. CLUSTERS OF MODERATE TO
ISOLATED STRONG CONVECTION ARE OVER NW VENEZUELA AND NORTHERN
COLOMBIA PROBABLY ASSOCIATED WITH THE COLOMBIAN LOW. MODERATE
TRADEWINDS ARE NOTED ACROSS THE BASIN WITH 20 TO 25 KT WINDS
OVER THE SOUTH-CENTRAL CARIBBEAN. IN THE UPPER LEVELS...THE
UPPER HIGH OVER THE GULF OF MEXICO EXTENDS A RIDGE OVER CUBA AND
THE WEST-CENTRAL CARIBBEAN. A TUTT LOW IS NEAR 20N62W WITH AN
UPPER TROUGH EXTENDING SW TO NEAR THE ABC ISLANDS. ANOTHER UPPER
HIGH LOCATED E OF THE LESSER ANTILLES NEAR 13N53W DOMINATES THE
WINDWARD ISLANDS AND THE FAR SE CARIBBEAN.

THE ATLANTIC OCEAN...
A 1014 MB LOW IS OVER THE W ATLANTIC NEAR 31N75W.  A SURFACE
TROUGH EXTENDS SW FROM THE LOW TO 26N78W. SCATTERED MODERATE
CONVECTION IS WITHIN 125 NM AHEAD OF THE TROUGH AXIS. A 1027 MB
HIGH IS OVER THE CENTRAL ATLANTIC NEAR 34N36W PRODUCING FAIR
WEATHER. A RIDGE AXIS EXTENDS SW TO 25N57W. IN THE UPPER
LEVELS...A RIDGE ANCHORED ON A HIGH OVER THE GULF OF MEXICO
EXTENDS ACROSS CUBA AND THE BAHAMAS INTO THE W ATLC W OF 68W
WITH DRY AIR AND STRONG SUBSIDENCE. AN UPPER LOW IS NEAR 20N62W.
ABUNDANT UPPER LEVEL MOISTURE IS WRAPPING AROUND THIS LOW
COVERING THE ATLC BETWEEN 50W AND 68W. THE UPPER LEVEL HIGH E OF
THE LESSER ANTILLES EXTENDS A RIDGE N TO 30N50W. ANOTHER UPPER
LEVEL LOW IS CENTERED FURTHER E NEAR 20N42W WHILE A LARGE UPPER
LEVEL HIGH IS OVER THE E ATLANTIC CENTERED NEAR 26N23W.

$$
GR




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