[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 311756
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN JAN 31 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.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED FROM THE CENTRAL LIBERIA COAST NEAR
6N10W CONTINUING WESTWARD ALONG 3N20W 2N30W 1N40W TO THE
NORTHEAST BRAZIL COAST NEAR ILHA DE MARAJO. AN AREA OF SCATTER
MODERATE TO STRONG CONVECTION IS ALONG THE ITCZ FROM 19W TO 30W.

...DISCUSSION...

THE GULF OF MEXICO...
THE COLD FRONT THAT BROUGHT US HAS MOVED OUT OF THE
AREA...LEAVING A COOL AND DRY AIRMASS ACROSS MOST OF THE REGION.
SHIP AND OIL PLATFORM OBSERVATIONS OVER THE GULF SHOW
NORTH-NORTHEAST WINDS 10 TO 20 KT ACROSS THE REGION...BECOMING
MORE EASTERLY OVER THE NEXT 24 HOURS. SATELLITE WATER VAPOR
IMAGERY SHOWS MID TO UPPER LEVEL MOISTURE FROM THE EASTERN
TROPICAL PACIFIC MOVING ACROSS MEXICO INTO THE GULF...THIS
FEATURE IS BRINGING A WARM AND MOIST UPPER LEVEL AIRMASS ACROSS
MUCH OF THE REGION...SEEN AS UPPER LEVEL CLOUDS.
HOWEVER...LATEST IMAGES INDICATE THAT THE SOURCE OF MOISTURE HAS
SHUT DOWN. THUS...THESE UPPER LEVEL CLOUDS OVER THE GULF
SHOULD CLEAR OVER THE NEXT 24 TO 36 HOURS. COMPUTER MODELS
INDICATE AT AN AREA OF WEAK LOW PRESSURE DEVELOPING OVER THE
SOUTHEAST CORNER OF THE BASIN NEAR 23N85W.

THE CARIBBEAN SEA...
A COLD FRONT ENTERS THE DISCUSSION AREA THROUGH WESTERN CUBA AND
CONTINUES SOUTH-SOUTHWEST TO 20N86W...BECOMING STATIONARY TO THE
NORTH CENTRAL COAST OF HONDURAS. THIS FRONTAL SYSTEM IS BRINGING
SCATTERED SHOWERS 60 NM WEST OF THE COLD FRONT AND STATIONARY
FRONT. AN AREA OF WEAK CONVERGENCE WITHIN 70 NM OFF THE NORTHERN
COAST OF NICARAGUA IS GENERATING SCATTER SHOWERS EAST IN THIS
AREA. ELSEWHERE EAST OF 78W...UPPER LEVEL RIDGE OF HIGH PRESSURE
IS OVER THE EASTERN CARIBBEAN SEA. THIS FEATURE IS BRINGING
SUBSIDENT DRY AIR ALOFT...SUPPRESSING ANY SIGNIFICANT CONVECTION
ACROSS THE CENTRAL AND EASTERN BASIN. ONLY SCATTERED SHOWERS ARE
MOVING ACROSS THE NORTHEAST BASIN DUE TO AN OLD DISSIPATED
FRONTAL BOUNDARY. MARINE OBSERVATIONS SHOW EASTERLY WINDS 15 TO
20 KT OVER THE EAST AND CENTRAL BASIN. WINDS OVER THE NORTHWEST
BASIN...NORTH OF 18N WEST OF 79W...ARE SHIFTING SOUTHEAST 10 TO
15 KT...DUE TO THE FRONTAL SYSTEM. OVER THE NEXT 24 HOURS LOOK
FOR CONTINUED SCATTERED SHOWERS ALONG AND NEAR THE FRONT.

THE ATLANTIC OCEAN...
A COLD FRONT IS OVER THE WESTERN ATLANTIC FROM 32N70W TO THE
STRAIGHTS OF FLORIDA. SCATTERED SHOWERS ARE WITHIN 45 NM OF THE
FRONT. GALE FORCE WINDS ARE IN EFFECT NORTH OF 30N EAST OF THE
FRONT TO 65W...WITH SEAS 8 TO 11 FEET IN THIS AREA...EXPECTED TO
DECREASE BELOW GALE FORCE CRITERIA OVER THE NEXT 12 HOURS.

A 1022 MB HIGH IS CENTERED OVER THE CENTRAL ATLANTIC NEAR
27N49W. INFRA-RED SATELLITE IMAGERY SHOWS A BROAD CLUSTER OF
WEAK SCATTER SHOWERS FROM 14N TO 25N BETWEEN 45W AND 52W THESE
SHOWERS ARE REMNANTS OF OLD DISSIPATED FRONTAL BOUNDARIES FROM A
1000 MB LOW CURRENTLY CENTERED OVER THE EASTERN ATLANTIC NEAR
28N25W. WATER VAPOR IMAGERY SHOWS THIS LOW PRESSURE SYSTEM HAS
LOST UPPER LEVEL SUPPORT. ONLY AN UPPER LEVEL CLOSED LOW IS
SPINNING OVER THE SURFACE LOW. NEVERTHELESS...THIS SYSTEM
CONTINUES TO PRODUCE MULTIPLE SURGES OF CLOUD BOUNDARIES
RESULTING IN SEVERAL LAYERS OF FRONTS AROUND THE CENTER. TWO
OCCLUDED FRONTS EXTEND AROUND THE LOW ALONG THE NORTHERN
SEMI-CIRCLE. THE FIRST OCCLUDED FRONT BECOMES COLD FRONT ALONG
28N24W 26N23W 24N22W. THE SECOND OCCLUDED FRONT BECOMES COLD
FRONT ALONG 27N26W 25N26W 24N27W. THE CONVECTION WITHIN THESE
TWO FRONTS COVER AN AREA FROM 24N TO 30N BETWEEN 20W AND 30W.
GALE FORCE WINDS ARE IN EFFECT NORTH OF 27N EAST OF 37W...WITH
SEAS 14 TO 17 FEET IN THIS AREA...EXPECTED TO DECREASE BELOW
GALE FORCE CRITERIA OVER THE NEXT 6 TO 10 HOURS.

EXPECT...THE COLD FRONT OVER THE WESTERN ATLANTIC TO CONTINUE TO
MOVE EASTWARD OVER THE NEXT 24 HOURS WITH CONVECTION AHEAD OF
IT. ALSO...EXPECT A GOOD AMOUNT OF COLD AIR ADVECTION BEHIND
THIS FRONT. FURTHERMORE...EXPECT THE EASTERN ATLANTIC LOW
PRODUCE MORE CONVECTION AS IT MOVES EAST-NORTHEAST OVER THE NEXT
24 HOURS.

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

$$

GARCIA


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