[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 020008
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU NOV 01 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
SECTIONS OF SOUTH AMERICA...AND THE 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 FEATURE...
AIR FORCE RECONNAISSANCE PLANE FINDS HURRICANE NOEL AS IT MOVES
AWAY FROM THE BAHAMAS. AT 02/0000 UTC...THE CENTER OF
RECENTLY-UPGRADED HURRICANE NOEL WAS LOCATED NEAR LATITUDE 26.5
NORTH...LONGITUDE 76.5 WEST OR ABOUT 100 NM NORTH-NORTHEAST OF
NASSAU IN THE BAHAMAS AND ABOUT 700 NM WEST-SOUTHWEST OF
BERMUDA. NOEL HAS INCREASED ITS FORWARD SPEED AND IS NOW MOVING
TOWARD THE NORTH-NORTHEAST NEAR 15 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE HAS DROPPED TO 981 MB. MAXIMUM SUSTAINED WIND SPEED ARE
NEAR 65 KT WITH HIGHER GUSTS. SEE THE NHC FORECAST ADVISORY
UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC AND THE PUBLIC
ADVISORY UNDER MIATCPAT1/WTNT31 KNHC FOR MORE DETAILS. DEEP
CONVECTION REMAINS WITHIN 240 NM NE SEMICIRCLE. SIGNIFICANT
RAINFALL ACCUMULATIONS ARE EXPECTED OVER PORTIONS OF THE
BAHAMAS. WHILE THE STORM IS EXPECTED TO MOVE AWAY FROM
FLORIDA...THE MARINE THREAT WILL NOT END. STRONG N WINDS AND
LARGE NE SWELLS ARE EXPECTED TO PERSIST THROUGH MUCH OF THE
UPCOMING WEEKEND...AS NOEL BECOMES AN INTENSE EXTRATROPICAL
CYCLONE OVER THE NW ATLC AND INTERACTS WITH STRONG HIGH PRESSURE
OVER THE MIDDLE AND EASTERN PORTIONS OF THE UNITED STATES.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 10N14W 5N25W 6N38W 7N43W 3N54W.
SCATTERED MODERATE CONVECTION IS WITHIN 180NM N OF AXIS BETWEEN
22W-30W. SIMILAR ACTIVITY IS NEAR 5N20W. A TROUGH IS EMBEDDED IN
THE ITCZ ALONG 41W FROM 5N-16N...THAT IS GENERATING ISOLATED
SHOWERS/TSTMS WITHIN 90 NM OF THE AXIS. THIS MAY ACTUALLY BE THE
TROPICAL WAVE THAT APPEARS TO HAVE PASSED DAKAR AROUND 12Z OCT
27. CURRENTLY...THIS SYSTEM SHOWS UP WELL IN LOW LEVEL SATELLITE
DERIVED WINDS AND VORTICITY...AND THE UW CIMSS TPW PRODUCT THAT
DEPICTS A SURGE OF MOISTURE MOVING WWD ASSOCIATED WITH THIS
TROUGH. THEREFORE...A TROPICAL WAVE WILL BE ADDED TO THE 0000
UTC SFC MAP.

DISCUSSION...
GULF OF MEXICO...
STRONG N TO NE WINDS CONTINUES TO BLOW ACROSS THE E GULF THANKS
TO A TIGHT PRES GRADIENT BETWEEN TROPICAL STORM NOEL AND STRONG
HIGH PRES TO ITS NORTH. THESE WINDS ARE FORECAST TO DIMINISH
FRIDAY AFTERNOON. NE WINDS OF 10 TO 15 KT ARE FOUND OVER THE
WESTERN GULF. THESE WINDS ARE ADVECTING LOW LEVEL MOISTURE
AGAINST THE EASTERN SLOPES OF THE SIERRA MADRE MOUNTAINS IN
MEXICO. MOSAIC DOPPLER RADAR SHOWS BANDS OF SHOWERS MOVING FROM
NORTH TO SOUTH ACROSS THE FLORIDA PENINSULA/STRAITS INTO WESTERN
CUBA ASSOCIATED WITH THE CIRCULATION AROUND NOEL. MOST OF THIS
ACTIVITY THINS OUT EVEN FURTHER AS IT TRAVERSES INTO THE GULF.
ALOFT...THE FLOW IS FAIRLY ZONAL TO THE N OF A FLAT UPPER RIDGE
CENTERED OVER THE CARIBBEAN. A WEAK SHORTWAVE TROUGH IS OVER THE
FLORIDA PENINSULA/NE GULF. NOEL IS ACCELERATING IN THE
SOUTHWESTERLY FLOW AHEAD OF THIS TROUGH. WATER VAPOR IMAGERY
REVEALS WIDESPREAD DRY AIR/SUBSIDENCE ACROSS THE REGION WHICH IS
HELPING TO SUPPRESS SIGNIFICANT SHOWER ACTIVITY. LOOKING
AHEAD...A COLD FRONT WILL MOVE INTO THE N CENTRAL GULF WATERS
EARLY FRI REACHING THE SE PORTION OF THE GULF EARLY SAT.

CARIBBEAN SEA...
SATELLITE IMAGERY AND DOPPLER RADAR DATA FROM CAMAGUEY CUBA
REVEAL LINES OF SHOWERS MOVING EWD OVER THE ERN PORTION OF THE
COUNTRY. ADDITIONAL RAINFALL ACCUMULATIONS OF 1 TO 2 INCHES ARE
EXPECTED OVER EASTERN CUBA...WHERE THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES. CONVECTION IS
FLARED UP THIS EVENING OVER JAMAICA...THE GULF OF HONDURAS AND
THE SW CARIBBEAN. ALL THIS SHOWER/TSTM ACTIVITY IS ASSOCIATED
WITH A TRAILING TROUGH HANGING SWD FROM TROPICAL STORM NOEL...A
DEEP LOW LEVEL CONVERGENT FLOW ON THE E SIDE OF NOEL AND A
DIFFLUENT PATTERN ALOFT RELATED TO AN UPPER RIDGE THAT DOMINATES
THE CARIBBEAN SEA. THE AIR DRIES OUT SOME TO OVER THE FAR NW
CARIBBEAN DRIVEN BY FRESH NWLY WINDS. THE E CARIB IS FAIRLY
TRANQUIL UNDER MODERATE TRADE WIND FLOW AND DRIER MID/UPPER AIR
ADVECTED INTO THE REGION BY NLY WINDS BETWEEN AN UPPER LOW E OF
THE AREA AND AN UPPER HIGH CENTERED SOUTH OF JAMAICA.

ATLANTIC OCEAN...
TROPICAL STORM NOEL REMAINS THE MAIN FEATURE IN THE ATLC WHICH
IS MOVING TOWARD THE NORTH-NORTHEAST WITH AN INCREASE IN FORWARD
SPEED. FOR STORM SPECIFICS SEE THE SPECIAL FEATURE SECTION
ABOVE. IN ADDITION TO THE WIND FIELD DIRECTLY ASSOCIATED WITH
NOEL...THE TIGHT PRES PATTERN SET UP BETWEEN THE TROPICAL STORM
AND STRONG HIGH PRES NE OF BERMUDA IS PRODUCING STRONG GUSTY
WINDS...OCCASIONALLY TO GALE FORCE W OF 70W...AND LARGE SEAS
OVER MUCH OF THE WRN ATLC. STRONG WINDS AND LARGE SEAS EXPECTED
TO PERSIST OVER THE WRN PORTION OF THE AREA OVER THE NEXT COUPLE
OF DAYS AS NOEL TRANSITIONS TO A POWERFUL EXTRATROPICAL STORM.
NUMEROUS MODERATE TO STRONG CONVECTION IS FROM 25N-29N BETWEEN
72W-77W. A STATIONARY FRONT ENTERS THE AREA NEAR 31N36W THEN
CONTINUES W AND NW ALONG 26N50W 28N65W 31N78W. A 150-200 NM BAND
OF MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS IS ASSOCIATED WITH
THE FRONT. AN UPPER TROUGH NEAR 50W IS PROVIDING SOME SUPPORT TO
THE ABOVE MENTIONED FRONTAL BOUNDARY. THIS FEATURE IS HELPING TO
TIGHTEN THE GRADIENT OVER THE CENTRAL ATLC. A CUT-OFF LOW IN THE
TROPICAL ATLC NEAR 11N54W IS PRODUCING A SMALL AREA OF
CLOUDINESS AND ISOLATED SHOWERS FROM 9N-13N BETWEEN 50W-55W.
THE REMAINDER OF THE E ATLC IS FAIRLY QUIET UNDER MODERATE SFC
RIDGING AND AN ELONGATED UPPER RIDGE/TROUGH PATTERN.

$$
GR




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