[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 011118
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI JAN 1 2010

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 THE 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1150 UTC.

...THE ITCZ...

THE ITCZ AXIS IS ANALYZED FROM WEST AFRICA...OVER THE CENTRAL
COAST OF GUINEA NEAR 10N14W...THROUGH 7N20W 5N30W 2N40W...TO
NORTHEAST BRAZIL NEAR THE CITY OF MACAPA AT EQ50W. MODERATE
CONVECTION IS FROM 2N TO 6N BETWEEN 12W AND 26W.

...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT EXTENDS SOUTHWEST ACROSS NORTHERN FLORIDA TO THE
WEST CENTRAL BASIN ALONG 30N80W 28N84W 26N91W 23N94W. THIS
FRONT IS MOVING EASTWARD ACROSS THE GULF INTO THE FLORIDA
PENINSULA. SHIP AND BUOY OBSERVATIONS SHOW NORTH TO NORTHWEST
WINDS 15 TO 30 KTS BEHIND THE FRONT. TO THE EAST OF THE FRONT
NORTH OF 22N...OBSERVATIONS SHOW SOUTH TO SOUTHWEST WINDS 10 TO
15 KTS. THIS LOW PRESSURE SYSTEM WILL CONTINUE ON A
EAST-NORTHEAST TRAJECTORY INTO THE ATLANTIC OCEAN OVER THE NEXT
24 HOURS...LEAVING BEHIND GALE FORCE WINDS OVER THE WESTERN
GULF. IN THE UPPER LEVELS OF THE ATMOSPHERE...A WIDE TROUGH
COVERING MUCH OF THE CENTRAL AND EASTERN CONTINENTAL US IS
PRODUCING LIGHT TO MODERATE SOUTHWEST UPPER LEVEL FLOW NORTH OF
25N. WATER VAPOR IMAGERY SHOWS THIS UPPER LEVEL FLOW
TRANSPORTING MOISTURE FROM THE EASTERN TROPICAL PACIFIC INTO THE
GULF OF MEXICO...THIS MOISTURE IS BEEN LIFTED BY A FAST MOVING
SHORTWAVE ENTERING THE NORTHWEST BASIN...FURTHER SUPPORTING
CONVECTION IN THIS REGION. RADAR IMAGERY SHOWS A FAST MOVING
BROAD LINE OF MODERATE TO HEAVY SHOWERS WITH EMBEDDED
THUNDERSTORMS MOVING ACROSS THE CENTRAL GULF INTO THE NORTHEAST
BASIN. THESE SHOWERS ARE ENTERING THE FLORIDA PANHANDLE OVER THE
NEXT HOUR OR SO. ANOTHER LINE OF HEAVY SHOWERS AND THUNDERSTORMS
IS ENTERING THE WEST CENTRAL FLORIDA COAST...FROM TAMPA TO FORT
MYERS. THE COLD FRONT WILL CONTINUE TO SWEEP DOWN OVER THE GULF
WITH FURTHER CONVECTION IN THIS REGION. NORTHERLY WINDS 25 TO 30
KTS WILL BE BEHIND THIS FRONT WITH A LOT OF COLD AIR ADVECTION.

CARIBBEAN SEA...
UPPER LEVEL HIGH PRESSURE CONTINUES TO DOMINATE MOST OF THE
CARIBBEAN BASIN...BRINGING STRONG SUBSIDENCE OF AIR ALOFT AND
SUPPRESSING DEEP CONVECTION ACROSS THE BASIN. NEVERTHELESS...THE
TAIL END OF A DISSIPATING STATIONARY FRONT IS OVER THE LEEWARD
ISLANDS...PASSING 70 NM SOUTH OF THE ISLAND OF PUERTO RICO AND
HISPANIOLA. THUS...BROKEN TO OVERCAST LOW CLOUDS ARE OBSERVED
NORTH OF 15N BETWEEN 62W AND 72W. DOPPLER RADAR IMAGERY SHOWS AN
AREA OF WEAK TO MODERATE SHOWERS MOVING IN WEST-SOUTHWEST
DIRECTION 30 NM SOUTH OF PUERTO RICO. SATELLITE IMAGERY
INDICATES THESE SHOWERS MAY EXTEND SOUTHWESTWARD TO 16N71W. SHIP
AND BUOY OBSERVATIONS SHOW EASTERLY WINDS 10 TO 15 KTS ACROSS
THE BASIN. THE ACTIVITY IN THE NORTHEAST BASIN WILL LESSEN AS
THE FRONT CONTINUES TO DISSIPATE. UPPER LEVEL RIDGE OF HIGH
PRESSURE WILL KEEP DEEP CONVECTION FROM HAPPENING OVER THE
CARIBBEAN. HOWEVER...THIS RIDGE WILL WEAKEN OVER THE NEXT 24
HOURS AS AN UPPER LEVEL TROUGH SWINGS NORTH OF THE CARIBBEAN
BASIN NEAR THE 20N LINE...SUPPORTING A COLD FRONT THAT WILL
ENTER THE NORTHWEST BASIN BRINGING CONVECTION OVER THE YUCATAN
PENINSULA AND THE NORTHWEST CARIBBEAN.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH WILL ENTER THE WEST ATLANTIC REGION OVER
THE NEXT 24 HOURS...PUSHING ALONG A SURFACE LOW PRESSURE SYSTEM
OFF THE NORTH CAROLINA COAST INTO THE WESTERN BASIN WITH FRONTAL
CONVECTION. AHEAD OF THIS SYSTEM THERE IS A SURFACE HIGH
PRESSURE OF 1026 MB OVER 32N59W. THUS...TIGHT SURFACE PRESSURE
GRADIENT IN BETWEEN THESE TWO SYSTEMS WILL DEVELOP GALE FORCE
WINDS OVER THE NEXT 24 HOURS 200 NM NE OF THE BAHAMAS. A SHARP
UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLANTIC. THIS UPPER
LEVEL TROUGH IS SUPPORTING THE TAIL END OF A COLD FRONT THAT
ENTERS THE CENTRAL ATLANTIC NEAR 32N30W AND EXTENDS SOUTHWEST
ALONG 21N40W 16N50W TO THE SOUTHEAST OF THE ISLAND HISPANIOLA.
BROKEN STRATOCUMULUS CLOUDS ARE WEST OF THE FRONT TO 60W.
SCATTERED WEAK CONVECTION IS OCCURRING WITHIN 150 NM EAST OF THE
COLD FRONT NORTH OF 22N. THIS SYSTEM WILL MOVE TO THE EAST
ATLANTIC IN 24 TO 36 HOURS...BRINGING CONVECTION TO THIS REGION.

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

$$

GARCIA




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