[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200541
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT MAY 20 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 18W S OF 8N MOVING W NEAR 10 KT. WELL
DEFINED CYCLONIC TURNING IS EVIDENT ON SATELLITE IMAGERY
ASSOCIATED WITH THE WAVE. SCATTERED MODERATE CONVECTION IS W OF
THE WAVE AXIS FROM 1N-5N BETWEEN 19W-25W. SCATTERED SHOWERS AND
ISOLATED TSTMS ARE TO THE E OF THE AXIS.

TROPICAL WAVE IS ALONG 44W S OF 5N MOVING W 10-15 KT. THIS WAVE
HAS AN INVERTED V PATTERN EMBEDDED WITHIN THE ITCZ. SCATTERED
MODERATE CONVECTION IS WITHIN A FEW HUNDRED NM EITHER SIDE OF
THE WAVE AXIS. MODELS HAVE THE WAVE INITIALIZED FAIRLY WELL AND
TRACK THE FEATURE QUICKLY WWD ACROSS S AMERICA UNDER THE STRONG
CNTRL ATLC RIDGE.

TROPICAL WAVE IS ALONG 80W S OF 12N DRIFTING W. THIS WAVE HAS
SLOWED CONSIDERABLY OVER THE PAST 24 HOURS DUE TO WEAK STEERING.
THE WAVE HAS BECOME RATHER DIFFICULT TO LOCATE AS IT IS EMBEDDED
WITHIN AREAS OF CONVECTION ASSOCIATED WITH AN UPPER LEVEL RIDGE
AND THE TAIL END OF SFC TROUGH IN THE CARIBBEAN.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N10W 4N20W 3N30W 2N42W EQ50W.
SCATTERED MODERATE/STRONG CONVECTION IS FROM 1N-5N BETWEEN
19W-25W TRIGGERED BY THE TROPICAL WAVE ALONG 18W. SIMILAR
CONVECTION IS WITHIN 240 NM EITHER SIDE OF THE AXIS W OF 35W
ASSOCIATED WITH THE TROPICAL WAVE ALONG 44W. ELSEWHERE...
ISOLATED/SCATTERED SHOWERS ARE WITHIN 240 NM EITHER SIDE OF THE
AXIS.

...DISCUSSION...
GULF OF MEXICO...
PLEASANT WEATHER CONTINUES ACROSS THE GULF OF MEXICO THANKS TO A
1016 MB HIGH CENTERED IN THE CNTRL GULF NEAR 26N88W. SKIES ARE
GENERALLY FAIR TO MOSTLY CLEAR ACROSS THE REGION. SFC WINDS ARE
LIGHT EXCEPT FOR AN AREA OF 15-20 KT SLY RETURN FLOW IN THE NW
GULF. IN THE UPPER LEVELS...A DEEP LAYERED TROUGH THAT IS
GRADUALLY MOVING OUT OF THE NEW ENGLAND STATES EXTENDS SWWD INTO
THE NE GULF. AN UPPER RIDGE IS BUILDING OVER MEXICO AND THE
W/CNTRL U.S. DRY/STABLE AIR ALOFT IS WIDESPREAD WITH A SWATH OF
ENHANCED SUBSIDENCE DUE TO UPPER LEVEL CONFLUENCE FROM 26N-28N
ACROSS THE WIDTH OF THE GULF. COMPUTER MODELS SUGGEST THAT WEAK
SFC HIGH PRES WILL REMAIN IN THE REGION FOR THE NEXT SEVERAL
DAYS MAINTAINING FAIR WEATHER AND LIGHT TO MODERATE WINDS.
HOWEVER...SOME MOISTURE WILL BACK INTO THE SE GULF FROM THE
CARIBBEAN BEGINNING ON SUN.

CARIBBEAN SEA AND ATLANTIC OCEAN W OF 55W...
AN UPPER LEVEL TROUGH/RIDGE PATTERN REMAINS IN PLACE ACROSS THIS
AREA. A DEEP LAYERED LOW OVER VERMONT HAS A LONGWAVE TROUGH THAT
DIGS INTO THE DISCUSSION AREA IN THE W ATLC. THE COLD FRONT HAS
BECOME STATIONARY ALONG 32N60W 25N73W TO A 1012 MB LOW S OF CUBA
NEAR 18N79W. A WEAK SFC TROUGH IS DRAPED SWD FROM THE LOW TO
15N80W. SFC FORCING AND UPPER LEVEL DIVERGENCE IS PRODUCING
CLUSTERS OF SCATTERED MODERATE CONVECTION WITHIN 240 NM E OF THE
FRONTAL BOUNDARY. CURRENTLY...THE STRONGEST CLUSTER IS NE OF THE
SFC LOW OVER E CUBA WHERE CLOUD TOP TEMPS ARE COLDER THAN -85C.
SCATTERED SHOWERS ARE S OF THE LOW...NEAR THE SFC TROUGH...W OF
78W. FARTHER EAST...A SHARP UPPER RIDGE STRETCHES FROM COLOMBIA
TO THE CENTRAL ATLC. AN UPPER LEVEL ANTICYCLONE S OF HISPANIOLA
NEAR 18N72W IS EMBEDDED WITHIN THIS UPPER RIDGE. STRONG
SUBSIDENCE COVERS THE E CARIBBEAN AND MUCH OF COLOMBIA...
STRETCHING WWD MINIMIZING ANY TSTM ACTIVITY E OF 76W. A FEW
PATCHES OF LOW LEVEL TRADE WIND SHOWERS ARE OVER THE LESSER
ANTILLES MOVING TOWARDS PUERTO RICO. SFC WINDS REMAIN WEAK IN
THE W CARIBBEAN WHILE MORE MODERATE TRADES ARE E OF 75W.
TRADEWINDS ARE LIKELY TO BECOME MORE UNIFORM AND STRENGTHEN AS
THE SFC TROUGH DISSIPATES IN THE CARIBBEAN AND THE SPRAWLING
CNTRL ATLC RIDGE BUILDS INTO THE AREA. MODELS ANTICIPATE THE
STUBBORN FRONTAL BOUNDARY TO SLOWLY WEAKEN AND CONTINUE TO LIFT
NWD THIS WEEKEND FINALLY DISSIPATING BY EARLY NEXT WEEK. UNTIL
THEN...SHOWERS AND TSTMS ARE LIKELY TO PERSIST E OF THE BOUNDARY.

THE REMAINDER OF ATLANTIC OCEAN...
A SHARP UPPER LEVEL TROUGH IS OVER THE CNTRL ATLC WITH THE AXIS
EXTENDING THRU 30N35W THROUGH AN UPPER LOW NEAR 20N43W INTO THE
DEEP TROPICS NEAR 10N50W. THE SFC REFLECTION OF THE UPPER LOW
APPEARS TO BE HAVE DISSIPATED AS SFC WINDS DO NOT SHOW ANY
SIGNAL. AN UPPER RIDGE EXTENDS OVER THE E ATLC FROM AN UPPER
HIGH LOCATED NEAR THE CAPE VERDE ISLANDS N TO 30N25W. UPPER
DIFFLUENCE TO THE S OF THE HIGH IS ENHANCING CONVECTION ALONG
THE ITCZ E OF 28W. MODERATE TO STRONG SUBSIDENCE COVERS THE E
ATLC E OF 30W FROM 10N-22N. AT THE SFC...A SPRAWLING 1031 MB
HIGH CENTERED NEAR 34N28W COVERS THE ENTIRE REGION SUPPLYING
FAIR WEATHER ACROSS A GOOD PORTION OF THE ATLANTIC OCEAN.
TRADE WINDS ARE RATHER STRONG ACROSS THE AREA AND WILL
LIKELY REMAIN THAT WAY FOR THE NEXT FEW DAYS.

$$
CANGIALOSI


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