[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191034
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON MAY 19 2008

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS TITLED ALONG 40W/41W S OF 13N MOVING W 10-15
KT. EARLY MORNING VIS IMAGES SHOW A FAINT APEX OR WEAK
INVERTED V PATTERN IN THE LOW-LEVEL CLOUDS. HOWEVER...MOST OF
THE SCATTERED SHOWERS AND TSTMS ARE LINEAR IN STRUCTURE AND
EMBEDDED WITHIN THE ITCZ WITHIN 300 NM EITHER SIDE OF THE AXIS
FROM 3N-8N.

A TROPICAL WAVE HAS BEEN ADJUSTED W SLIGHTLY IN THE CARIBBEAN
ALONG 65W/66W S OF 13N MOVING W 10-15 KT. THE ADJUSTMENT WAS
BASED ON A WWD MOVING MOISTURE BULGE EVIDENT ON THE MIMIC TPW
ANIMATION THAT IS VERY LIKELY ASSOCIATED WITH THIS WEAK FEATURE.
MUCH OF THE WAVE IS NOW INLAND OVER SOUTH AMERICA...WHICH WILL
MAKE IT DIFFICULT TO TRACK FOR THE NEXT COUPLE OF DAYS. THIS
WAVE MAY BE ENHANCING CONVECTION W OF THE AXIS OVER WRN
VENEZUELA.

..THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N13W 5N20W 4N30W 4N40W 3N52W.
SCATTERED MODERATE TO STRONG CONVECTION IS FROM 1N-8N E OF 16W
AND FROM 4N-7N BETWEEN 48W-55W. SCATTERED MODERATE CONVECTION IS
WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 22W-30W.

...DISCUSSION...

THE GULF OF MEXICO...

STRONG SW FLOW ALOFT LIES OVER MUCH OF THE GULF OF MEXICO
MOISTENING THE MID AND UPPER LEVELS SE OF A LINE FROM NE MEXICO
TO THE BIG BEND AREA OF FLORIDA. THE COMBINATION OF THIS UPPER
FLOW REGIME AND LOW-LEVEL CONVERGENCE ALONG A DISSIPATING
FRONTAL BOUNDARY FROM N FLORIDA TO 22N92W IS PRODUCING SCATTERED
SHOWERS AND TSTMS WITHIN 90 NM OF THE FRONT E OF 90W...INCLUDING
A 60 NM BAND OF SHOWERS N OF A LINE FROM SARASOTA TO VERO BEACH
FLORIDA. SIMILAR ACTIVITY IS OVER THE S BAY OF CAMPECHE DRAWN
FROM THE TROPICAL EPAC AND ENHANCED BY DIFFLUENT FLOW ALOFT.
DRIER AIR HAS WORKED SE OVER THE REMAINDER OF THE GULF
SUPPRESSING DEEP CLOUD FORMATION. SFC WINDS ARE MAINLY LIGHT
ACROSS THE REGION DUE TO THE WEAK FRONT AND A 1013 MB HIGH OVER
THE NW GULF.

THE CARIBBEAN SEA...

LARGE SCALE MID TO UPPER RIDGING LIES OVER THE REGION...THOUGH
IT IS INTERRUPTED SLIGHTLY BY A SMALL UPPER LOW NEAR 16N66W. THE
UPPER LOW AND MUCH OF THE AREA N OF 14N IS EMBEDDED IN A
SUBSIDENT ENVIRONMENT...PROVIDING WIDESPREAD FAIR WEATHER
BESIDES FOR A PASSING SHOWER OR TWO N OF 16N E OF 80W. S OF
14N...THERE IS A FAIR AMOUNT OF MOISTURE IN PLACE BUT MOST OF
THE DEEP CONVECTIVE ACTIVITY IS INLAND OVER SOUTH AMERICA.
HOWEVER...SOME OF THESE PATCHES HAVE MOVED INTO THE SW CARIB
WATERS S OF 13N W OF 76W OVER THE PAST FEW HOURS. ELY TRADES ARE
MAINLY MODERATE ACROSS THE CENTRAL AND E PORTIONS. THESE WINDS
VEER SE OVER THE NW WATERS IN RESPONSE TO THE FRONT IN THE GULF
OF MEXICO. LITTLE SIGNIFICANT CHANGE IS EXPECTED OVER THE NEXT
DAY OR SO.

THE ATLANTIC OCEAN...

SFC HIGH PRES CENTERED S OF THE AZORES NEAR 33N26W DOMINATES THE
THE SFC PATTERN THIS MORNING. THIS FEATURE IS PROVIDING MAINLY
LIGHT WINDS ACROSS THE BULK OF THE SUBTROPICS...EXCEPT FOR THE
FAR NW PORTION WHERE THE PRESSURE GRADIENT TIGHTENS IN RESPONSE
TO A LOW PRES SYSTEM OVER SOUTHERN CANADA. IN FACT...GALE
CONDITIONS HAVE DEVELOPED JUST N OF OUR FORECAST AREA OFF THE SE
CONUS. N TO NE WINDS ARE ALSO ENHANCED NEAR THE COAST OF AFRICA
FROM 16N-28N DUE TO INVERTED TROUGHING OVER THE CONTINENT. IN
THE MID AND UPPER LEVELS...A LARGE SCALE RIDGE LIES OVER MUCH OF
THE CENTRAL AND WESTERN ATLANTIC POSITIONED NEAR 22N66W. THIS
BROAD SYSTEM IS PROVIDING DRY STABLE AIR ALOFT ACROSS MUCH OF
THE AREA W OF 50W. AN UPPER TROUGH LIES ALONG 32W/33W PRODUCING
SCATTERED SHOWERS FROM 23N-27N BETWEEN 28W-32W. AN ASSOCIATED
BENIGN SFC TROUGH...REMNANTS OF A FRONT...EXTENDS FROM 31N42W TO
25N47W. RIDGING LIES OVER THE DEEP TROPICS WITH ONE ANTICYCLONE
CENTERED OVER W AFRICA NEAR 12N14W AND ANOTHER OVER VENEZUELA
NEAR 8N63W. DIFFLUENT FLOW ALOFT BETWEEN THESE SYSTEMS MAY BE
ENHANCING CONVECTION WITHIN THE ITCZ.  VISIBILITY IS LIKELY
REDUCED IN THE SMOKE PLUMES DIRECTLY DOWNWIND FROM BRUSH FIRES
NEAR LAKE OKEECHOBEE FLORIDA...NEAR MIAMI FLORIDA AND ABACO
BAHAMAS.

$$
CANGIALOSI




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