[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211750
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN FEB 21 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 COAST OF LIBERIA NEAR 5N10W
ALONG 2.5N20W 2N30W 4N40W TO THE NE BRAZIL COAST NEAR 2N51W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALONG THE ITCZ
BETWEEN 32W AND 42W.

...DISCUSSION...

GULF OF MEXICO...
A RATHER EAST TO WEST ORIENTED SUBTROPICAL JET STREAM IS MOVING
ACROSS THE GULF OF MEXICO NORTH OF 21N...MOVING ALONG WITH THE
UPPER LEVEL ZONAL FLOW. UPPER LEVEL DIVERGENCE FROM THE JET
STREAK'S FRONT LEFT QUADRANT...AHEAD OF A SHORTWAVE OVER THE
NORTH CENTRAL GULF...IS ENHANCING SURFACE CONVERGENCE ON THE
EASTERN HALF THE GULF...NORTH OF 22N EAST OF 90W. OVER THE NEXT
6 TO 12 HOURS...LOOK FOR THE SURFACE CONVERGENCE TO MOVE
EASTWARD INTO THE FLORIDA PENINSULA. DOPPLER RADAR IMAGERY SHOWS
SCATTERED MODERATE TO HEAVY SHOWERS WITH POSSIBLE THUNDERSTORMS
IN THIS AREA. SOUTH TO SOUTHEAST SFC WINDS ARE NOTED ACROSS THE
REGION. THIS SURFACE FLOW IS PUSHING A WARM AND MOIST AIRMASS
NORTHWARD INTO THE SOUTHERN US STATES. THUS...A WARM FRONT IS
ANALYZED FROM KEY WEST FLORIDA TO THE NORTHWEST CORNER OF THE
BASIN ALONG 26N84W 28N89W 28N94W 27N96W. COMPUTER MODELS
INDICATE THIS FRONT WILL CONTINUE TO MOVE NORTHWARD AS A COLD
FRONT CURRENTLY OVER CENTRAL TEXAS ENTERS THE NORTHWEST BASIN
OVER THE NEXT 12 TO 18 HOURS. ALSO...A TROUGH IS ALONG THE COAST
OF MEXICO FROM TAMPICO TO VERACRUZ BRINGING A FEW ISOLATED
SHOWERS 30 NM ON EITHER SIDE OF THE TROUGH.

CARIBBEAN SEA...
THE REMNANTS OF AT WEAK STATIONARY FRONT CONTINUE TO CREATE
CONVECTION NEAR THE US/UK VIRGIN ISLANDS AND PUERTO RICO. THE
WEAK STATIONARY FRONT ENTERS THROUGH ANGUILLA...EXTENDING
WESTWARD TO NEAR 16N71W. MULTIPLE SCATTER SHOWERS ARE NOTED ON
DOPPLER RADAR IMAGERY OVER THE MENTIONED ISLANDS. ALSO...AN
AREA OF CONVERGENCE IS FOUND OVER HISPANIOLA FROM A SURFACE
TROUGH THAT ENTERS THE NORTH CENTRAL DOMINICAN REPUBLIC AND
CONTINUES SW TO SOUTHEAST HAITI. THIS FEATURE COMBINED WITH THE
WEAKENING STATIONARY FRONT IS BRINGING CONTINUOUS CONVECTION TO
THE NORTHEAST CARIBBEAN BASIN FROM 16N TO 20N BETWEEN 62W AND
72W. ELSEWHERE OUTSIDE THIS BOX...DRY SUBSIDENT AIR ALOFT IS
BRINGING FAIR WEATHER WITH MODERATE EASTERLY WINDS ACROSS THIS
REGION. OVER THE NEXT 24 HOURS...LOOK FOR WEAK CONVECTION TO
CONTINUE TO DEVELOP NEAR THE WEAK STATIONARY FRONT AND SURFACE
TROUGH. ALSO IN 24 HOURS...WINDS OVER THE NW BASIN...NORTH OF
16N WEST OF 92W...WILL START TO SHIFT SOUTHEASTERLY AS A COLD
FRONT APPROACHES THIS REGION.

ATLANTIC OCEAN...
UPPER LEVEL ZONAL FLOW IS NOTED ACROSS THE DISCUSSION
AREA...ALONG WITH THE SUBTROPICAL JET STREAM MOVING ACROSS THE
ATLANTIC NORTH OF 21N. AN UPPER LEVEL SHORTWAVE IS MOVING ACROSS
THE WESTERN ATLANTIC...SUPPORTING A RATHER WEAK SURFACE TROUGH
THAT EXTENDS FROM THE NORTH CENTRAL DOMINICAN REPUBLIC TO NEAR
22N63W...BRINGING SCATTER SHOWERS WITHIN 60 NM ON EITHER SIDE OF
THE TROUGH. ALSO...THE REMNANTS OF A WEAKENING FRONTAL SYSTEM
THAT EXTENDS FROM NORTHWEST AFRICA TO THE LESSER ANTILLES
CONTINUE TO PRODUCE SCATTER SHOWERS ACROSS THE ATLANTIC. THIS
FRONT ENTERS THE DISCUSSION AREA AS AN ACTIVE COLD FRONT ALONG
30N10W AND CONTINUES SOUTHWEST ALONG 25N22W...BECOMING
DISSIPATING COLD FRONT FROM 23N35W TO 21N45W...BECOMING
DISSIPATING STATIONARY TO 18N62W. SCATTER SHOWERS ARE 80 NM EAST
OF THE COLD FRONT WHILE SCATTER SHOWERS ARE 80 NM ON EITHER SIDE
OF THE STATIONARY FRONT. IN 24 HOURS...THIS FRONT WILL CONTINUE
TO DISSIPATE WHILE SLOWLY SHIFTING EASTWARD ACROSS THE AREA.
ELSEWHERE ACROSS THE REGION...HIGH PRESSURE IS ENTERING THE
WESTERNS BASIN PROVIDING FAIR WEATHER WEST OF 50W NORTH OF 20N.
DRY SUBSIDENT AIR ALOFT IS NOTED SOUTH OF 17N EAST OF 60W.

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

$$

GARCIA




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