[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221136
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT JAN 22 2011

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...

THE ITCZ AXIS IS ANALYZED FROM THE COAST OF SIERRA LEONE NEAR
8N13W CONTINUING SW ALONG 5N20W CROSSING THE EQUATOR NEAR 30W TO
THE COAST OF BRAZIL NEAR 3S40W. SCATTERED MODERATE TO HEAVY
SHOWERS ARE WITHIN 70 NM ON EITHER SIDE OF THE AXIS BETWEEN
20W-30W. SIMILAR ACTIVITY IS W OF 35W S OF 2N.

...DISCUSSION...

THE GULF OF MEXICO...
THE COLD FRONT THAT WAS TRAVELING ACROSS THE GULF OVER THE PAST
FEW DAYS IS NOW IN THE WEST ATLC AND THE FAR NW CARIBBEAN. AS A
RESULT...COLD AIR ADVECTION HAS TAKEN PLACE ACROSS THE AREA WITH
LOW LEVEL STRATOCUMULUS CLOUDS AND NNW WINDS UP TO 15 KT. THIS
FLOW WILL CONTINUE AS A SURFACE RIDGE BUILDS OVER THE NW AND N
CENTRAL BASIN OVER THE NEXT 24 HOURS MAINTAINING FAIR WEATHER
CONDITIONS ACROSS THE AREA.

THE CARIBBEAN SEA...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE OVER THE FAR NW
BASIN...WITHIN 40 NM ON EITHER SIDE OF THE COLD FRONT THAT
ENTERS THE BASIN ACROSS WESTERN CUBA EXTENDING WSW TO N CENTRAL
HONDURAS ALONG 23N82W 20N85W 15N86W. THIS FRONT IS EXPECTED TO
CONTINUE TO EXPAND EAST ACROSS THE WESTERN CARIBBEAN SEA WITH
CONVECTION OVER THE NEXT 24 HOURS. A PAIR OF WEAK SURFACE
TROUGHS ARE ANALYZED OVER THE CENTRAL BASIN. THE FIRST ONE ALONG
76W FROM 13N-18N...AND THE SECOND ONE ALONG 70W FROM 14N-17N.
SCATTERED SHOWERS ARE WITHIN 90 NM ON EITHER SIDE OF BOTH
SYSTEMS. COMPUTER MODELS SUGGEST THESE TWO SYSTEM WILL CONTINUE
TO DRIFT WESTWARD OVER THE NEXT 24 HOURS. OTHERWISE...MOSTLY
FAIR WEATHER IS ELSEWHERE ACROSS THE AREA...DUE TO A DRY AND
STABLE AIR MASS COVERING THE BASIN WITH ZONAL WLY FLOW ALOFT
AROUND A BROAD UPPER LEVEL RIDGE. A WEAK PRESSURE GRADIENT
ACROSS THE CARIBBEAN SEA E OF 80W...MAINTAINING 5-15 KT TRADE
WINDS ACROSS MUCH OF THE BASIN.

THE ATLANTIC OCEAN...
A COLD FRONT IS MOVING ACROSS THE W ATLC...ENTERING THE
DISCUSSION AREA NEAR 32N66W...CONTINUING SW TO WESTERN CUBA
ALONG 27N74W 23N82W AND INTO THE CARIBBEAN SEA. THIS SYSTEM IS
SUPPORTED BY A LONGWAVE UPPER TROUGH MOVING OFF THE EASTERN
CONUS SEABOARD. THIS UPPER LEVEL SUPPORT HAS ALSO PROMOTED
CYCLOGENESIS OVER THE FAR WEST ATLC IN THE LAST SEVERAL HOURS.
THUS A 1006 MB LOW HAS BEEN ANALYZED NEAR 29N77W. COMPUTER
MODELS SUGGEST THIS LOW WILL INTENSIFY WHILE TRACKING NE OUT OF
THE AREA OF DISCUSSION OVER THE NEXT 24 HOURS. GALE FORCE WINDS
ARE EXPECTED N OF 27N WITH SEAS TO 11 FT IN THE NEXT 18 HOURS. A
SURFACE TROUGH IS ANALYZED 50 NM EAST OF THE COLD FRONT S OF
27N. THE COMBINATION OF THESE TWO BOUNDARIES ARE GENERATING
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 150 NM AHEAD
OF THE COLD FRONT. A BROAD UPPER LEVEL RIDGE COVERS THE REST OF
THE BASIN E OF 65W ANCHORED BY A 1019 MB HIGH NEAR 27N47W...
PROVIDING GENERALLY FAIR WEATHER CONDITIONS ACROSS MUCH OF THE
CENTRAL AND ERN ATLC. DESPITE THE FAIR WEATHER...A WEAK LOW
PRESSURE SYSTEM DIPS S INTO THE SURFACE RIDGE NEAR 32N30W. A
SURFACE TROUGH EXTENDS SSW FROM THE LOW CENTER TO NEAR 29N33W
WITH ISOLATED SHOWERS N OF 28N BETWEEN 26W-32W. ALSO...A WEAK
UPPER LEVEL CYCLONE SPINS NEAR 35N17W. THE TAIL END OF THE
ASSOCIATED COLD FRONT EXTENDS EAST OF THE CANARY ISLANDS
SUPPORTING ISOLATED SHOWERS AFFECTING THE COASTAL WATERS OF
MOROCCO.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$

GARCIA



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