[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201027
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 19W S OF 9N MOVING W NEAR 10-15 KT. EARLY
VISIBLE SATELLITE PICTURES INDICATE BROAD CYCLONIC TURNING
ASSOCIATED WITH THE WAVE. SCATTERED MODERATE CONVECTION IS W OF
THE WAVE AXIS FROM 1N-5N BETWEEN 22W-27W. SCATTERED SHOWERS AND
TSTMS ARE E OF THE AXIS.

TROPICAL WAVE IS ALONG 45W S OF 7N 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 11N 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 SHOWERS AND TSTMS ASSOCIATED WITH AN UPPER LEVEL RIDGE
AND THE TAIL END OF SFC TROUGH IN THE CARIBBEAN.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N11W 4N20W 3N35W 2N44W EQ50W.
SCATTERED MODERATE/STRONG CONVECTION IS FROM 1N-5N BETWEEN
21W-27W TRIGGERED BY THE TROPICAL WAVE ALONG 19W. SIMILAR
CONVECTION IS WITHIN 240 NM EITHER SIDE OF THE AXIS W OF 35W
ASSOCIATED WITH THE TROPICAL WAVE ALONG 45W. 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
1017 MB HIGH CENTERED IN THE CNTRL GULF NEAR 26N87W. 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 OVER THE NE
U.S./S CANADA 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 25N-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 S CANADA NEAR 47N73W HAS A
LONGWAVE TROUGH THAT DIGS INTO THE DISCUSSION AREA IN THE W
ATLC. THE COLD FRONT HAS BECOME STATIONARY ALONG 32N61W 25N73W
TO A 1014 MB LOW S OF CUBA NEAR 19N78W. A WEAK SFC TROUGH IS
DRAPED SWD FROM THE LOW TO 14N80W. 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 120 NM N OF HISPANIOLA
WHERE CLOUD TOP TEMPS ARE COLDER THAN -80C. 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 N S AMERICA... STRETCHING WWD
MINIMIZING ANY TSTM ACTIVITY E OF 77W. 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 THAT THE STUBBORN
FRONTAL BOUNDARY WILL 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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