[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 020548
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI SEP 02 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
0345 UTC.

...SPECIAL FEATURES...

TROPICAL DEPRESSION LEE IS CENTERED NEAR 32.4N 52.5W...OR 635 NM
E OF BERMUDA...AT 02/0300 UTC MOVING WNW AT 6 KT. MAXIMUM
SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 1010 MB. THIS IS THE LAST ADVISORY
TO BE ISSUED BY THE NATION HURRICANE CENTER. SEE HIGH SEAS
FORECAST UNDER AWIPS/WMO HEADERS NFDHSFAT1/FZNT01 KWBC FOR MORE
INFORMATION UNLESS THIS SYSTEM REGENERATES. LEE HAS A COMPLETELY
EXPOSED LOW-LEVEL CIRCULATION WITH NO ASSOCIATED DEEP
CONVECTION. LEE IS EMBEDDED WITHIN AN AREA OF DRY AIR AND WITH
AN UPPER LOW TO ITS W ANY SHOWERS/THUNDERSTORMS ARE BEING PUSHED
WELL TO THE E OF THE LOW LEVEL CENTER. THIS FEATURE WILL NO
LONGER BE LISTED IN THIS PRODUCT AS IT IS N OF THE REGION.

TROPICAL DEPRESSION FOURTEEN IS CENTERED NEAR 20.4N 47.4W...OR
900 NM E OF THE NORTHERN LEEWARD ISLANDS...AT 02/0300 UTC MOVING
NW AT 10 KT. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO
40 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. SEE LATEST
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT34
KNHC FOR MORE DETAILS. THE LOW LEVEL CENTER IS PARTIALLY
EXPOSED...BEING COVERED MOSTLY BY HIGH CIRRUS CLOUDS. AN UPPER
LOW TO ITS SW IS PRODUCING SOMEWHAT OF A SSW SHEAR AND DRAWING
THE DEEPEST CONVECTION NW OF THE LOW LEVEL CENTER. SCATTERED
MODERATE/STRONG CONVECTION IS WITHIN 60 NM OF LINE
20N48W-23N50.5W. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG
CONVECTION ARE WITHIN 90 NM OF LINE 19N43W-24N50W. THE UPPER
LEVEL ENVIRONMENT IS NOT EXPECTED TO THAT FAVORABLE FOR
STRENGTHENING FOR AT LEAST THE NEXT DAY OR TWO ALTHOUGH THE
SHEAR IS EXPECTED TO LESSEN AFTER THAT TIME.

A 1008 MB LOW IS EMBEDDED WITHIN THE ITCZ NEAR 7N35W MOVING W
RATHER RAPIDLY NEAR 20 KT. THIS LOW CONTINUES TO BECOME BETTER
ORGANIZED AND IS IN A FAVORABLE ENVIRONMENT TO CONTINUE THIS
TREND. SCATTERED MODERATE/STRONG CONVECTION IS N OF OF THE LOW
WITHIN 45 NM OF LINE 8N35.5W-11N34W. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS AHEAD OF THE LOW LEVEL CENTER FROM 7N10N
BETWEEN 36W-41W. CONDITIONS ARE TO REMAIN FAVORABLE FOR FURTHER
STRENGTHENING AND TROPICAL CYCLONE DEVELOPMENT IS POSSIBLE ANY
TIME WITHIN THE NEXT 36 HRS.

...TROPICAL WAVES...

TROPICAL WAVE IS OFF THE COAST AFRICA ALONG 20W MOVING W NEAR 10
KT. BROAD CYCLONIC TURNING IS OBSERVED ON INFRARED SATELLITE
IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM
13N-16N E OF THE WAVE AXIS TO THE COAST OF AFRICA.

TROPICAL WAVE ENTERING THE SE CARIBBEAN ALONG 61W/62W S OF 13N
MOVING W 5-10 KT. WAVE APPEARS WELL DEFINED INLAND OVER
VENEZUELA WITH LITTLE EVIDENCE IN THE CARIBBEAN SEA AND THE
ASSOCIATED DEEP CONVECTION IS WELL INLAND AS WELL.

TROPICAL WAVE MOVING OVER CENTRAL AMERICA IS ALONG 86W S OF 18N
MOVING W 15 KT. WELL DEFINED CYCLONIC TURNING IS OBSERVED IN
THE E PACIFIC REGION WITH LITTLE EVIDENCE IN THE CARIBBEAN. ALL
ASSOCIATED DEEP CONVECTION IS INLAND OVER CENTRAL AMERICA INTO
THE E PACIFIC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 16N16W 13N25W 11N34W...THEN ALONG
5N37W 10N44W 13N50W 14N59W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS WITHIN A 60 NM RADIUS OF 6N34.5W. THE REMAINDER OF
THE CONVECTION IS ASSOCIATED WITH THE TROPICAL WAVE AND LOW.

...DISCUSSION...

GULF OF MEXICO...
A LARGE BUT ELONGATED UPPER LEVEL HIGH IS CENTERED ALONG THE
NORTH AND SOUTH CAROLINA COASTLINE AND AN ASSOCIATED RIDGE AXIS
EXTENDS SW ACROSS THE FLORIDA PANHANDLE TO JUST OFF THE TEXAS
COAST. THIS FEATURE IS PRODUCING A LARGE SWATH OF E/SE FLOW OVER
MAJORITY OF THE GULF OF MEXICO...WHICH ALSO HAPPENS TO BE
PUMPING LARGE AMOUNTS OF TROPICAL MOISTURE OVER THE AREA FROM
THE W ATLC. AN INVERTED UPPER TROUGH LOCATED ON THE SW SIDE OF
THE RIDGE...EXTENDING FROM THE CENTRAL BAY OF CAMPECHE TO
EXTREME NE MEXICO. THE UPPER TROUGH IS PRODUCING AN AREA OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ON ITS DIFFLUENT W
SIDE FROM 21N-25N W OF 94W TO INLAND OVER MEXICO. DIURNAL
SCATTERED MODERATE TO STRONG CONVECTION WHICH DEVELOPED OVER THE
YUCATAN PENINSULA EARLIER IS BEING DRAWN UP THE E SIDE OF THE
TROUGH AND IS NOW S OF 22N BETWEEN 91W-95W. SCATTERED
THUNDERSTORMS THAT DEVELOPED OVER FLORIDA HAVE MOVED INTO THE E
GULF FROM 25N-27N...AND OVER CUBA INTO THE STRAITS OF FLORIDA.
ALTHOUGH GENERAL HIGH PRESSURE IS CENTERED OVER THE AREA AT THE
SURFACE...A WEAK SURFACE TROUGH EXTENDS FROM A 1012 MB LOW NEAR
JACKSONVILLE FLORIDA SW ALONG 27N85W TO 26N93W AND THIS COULD BE
A FOCUS FOR THUNDERSTORMS IN THE COMING DAYS. DEEP TROPICAL
MOISTURE COVERS VIRTUALLY THE ENTIRE AREA AT THE MOMENT...WHICH
EXPLAINS THE HIGH COVERAGE OF THUNDERSTORM ACTIVITY...BUT A
MID/UPPER LEVEL TROUGH IS EXPECTED TO MOVE INTO THE LATE IN THE
WEEKEND AND WILL PUSH THIS AIR MASS OVER THE S GULF BY MON.

CARIBBEAN...
AN ELONGATED CLOSED UPPER LOW IS CENTERED S OF CUBA OVER THE
CAYMAN ISLANDS WITH THE TROUGH EXTENDING FROM E CUBA TO THE
COAST OF THE YUCATAN PENINSULA. A FAIRLY SOLID JET IS RACING
FROM NICARAGUA/HONDURAS TO ACROSS HISPANIOLA INTO THE SW ATLC
AND IS PUMPING MOISTURE NE ALTHOUGH SCATTERED MODERATE/ISOLATED
STRONG TO SCATTERED STRONG CONVECTION SEEMS TO BE FOCUSED OVER
THE NE CARIBBEAN N OF 18N TO INLAND OVER CUBA FROM 77W-87W.
ELSEWHERE...A RIDGE AXIS EXTENDS FROM A HIGH OVER THE
LEEWARD/VIRGIN ISLANDS NEAR 18N64W SW TO A SECOND N OF COLOMBIA
NEAR 13N73W CONTINUING TO A THIRD N OF PANAMA NEAR 11N82W. THIS
IS KEEPING THE STRONGEST SUBSIDENCE OVER THE E/CENTRAL CARIBBEAN
AND HENCE NO CONVECTION E OF 77W. A LARGE AREA OF DRY AIR IS
EXPECTED TO REMAIN OVER THE CARIBBEAN THROUGH AT LEAST MON WITH
THE GREATEST MOISTURE LIMITED TO THE FAR SW CARIBBEAN AND NEAR
THE YUCATAN CHANNEL.

WEST ATLANTIC...
A STATIONARY FRONT IS HUNG-UP ALONG THE N PORTION OF THE W ATLC
HOOKING UP WITH A 1012 MB LOW NEAR JACKSONVILLE FLORIDA. THE
TEMP/DEWPOINT CONTRASTS REMAIN IN CONTRARY TO A FRONTAL BOUNDARY
BUT THERE IS SOME SORT OF WIND SHIFT BOUNDARY. THIS SURFACE
LOW/TROUGH IS BENEATH THE UPPER RIDGE AXIS THAT HAS BEEN
CONTROLLING THE GULF FOR THE PAST FEW DAYS. IN ADDITION...A 1012
MB LOW REMAINS S OF BERMUDA NEAR 31N65W WITH A SURFACE TROUGH
EXTENDING SW TO 25N71W. THIS FEATURE LIES JUST W OF AN UPPER LOW
THAT HAS BEEN IN PLACE FOR A FEW DAYS NEAR 31N57W...WITH AN
EXTENSIVE TROUGH WHICH EXTENDS SW TO A DEVELOPING UPPER LOW N OF
THE MONA PASSAGE NEAR 23N68W TO E CUBA...WHICH THEN CONNECTS TO
THE UPPER LOW OVER THE NW CARIBBEAN. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE NEAR THE SURFACE TROUGH FROM 24N-31N BETWEEN
60W-72W. THE UPPER RIDGE IS EXPECTED TO TURN MORE E/W OVER THE
NEXT FEW DAYS THUS PUSHING THE UPPER TROUGH TO THE E. THE UPPER
TROUGH IS FORECASTED TO BECOME A COMPLEX SERIES OF UPPER LOWS
WHICH COULD BRING MORE UNSETTLED WEATHER TO THE AREA. THIS MODEL
RUN IS VERY DIFFERENT THAN THE PAST FEW NIGHTS...SO THIS
SCENARIO COMES TRUE REMAINS TO BE SEAN.

EAST/CENTRAL ATLANTIC...
A PAIR OF TROPICAL DEPRESSIONS...LEE AND FOURTEEN...ARE CENTERED
OVER THE CENTRAL ATLC AND BOTH ARE INTERMINGLED WITH STRONG
SHEAR-INDUCING UPPER LOWS NEAR 18N52W AND 31N57W. FARTHER E OVER
THE E ATLC...BROAD NW FLOW EXTENDS OVER THE SUBTROPICS E OF
45W AND IS DIGGING AN UPPER TROUGH TOWARDS THE CANARY ISLANDS
THEN LIFTING NE OVER MOROCCO AND PORTUGAL. A SHORTWAVE IS
DROPPING DOWN THE BACK SIDE OF THE TROUGH AND IS EXPECTED TO
DEVELOP A CUT-OFF LOW JUST SSW OF THE AZORES IN THE NEXT 36 TO
48 HRS. A WEAK UPPER HIGH IS LOCATED S OF THE TROUGH NEAR 13N36W
WITH FAIRLY CONSISTENT EASTERLY FLOW S OF 15N.

$$
WALLACE


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