[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291752
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST FRI JAN 29 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...ITCZ...
THE ITCZ AXIS IS CENTERED FROM THE SOUTHERN LIBERIA COAST NEAR
4N8W CONTINUING WESTWARD ALONG 2N20W 1N30W 1N40W TO THE
NORTHEAST BRAZIL COAST NEAR EQ51W. SCATTERED WEAK TO MODERATE
CONVECTION IS FOUND WITHIN 150 NM ON EITHER SIDE OF THE ITCZ
BETWEEN 15W AND 22W.

...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT HAS JUST ENTERED THE NORTHWEST GULF...EXTENDING
FROM A LOW PRESSURE CENTER OVER SOUTHWESTERN LOUISIANA. THE
FRONT IS ANALYZED ALONG 29N94W 27N96W 25N96W 23N97W. DOPPLER
RADAR SHOWS A LINE OF HEAVY SHOWERS AND THUNDERSTORMS ALONG THE
FRONT NORTH OF 24N...AND SHOWERS EXTENDING EAST TO THE COAST OF
MISSISSIPPI. SATELLITE WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL
SHORTWAVE BEHIND THIS FRONTAL SYSTEM. A SECOND WAVE IS OVER
EASTERN TEXAS...FURTHER ENHANCING THE CONVECTION ENTERING THE
GULF. MID TO UPPER LEVEL MOISTURE FROM THE EASTERN TROPICAL
PACIFIC IS MOVING ACROSS MEXICO INTO THE GULF...SUPPORTING UPPER
LEVEL CLOUDS ACROSS MUCH OF THE AREA. SHIP AND OIL PLATFORM
OBSERVATIONS SHOW SOUTH-SOUTHEAST WINDS 15 TO 20 KT OVER THE
ENTIRE BASIN...EXCEPT NORTHWEST WINDS 20 TO 30 KT BEHIND THE
COLD FRONT. GALE FORCE WINDS ARE EXPECTED TO DEVELOP BEHIND THE
FRONT SOUTH OF 22N. THIS FRONT WILL CONTINUE TO MOVE EASTWARD
BRINGING CONVECTION AHEAD OF IT. IN 24 HOURS THE FRONT IS
EXPECTED TO EXTEND FROM THE FLORIDA PANHANDLE TO THE BAY OF
CAMPECHE.

CARIBBEAN SEA...
UPPER LEVEL RIDGE OF HIGH PRESSURE DOMINATES MOST OF THE
CARIBBEAN SEA. THIS FEATURE IS BRINGING SUBSIDENT DRY AIR
ALOFT...SUPPRESSING ANY SIGNIFICANT CONVECTION ACROSS THE
REGION. AT SURFACE...MARINE OBSERVATIONS SHOW EASTERLY WINDS 10
TO 20 KT OVER THE ENTIRE BASIN. NEVERTHELESS...A SHEAR LINE IS
ANALYZED ALONG THE NORTHERN VENEZUELA COAST. THIS FEATURE IS
INCREASING THE WINDS UP TO 25 KT WITHIN 100NM OFF THE COAST OF
VENEZUELA. FURTHERMORE...A TIGHT PRESSURE GRADIENT NORTH OF THE
COLOMBIA COAST IS CREATING GALE FORCE WINDS FROM 11N TO 15N
BETWEEN 72W AND 77W...WITH SEAS 12 TO 16 FEET IN THIS AREA.
COMPUTER MODELS PROJECT WINDS OVER THE NORTHWEST CARIBBEAN
SHIFTING SOUTH-SOUTHEAST AHEAD OF A COLD FRONT ENTERING THE
NORTHWEST BASIN OVER THE NEXT 24 TO 36 HOURS.

ATLANTIC OCEAN...
UPPER LEVEL RIDGE IS OVER MOST OF THE WESTERN AND CENTRAL
ATLANTIC BASIN...SUPPORTING A SURFACE 1021 MB HIGH NEAR 29N63W.
THIS FEATURE IS BRINGING MOSTLY FAIR WEATHER TO THE WESTERN AND
CENTRAL REGION NORTH OF 22N WEST OF 48W. A WEAKENING COLD FRONT
CONTINUES TO SLOWLY MOVE ACROSS THE CENTRAL ATLANTIC. THIS FRONT
ENTERS THE DISCUSSION AREA NEAR 32N44W...AND CONTINUES SOUTHWEST
ALONG 24N45W 20N50W 20N57W. A SHEAR LINE CONTINUES WESTWARD TO
THE NORTHERN DOMINICAN REPUBLIC. SCATTERED SHOWERS ARE WITHIN 50
NM ON EITHER SIDE OF THE FRONTAL BOUNDARIES. THE COLD FRONT IS
EXPECTED TO DISSIPATE OVER THE NEXT 24 TO 36 HOURS...WHILE THE
SHEAR LINE MAY LINGER UP TO 48 HOURS. TIGHTENING SURFACE
PRESSURE GRADIENT OVER THE CENTRAL ATLANTIC WILL CREATE GALE
FORCE WINDS NORTH OF 27N BETWEEN 41W AND 46W...WITH SEAS 12 TO
16 FT IN THIS REGION.

A COMPLEX 997 MB LOW PRESSURE SYSTEM IS ANALYZED OVER THE
EASTERN BASIN...SPINNING NEAR 32N32W. THIS SYSTEM IS SLOWLY
MOVING NORTHWEST. WATER VAPOR IMAGERY SHOWS THIS SYSTEM IS
SLOWLY LOOSING UPPER LEVEL SUPPORT AS. NEVERTHELESS...THIS
SYSTEM CONTINUES TO PRODUCE MULTIPLE SURGES OF CLOUD BOUNDARIES
RESULTING IN SEVERAL LAYERS OF FRONTS AROUND THE CENTER. THE
FIRST ONE ANALYZED EXTENDS AROUND THE LOW ALONG THE NORTHEAST
SEMI-CIRCLE AS AN OCCLUDED FRONT AND BECOMES COLD FRONT ALONG
30N27W 28N30W 29N34W. THE SECOND ONE EXTENDS AROUND THE LOW
ALONG THE NORTHERN SEMI-CIRCLE AS AN OCCLUDED FRONT AND
CONTINUES AS A COLD FRONT ALONG 30N24W 25N26W 21N33W. SCATTERED
SHOWERS ARE WITHIN 140 NM WITHIN THESE TWO FRONTS...AS WELL AS
NORTH OF THE ENTIRE SYSTEM OUT OF THE DISCUSSION AREA.

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

$$

GARCIA




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