[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261742
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE JUN 26 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 32W/33W SOUTH OF 15N MOVING WEST 10-15
KT. WIDELY SCATTERED MODERATE CONVECTION IS NOTED WITHIN 120 NM
W AND WITHIN 180 NM E OF THE WAVE AXIS.

A TROPICAL WAVE IS ALONG 69W SOUTH OF 20N MOVING WEST 10-15 KT.
THE AXIS EXTENDS FROM THE EASTERN PORTION OF DOMINICAN REPUBLIC
TO THE ABC ISLANDS/NORTHERN VENEZUELA. MOST OF THE CONVECTIVE
ACTIVITY ASSOCIATED WITH THE WAVE IS NORTH OF PUERTO RICO FROM
19N23N BETWEEN 63W-68W. A PATCH OF SAHARAN DUST IS NOTED BEHIND
THE WAVE AXIS COVERING THE E CARIBBEAN WITH A DRY AND STABLE AIR
MASS.

A WEAK TROPICAL WAVE IS ALONG 80W SOUTH OF 20N MOVING WEST 10-15
KT. THE WAVE IS INTERACTING WITH AN UPPER TROUGH THAT EXTENDS S
FROM AN UPPER LOW IN THE CENTRAL BAHAMAS. CONVECTION IS FLARING
BETWEEN E CUBA AND JAMAICA AND OVER THE SW CARIBBEAN.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 10N14W 8N30W 8N35W 8N50W 6N57W.
BESIDES THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...
SCATTERED MODERATE CONVECTION IS OBSERVED WITHIN 60 NM SOUTH OF
THE AXIS E OF 16W...AND WITHIN 120-140 NM EITHER SIDE OF THE
AXIS BETWEEN 38W-42W.

...DISCUSSION...
THE GULF OF MEXICO...
AN UPPER ANTICYCLONE REMAINS OVER CENTRAL MEXICO NEAR 20N100W
WITH THE RIDGE AXIS EXTENDING NE ALONG THE COAST OF TEXAS. THIS
RIDGE COVERS THE WESTERN HALF OF THE GULF. DEBRIS MOISTURE FROM
CONVECTION OVER INTERIOR MEXICO IS ADVECTED EASTWARD OVER THE SW
GULF AND THE BAY OF CAMPECHE OF MEXICO. WV IMAGERY SHOWS AN
UPPER LOW OVER THE SE GULF WITH A TROUGH REACHING THE YUCATAN
PENINSULA AND BELIZE. THE LOW/TROUGH ARE GENERATING SCATTERED
SHOWERS AND ISOLATED TSTMS OVER THE E GULF E OF 85W. AT THE
SURFACE...A RIDGE ANCHORED ON A HIGH OVER THE SE U.S. DOMINATES
THE REGION GIVING THE AREA E TO SE WINDS OF 15 TO 20 KT. THE
STRONGEST WINDS ARE OVER THE WESTERN HALF OF THE GULF. A
QUIKSCAT PASS FROM THIS MORNING CONFIRMED THESE MODERATE WINDS.

THE CARIBBEAN SEA...
A LARGE UPPER LOW OVER THE CENTRAL BAHAMAS HAS A TROUGH
EXTENDING SOUTH ACROSS EASTERN CUBA/JAMAICA INTO THE CENTRAL
CARIBBEAN. UPPER FLOW W OF THE TROUGH IS ADVECTING MOISTURE SE
OVER THE NW CARIBBEAN WHILE UPPER DIFFLUENCE E OF THE TROUGH IS
ENHANCING THE DEVELOPMENT OF MODERATE CONVECTION BETWEEN E CUBA
AND JAMAICA AND OVER THE SW NORTH ATLC. ANOTHER UPPER RIDGE
CENTERED ON A HIGH OVER N VENEZUELA DOMINATES THE E CARIBBEAN
WITH DRY AIR/SUBSIDENCE. SCATTERED MODERATE CONVECTION IS OVER
COSTA RICA AND PANAMA DUE TO THE CLOSE PROXIMITY OF THE EPAC
ITCZ AND A TROPICAL WAVE. THE COMBINATION OF THE ATLC RIDGE
LOCATED N OF THE AREA AND THE COLOMBIAN LOW IS PRODUCING BRISK
ELY TRADE WINDS ACROSS THE SOUTH-CENTRAL CARIBBEAN. THIS WEATHER
PATTERN WILL PERSIST OVER THE NEXT COUPLE OF DAYS. THERE ARE TWO
TROPICAL WAVES MOVING WWD ACROSS THE AREA. SEE ABOVE. CLOUD
LINES OR STREAMERS HAVE DEVELOPED ACROSS THE LESSER ANTILLES
UNDER THE ELY WIND FLOW. TRADE WINDS SHOWERS ARE OVER THE
REMAINDER OF THE SEA.

THE ATLANTIC OCEAN...
THE LARGE CYCLONIC CIRCULATION PREVIOUSLY MENTIONED OVER THE
CENTRAL BAHAMAS IS FORECAST TO SLOWLY MOVE W TOWARDS SOUTH
FLORIDA HELPING TO GENERATE A FEW STRONG TSTMS THIS AFTERNOON
INTO EARLY THIS EVENING. AN UPPER RIDGE EXTENDS MAINLY N FROM
THE E CARIBBEAN INTO THE W ATLC BETWEEN 60W-70W. A BROAD
CYCLONIC CIRCULATION IS OVER THE CENTRAL ATLC NEAR 22N48W WITH A
TROUGH EXTENDING SW TO NEAR 10N55W. VERY DRY AIR IS OVER THE
TROPICAL NORTH ATLC UNDER THE INFLUENCE OF THIS TROUGH. A JET
STREAM BRANCH LIES SOUTH AND E OF THE LOW/TROUGH ADVECTING A
PLUME OF MOISTURE NWD OVER THE CENTRAL ATLC BEYOND 31N41W. AT
THE SURFACE...A COUPLE OF WEAK TROUGHS ARE OVER THE W ATLC. THE
FIRST ONE...IS A REFLECTION OF THE UPPER LOW OVER THE CENTRAL
BAHAMAS AND LIES ALONG 76W/77W. THE SECOND ONE IS AN EXTENSION
OF A STATIONARY FRONT AND GOES FROM 31N60W TO 28N65W. SCATTERED
SHOWERS AND ISOLATED TSTMS ARE ASSOCIATED WITH THIS TROUGH. THE
REMAINDER OF THE FORECAST AREA IS UNDER THE INFLUENCE OF THE
AZORES HIGH WHICH IS CENTERED NEAR 36N38W. THIS FEATURE IS
PRODUCING MOSTLY FAIR WEATHER AND MODERATE TRADE WINDS UP TO 20
KT ACROSS THE EAST AND CENTRAL ATLC.

$$
GR


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