[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 021139
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST MON JAN 02 2012

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1100 UTC.

...ITCZ/MONSOON TROUGH...

THE ITCZ EXTENDS FROM THE COAST OF LIBERIA NEAR 6N10W ALONG
7N14W 2N23W CROSSING THE EQUATOR AT 30W TO 2S37W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FROM 1N-5N BETWEEN
13W-26W.

...DISCUSSION...

GULF OF MEXICO...
A FAST MOVING COLD FRONT BISECTS THE GULF OF MEXICO AS IT
CONTINUES TO SPEED ACROSS BASIN CURRENTLY EXTENDING FROM NRN
FLORIDA NEAR 30N81W ALONG 26N87W 23N93W TO THE COAST OF MEXICO
NEAR 19N96W...AS OF 0900 UTC. A VERY THIN LINE OF SHOWERS IS
JUST AHEAD OF THE FRONT ACROSS THE NE AND CENTRAL GULF WITH
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IN THE SW GULF FROM
19N-23N BETWEEN 93W-97W. THE SE GULF REMAINS UNDER CLEAR SKIES
DUE TO DRY AIR ALOFT. AN UPPER LEVEL TROUGH N OF THE DISCUSSION
AREA ACROSS THE ERN CONUS...ALONG WITH A SHORTWAVE TROUGH WITH
AXIS DOWN THE E MEXICAN COAST IS SUPPORTING THE FRONT AND
PROVIDING MAINLY WSW FLOW ALOFT ACROSS THE GULF. THE SHORTWAVE
TROUGH IS ALSO CONTRIBUTING TO THE ENHANCED SHOWER/THUNDERSTORM
ACTIVITY IN THE SW GULF. EXPECT THE FRONT TO PASS THROUGH BY
TONIGHT. STRONG NLY WINDS OF MOSTLY 25 KTS ARE BEHIND THE FRONT
WITH GALE FORCE WINDS IN THE FAR SW CORNER. THE AREA OF STRONG
WINDS WILL EXPAND EWD AS THE FRONT CONTINUES TO PASS THROUGH THE
BASIN.

CARIBBEAN SEA...
MAINLY SW FLOW ALOFT COVERS THE CARIBBEAN TONIGHT BETWEEN A
BROAD UPPER LEVEL RIDGE IN THE W ATLC AND AN UPPER LEVEL TROUGH
MOVING INTO THE GULF OF MEXICO. MOST OF THE BASIN IS COVERED
WITH DRY AIR ALOFT WHICH IS HELPING MAINTAIN FAIR CONDITIONS AND
MOSTLY CLEAR SKIES. HOWEVER...A PATCH OF DEEP LAYER MOISTURE IS
OVER THE FAR NW CARIBBEAN N OF HONDURAS WHICH COMBINED WITH
UPPER LEVEL DIFFLUENCE AROUND THE E SIDE OF THE UPPER TROUGH IS
HELPING ENHANCE STRONG SHOWERS/THUNDERSTORMS FROM 16N-20N
BETWEEN 85W-89W. NE-E TRADEWIND FLOW OF 20-25 KTS IS ACROSS THE
AREA REACHING 30 KTS IN THE SW CARIBBEAN NEAR THE COAST OF
COLOMBIA. THE STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE
ACROSS THE W ATLC AND LOWER PRESSURES OVER S AMERICA IS HELPING
MAINTAIN THE STRONG WINDS. THIS WILL PERSIST THROUGHOUT THE DAY
UNTIL THE COLD FRONT IN THE GULF OF MEXICO REACHES THE NW
CARIBBEAN AND W ATLC TONIGHT ALLOWING THE PRESSURE GRADIENT TO
RELAX.

ATLANTIC OCEAN...
THE COLD FRONT OVER THE ERN CONUS AND GULF OF MEXICO HAS MOVED
INTO THE W ATLC ENTERING THE DISCUSSION AREA NEAR 32N77W TO THE
COAST OF FLORIDA NEAR 30N81W. A LINE OF SHOWERS IS JUST AHEAD OF
THE AXIS. THE FRONT IS SUPPORTED BY AN UPPER LEVEL TROUGH MOVING
OVER THE FAR W ATLC. AN UPPER LEVEL RIDGE IS TO THE E WITH AXIS
ALONG 55W. A WEAK SHORTWAVE UPPER TROUGH EMBEDDED WITHIN THE
LARGE SCALE TROUGH IS SUPPORTING A SURFACE TROUGH ALONG 29N71W
TO THE BAHAMAS NEAR 24N77W. SCATTERED SHOWERS/THUNDERSTORMS ARE
NEAR THE NRN TIP OF THE SURFACE TROUGH FROM 29N-31N BETWEEN
68W-71W. A DISSIPATING COLD FRONT IS ALSO ALONG 31N54W TO 29N64W
WITH POSSIBLE ISOLATED SHOWERS ALONG IT. THIS PORTION OF THE
FRONT HAS LOST ITS UPPER LEVEL SUPPORT AS THE UPPER TROUGH
REMAINS N OF THE DISCUSSION AREA AND HAS SHIFTED E WITH AXIS
ALONG 42W. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE
RIDGING AROUND A 1035 MB HIGH NEAR 35N21W PROVIDING MOSTLY FAIR
WEATHER. IT IS SUPPORTED BY AN UPPER LEVEL RIDGE ALONG 21W. A
WEAK UPPER LEVEL LOW IS S OF THE RIDGE NEAR 25N28W SUPPORTING
SOME UPPER LEVEL CLOUDS OVER THE WRN COAST OF AFRICA.

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

$$
WALTON






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