[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 021741
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON OCT 02 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
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...WEATHER OBSERVATIONS...RADAR...
AND METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...
TROPICAL STORM ISAAC WAS CENTERED NEAR 44.3N 55.0W OR ABOUT 165
NM SOUTH-SOUTHWEST OF CAPE RACE NEWFOUNDLAND AT 02/1500 UTC.
ISAAC IS MOVING TOWARD THE NORTH-NORTHEAST AT 36 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 994 MB. MAXIMUM SUSTAINED WIND SPEED
IS 50 KT WITH GUSTS TO 60 KT. ISAAC IS LOSING TROPICAL
CHARACTERISTICS AND IS EXPECTED TO BECOME AN EXTRATROPICAL LOW
LATER TODAY. SEE THE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY
UNDER MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
A 1010 MB LOW IS ABOUT 585 NM SW OF THE CAPE VERDE ISLANDS NEAR
9N32W MOVING W 10-15 KT. SHOWER AND THUNDERSTORM ACTIVITY
ASSOCIATED WITH THIS BROAD LOW REMAINS MINIMAL. UPPER LEVEL
WINDS ARE NOT CONDUCIVE FOR DEVELOPMENT OF THIS SYSTEM AS IT
MOVES SLOWLY WEST-NORTHWESTWARD.

A LOW AMPLITUDE TROPICAL WAVE IS ALONG 45W S OF 17N MOVING W
10-15 KT. THERE IS SOME SUBTLE CYCLONIC TURNING OF THE LOW TO
MID CLOUD FIELD FROM 10N-15N BETWEEN 40W-49W...BUT SHOWER AND
TSTM ACTIVITY IS MINIMAL ASIDE FROM A SMALL CLUSTER OF SCATTERED
MODERATE CONVECTION JUST E OF THE WAVE FROM 12N-13N BETWEEN
41W-44W.

AN EASTERN CARIBBEAN SEA TROPICAL WAVE PREVIOUSLY ALONG 69W HAS
BEEN REPOSITIONED TO 62W S OF 20N BASED ON THIS MORNINGS VISIBLE
IMAGERY...ALONG WITH SOUNDING DATA FROM GUADELOUPE THAT SHOWS
THE LOW LEVEL WINDS HAVE SHIFTED FROM NE TO E TO SE OVER THE
PAST COUPLE OF DAYS. SEVERAL STATIONS IN THE LESSER ANTILLES ARE
ALSO REPORTING SE WINDS. THIS WAVE IS ESTIMATED TO BE MOVING W
10-15 KT. AN INVERTED V PATTERN IS SEEN ON SATELLITE IMAGERY
MOVING INTO THE FAR ERN CARIBBEAN...THOUGH SHOWER/TSTM ACTIVITY
IS ISOLATED AT BEST WITHIN 100NM OF THE AXIS.

TROPICAL WAVE IS ALONG 81W S OF 20N MOVING W AT 10-15 KT.
ISOLATED SHOWERS WITH EMBEDDED TSTMS DOT THE SW CARIBBEAN AND
COASTAL CENTRAL AMERICA FROM 9N-14N BETWEEN 78W-84W...AND IN THE
NW CARIBBEAN FROM 16N-20N BETWEEN 82W-88W...THOUGH SOME OF THIS
MAY BE MORE ASSOCIATED WITH UPPER DIFFLUENCE.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 12N16W 10N28W 9N36W 10N43W 11N60W.
OUTSIDE OF THE TROPICAL WAVES AND THE LOW NEAR 9N32W...DEEP
CONVECTION IS OVERALL MINIMAL WITHIN 200NM OF THE AXIS. SMALL
CLUSTERS OF SCATTERED MODERATE CONVECTION ARE NOTED FROM 6N-7N
BETWEEN 35W-38W...AND FROM 11N-13N BETWEEN 54W-56W.


...DISCUSSION...
GULF OF MEXICO...
ANTICYCLONIC FLOW AROUND A BROAD MID TO UPPER HIGH OVER SE
MEXICO/S OF THE BAY OF CAMPECHE IS DOMINATING MUCH OF THE GULF
THIS AFTERNOON. THERE IS A SHORT WAVE UPPER TROUGH WITH A
POSITIVE TILT ALIGNED SW TO NE THROUGH CENTRAL MEXICO AND TEXAS.
ASSOCIATED CLOUDINESS IS OVER THE NW GULF WITH HIGH CLOUDS
STREAMING TO THE NE. THE ERN GULF IS DOMINATED BY DRY MID TO
UPPER AIR ASIDE FROM A FEW ISOLATED SHOWERS IN THE FAR SE GULF
FROM 23N-25N BETWEEN 83W-88W. AT THE SURFACE...CLOCKWISE
EASTERLY FLOW IS OBSERVED AROUND THE SRN PERIPHERY OF A 1027MB
HIGH NEAR BLACKSBURG VIRGINIA...MOSTLY IN THE 10 TO 20 KT RANGE.
HIGH PRESSURE WILL REMAIN QUASI-STATIONARY NORTH OF THE AREA
OVER THE NEXT FEW DAYS ALLOWING MODERATE E FLOW TO
PERSIST...WITH E SWELL BUILDING FOR MAINLY THE WRN GULF WATERS
AND AFFECTING COASTAL TX/NE MEXICO THROUGH THE SECOND HALF OF
THE WEEK.

CARIBBEAN SEA...
THE UPPER HIGH OVER SRN MEXICO/S OF THE BAY OF CAMPECHE IS ALSO
DOMINATING THE WRN CARIBBEAN. THERE IS SOME UPPER DIFFLUENCE
NOTED BETWEEN THIS FEATURE AND THE TROUGHING OFF THE EASTERN
SEABOARD OF THE UNITED STATES THAT MAY BE HELPING TO SUPPORT THE
ISOLATED SHOWER/TSTM ACTIVITY IN THE NW CARIBBEAN...AS IT
INTERACTS WITH THE TROPICAL WAVE MOVING THROUGH THE AREA. A MID
TO UPPER LEVEL LOW IS SEEN JUST S OF THE DOMINICAN REPUBLIC NEAR
17N69W...THOUGH NOT MUCH SHOWER ACTIVITY IS NOTED IN THIS
VICINITY IN THE MIDST OF DRY AIR PRESENT. HIGH CLOUDS ARE
STREAMING NE THROUGH THE FAR ERN CARIBBEAN ON THE SE SIDE OF
THIS UPPER LOW...THAT APPEARS TO BE INTERACTING WITH THE
TROPICAL WAVE MOVING THROUGH THE AREA. ELSEWHERE AT THE
SURFACE...TRADES 15 TO 20 KT DOMINATE AND WILL PERSIST THE NEXT
COUPLE OF DAYS WITH HIGH PRESSURE N OF THE AREA AND LOWER
PRESSURE NEAR THE COLOMBIAN COAST.

ATLANTIC OCEAN...
VERY DRY MID TO UPPER LEVEL AIR IS SEEN ON WV IMAGERY JUST OFF
THE SE US AND FLORIDA COAST THIS AFTERNOON WITH DEEP LAYER
TROUGHING PUSHING OFF THE EAST COAST. PERHAPS MORE INTERESTING
WEATHER IS AT THE SURFACE WHERE FRESH NE FLOW IS DEVELOPING
ACROSS SRN FLORIDA AND THE ADJACENT ATLC WATERS...WITH A
1027MB SURFACE HIGH BUILDING INTO THE AREA FROM ITS CENTER NEAR
BLACKSBURG VIRGINIA. AVAILABLE CMAN/BUOY OBSERVATIONS OFF
FLORIDA GENERALLY SHOW 15-20 KT ENE/NE WINDS. THIS IS EXPECTED
TO PERSIST OVER THE NEXT FEW DAYS WITH HIGH PRESSURE REMAINING
QUASI-STATIONARY N OF THE AREA. ASSOCIATED SHORT PERIOD NE WIND
WAVES WILL BUILD ACROSS FL AND EXPOSED BEACHES IN THE BAHAMAS
THROUGH MIDWEEK...SEE STATEMENTS FROM LOCAL WEATHER SERVICE
OFFICES FOR MORE DETAILS. A SURFACE TROUGH CONTINUES TO EXTEND
NE THROUGH THE TURKS/CAICOS INTO THE SW NORTH ATLC...ALONG
20N72W 32N64W. THIS IS HELPING TO SPARK PATCHES OF SCATTERED
MODERATE CONVECTION FROM 20N-32N BETWEEN 66W-75W. THIS TROUGH IS
ASSOCIATED WITH CONFLUENCE BETWEEN THE HIGH BUILDING DOWN THE SE
US AND A 1031MB CENTRAL ATLC HIGH NEAR 40N40W. BROAD MID TO
UPPER LEVEL HIGH PRESSURE IS DOMINATING THE AREA FROM 20N-40N
BETWEEN 40W-68W WITH A FEW EMBEDDED HIGH CENTERS. A DRY UPPER
LOW IS E OF THE WINDWARD ISLANDS NEAR 16N51W...WITH A STRONGER
AND DEEPER LAYER LOW NEAR 30N30W THAT HAS A FRONTAL BOUNDARY
EXTENDING S TO 22N31W FROM THE SURFACE LOW NEAR 32N29W.
CLOUDINESS AND ISOLATED SHOWERS ASSOCIATED WITH THIS SYSTEM ARE
FROM 24N-35N BETWEEN 20W-35W. THE SW FLOW BETWEEN THIS UPPER LOW
AND THE UPPER HIGH OVER WRN AFRICA IS PRODUCING SHEAR OVER THE
LOW NEAR 9N32W.


$$
WILLIS




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