[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261203
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN AUG 26 2012

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1115 UTC.

...SPECIAL FEATURES...

THE CENTER OF TROPICAL STORM ISAAC AT 26/1200 UTC IS NEAR 23.5N
80.0W. THIS POSITION IS ABOUT 135 MI...220 KM ESE OF KEY WEST
FLORIDA...OR ABOUT 155 MI...245 KM E OF HAVANA CUBA. ISAAC IS
MOVING WNW AT 17 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS
995 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO
65 KT. PLEASE READ THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY...MIATCPAT4/WTNT34
KNHC FOR MORE DETAILS. THE RAIN IMPACTS OF ISAAC SPREAD ACROSS A
LARGE AREA FROM THE ERN CARIBBEAN ALL THE WAY INTO THE SE GULF
OF MEXICO. SCATTERED HEAVY SHOWERS AND THUNDERSTORMS ARE ACROSS
THE BAHAMAS AND STRAITS OF FLORIDA S OF 28N W OF 73W...INCLUDING
THE NRN COASTAL WATERS OF HISPANIOLA...CUBA...AND TURKS AND
CAICOS. SIMILAR CONVECTION IS OVER THE SE GULF OF MEXICO S OF
27N E OF 85W.

A 1009 MB LOW AND ASSOCIATED TROPICAL WAVE AXIS IS CENTERED NEAR
16N34W MOVING WNW AT 10-15 KT. THIS SYSTEM IS EMBEDDED IN THE
BROAD SCALE MONSOON GYRE ON SATELLITE IMAGERY...WITHIN A LARGE
SURGE OF DEEP LAYER MOISTURE PRESENT ACROSS MUCH OF THE CENTRAL
TROPICAL ATLC. THE SYSTEM REMAINS DISORGANIZED DUE TO
UNFAVORABLE UPPER LEVEL WINDS AND A THICK LAYER OF SAHARAN DUST
SURROUNDING THE WAVE AND ASSOCIATED LOW. SCATTERED MODERATE
CONVECTION IS FROM 15N-21N BETWEEN 31W-37W. ENVIRONMENTAL
CONDITIONS APPEAR CONDUCIVE FOR DEVELOPMENT...AND THIS LOW COULD
BECOME A TROPICAL DEPRESSION OVER THE NEXT DAY OR TWO. THIS
SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS WEST AFRICA...ENTERING THE ERN
TROPICAL ATLC OVER THE COAST OF MAURITANIA AT 17N20W CONTINUING
WSW ALONG 18N25W TO THE SPECIAL FEATURE 1009 MB LOW AND
ASSOCIATED TROPICAL WAVE NEAR 16N34W AND ALONG 10N39W TO
8N48W...WHERE THE ITCZ CONTINUES ALONG 9N55W TO NEAR THE COAST
OF VENEZUELA AT 10N64W. WHILE NO CONVECTION IS NOTED AROUND THE
ITCZ...SCATTERED MODERATE CONVECTION IS WITHIN 70 NM ON EITHER
SIDE OF THE MONSOON TROUGH BETWEEN 37W-47W...AND OFF THE COAST
OF WEST AFRICA FROM 8N-16N E OF 22W.

...DISCUSSION...

GULF OF MEXICO...
SEVERAL OUTER BANDS OF STRONG CONVECTION ASSOCIATED TO TROPICAL
STORM ISAAC HAVE MADE THEIR WAY IN ACROSS THE SRN FLORIDA
PENINSULA AND THE ERN GULF THROUGH THE STRAITS OF FLORIDA THIS
MORNING...AS MOSAIC DOPPLER RADAR IMAGERY CURRENTLY INDICATES
THE ACTIVITY EXTENDS S OF 27N E OF 85W. WEATHER CONDITIONS ARE
EXPECTED TO DETERIORATE ACROSS THE ERN GULF E OF 87W DURING THE
NEXT 24 HOURS...AS ISAAC ENTERS THE BASIN AND GAINS STRENGTH TO
POSSIBLE HURRICANE STATUS. ALL INTERESTS IN THE EASTERN GULF
SHOULD MONITOR THE PROGRESS OF ISAAC. WEAK SURFACE RIDGING AND
DRY AIR ALOFT EMBEDDED IN AN ELONGATED UPPER LOW OFF THE NRN
COAST OF THE YUCATAN PENINSULA ARE KEEPING THE REMAINDER OF THE
BASIN UNDER FAIR WEATHER CONDITIONS THIS MORNING.

CARIBBEAN SEA...
ALTHOUGH THE CENTER OF TROPICAL STORM ISAAC IS OUT OF THE
CARIBBEAN SEA...THE BROAD CYCLONIC WIND FIELD AND AVAILABLE
MOISTURE CONTINUE TO GENERATE STRONG CONVECTION...GUSTY WINDS
AND SIGNIFICANT RAINFALL ACROSS THE NE AND N-CENTRAL BASINS
...ESPECIALLY HISPANIOLA AND CUBA...WHERE EARLIER REPORTS FROM
THIS COUNTRY INDICATED RAINFALL ACCUMULATIONS OF UP TO NEAR 5
INCHES IN THE LAST 3 HOURS OVER THE FAR SE PORTION OF THE
ISLAND. FLOODING AND MUDSLIDES ARE LIKELY ACROSS THIS REGION AS
SATELLITE IMAGERY CONTINUES TO SHOW RAINFALL DEVELOPMENT AGAIN
THIS MORNING. AN EARLIER SCATTEROMETER PASS REVEALED A SURFACE
TROUGH EXTENDING FROM THE COAST OF CUBA NEAR 21N78W TO 19N85W.
DUE TO THE LARGE CIRCULATION...MUCH OF THE NORTHERN CARIBBEAN
WILL CONTINUE TO EXPERIENCE GUSTY WINDS AND HEAVY RAIN AS THE
STORM CONTINUES TOWARDS THE GULF OF MEXICO. THE NW AND SW
CARIBBEAN ARE THE ONLY AREAS STILL UNDER MOSTLY FAIR CONDITIONS
DUE TO DRY AIR ALOFT. ALL INTERESTS IN THE NORTHERN CARIBBEAN
SHOULD CONTINUE TO MONITOR THE PROGRESS OF ISAAC.

ATLANTIC OCEAN...
THE COMBINATION OF LOW-LEVEL MOISTURE BEING DRAWN ACROSS THE
BAHAMAS DUE TO TROPICAL STORM ISAAC AND DIFFLUENCE ALOFT AROUND
AN UPPER TROUGH OVER THE S-EASTERN CONUS IS HELPING PRODUCE
SCATTERED HEAVY SHOWERS AND THUNDERSTORMS ACROSS THE BAHAMAS AND
STRAITS OF FLORIDA S OF 28N W OF 73W...ALSO INCLUDING THE NRN
COASTAL WATERS OF HISPANIOLA...CUBA...AND TURKS AND CAICOS. THE
UPPER LEVEL OUTFLOW-CIRRUS FROM ISAAC COVERS THE MAJORITY OF THE
WEST ATLC W OF 71W. ALL INTERESTS IN THE FAR WESTERN ATLC SHOULD
CONTINUE TO MONITOR THE PROGRESS OF ISAAC. A BROAD UPPER LOW IS
CENTERED NEAR 20N60W WITH MINIMAL ACTIVITY WITHIN 100 NM NE OF
THE UPPER LOW CENTER. THE REMAINDER OF THE ATLC BASIN DISCUSSION
AREA IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1024 MB
HIGH NEAR 32N50W AND A 1022 MB HIGH NEAR 33N28W. THE FAIR
WEATHER IS ENHANCED ALOFT BY SAHARAN DUST NOTED ON METEOSAT-9
AND GOES-R ENHANCEMENT IMAGERY. EMBEDDED IN THIS DRY
ENVIRONMENT...AN UPPER LOW WOBBLES NEAR 33N18W. EXPECT WEATHER
CONDITIONS TO CONTINUE TO DETERIORATE OVER THE WRN ATLC TODAY
AS TROPICAL STORM ISAAC MOVES INTO THE FLORIDA STRAITS.

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

$$

GARCIA




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