[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 182353
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN JUL 18 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC...

...TROPICAL WAVES...

TROPICAL WAVE HAS MOVED OFF THE W COAST OF AFRICA ALONG 21W S OF
20N MOVING W NEAR 15 KT. LOW-MID LEVEL CYCLONIC CURVATURE IS
EVIDENT IN SATELLITE IMAGERY AND SATELLITE DERIVED WINDS. A
SURGE OF DEEP LAYER MOISTURE IS ALSO PRESENT IN TOTAL
PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 5N-18N BETWEEN 14W-23W...AND SW OF THE WAVE
AXIS FROM 3N-9N BETWEEN 24W-30W.

TROPICAL WAVE IS JUST E OF THE LESSER ANTILLES ALONG 61W S OF
19N MOVING W NEAR 15 KT. BROAD CYCLONIC FLOW ENCOMPASSES THE
WAVE AXIS EVIDENT IN SATELLITE IMAGERY. A LARGE AREA OF DEEP
LAYER MOISTURE ALSO ACCOMPANIES THE WAVE SEEN IN TOTAL
PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO STRONG
CONVECTION IS FROM 14N-22N BETWEEN 54W-67W. GUSTY WINDS AND
LOCALLY HEAVY RAINFALL ASSOCIATED WITH THIS SYSTEM COULD AFFECT
THE LEEWARD ISLANDS...THE VIRGIN ISLANDS...PUERTO RICO...THE
DOMINICAN REPUBLIC...HAITI...AND THE TURKS AND CAICOS ISLANDS
DURING THE NEXT COUPLE OF DAYS.

TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN ALONG 77W S OF 20N
MOVING W 15-20 KT. WAVE LIES EMBEDDED WITHIN A LARGE AREA OF
DEEP LAYER MOISTURE THAT IS ACROSS CENTRAL THE CARIBBEAN.
SCATTERED MODERATE/STRONG CONVECTION IS FROM 14N-22N BETWEEN
70W-80W AFFECTING AREAS S OF WESTERN HISPANIOLA...JAMAICA AND
EASTERN CUBA.

TROPICAL WAVE IS OVER THE NW CARIBBEAN FROM WESTERN CUBA NEAR
23N82W TO EAST HONDURAS NEAR 15N85W MOVING W NEAR 5 KT. WAVE
LIES EMBEDDED IN A BROAD AREA OF ENHANCED MOISTURE ACROSS THE
WRN CARIBBEAN. SATELLITE IMAGERY INDICATES BROAD CYCLONIC
ROTATION IN THE VICINITY OF THE WAVE AXIS. SCATTERED MODERATE TO
ISOLATED STRONG CONVECTION IS FROM 12N-25N BETWEEN 80W-91W
INCLUDING INLAND PORTIONS OF CENTRAL AMERICA...THE YUCATAN
PENINSULA...CUBA...AND THE STRAITS OF FLORIDA.

...ITCZ...

THE ITCZ AXIS IS ANALYZED ALONG 7N23W 8N30W 9N40W 7N50W 8N60W.
MODERATE TO ISOLATED STRONG CONVECTION IS FROM 3N TO 9N BETWEEN
24W AND 30W. SCATTERED WEAK TO MODERATE CONVECTION IS WITHIN 100
NM ON EITHER SIDE OF THE ITCZ AXIS W OF 42W.

...DISCUSSION...

GULF OF MEXICO...
THE SURFACE TROUGH THAT HAS BEEN GENERATING THE CONVECTIVE
WEATHER ACROSS THE GULF OVER THE PAST FEW DAYS IS NOW OVER THE
FAR SW BASIN EXTENDING WITHIN 40 NM ALONG THE COAST OF MEXICO
FROM 23N96W TO 18N95W...PRODUCING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS S OF 25N W OF 94W. AT THIS POINT...MOST OF THE
MOISTURE AND ENERGY FROM THIS SYSTEM HAVE BEEN TRANSFERRED ALOFT
TO THE NORTH CENTRAL GULF COAST AFFECTING THE COASTAL WATERS OF
LOUISIANA AND MISSISSIPPI WITHIN 150 NM OFFSHORE WITH SCATTERED
MODERATE TO ISOLATED HEAVY SHOWERS. A BROADER AREA OF LOWER
PRESSURE/CYCLONIC FLOW ASSOCIATED WITH A TROPICAL WAVE CURRENTLY
OVER THE NW CARIBBEAN IS STARTING TO ENTER THE SE GULF THROUGH
THE YUCATAN CHANNEL...WESTERN CUBA...THE SOUTHERN FLORIDA
PENINSULA INCLUDING THE STRAITS...GENERATING SCATTERED MODERATE
TO HEAVY SHOWERS AND THUNDERSTORMS S OF 27N E OF 88W. THIS
SYSTEM WILL CONTINUE TO MOVE W WITH SHOWERS AND THUNDERSTORMS
SPREADING ACROSS THE SOUTHERN HALF OF THE GULF OVER THE NEXT FEW
DAYS. THE REMAINDER OF THE BASIN WILL CONTINUE UNDER MORE STABLE
CONDITIONS WITH A FEW ISOLATED SHOWERS EMBEDDED IN THE ESE FLOW.

CARIBBEAN SEA...
SATELLITE DATA INDICATES SIGNIFICANT MOISTURE AND UNSTABLE
CONDITIONS ACROSS MUCH OF THE CARIBBEAN ASSOCIATED WITH A SERIES
OF TROPICAL WAVES. SEE TROPICAL WAVES SECTION ABOVE FOR MORE
DETAILS. BESIDES THE TROPICAL WAVES...SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE ALSO IN THE SW CARIBBEAN S OF 13N W OF 75W
ASSOCIATED WITH AN EXTENSION OF THE ITCZ ACROSS NICARAGUA TO NRN
COLOMBIA. ALOFT...AN UPPER LEVEL LOW N OF PUERTO RICO IS
PROVIDING A DIFFLUENT ZONE ALOFT OVER THE LEEWARD ISLANDS WHICH
IS ENHANCING CONVECTION NEAR THE TROPICAL WAVE JUST E OF THE
LESSER ANTILLES. EXPECT CONTINUED SHOWER ACTIVITY ACROSS MUCH OF
THE BASIN AS THE TROPICAL WAVES PROGRESS WESTWARD BRINGING
SIGNIFICANT MOISTURE AND CONVECTION ACROSS THE AREA.

ATLANTIC OCEAN...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH
TROPICAL WAVES IN THE WRN AND CENTRAL CARIBBEAN ARE AFFECTING
PORTIONS OF THE FAR WEST ATLANTIC INCLUDING THE BAHAMAS AND
FLORIDA STRAITS. SCATTERED MODERATE TO ISOLATED HEAVY SHOWERS
AND THUNDERSTORMS ARE FROM 18N TO 30N BETWEEN 60W AND 70W...DUE
TO AN UPPER LEVEL LOW SPINNING NEAR 25N66W ENHANCING THE
CONVECTION ASSOCIATED TO A TROPICAL WAVE JUST E OF THE LESSER
ANTILLES. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE
RIDGING AROUND A 1025 MB HIGH NEAR 30N55W AND A 1028 MB HIGH E
OF THE AZORES NEAR 38W22N. A DRY SAHARAN AIR LAYER ACCOMPANIED
BY DUST COVERS MUCH OF THE TROPICAL ATLC SUPPRESSING CONVECTION
IN THIS REGION.

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

$$

GARCIA




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