[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 110555
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT JUNE 11 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...SPECIAL FEATURE...
TROPICAL STORM ARLENE IS CENTERED NEAR 27.5N 86.6W AT 11/0600
UTC...OR ABOUT 190 MILES SOUTHEAST OF THE MOUTH OF THE
MISSISSIPPI RIVER OR 210 MILES SOUTH OF PENSACOLA FLORIDA MOVING
N-NW AT 14 KT. MAXIMUM SUSTAINED WIND SPEED 60 KT GUSTING TO 75
KT. MINIMUM CENTRAL PRESSURE 989 MB. SEE LATEST NHC FORECAST/
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC AND/OR
MIATCPAT1/WTNT31 FOR MORE DETAILS. BULK OF THE CONVECTION
ASSOCIATED WITH ARLENE REMAINS NE OF THE LOW LEVEL CENTER
TONIGHT. THE SHARP UPPER TROUGH THAT HAS PLAGUED THE GULF FOR
THE PAST WEEK HAS RELAXED OVER THE PAST 24 HOURS. ARLENE REMAINS
ALONG THE NW PERIPHERY OF AN UPPER RIDGE AXIS EXTENDING OVER THE
NW CARIBBEAN. THIS POSITION IS GENERALLY A FAVORABLE SPOT FOR
INTENSIFICATION WITH MORE OF A SSE FLOW AFFECTING THE TROPICAL
CYCLONE RATHER THAN SW. DRY AIR ALOFT IS BEING ENTRAINED INTO
ARLENE AND COULD IMPEDE FURTHER DEVELOPMENT. HOWEVER WITH THE
CYCLONE VERY CLOSE TO HURRICANE STRENGTH FURTHER INTENSIFICATION
IS EXPECTED BEFORE ARLENE MAKES LANDFALL LATER TODAY. HEAVY
RAINS/THUNDERSTORMS HAVE BEEN AFFECTING FLORIDA EXCEPT IN THE
EXTREME NE. THIS WILL CONTINUE THROUGH THIS MORNING WITH RAINS
DECREASING ALONG THE E COAST FROM SOUTH TO NORTH.

...TROPICAL WAVES...

CENTRAL ATLC TROPICAL WAVE IS ALONG 37W S OF 16N MOVING W 5-10
KT. WAVE REMAINS ALONG THE LEADING EDGE OF AFRICAN DUST WITH A
SLIGHT CURVATURE NOTED ON INFRARED SATELLITE IMAGERY.

W ATLC TROPICAL WAVE IS ALONG 56W/57W S OF 16N MOVING W 10-15
KT. WAVE IS BENEATH A COL BETWEEN UPPER RIDGES ACROSS THE
TROPICAL ATLC. THIS SCENARIO IS ENHANCING CONVECTION ASSOCIATED
WITH THIS WAVE. SCATTERED/NUMEROUS STRONG CONVECTION IS WITHIN
120 NM OF LINE FROM 10N50W-17N56W.

CARIBBEAN TROPICAL WAVE IS ALONG 78W S OF 17N MOVING W 5-10 KT.
STRONG N UPPER FLOW OVER THE AREA IS MASKING THE EXACT POSITION
BUT THERE IS SOME HINT IN THE LOW CLOUDS THAT COULD BE THE
WAVE'S LOCATION. WAVE COUPLED WITH A WEAK 1007 MB LOW OVER
COLOMBIA ARE ENHANCING SCATTERED/NUMEROUS STRONG CONVECTION
COVERING THE AREA S OF 12N BETWEEN 72W-78W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 15N16W 8N24W 5N38W 10N60W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM S OF THE
AXIS FROM 45W-56W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE
FROM 1N-10N BETWEEN 12W-39W.

...DISCUSSION...

GULF OF MEXICO...
ARLENE DOMINATES THE WEATHER PICTURE IN THE GULF WITH OVERCAST
MULTILAYERED CLOUDS WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS COVERING THE AREA N OF 27N E OF 89W AND E OF 84W N
OF CUBA. IN THE UPPER LEVELS...THE SHARP UPPER TROUGH THAT HAS
PLAGUED THE GULF FOR THE PAST WEEK HAS RELAXED OVER THE PAST 24
HOURS WITH A BROAD MID/UPPER TROUGH EXTENDING FROM THE CENTRAL
UNITED STATES S ALONG THE TEXAS/MEXICAN COAST TO THE W BAY OF
CAMPECHE. THIS IS PRODUCING SW UPPER FLOW ACROSS THE ENTIRE
GULF. THE WET PATTERN SHOULD CONTINUE FOR THE WEEKEND AS THE
UPPER LEVEL RIDGE REMAINS OFF THE E COAST OF FLORIDA. REMAINDER
OF THE GULF IS UNDER STRONG SUBSIDENCE AND DRY AIR...RESULTING
IN CLEAR SKIES.

CARIBBEAN SEA...
UNSETTLED WEATHER PATTERN CONTINUES OVER THE CARIBBEAN WITH A
MID/UPPER LEVEL HIGH OVER THE W CARIBBEAN NEAR 16N82W AND A
RIDGE AXIS EXTENDING N ACROSS CUBA INTO THE W ATLC. A MID/UPPER
TROUGH FROM THE CENTRAL ATLC CONTINUES TO CLIP THE NE CARIBBEAN
FROM HISPANIOLA TO THE N LEEWARD ISLANDS. UPPER LEVEL SE TO S
FLOW DOMINATES THE REMAINDER OF THE AREA. DIFFLUENCE OVER THE
GREATER ANTILLES CONTINUES TO GENERATE SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS FROM 15N-20N BETWEEN 59W-71W. A LOWER
EXTENT OF A RAINBAND FROM T.S. ARLENE IS OVER CUBA N OF 19N FROM
77W-81W WITH SIMILAR SHOWER ACTIVITY AS ABOVE. MOIST SW FLOW
CONTINUES IN THE LOW LEVELS OVER CENTRAL AMERICA BRINGING HEAVY
RAINS TO THE WESTWARD SLOPES OF THE MOUNTAIN RANGES. A WET
WEEKEND IS LIKELY FOR THE N CARIBBEAN WITH PLENTY OF UPPER
SUPPORT AND DEEP-LEVEL MOISTURE FOR HEAVY RAIN...ALONG WITH A
TROPICAL WAVE MOVING IN FROM THE W TROPICAL ATLC TO PROVIDE
ANOTHER FOCUS FOR RAIN.

ATLANTIC OCEAN...
MID/UPPER LEVEL RIDGE IN THE FAR W ATLC EXTENDS FROM AN UPPER
HIGH IN THE W CARIBBEAN ACROSS CENTRAL CUBA THEN JUST OFF THE E
COAST OF FLORIDA TO THE COAST OF CAROLINAS. THIS RIDGE IS
FORECASTED TO REMAIN NEARLY STATIONARY FOR THE NEXT COUPLE OF
DAYS AND WITH THE LANDFALL OF ARLENE WILL BRING ANOTHER WET
WEEKEND TO FLORIDA AND THE FAR SE UNITED STATES. OVERCAST
MULTILAYERED CLOUDS WITH SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS COVER THE W ATLC INCLUDING THE N BAHAMAS W OF 75W
RESULTS OF THE OUTFLOW FROM ARLENE. OVER THE CENTRAL ATLC...A
MID/UPPER LEVEL LOW REMAINS NOW CENTERED NEAR 26N61W WITH AN
UPPER TROUGH DIPPING AS FAR S AS 18N FROM 55W-70W INCLUDING THE
NE CARIBBEAN ISLANDS FROM  HISPANIOLA TO THE N LEEWARD ISLANDS.
A BUILDING MID/UPPER LEVEL RIDGE TO THE E OF THIS SYSTEM AND A
SURFACE TROUGH THAT EXTENDS FROM 28N63W THROUGH THE MONA PASSAGE
TO 17N69W IN THE N CARIBBEAN ARE RESPONSIBLE FOR A LARGE AREA OF
SCATTERED SHOWERS S OF 30N FROM 50W-65W WITH HEAVIEST AREA OF
ACTIVITY ENHANCED BY THE TROPICAL WAVE ALONG 56W/57W. THE UPPER
LOW AND SURFACE TROUGH ARE FORECASTED TO RETROGRADE SLOWLY W
OVER THE NEXT COUPLE OF DAYS CONTINUING THE SHOWER ACTIVITY FOR
THE WEEKEND. BROAD UPPER TROUGH COVERS THE REMAINDER OF THE ATLC
E OF 45W...THUS RESULTING IN LITTLE INTEREST WEATHER-WISE. AT
THE SURFACE...BROAD BUT WEAK HIGH PRESSURE DOMINATES THE ATLC N
OF 20N FROM 20W-50W AND N OF 25N W OF 50W TO THE E COAST OF THE
UNITED STATES. FARTHER S IN THE TROPICAL ATLC...MID/UPPER RIDGE
EXTENDS ALONG 11N/12N E OF 50W THUS SUPPRESSING THE ITCZ AXIS
TO THE S. AREA OF AFRICAN DUST CAN BE SEEN ON THE LAST VISIBLE
SATELLITE IMAGES FROM YESTERDAY E OF 35W.

$$
WALLACE


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