[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 062347
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED JUL 06 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC EXTENDS FROM 11N40W
TO 4N43W MOVING W 10-15 KT. WHILE THIS WAVE IS LOW AMPLITUDE AND
MAINLY EMBEDDED WITHIN THE ITCZ...A TRACKABLE AND COHERENT
FEATURE CAN BE TRACED BACK TO AFRICA. CURRENTLY SCATTERED
MODERATE/STRONG CONVECTION IS FROM 4N-10N BETWEEN 40W-50W.

TROPICAL WAVE APPROACHING THE LESSER ANTILLES EXTENDS FROM
20N56W TO 13N59W MOVING W 15-20 KT. THE WAVE PRECEDES A LARGE
SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER
IMAGERY. SCATTERED MODERATE/STRONG CONVECTION IS MOVING ACROSS
THE WINDWARD ISLANDS FROM 12N-18N BETWEEN 57W-62W. SOME OF THIS
ACTIVITY MAY BE ASSOCIATED WITH A SURFACE TROUGH JUST W OF THE
WAVE AXIS AS WELL AS DIFFLUENCE ALOFT.

TROPICAL WAVE IS ACROSS THE YUCATAN PENINSULA EXTENDING FROM
24N85W TO 18N90W MOVING WNW AT 10-15 KT. THE WAVE LIES IN A
BROAD AREA OF CYCLONIC FLOW AS WELL AS IN A LARGE AREA
OF DEEP LAYER MOISTURE COVERING MUCH OF THE NW CARIBBEAN AND SE
GULF OF MEXICO. THE WAVE ALSO IS UNDER AN AREA OF DIFFLUENCE
ALOFT FURTHER SUPPORTING CONVECTION. NUMEROUS STRONG CONVECTION
IS OVER THE YUCATAN...GUATEMALA...AND BELIZE FROM 16N-19N
BETWEEN 88W-91W. SCATTERED MODERATE/STRONG CONVECTION IS FROM
19N-23N BETWEEN 86W-90W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN
AT 21N ALONG 16N12W 11N20W. THE ITCZ CONTINUES FROM 11N20W ALONG
10N30W 9N39W 4N53W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 6N-8N BETWEEN 34W-36W. ISOLATED
MODERATE/STRONG CONVECTION IS FROM 3N-9N BETWEEN 50W-55W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL LOW CONTINUES TO SPIN OVER THE GULF OF MEXICO
THIS EVENING NEAR 27N91W WITH TROUGH AXIS EXTENDING FROM CENTRAL
ALABAMA TO THE BAY OF CAMPECHE. DRY AIR IS WRAPPING AROUND THE
WRN SIDE OF THE UPPER TROUGH MAINTAINING FAIR SURFACE CONDITIONS
W OF 87W BESIDES A FEW ISOLATED SHOWERS/THUNDERSTORMS ACROSS
LOUISIANA AND ERN TEXAS. THE ERN GULF IS EXPERIENCING MOIST
CONDITIONS WITH A LARGE AREA OF DEEP LAYER MOISTURE COVERING THE
SE GULF EXTENDING FROM THE WRN ATLC AND NW CARIBBEAN. SOME OF
THIS IS ASSOCIATED WITH A TROPICAL WAVE ACROSS THE YUCATAN
PENINSULA. SEE TROPICAL WAVE SECTION FOR MORE DETAILS. A SURFACE
TROUGH IS E OF THE FLORIDA PENINSULA SUPPORTING SHOWER ACTIVITY
AS WELL. THIS AREA ALSO LIES UNDERNEATH THE DIFFLUENT SIDE OF
THE UPPER TROUGH WHICH IS HELPING ENHANCE ACTIVITY. THE
COMBINATION OF THESE FEATURES IS SUPPORTING A WIDE AREA OF
SHOWERS/THUNDERSTORMS ACROSS CUBA...THE STRAITS OF FLORIDA...AND
SRN FLORIDA S OF 28N E OF 85W. A FEW SHOWERS/THUNDERSTORMS ARE
ALSO OVER NRN FLORIDA. EXPECT MOIST CONDITIONS TO REMAIN OVER
THE ERN GULF AS THE TROPICAL WAVE MOVES WNW...AND THE SURFACE
TROUGH E OF THE BASIN MOVES W. THE UPPER LOW IS ALSO EXPECTED TO
REMAIN RELATIVELY STATIONARY PLACING THE ERN GULF UNDER A
DIFFLUENT ZONE.

CARIBBEAN SEA...
THE NW CARIBBEAN REMAINS UNDER ENHANCED DEEP LAYER MOISTURE
STILL REMAINING FROM A TROPICAL WAVE THAT IS NOW OVER THE
YUCATAN PENINSULA. CURRENTLY STRONG SHOWERS/THUNDERSTORMS ARE
ACROSS MUCH OF CUBA WITH SOME SLIGHTLY LIGHTER ACTIVITY S OF THE
ISLAND N OF 18N BETWEEN 79W-85W. ALOFT...AN UPPER LEVEL RIDGE IS
CENTERED S OF CUBA NEAR 20N82W WITH AXIS EXTENDING TO THE NE.
DRY AIR IS WRAPPING AROUND THE SE SIDE OF THE RIDGE PROVIDING
FAIR CONDITIONS ACROSS THE SW AND CENTRAL CARIBBEAN. THIS IS
PROVIDING SOME BRIEF RELIEF TO HISPANIOLA WHERE RAINFALL AMOUNTS
HAVE BEEN REPORTED UP TO 8 INCHES OVER THE PAST 24 HOURS. AN
AREA OF SHOWERS/THUNDERSTORMS IS IN THE FAR SW CARIBBEAN S OF
12N W OF 79W INFLUENCED BY THE MONSOON TROUGH EXTENDING ACROSS
COSTA RICA TO NRN COLOMBIA. THE ERN CARIBBEAN IS ALSO UNDER
MOIST CONDITIONS AS AN AREA OF DEEP LAYER MOISTURE MOVES INTO
THE AREA FROM THE WRN TROPICAL ATLC. SOME OF THIS MOISTURE IS
ASSOCIATED WITH A SURFACE TROUGH EXTENDING FROM 15N60W TO
10N64W...AND WITH A TROPICAL WAVE STILL E OF THE ISLANDS. STRONG
SHOWERS/THUNDERSTORMS ARE MOVING ACROSS THE WINDWARD ISLANDS
FROM 12N-17N E OF 63W WITH MORE ISOLATED ACTIVITY FROM 12N-16N
BETWEEN 63W-69W. SOME OF THIS PRECIPITATION IS ENHANCED BY
DIFFLUENCE ALOFT AROUND AN UPPER LEVEL TROUGH IN THE CENTRAL
ATLC THAT EXTENDS INTO THE NE CARIBBEAN. EXPECT MOIST CONDITIONS
TO CONTINUE OVER THE ERN CARIBBEAN AND MOVE INTO THE CENTRAL
BASIN AS THE SURFACE TROUGH AND TROPICAL WAVE MOVE WWD.

ATLANTIC OCEAN...
DESPITE UPPER LEVEL RIDGING COVERING THE FAR W ATLC...A SURFACE
TROUGH EXTENDING OFF THE E COAST OF FLORIDA FROM NEAR 28N78W TO
23N71W IS SUPPORTING A LARGE AREA OF SHOWERS/THUNDERSTORMS S OF
28N W OF 74W WITH THE STRONGEST ACTIVITY OVER ERN CUBA. TO THE
E...AN UPPER LEVEL TROUGH EXTENDS FROM NEAR 36N46W TO 19N67W
ENHANCING SHOWER ACTIVITY NEAR A TROPICAL WAVE E OF THE LESSER
ANTILLES. SEE TROPICAL WAVE SECTION FOR MORE DETAILS. THE
REMAINDER OF THE BASIN IS DOMINATED BY BROAD SURFACE RIDGING
AROUND A 1031 MB HIGH NEAR 40N34W PROVIDING FAIR CONDITIONS.
ALOFT...AN UPPER LEVEL RIDGE IS ALONG 33W WITH AN UPPER LEVEL
TROUGH JUST W OF THE CANARY ISLANDS.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
WALTON





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