[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 171042
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED JUN 17 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 87W/88W S OF 19N MOVING W 15-20 KT. THE
WAVE COINCIDES WITH A DEEP MOISTURE MAXIMUM BASED ON TOTAL
PRECIPITABLE WATER IMAGERY. THE WAVE IS SUPPORTING ISOLATED MODERATE
CONVECTION FROM 11N-15N BETWEEN 86W-88W AND FROM 16N-19N BETWEEN
82W-88W. THIS CONVECTION IS ALSO SUPPORTED BY UPPER LEVEL DIFFLUENCE
ASSOCIATED WITH AN UPPER LEVEL HIGH OVER THE BAY OF CAMPECHE.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 10N12W 7N22W 6N32W 4N42W AND INTO NE
BRAZIL NEAR THE EQUATOR ALONG 51W. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS FROM 5N-10N BETWEEN 12W-16W. SCATTERED MODERATE
CONVECTION IS WITHIN 150/200 NM ON EITHER SIDE OF THE AXIS BETWEEN
16W-41W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION S OF 2N
BETWEEN 38W-44W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE TROUGH IS AFFECTING PORTIONS OF THE S GULF EXTENDING FROM
N OF THE YUCATAN PENINSULA NEAR 22N91W TO S GUATEMALA NEAR 15N91W.
LOW LEVEL CONVERGENCE NEAR THIS TROUGH AND UPPER LEVEL DIFFLUENCE
AROUND AN UPPER LEVEL HIGH OVER THE BAY OF CAMPECHE NEAR 21N93W ARE
SUPPORTING ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS S OF 21N BETWEEN
92W-96W. STRONGER CONVECTION ASSOCIATED WITH THIS TROUGH EXTENDS
INTO THE E PACIFIC.THE SURFACE TROUGH IS FORECAST TO MOVE W ACROSS
THE BAY OF CAMPECHE LATER TODAY. AN UPPER LEVEL SHORTWAVE TROUGH E
OF THE GEORGIA COAST IS SUPPORTING ISOLATED SHOWERS/POSSIBLE
THUNDERSTORMS OVER S FLORIDA AND THE FLORIDA KEYS FROM 24N-26N E OF
82W. ELSEWHERE...A STATIONARY 1017 MB SURFACE HIGH REMAINS NEAR
28N87W BRINGING FAIR WEATHER ACROSS THE REMAINDER OF THE GULF OF
MEXICO. ANTICYCLONIC FLOW AROUND THE SURFACE HIGH IS AFFECTING MUCH
OF THE GULF...WITH SE WINDS OF 15 KT OCCURRING IN THE NW GULF W OF
95W. EXPECT A TROPICAL WAVE CURRENTLY OVER THE GULF OF HONDURAS TO
MOVE THROUGH THE BAY OF CAMPECHE TONIGHT AND THURSDAY. A COLD FRONT
IS FORECAST TO MOVE INTO THE NE GULF OF MEXICO THURSDAY AND
DISSIPATE FRIDAY.


CARIBBEAN SEA...
A TROPICAL WAVE IS IN THE FAR W CARIBBEAN...SEE ABOVE. THE WAVE
ALONG WITH UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN UPPER LEVEL
HIGH OVER THE BAY OF CAMPECHE NEAR 21N93W ARE SUPPORTING ISOLATED
SHOWERS/POSSIBLE THUNDERSTORMS ACROSS THE NW CARIBBEAN FROM 16N-19N
W OF 82W AND OVER FAR W CUBA. THE CENTRAL ATLC IS EXPERIENCING
GENERALLY FAIR WEATHER. NLY UPPER LEVEL FLOW BETWEEN THE UPPER LEVEL
HIGH OVER THE BAY OF CAMPECHE AND AN UPPER LEVEL TROUGH EXTENDING
FROM THE W/CENTRAL ATLC ACROSS THE CENTRAL CARIBBEAN TO THE COAST OF
COLUMBIA NEAR 8N77W IS LIMITING THE DEEP LAYER MOISTURE.
HOWEVER...UPPER LEVEL DIFFLUENCE AT THE BASE OF THE UPPER TROUGH IS
SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS OVER COSTA RICA AND N
COLUMBIA. ALSO...UPPER LEVEL DIFFLUENCE E OF THE UPPER TROUGH IS
SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS ACROSS PORTIONS OF THE
DOMINICAN REPUBLIC...PUERTO RICO AND THE ADJACENT COASTAL WATERS N
OF 17N BETWEEN 65W-70W.

ATLANTIC OCEAN...
A SURFACE TROUGH E OF THE FLORIDA PENINSULA FROM 28N80W TO 31N88W
IS SUPPORTING ISOLATED SHOWERS/THUNDERSTORMS N OF 29N W OF 78W. THIS
ACTIVITY IS ENHANCED BY A SHORTWAVE UPPER LEVEL TROUGH E OF THE
GEORGIA COAST. SIMILAR ACTIVITY ASSOCIATED WITH THE UPPER LEVEL
SHORTWAVE TROUGH IS ALSO OVER THE FAR NW BAHAMAS FROM 24N-27N W OF
78W. AN UPPER LEVEL TROUGH IS OVER THE W/CENTRAL ATLC EXTENDING FROM
30N63W TO 20N70W AND OVER THE CENTRAL CARIBBEAN SUPPORTING ISOLATED
SHOWERS/THUNDERSTORMS ACROSS PUERTO RICO AND THE ADJACENT COASTAL
WATERS S OF 20N BETWEEN 67W-71W AND FROM 21N-23N BETWEEN 64W-67W.
UPPER LEVEL DIFFLUENCE NEAR AN UPPER LEVEL LOW NEAR 31N43W IS
SUPPORTING AN AREA OF SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS FROM
30N-32N BETWEEN 42W-45W. A 1012 MB SURFACE LOW IS IN THE FAR NE
PORTION OF THE ATLC NEAR 30N18W. SURFACE CONVERGENCE ASSOCIATED WITH
THE LOW IS SUPPORTING ISOLATED SHOWERS N OF 30N BETWEEN 16W-18W. THE
REMAINDER OF THE ATLC IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED
BY A 1027 MB HIGH N OF THE DISCUSSION AREA NEAR 34N36W BRINGING FAIR
WEATHER ACROSS THE BASIN. IN THE UPPER LEVELS...A BROAD UPPER LEVEL
RIDGE EXTENDS FROM AN UPPER LEVEL HIGH NEAR 12N42W TO 28N34W. AN
UPPER LEVEL LOW IS CENTERED DIRECTLY OVER THE SURFACE LOW NEAR
31N18W. EXPECT A WEAK COLD FRONT TO MOVE OVER THE NW WATERS LATER
TODAY...STALL AND SLOWLY DISSIPATE BY THURSDAY.

$$
WALTON





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