[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 042351
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT SEP 04 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
2315 UTC.

...SPECIAL FEATURES...

TROPICAL STORM EARL IS CENTERED NEAR 49.4N 60.4W AT 05/0000 UTC
OR ABOUT 50 NM SSW OF CAPE WHITTLE QUEBEC MOVING NNE AT 39 KT.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 966 MB. MAXIMUM SUSTAINED
WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. NUMEROUS SHOWERS ARE
ACROSS PORTIONS OF CANADA FROM 49N-57N BETWEEN 51W-76W. SEE
LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS
MIATCPAT2/ WTNT32 KNHC AND THE FULL FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS.

A 1007 MB LOW...REMNANT OF GASTON...IS E OF THE LESSER ANTILLES
NEAR 17N47W MOVING WNW NEAR 10 KT. SATELLITE IMAGERY INDICATES A
CURVED BAND SWIRLING AROUND THE WRN SEMICIRCLE FEEDING INTO THE
LOW. SCATTERED MODERATE CONVECTION IS ASSOCIATED WITH THIS BAND
FROM 17N-19N BETWEEN 45W-50W. ENVIRONMENTAL
CONDITIONS ARE FAVORABLE FOR RE-DEVELOPMENT OF THIS SYSTEM AND A
TROPICAL DEPRESSION COULD RE-FORM IN THIS AREA AT ANY TIME.

A BROAD AREA OF LOW PRESSURE IS ACROSS THE SW GULF WHERE A
SURFACE TROUGH IS ANALYZED ALONG 27N89W 24N93W 20N94W.
SHOWERS/THUNDERSTORMS ARE WITHIN 90 NM EITHER SIDE OF THE TROUGH
AXIS WITH STRONGER ACTIVITY COVERING MUCH OF THE BAY OF
CAMPECHE. THE ACTIVITY HAS GAINED SOME SLIGHT ORGANIZATION AND
SOME DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT COUPLE
OF DAYS.

...TROPICAL WAVES...

TROPICAL WAVE IS OVER INTERIOR W AFRICA ALONG 14N7W 5N8W MOVING
W NEAR 10 KT. SATELLITE IMAGERY INDICATES CYCLONIC FLOW NEAR THE
WAVE AXIS CONCENTRATED NEAR A 1009 MB LOW ALONG AND THE AXIS
NEAR 8N. HOVMOLLER DIAGRAM EXAMINATION AND UPPER AIR
TIME-SECTION ANALYSES INDICATE THIS WAVE PASSED NIAMEY NIGER
AROUND 03/2100 UTC. SCATTERED MODERATE/STRONG CONVECTION IS W OF
THE WAVE AXIS FROM 6N-13N BETWEEN 9W-15W.

TROPICAL WAVE EXTENDS JUST E OF THE CAPE VERDE ISLANDS ALONG
20N19W 14N23W 8N26W MOVING W 5-10 KT. THE WAVE IS EMBEDDED
WITHIN A BROAD LOW-LEVEL CYCLONIC GYRE WITH SW MONSOONAL FLOW E
OF THE WAVE AXIS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS W OF THE WAVE AXIS FROM 12N-15N BETWEEN 24W-27W.

...ITCZ...

A MONSOONAL TROUGH AXIS EXTENDS ALONG 7N28W 8N36W. THE ITCZ AXIS
BEGINS W OF THE TROUGH ALONG 11N41W 9N50W 8N59W 6N66W. SCATTERED
MODERATE/STRONG CONVECTION IS NEAR THE TROUGH FROM 3N-9N BETWEEN
27W-38W. ISOLATED MODERATE/STRONG CONVECTION IS FROM 6N-9N
BETWEEN 43W-46W.

...DISCUSSION...

GULF OF MEXICO...
A LONGWAVE UPPER LEVEL TROUGH COVERING MUCH OF THE ERN CONUS
DIGS SWD ACROSS THE NRN GULF OF MEXICO SUPPORTING A STATIONARY
FRONT LINING THE NE GULF COAST FROM S OF ERN LOUISIANA NEAR
29N90W ACROSS THE FLORIDA PANHANDLE NEAR 31N84W CONTINUING NE
ACROSS GEORGIA. A SHORTWAVE UPPER LEVEL TROUGH EXTENDS OFF THE
LONGWAVE S OF LOUISIANA EXTENDING TO THE YUCATAN PENINSULA
SUPPORTING A SURFACE TROUGH EXTENDING ALONG 27N89W 24N93W
20N94W. SEE SPECIAL FEATURES ABOVE FOR MORE DETAILS. A SECOND
SURFACE TROUGH IS NW OF THIS TROUGH PARALLELING THE TEXAS
COASTLINE ALONG 28N93W TO 25N97W. THE COMBINATION OF SURFACE
CONVERGENCE NEAR ALL THESE FEATURES ALONG WITH DIFFLUENCE ALOFT
AROUND THE UPPER LEVEL TROUGH IS SUPPORTING SCATTERED
SHOWERS/THUNDERSTORMS ACROSS MUCH OF THE CENTRAL AND WRN GULF S
OF 28N BETWEEN 87W-100W. AN UPPER LEVEL RIDGE IS OVER THE FAR SW
GULF CENTERED NEAR 19N94W. A SECOND UPPER LEVEL RIDGE IS OVER
THE FAR SE GULF CENTERED OVER THE STRAITS OF FLORIDA NEAR
24N82W. EXPECT CONTINUED SHOWER ACTIVITY ACROSS THE SW GULF OVER
THE NEXT 24 HRS WITH POSSIBLE CYCLOGENESIS IN THE SW GULF NEAR
THE SURFACE TROUGH. AS MENTIONED BEFORE...SEE SPECIAL FEATURES
ABOVE FOR MORE DETAILS ON THIS TROUGH.

CARIBBEAN SEA...
MAINLY NE FLOW ALOFT COVERS THE WRN CARIBBEAN AROUND AN UPPER
LEVEL RIDGE CENTERED OVER THE STRAITS OF FLORIDA. THIS IS
PROVIDING AN AREA OF DIFFLUENCE ALOFT ENHANCING CONVECTION NEAR
A SURFACE TROUGH ANALYZED IN THE SW CARIBBEAN ALONG 14N82W TO
NRN COLOMBIA NEAR 9N76W. SCATTERED MODERATE/STRONG CONVECTION IS
WITHIN 90 NM EITHER SIDE OF THE TROUGH AXIS. SCATTERED MODERATE
CONVECTION IS ALSO S OF JAMAICA FROM 15N-18N BETWEEN 76W-80W.
SHOWERS/THUNDERSTORMS AREA ALSO ACROSS MUCH OF CUBA DUE TO THE
COMBINATION OF DAYTIME HEATING AND INSTABILITY. THE ERN
CARIBBEAN IS EXPERIENCING MOSTLY FAIR CONDITIONS UNDER THE
INFLUENCE OF DRY AIR ALOFT AROUND AN UPPER LEVEL TROUGH CENTERED
S OF THE VIRGIN ISLANDS NEAR 17N65W. EXPECT CONTINUED SHOWER
ACTIVITY ACROSS THE WRN CARIBBEAN DUE TO ENHANCED MOISTURE
ASSOCIATED WITH THE SURFACE TROUGH IN THE SW CARIBBEAN.

ATLANTIC OCEAN...
AN UPPER LEVEL RIDGE COVERS THE SW ATLC CENTERED OVER THE
STRAITS OF FLORIDA NEAR 24N82W SUPPORTING A SURFACE RIDGE
ANCHORED BY A 1018 MB HIGH NEAR 26N68W. MODERATE MOISTURE IS
ACROSS THE AREA SUPPORTING WIDELY ISOLATED SHOWERS/THUNDERSTORMS
S OF 29N W OF 64W. FARTHER E...SURFACE RIDGING DOMINATES
ANCHORED BY A PAIR OF 1021 MB HIGHS CENTERED NEAR 33N41W AND
34N30W PROVIDING MOSTLY FAIR WEATHER ACROSS THE CENTRAL AND ERN
ATLC N OF 20N. ALOFT...AN UPPER LEVEL TROUGH IS E OF THE UPPER
RIDGE CENTERED S OF THE VIRGIN ISLANDS. AN UPPER LEVEL RIDGE
COVERS MUCH OF THE CENTRAL ATLC CENTERED NEAR 22N37W. A
SHORTWAVE UPPER LEVEL TROUGH COVERS THE FAR E ATLC EXTENDING
FROM THE CANARY ISLANDS TO THE CAPE VERDE ISLANDS.

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

$$
WALTON





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