[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 051751
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI JUN 05 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...

A WEAK TROPICAL WAVE IS ALONG 36W/37W S OF 8N MOVING W AT 15 KT.
THIS WAVE HAS BECOME INCREASING SUPPRESSED BY A MID-LEVEL DRY
SAHARAN AIR LAYER AND LACKS ANY SIGNIFICANT CLOUD SIGNATURE OR
DEEP CONVECTION. SCATTERED SHOWERS REMAIN CONFINED ALONG THE
ITCZ AXIS S OF 4N BETWEEN 35W-38W.

A TROPICAL WAVE EXTENDS FROM 19N48W TO 10N50W TO 4N50W MOVING W
NEAR 15 KT. THIS WAVE IS ASSOCIATED WITH A HIGHLY AMPLIFIED
MAXIMUM IN DEEP LAYER MOISTURE BASED ON THE TOTAL PRECIPITABLE
WATER PRODUCT FROM CIMSS. SATELLITE IMAGERY INDICATES THAT THE
WAVE IS ASSOCIATED WITH A LARGE INVERTED-V SIGNATURE IN THE LOW
LEVEL CLOUD FIELD AND APPEARS ALONG THE LEADING EDGE OF A DRY
LOW/MID-LEVEL SAHARAN AIR LAYER...WHICH IS SUPPRESSING DEEP
CONVECTION E OF THE WAVE TO THE W AFRICAN COAST. HOWEVER...
SCATTERED MODERATE CONVECTION IS FROM 6N-10N BETWEEN 46W-54W.

A TROPICAL WAVE IS ALONG 88W/89W OVER WESTERN HONDURAS AND
EL-SALVADOR EXTENDING INTO THE E PACIFIC REGION. FOR MORE
DETAILS PLEASE REFER TO THE E PACIFIC TROPICAL WEATHER
DISCUSSION UNDER AWIPS HEADER TWDEP OR WMO HEADER AXPZ20 KNHC
FOR MORE INFORMATION.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N13W 7N20W 3N34W 3N38W 4N48W.
SCATTERED MODERATE CONVECTION IS FROM 2N-6N BETWEEN THE PRIME
MERIDIAN AND 13W. SIMILAR CONVECTION IS FROM 2N-7N BETWEEN
18W-25W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL TROUGH IS PRESENT ACROSS THE GULF REGION WITH
AXIS EXTENDING FROM THE NW CARIBBEAN N TO BEYOND 30N87W AND OVER
THE SE CONUS. THIS UPPER TROUGH SUPPORTS A 1008 MB LOW CENTERED
NEAR 31N86W AND EXTENDS A COLD FRONT INTO THE GULF ALONG 29N86W
26N88W 24N92W TO 24N94W WHERE IT CONTINUES STATIONARY INTO DEEP
SRN TEXAS NEAR BROWNSVILLE. UPPER LEVEL DIFFLUENCE IN MOIST SWLY
FLOW ALOFT E OF THE UPPER LEVEL TROUGH AXIS ALONG WITH THE
PRESENCE OF THE SURFACE COLD FRONT...ARE SUPPORTING NUMEROUS
SHOWERS AND SCATTERED TSTMS ACROSS THE NE GULF N OF 26N AND
ACROSS NRN FLORIDA. ACROSS MUCH OF THE W GULF...DEEP LAYER DRY
AIR IN NWLY FLOW ALOFT IS SUPPORTING GENERALLY FAIR WEATHER. THE
COLD FRONT IS FORECAST TO MOVE EWD ACROSS NRN FLORIDA AND THE NE
GULF WATERS SLOWLY DISSIPATING THROUGH SATURDAY.

CARIBBEAN SEA...
DEEP LAYER DRY AIR IN NWLY FLOW ALOFT IS RESULTING IN GENERALLY
FAIR WEATHER ACROSS MUCH OF THE CARIBBEAN. HOWEVER...UPPER LEVEL
MOISTURE AND HIGH LEVEL CLOUDS CONTINUE TO STREAM E-NE ACROSS
THE NW CARIBBEAN. A SURFACE RIDGE N OF THE CARIBBEAN IN THE
CENTRAL ATLC COMBINED WITH BROAD LOW PRESSURE OVER THE SW
CARIBBEAN AND COLOMBIA WILL CONTINUE TO PRODUCE ELY TRADE WINDS
OF 20 TO 25 KT ACROSS MUCH OF THE BASIN S OF 18N. THE TRADE
WINDS ARE ADVECTING POCKETS OF LOW LEVEL MOISTURE AND ISOLATED
SHOWERS WWD ACROSS THE CARIBBEAN...WITH THE GREATEST AREA OF
THESE SHOWERS NE OF A LINE FROM 10N61W OVER TRINIDAD TO 18N72W
OVER S/CENTRAL HISPANIOLA. THIS AREA INCLUDES ERN HISPANIOLA...
PUERTO RICO...AND THE LESSER ANTILLES. SCATTERED SHOWERS AND
TSTMS ARE ALSO ACROSS THE SW CARIBBEAN S OF 13N W OF 75W AIDED
BY LOW-LEVEL SPEED CONVERGENCE OF THE ELY TRADE WINDS AS WELL AS
UPPER LEVEL RIDGING AND DIFFLUENCE ACROSS NRN SOUTH AMERICA AND
THE WRN CARIBBEAN. THE TRADES ARE FORECAST TO RELAX LATE
SATURDAY THROUGH EARLY NEXT WEEK AS THE SURFACE RIDGE IN THE
CENTRAL ATLC WEAKENS.

ATLANTIC OCEAN...
UPPER LEVEL DIFFLUENCE IN MOIST SWLY FLOW ALOFT OVER THE SW
NORTH ATLC IS RESULTING IN SCATTERED SHOWERS AND TSTMS N OF 23N
W OF 74W INCLUDING THE BAHAMAS AND ADJACENT NEARBY COASTAL
WATERS. ADDITIONALLY...SCATTERED SHOWERS ARE OCCURRING FROM
24N-31N BETWEEN 52W-61W...WHERE ATMOSPHERIC INSTABILITY IS
PRESENT NEAR AN UPPER LEVEL LOW CENTERED NEAR 29N59W. ACROSS
MUCH OF THE CENTRAL AND E ATLC...A BROAD SURFACE RIDGE IS
RESULTING IN GENERALLY FAIR WEATHER ANCHORED ON A 1028 MB
SURFACE HIGH NEAR 35N42W. ACROSS THE TROPICAL ATLC...AN UPPER
LEVEL RIDGE IS S OF 15N E OF 50W WITH AN UPPER LEVEL HIGH NEAR
6N24W. UPPER LEVEL DIVERGENCE NEAR THE UPPER LEVEL HIGH AND
RIDGE IS ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ.

$$
HUFFMAN





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