[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201802
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST FRI FEB 20 2015

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...SPECIAL FEATURES...

...GALE WARNING FOR THE SW CARIBBEAN...
A GALE WARNING WILL GO INTO EFFECT ALONG THE COAST OF COLOMBIA
SATURDAY MORNING FROM 10N TO 13N BETWEEN 73.5W AND 76W. SEAS
WILL RANGE FROM 9 TO 12 FT. WINDS AND SEAS ARE EXPECTED TO
DIMINISH BY SATURDAY NIGHT. PLEASE SEE THE LATEST HIGH SEAS
FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE
DETAILS.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC
NEAR 05N10W TO 01N20W WHERE THE ITCZ BEGINS AND CONTINUES ALONG
01S30W TO THE NE COAST OF BRAZIL NEAR 05S37W. SCATTERED MODERATE
CONVECTION IS WITHIN 75 NM EITHER SIDE OF BOTH THE MONSOON
TROUGH AND THE ITCZ.

...DISCUSSION...

GULF OF MEXICO...

A PAIR OF HIGH PRESSURE CENTERS OVER THE MIDDLE ATLC STATES
ANCHORS A BROAD SURFACE RIDGE THAT EXTENDS FROM THE GREAT
LAKES...ACROSS THE EASTERN CONUS...THE SW N ATLC AND THE GULF OF
MEXICO. THIS RIDGE IS ADVECTING COLD AIR ACROSS THE FLORIDA
PENINSULA AS WELL AS THE EASTERN AND CENTRAL GULF. IN TERMS OF
WINDS...NORTHEASTERLY TO EASTERLY WIND FLOW IN THE RANGE OF 10
TO 20 KT COVERS THE BASIN E OF 90W...SOUTHEASTERLY TO SOUTHERLY
FLOW OF 20 TO 25 KT IS ELSEWHERE W OF 90W. MOISTURE CONVERGENCE
ALONG THE NW GULF COAST AND W OF 96W SUPPORT BROKEN TO OVERCAST
SKIES WITH POSSIBLE ISOLATED SHOWERS...FAIR WEATHER PREVAILS
ELSEWHERE. A STATIONARY FRONT ASSOCIATED WITH A CENTER OF LOW
PRESSURE OVER THE CENTRAL AND SOUTHERN PLAINS EXTENDS SE ACROSS
TEXAS WITH TAIL REACHING FROM 29N94W TO 28N90W. ALOFT...A RIDGE
STARTING TO MOVE ACROSS THE BASIN PROVIDES NORTHWESTERLY FLOW.
SURFACE RIDGING WILL CONTINUE TO DOMINATE ACROSS THE BASIN
THROUGH SATURDAY NIGHT. A NEW COLD FRONT WILL ENTER THE NW TO N
GULF SUNDAY MORNING.

CARIBBEAN SEA...

A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE FAR WESTERN ATLC WITH
BASE EXTENDING ACROSS THE CENTRAL CARIBBEAN SEA. THIS TROUGH
ALOFT SUPPORTS A COLD FRONT EXTENDING TO THE SW N ATLC TO NE
DOMINICAN REPUBLIC WHERE IT TRANSITIONS TO A STATIONARY FRONT SW
ACROSS HISPANIOLA TO 18N74W TO EASTERN JAMAICA TO COSTA RICA
ADJACENT WATERS NEAR 10N82W. LOW-LEVEL MOISTURE CONVERGENCE
ALONG THE FRONT AND TROUGHING ALOFT SUPPORT SCATTERED SHOWERS
AND ISOLATED TSTMS OVER HISPANIOLA AND WITHIN 100 NM EITHER SIDE
OF THE FRONTAL BOUNDARY. RAINSHOWERS ARE OVER THE CENTRAL BASIN
S OF 16N BETWEEN 68W AND 73W AND THE LESSER ANTILLES ASSOCIATED
WITH TWO MOIST AIR MASSES MOVING ACROSS THOSE REGIONS. SHOWERS
AND TSTMS ARE FORECAST FOR WESTERN PUERTO RICO THIS AFTERNOON AS
THE COLD FRONT OVER THE SW N ATLC CONTINUES TO DRIFT EASTWARD.
THE SURFACE RIDGE COVERING THE SW N ATLC AND THE GULF OF MEXICO
IS PROVIDING NORTHEASTERLY FLOW OF 20 TO 25 KT WEST OF THE
STATIONARY FRONT. TRADES OF 15 TO 20 KT DOMINATES ELSEWHERE. THE
RIDGE ACROSS THE GULF OF MEXICO IS FORECAST TO DRIFT E-NE
RESULTING IN AN INCREASE ON THE SURFACE PRESSURE GRADIENT IN THE
SW CARIBBEAN AND THE DEVELOPMENT OF GALE FORCE WINDS. SEE
SPECIAL FEATURES SECTION.

...HISPANIOLA...

A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE FAR WESTERN ATLC WITH
BASE EXTENDING ACROSS THE CENTRAL CARIBBEAN SEA. THIS TROUGH
ALOFT SUPPORTS A COLD FRONT EXTENDING TO THE SW N ATLC TO NE
DOMINICAN REPUBLIC WHERE IT TRANSITIONS TO A STATIONARY FRONT SW
ACROSS HISPANIOLA TO 18N74W TO EASTERN JAMAICA TO COSTA RICA
ADJACENT WATERS NEAR 10N82W. LOW-LEVEL MOISTURE CONVERGENCE
ALONG THE FRONT AND TROUGHING ALOFT SUPPORT SCATTERED SHOWERS
AND ISOLATED TSTMS OVER HISPANIOLA. SHOWERS ARE FORECAST TO
CONTINUE THROUGH SATURDAY MORNING.

ATLANTIC OCEAN...

A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE FAR WESTERN ATLC WITH
BASE EXTENDING ACROSS THE CENTRAL CARIBBEAN SEA. A COLD FRONT IS
BEING SUPPORTED BY THE TROUGH ALOFT ENTERING THE SW N ATLC ALONG
30N60W SW TO NE DOMINICAN REPUBLIC NEAR 19N70W WHERE IT
TRANSITIONS TO A STATIONARY FRONT SW TO COSTA RICA ADJACENT
WATERS NEAR 10N82W. SCATTERED MODERATE CONVECTION IS WITHIN 130
NM E OF THE COLD FRONT N OF 24N. SCATTERED SHOWERS ARE WITHIN 75
NM EITHER SIDE OF THE COLD FRONT S OF 24N. A 1040 MB HIGH NEAR
36N34W ANCHORS A BROAD SURFACE RIDGE THAT COVERS THE REMAINDER
CENTRAL AND EASTERN ATLC N OF 16N. THE FRONT WILL BECOME
STATIONARY AND STARTS TO DISSIPATE SATURDAY TO SATURDAY NIGHT. A
NEW COLD FRONT ENTERS THE SW N ATLC SUNDAY NIGHT TO MONDAY
MORNING.

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

$$
NR


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