[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 290553
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT WED JUL 29 2009

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 24W S OF 24N MOVING W NEAR 12 KT. THIS
WAVE IS EMBEDDED WITHIN A VERY BROAD LOW/MID LEVEL CYCLONIC
CIRCULATION WITH A WEAK 1012 MB LOW W OF THE CAPE VERDE ISLANDS
CENTERED NEAR 15N29W AS INDICATED BY AN EARLIER QSCAT PASS
AROUND 28/2030 UTC. THIS WAVE IS ALSO AT THE LEADING EDGE OF A
MOISTURE MAXIMUM AS INDICATED BY TOTAL PRECIPITABLE WATER
IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 8N-12N BETWEEN
22W-30W.

A TROPICAL WAVE IS ALONG 54W S OF 18N MOVING W NEAR 18 KT. THIS
WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE BASED ON
THE TOTAL PRECIPITABLE WATER PRODUCT. SCATTERED SHOWERS ARE FROM
10N-15N BETWEEN 50W-57W.

A TROPICAL WAVE IS ALONG 80W S OF 19N MOVING W NEAR 20 KT. A
MAXIMUM IN TOTAL PRECIPITABLE WATER IS ACROSS THE WRN IN
ASSOCIATION WITH THE WAVE. HOWEVER...DUE TO THE DRY AND STABLE
MIDDLE TO UPPER LEVEL AIR THAT COVERS MUCH OF THE CARIBBEAN...NO
SIGNIFICANT DEEP CONVECTION ACCOMPANIES THE WAVE.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 15N17W 16N23W 14N30W 10N37W INTO
ERN VENEZUELA NEAR 10N61W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 10N-18N BETWEEN 15W-20W. SIMILAR CONVECTION
IS FROM 8N-11N BETWEEN 32W-39W.

...DISCUSSION...

GULF OF MEXICO...
A BENIGN UPPER LOW IS CENTERED ALONG THE E/CENTRAL COAST OF
MEXICO NEAR TAMPICO GENERATING ISOLATED SHOWERS OVER THE BAY OF
CAMPECHE S OF 22N. AN UPPER LEVEL TROUGH IS OVER THE NRN GULF
WITH AN AXIS EXTENDING FROM NEW ORLEANS LOUISIANA TO 26N94W.
ATMOSPHERIC LIFT IN MOIST SWLY FLOW ALOFT OVER THE NE GULF
COMBINED WITH THE ATMOSPHERIC INSTABILITY TO THE E OF THE UPPER
LEVEL TROUGH AXIS ARE SUPPORTING SCATTERED SHOWERS AND ISOLATED
TSTMS N OF 29N AND INLAND OVER THE FLORIDA PANHANDLE. UPPER
LEVEL DIFFLUENCE LOCATED ON THE SERN QUADRANT OF AN UPPER LEVEL
HIGH OVER THE ERN GULF CENTERED NEAR 25N97W IS SUPPORTING
SCATTERED SHOWERS AND TSTMS FROM 23N-25N BETWEEN 81W-85W.
ELSEWHERE ACROSS THE GULF...A SURFACE RIDGE OF HIGH PRESSURE
EXTENDS ALONG 27N TO 94W AND IS EXPECTED TO REMAIN IN PLACE OVER
THE NEXT COUPLE OF DAYS PROVIDING GENERALLY FAIR WEATHER.

CARIBBEAN SEA...
UPPER LEVEL RIDGING DOMINATES ACROSS THE CARIBBEAN PROVIDING DRY
AIR AND MOSTLY STABLE CONDITIONS ALOFT. HOWEVER...WITH THE
TROPICAL WAVE ALONG 80W AND AN UPPER LEVEL RIDGE ACROSS SRN
PORTIONS OF CENTRAL AMERICA...SCATTERED SHOWERS AND ISOLATED
TSTMS ARE ACROSS THE GULF OF HONDURAS S OF 17N TO INLAND OVER
HONDURAS AND NICARAGUA BETWEEN 83W-89W. ACROSS MUCH OF THE
CENTRAL AND E CARIBBEAN...THE DEEP LAYER DRY AIR IS SUPPORTING
MOSTLY FAIR WEATHER WITH FRESH TO STRONG EASTERLY TRADE WINDS E
OF 80W. HOWEVER...A FEW ISOLATED FAST MOVING SHOWERS ARE
OBSERVED ON SATELLITE IMAGERY S OF 15N AND OVER THE WINDWARD
ISLANDS. AS THE TROPICAL WAVE ALONG 54W APPROACHES THE LESSER
ANTILLES OVER THE NEXT 24-36 HOURS...EXPECT INCREASED CLOUDINESS
AND SCATTERED SHOWER ACTIVITY WITH THE PASSAGE OF THE WAVE.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS N OF 25N BETWEEN 74W-78W OVER THE SW
NORTH ATLC WATERS THAT IS GENERATING ISOLATED SHOWERS FROM 26N
TO BEYOND 32N BETWEEN 72W-78W. A FEW LINGERING ISOLATED SHOWERS
AND TSTMS ALSO REMAIN ALONG THE ERN FLORIDA COAST N OF 28N AS AN
UPPER LEVEL DIFFLUENT PATTERN IS PRESENT DUE TO AN UPPER LEVEL
RIDGE EXTENDING NE FROM THE ERN GULF OF MEXICO TO NEAR 30N80W.
THE REMAINDER OF THE CENTRAL AND E ATLC ARE DOMINATED BY DRY
STABLE AIR AND FAIR WEATHER DUE TO A SURFACE RIDGE ANCHORED BY A
1031 MB HIGH CENTERED NEAR 33N57W.

$$
HUFFMAN





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