[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 021053
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED JUL 02 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND 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.

...SPECIAL FEATURE....

A STRONG TROPICAL WAVE IS OVER THE FAR E ATLANTIC NEARING THE
CAPE VERDE ISLANDS ALONG 21W S OF 19N MOVING W 10-15 KT. VISIBLE
IMAGERY REVEALS AN IMPRESSIVE CLOUD STRUCTURE WITH WELL DEFINED
MID-LEVEL TURNING ALONG THE WAVE AXIS NEAR 12N. HOWEVER...A 0714
UTC QSCAT PASS SUGGESTED THAT THE SFC CIRCULATION IS SITUATED
FARTHER E. WHILE CONVECTION HAS DECREASED SLIGHTLY...WITHIN 60
NM E AND 180 NM W OF THE WAVE AXIS S OF 15N...THIS SYSTEM HAS
GRADUALLY BECOME BETTER ORGANIZED AND THERE IS THE POTENTIAL FOR
IT TO BECOME A TROPICAL DEPRESSION OVER THE NEXT COUPLE OF DAYS.

...TROPICAL WAVES...

TROPICAL WAVE IS TITLED FROM NW TO SE ALONG 20N37W 6N33W.
DESPITE THE HIGH AMPLIFICATION NOTED IN THE TPW FIELD AND CLOUD
DRIFT WINDS...ORGANIZED DEEP CLOUDINESS IS MINIMAL WITH ONLY ONE
PATCH OF MODERATE CONVECTION NEAR THE INTERSECTION OF THE ITCZ
FROM 7N-10N BETWEEN 30W-35W.

TROPICAL WAVE IS ALONG 45W S OF 12N MOVING W 15 KT. THIS WAVE IS
WEAK AND MUCH LESS AMPLIFIED THAN THE ONES TO ITS E.
HOWEVER...IT IS LIKELY ENHANCING AN AREA OF SCATTERED MODERATE
CONVECTION NEAR THE INTERSECTION OF THE ITCZ FROM 5N-7N BETWEEN
43W-51W.

TROPICAL WAVE IS ALONG 56W S OF 17N MOVING W 15 KT. THIS WAVE IS
FAIRLY WELL DEFINED AS SATELLITE IMAGES AND THE TPW FIELD
CONTINUE TO SHOW AN INVERTED V-STRUCTURE. A WEAK LOW-MID LEVEL
LOW APPEARS TO BE FORMING ALONG THE AXIS NEAR 12N/13N AND SHOWER
AND TSTM ACTIVITY IS MAINLY CONFINED TO ITS W SIDE SHEARED BY
UPPER ELY FLOW FROM 12N-13N BETWEEN 56W-59W. EARLIER
SCATTEROMETER DATA REVEALED A SLIGHT WIND SHIFT ABOUT THE AXIS
AND AN INCREASE IN WINDS TO 20-25 KT E OF THE AXIS.

TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 72W S OF 13N
MOVING W 15 KT. THIS WAVE REMAINS WEAK AND CHALLENGING TO
LOCATE. THE CURRENT POSITION IS BASED MAINLY ON
CONTINUITY...WHICH MATCHES UP WELL WITH A WEAK MOISTURE SURGE
EVIDENT IN THE TPW FIELD. CONVECTION IS CONFINED TO OVER SOUTH
AMERICA.

TROPICAL WAVE IS OVER GUATEMALA AND THE YUCATAN PENINSULA ALONG
91W S OF 19N MOVING W 15 KT. THE INTERACTION WITH AN UPPER
DIFFLUENT ZONE IS PRODUCING A LARGE AREA OF SCATTERED MODERATE
TO STRONG CONVECTION OVER THE EPAC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N16W 9N30W 6N40W 5N50W 6N55W
10N62W. CONVECTION IS DESCRIBED IN THE TROPICAL WAVES SECTION
ABOVE.

...DISCUSSION...

THE GULF OF MEXICO...
LONGWAVE TROUGHING EXTENDS SSW FROM THE NORTHEAST U.S. TO THE
GULF OF MEXICO. ABUNDANT MID-HIGH LEVEL MOISTURE THAT HAS BEEN
LOCKED IN THIS AREA IS BEING DEEPENED BY DIFFLUENCE ALOFT TO
PRODUCE SCATTERED SHOWERS AND TSTMS FROM 22N-29N W OF 84W...AS
NOTED IN LIGHTNING DATA. THE HIGHEST FREQUENCY OF STRIKES ARE
OCCURRING OVER THE E GULF. ISOLATED ACTIVITY IS AFFECTING THE
BAY OF CAMPECHE ENHANCED BY THE N PORTION OF A TROPICAL WAVE.
OTHERWISE...THE SFC PRESSURE PATTERN REMAINS WEAK AS A FRONT HAS
DRIFTED N TO ALONG THE N GULF COAST WITH SFC RIDGING TRYING TO
BUILD W FROM THE ATLC. THIS OVERALL PATTERN IS PRODUCING LIGHT
AND VARIABLE WINDS ACROSS THE N WATERS AND LIGHT TO MODERATE E
TO SE WINDS OVER THE S WATERS.

THE CARIBBEAN SEA...
LITTLE CHANGE HAS OCCURRED IN THE LARGE SCALE PATTERN OVER THE
PAST 24 HOURS AS AN UPPER LOW REMAINS QUASI-STATIONARY E OF THE
BAHAMAS NEAR 25N69W WITH TROUGHING EXTENDING S TO NEAR 12N72W.
WHILE DRY AIR IS EVIDENT NEAR THE TROUGH AXIS...THE ATMOSPHERE
IS MOIST BOTH OVER THE FAR EASTERN AND WESTERN CARIBBEAN IN
DIFFLUENT ZONES. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OVER
THE NW AND SW WATERS BUT THE DEEPEST CONVECTIVE ACTIVITY HAS
PUSHED W OF THE AREA WITH A TROPICAL WAVE ALONG 91W. SCATTERED
SHOWERS AND ISOLATED TSTMS ARE AFFECTING THE WINDWARD ISLANDS
ASSOCIATED WITH A FAIRLY WELL DEFINED TROPICAL WAVE JUST E OF
THE AREA. TRADE WINDS ARE ON THE STRONG SIDE OVER THE S CENTRAL
AND SW WATERS DUE TO THE TIGHT PRESSURE GRADIENT BETWEEN STRONG
SUBTROPICAL RIDGING OVER THE CENTRAL ATLC AND SEMI-PERMANENT LOW
PRES TROUGHING OVER COLOMBIA.

THE ATLANTIC OCEAN...
A HIGHLY DIFFLUENT UPPER PATTERN...DUE TO LARGE SCALE TROUGHING
OVER THE EASTERN CONUS AND A NARROW RIDGE OVER THE BAHAMAS...IS
PRODUCING SCATTERED SHOWERS AND TSTMS N OF 24N W OF 70W.
OTHERWISE...THE REMAINDER OF THE SUBTROPICAL ATLC IS FAIRLY
STABLE WITH A FEW BENIGN UPPER LOWS SPINNING OVER THE CENTRAL
ATLC AND RIDGING HOLDING IN PLACE OVER THE E ATLC. IN THE DEEP
TROPICS...A LARGE SCALE RIDGE IS CENTERED NEAR 19N43W WITH MUCH
OF THE DEEP MOISTURE CONFINED TO THE TROPICAL WAVES...ESPECIALLY
THE VIGOROUS ONE IN THE FAR E ATLC.

$$
CANGIALOSI




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