[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141802
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN AUG 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...

TROPICAL DEPRESSION SEVEN WAS UPGRADED TO TROPICAL STORM GERT AT
14/1800 UTC. T.S. GERT IS CENTERED NEAR 28.6N 63.1W OR ABOUT 240
NM SSE OF BERMUDA AT 14/1800 UTC MOVING NNW AT 6 KT. ESTIMATED
CENTRAL PRESSURE IS 1009 MB. MAXIMUM SUSTAINED WIND SPEED IS 35
KT WITH GUSTS TO 45 KT. PLEASE SEE THE LATEST NHC INTERMEDIATE
PUBLIC ADVISORY MIATCPAT1/WTNT32 KNHC AND THE FORECAST/ADVISORY
UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 27N-29N
BETWEEN 61W-64W. SCATTERED SHOWERS COVER THE REMAINDER OF THE
AREA FROM 26N-32N BETWEEN 59W-63W.

A 1012 MB LOW IS CENTERED NEAR 23N59W WITH CLUSTERS OF SCATTERED
MODERATE/ISOLATED STRONG CONVECTION FROM 23N-25N BETWEEN
57W-60W. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN ONLY
MARGINALLY CONDUCIVE FOR DEVELOPMENT OVER THE NEXT COUPLE OF
DAYS DUE TO PROXIMITY TO T.S. GERT. THIS SYSTEM HAS A MEDIUM
CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS
AS IT MOVES TOWARD THE W-NW AT 13-17 KT.

...TROPICAL WAVES...

TROPICAL WAVE IN THE TROPICAL ATLC EXTENDS FROM 16N45W TO 10N43W
MOVING W NEAR 15-20 KT. WAVE IS EMBEDDED WITHIN AN AREA OF DEEP
LAYER MOISTURE AS DEPICTED IN TOTAL PRECIPITABLE WATER IMAGERY.
WAVE HAS BECOME TILTED NW/SE WITH SCATTERED MODERATE/ISOLATED
STRONG CONVECTION WELL TO THE W OF THE WAVE FROM 12N-16N BETWEEN
50W-54W.

TROPICAL WAVE EXTENDS FROM THE GULF OF MEXICO NEAR 22N90W TO
ACROSS S MEXICO NEAR 18N91W THEN INTO THE E PACIFIC REGION
MOVING W NEAR 15 KT. NO ASSOCIATED DEEP CONVECTION.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS OFF THE COAST OF W AFRICA NEAR 17N16W
CONTINUING ALONG 13N20W 10N37W TO 8N41W. THE ITCZ AXIS CONTINUES
FROM 8N41W TO INLAND OVER SOUTH AMERICA NEAR 7N54W. CLUSTERS OF
SCATTERED MODERATE CONVECTION ARE WITHIN 180 NM S OF THE ITCZ
BETWEEN 41W-50W. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE
FROM 4N-8N BETWEEN 19W-30W AND FROM 6N-11N E OF 19W TO INLAND
OVER W AFRICA.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH OVER THE E CONUS EXTENDS S TO THE N GULF COAST
WHERE AT 14/1500 UTC A SURFACE TROUGH EXTENDS FROM S GEORGIA
NEAR VALDOSTA ACROSS THE FLORIDA PANHANDLE NEAR PANAMA CITY INTO
THE GULF WATERS ALONG 30N88W THEN RETURNS INLAND OVER SE
LOUISIANA ACROSS LAKE PONTCHARTRAIN TO CENTRAL LOUISIANA.
SCATTERED TO HEAVY SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN
90 NM S OF THE SURFACE TROUGH BETWEEN APALACHICOLA FLORIDA AND
ATCHAFALAYA BAY LOUISIANA. EASTERLY FLOW ALOFT DOMINATES THE
GULF WATERS. A SURFACE RIDGE EXTENDS FROM THE W ATLC THROUGH THE
STRAITS OF FLORIDA THEN NW TO THE COAST OF W LOUISIANA/TEXAS
WITH A 1015 MB HIGH LOCATED NEAR 27N90W. ISOLATED SHOWERS DOT
THE REMAINDER OF THE GULF N OF 22N WITH ADDITIONAL ISOLATED
THUNDERSTORMS WITHIN 75/90 NM OF 24N E OF 91W TO OVER S FLORIDA
AND THE FLORIDA KEYS. THE SURFACE RIDGE WILL REMAIN THROUGH TUE.
A WEAK COLD FRONT WILL MOVE INTO THE FAR NE GULF ON MON THEN
STALL AND WEAKEN THROUGH WED. A SURFACE HIGH WILL THEN BECOME
CENTERED OVER THE NW GULF WED AND THU.

CARIBBEAN SEA...
EASTERLY FLOW ALOFT DOMINATES THE N CARIBBEAN N OF 17N WITH
LIGHT AND VARIABLE WINDS ALOFT COVERING THE REMAINDER OF THE
CARIBBEAN. THE EASTERLY FLOW ALOFT ACROSS THE N CARIBBEAN IS
USHERING IN SOME SCATTERED SHOWERS ACROSS HISPANIOLA...E CUBA
AND JAMAICA. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN
FROM COLOMBIA NEAR 10N75W TO ACROSS COSTA RICA/NICARAGUA BORDER
INTO THE E PACIFIC REGION GENERATING SCATTERED MODERATE/STRONG
CONVECTION WITHIN 60 NM OF LINE FROM 9N77W TO 11N80W INCLUDING
THE COAST OF PANAMA THEN STREAMS SCATTERED MODERATE/ISOLATED
STRONG CONVECTION WITHIN 90 NM OF LINE FROM 11N80W TO INLAND
OVER NICARAGUA NEAR 13N84W. THIS IS LEAVING THE REMAINDER OF THE
CARIBBEAN UNDER CLEAR SKIES THIS AFTERNOON. ATLC SURFACE RIDGE
WILL WEAKEN THROUGH MON ALLOWING FOR TRADE WINDS TO DIMINISH
SOME OVER THE W CARIBBEAN. THE 1012 MB LOW IN THE SPECIAL
FEATURES WILL PULL AWAY FROM THE CARIBBEAN THIS AFTERNOON AND
TONIGHT. THE TROPICAL WAVE IN THE TROPICAL ATLC IS EXPECTED TO
MOVE INTO THE E CARIBBEAN WED THEN REACH THE CENTRAL CARIBBEAN
THU.

ATLANTIC OCEAN...
THE PRIMARY CONCERN FOR THE AFTERNOON IS T.S. GERT IN THE
SPECIAL FEATURES...PRIMARILY FOR BERMUDA...SEE ABOVE. THE UPPER
TROUGH INLAND OVER THE E CONUS IS GENERATING SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS N OF 29N BETWEEN 75W-80W. AN UPPER RIDGE
COVERS THE REMAINDER OF THE W ATLC ANCHORED OVER THE N BAHAMA
ISLANDS WITH A WEAK SURFACE RIDGE ANCHORED BY A 1016 MB HIGH
NEAR 27N70W AND EXTENDING A RIDGE AXIS THROUGH THE STRAITS OF
FLORIDA INTO THE GULF OF MEXICO. UPPER LOW IS JUST N OF THE
VIRGIN ISLANDS NEAR 22N64W WITH AN UPPER TROUGH EXTENDING N TO
NEAR T.S. GERT. TO THE W OF THE UPPER TROUGH IS A SURFACE TROUGH
THAT EXTENDS FROM 23N65W TO THE E TIP OF THE DOMINICAN REPUBLIC.
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE W OF
THE TROUGH TO A LINE FROM 24N68W TO THE WINDWARD PASSAGE WITH
THE SHOWERS EXTENDING INLAND OVER HISPANIOLA. TO THE E OF THE
UPPER TROUGH IS THE 1012 MB LOW ALSO IN THE SPECIAL FEATURES
ABOVE. THE REMAINDER OF THE ATLC IS DOMINATED BY BENIGN UPPER
LEVEL FEATURES AND A SURFACE RIDGE THAT COVERS THE AREA N OF 20N
BETWEEN 20W-55W AND ANCHORED BY A 1022 MB HIGH NEAR 32N48W. DRY
SAHARAN AIR ALSO COVERS THE E ATLC N OF 15N E OF 55W AS SEEN ON
VISIBLE SATELLITE IMAGES. THE SURFACE HIGH OVER THE W ATLC WILL
DISSIPATE THROUGH TONIGHT AS T.S. GERT MOVES WNW. T.S. GERT IS
FORECAST TO MOVE N OF THE DISCUSSION AREA MON MORNING BEFORE
LIFTING FURTHER N. THE SURFACE TROUGH N OF THE GREATER ANTILLES
WILL TRACK W REACHING THE FAR SE BAHAMAS TONIGHT THEN MOVE
THROUGH THE REMAINDER ISLANDS THROUGH TUE BEFORE REACHING THE NW
BAHAMAS AND FLORIDA WED INTO THU. THE 1012 MB LOW IN THE SPECIAL
FEATURES SHOULD PASS THROUGH THE W/CENTRAL ATLC MON NIGHT...
POSSIBLY AS A TROPICAL CYCLONE. A WEAK COLD FRONT WILL ENTER THE
NW ATLC MON NIGHT AND DISSIPATE WED.

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

$$
PAW





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