[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 271129
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST TUE JAN 27 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 1115 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 4N8W 2N24W 1N40W TO THE EQUATOR 50W.
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 120 NM N OF
THE AXIS BETWEEN 36W-41W. SIMILAR CONVECTION IS S OF 5N W OF
47W.

...DISCUSSION...

THE GULF OF MEXICO...
FAIR AND MILD CONDITIONS EXIST ACROSS THE GULF BENEATH SLIGHT
RIDGING ALOFT AND E TO SE LOW-LEVEL FLOW ON THE S/SW PERIPHERY
OF W ATLC HIGH PRES. THERE COULD BE A FEW SHOWERS OVER THE
STRAITS OF FLORIDA AND FAR SE WATERS ASSOCIATED WITH WEAK
TROUGHING E OF THE AREA. THIS RATHER TRANQUIL PATTERN IS
EXPECTED TO CONTINUE UNTIL THE NEXT FRONT ENTERS THE NW WATERS
TUE NIGHT. NWP MODELS ARE SHOWING SUFFICIENT UPPER SUPPORT TO
PUSH THIS FRONT THROUGH THE ENTIRE GULF BY THE END OF THE
WEEK...BRINGING STRONG N WINDS AND COOLER AIR TO THE REGION.

THE CARIBBEAN SEA...
SFC OBS AND QSCAT DATA REVEAL STRONG ELY TRADES ACROSS THE
CARIBBEAN WITH SPEEDS MAINLY IN THE 20-25 KT RANGE...EXCEPT TO
GALE FORCE NEAR THE COAST OF COLOMBIA AS NOTED IN HI-RES QSCAT
DATA AND A COUPLE OF SHIP REPORTS. THIS STRONG FLOW IS
GENERATING ENOUGH INSTABILITY TO PRODUCE PATCHES OF LOW-LEVEL
CLOUDS WITH EMBEDDED SHOWERS. CLOUDINESS APPEARS MOST ORGANIZED
OVER THE NW CARIBBEAN LIKELY ENHANCED SOME BY A SFC TROUGH OVER
THE WRN ATLC. HOWEVER...ALL OF THIS MOISTURE IS SHALLOW IN
NATURE CAPPED BY ABUNDANT DRY STABLE AIR ALOFT...AS NOTED IN
SOUNDINGS AND WATER VAPOR IMAGERY. TRADE WINDS ARE EXPECTED TO
SLACKEN OVER THE W CARIBBEAN BY WED IN RESPONSE TO A FRONTAL
BOUNDARY...EXPECTED TO ENTER THE AREA ON FRI.

THE ATLANTIC OCEAN...
THE ATLC DISCUSSION ZONE REMAINS QUIET TONIGHT WITH THE ONLY
SYNOPTIC SFC FEATURES BEING A COUPLE OF LINGERING SFC TROUGHS
OVER THE W ATLC. ONE OLD FRONTAL BOUNDARY EXTENDS FROM 32N46W TO
26N59W TO 22N68W. SCATTERED CLOUDS AND EMBEDDED SHOWERS ARE
WITHIN 240 NM W OF THE TROUGH AXIS. THE OTHER TROUGH LINE
EXTENDS FROM BERMUDA TO 28N72W MARKED BY A NARROW LINE OF LOW
CLOUDS. A WEAK COLD FRONT IS LOCATED TO THE NW OF THIS TROUGH
ALONG THE NRN BORDER...BUT IS PRODUCING LITTLE SENSIBLE WEATHER
IN THE REGION. FARTHER E...STRONG HIGH PRES CENTERED NEAR 33N22W
IS MAINTAINING 20-25 KT NE/E TRADES ACROSS THE TROPICAL ATLC.
THE UPPER LEVEL PATTERN IS RATHER BENIGN. DIFFLUENCE ALOFT
BETWEEN WEAK TROUGHING OVER THE CENTRAL ATLC AND A E ATLC RIDGE
IS PRODUCING A BROKEN PLUME OF HIGH LEVEL CLOUDINESS...BUT NOT
MUCH IN THE WAY OF SIGNIFICANT MOISTURE. OTHERWISE...FAIRLY
STABLE CONDITIONS ARE PRESENT ELSEWHERE.

$$
CANGIALOSI





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