[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271744
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT THU MAR 27 2014

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
1715 UTC.

...SPECIAL FEATURES...
A STRONG PRESSURE GRADIENT EXISTS ACROSS THE SW CARIBBEAN SEA
BETWEEN STRONG HIGH PRESSURE CENTERED ACROSS THE SW NORTH ATLC
AND LOWER PRESSURE ACROSS THE NORTHWESTERN SOUTH AMERICAN
CONTINENT. GALE FORCE NE TO E WINDS ARE OCCURRING FROM 11N-13N
BETWEEN 74W-77W. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/
WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO
THE EQUATOR NEAR 30W. SCATTERED MODERATE CONVECTION IS S OF 07N
BETWEEN 07W-14W.

...DISCUSSION...

GULF OF MEXICO...
OVERALL WEST-SOUTHWESTERLY...ALMOST ZONAL...FLOW IS NOTED ALOFT
OVER THE GULF BASIN THIS AFTERNOON. WATER VAPOR IMAGERY
INDICATES THE SUBTROPICAL JET STREAM ADVECTING MOISTURE AND
CLOUDINESS FROM THE EASTERN PACIFIC OVER CENTRAL MEXICO TO THE
FLORIDA PENINSULA. A 240 NM WIDE SWATH OF MOISTURE WITH EMBEDDED
AREAS OF MID-LEVEL ENERGY ARE ALONG THIS STREAM GENERATING
SCATTERED SHOWERS AND TSTMS FROM BROWNSVILLE TEXAS E-NE TO
27N90W TO 29N81W..AND INTO THE SW NORTH ATLC REGION. MUCH OF
THIS PRECIPITATION IS OCCURRING WITHIN THE SOUTHWESTERN
PERIPHERY OF A SURFACE RIDGE ANCHORED ACROSS THE MID-ATLC COAST
THAT PLACES THE GULF WITHIN PRIMARILY SE WINDS IN THE RANGE OF
15 TO 20 KT. WINDS ARE EXPECTED TO INCREASE ACROSS EASTERN
PORTIONS OF THE GULF THROUGH THE EVENING AND OVERNIGHT HOURS
INTO FRIDAY AND GRADUALLY DIMINISH SLIGHTLY INTO THE EARLY PART
OF THE WEEKEND. BY LATE FRIDAY...THE NEXT AREA OF LOW PRESSURE
IS EXPECTED TO DEVELOP ACROSS THE ARKLATEX REGION AND MOVE NE
WITH THE ASSOCIATED COLD FRONT FORECAST TO EMERGE OFF THE TEXAS
AND LOUISIANA COAST EARLY SATURDAY.

CARIBBEAN SEA...
NORTHWESTERLY FLOW ALOFT INFLUENCES THE CARIBBEAN BASIN WITH
WATER VAPOR IMAGERY INDICATING RELATIVELY DRY AIR AND A
SUBSIDENT ENVIRONMENT IN PLACE THIS AFTERNOON. TWO FEATURES ARE
NOTED ACROSS THE CARIBBEAN...THE FIRST BEING A SHEAR LINE
ANALYZED FROM NORTHERN HISPANIOLA NEAR 20N71W EXTENDING W-SW TO
19N78W TO 18N85W. ISOLATED SHOWERS ARE MAINLY OCCURRING WITHIN
120 NM EITHER SIDE OF THE SHEAR LINE E OF 75W...WITH THE OTHER
IMPACT REMAINING STRONGER WINDS OCCURRING TO THE NORTH OF THE
LINE ACROSS THE SW NORTH ATLC AND AREAS BETWEEN CUBA AND THE
CAYMAN ISLANDS. THESE WINDS...NE TO E IN DIRECTION...RANGE
BETWEEN 20 AND 30 KT AS CAPTURED BY EARLY MORNING SCATTEROMETER
PASSES AT 27/1346 UTC AND 27/1442 UTC. THE REMAINING FEATURE IS
A GALE WARNING IN EFFECT FOR THE SW CARIBBEAN WATERS OFF THE
COAST OF COLOMBIA. THE STRONG PRESSURE GRADIENT CREATED BETWEEN
HIGH PRESSURE CENTERED ACROSS THE SW NORTH ATLC AND LOWER
PRESSURE ACROSS THE NORTHWESTERN SOUTH AMERICAN CONTINENT IS
EXPECTED TO RELAX SOMEWHAT BY SATURDAY AS THE HIGH PRESSURE
MOVES EASTWARD.

...HISPANIOLA...
CURRENTLY A SHEAR LINE IS ANALYZED FROM 20N69W TO 19N78W AND IS
PROVIDING FOCUS FOR ISOLATED SHOWERS ACROSS NORTHERN AND WESTERN
PORTIONS OF THE ISLAND...INCLUDING THE NORTHERN ADJACENT COASTAL
WATERS AS WELL. THIS BOUNDARY IS EXPECTED TO REMAIN DRAPED
ACROSS THE REGION THROUGH LATE FRIDAY...GRADUALLY BECOMING
DIFFUSE DURING THE WEEKEND. HIGHER PROBABILITY OF ISOLATED
SHOWER ACTIVITY IS ANTICIPATED FOR HISPANIOLA AS THE AREA OF
MAXIMUM LOW-LEVEL CONVERGENCE ALONG THE SHEAR LINE MOVES VERY
LITTLE DURING THE UPCOMING EVENING AND OVERNIGHT HOURS.

ATLANTIC OCEAN... MOSTLY ZONAL WESTERLY FLOW IS NOTED ON WATER
VAPOR IMAGERY OVER THE SW NORTH ATLC W OF 60W THIS AFTERNOON AS
HIGH PRESSURE AT THE SURFACE CONTINUES TO MOVE OFF THE MID-ATLC
COAST AND PROVIDE OVERALL NE TO E WINDS IN THE RANGE OF 15 TO 25
KT. HOWEVER...A WEAK MID-LEVEL SHORTWAVE TROUGH IS FOCUSED IN
THE VICINITY OF 31N80W AND WHILE LARGELY OVERSHADOWED BY THE
SURFACE RIDGING IN PLACE...IS PRODUCING SCATTERED SHOWERS ACROSS
THE CENTRAL FLORIDA PENINSULA INTO THE SW NORTH ATLC FROM 28N-
31N W OF 79W. FARTHER EAST...AN UPPER LEVEL TROUGH AXIS EXTENDS
ALONG 57W REMAINING N OF 28N THAT SUPPORTS A COLD FRONT ANALYZED
FROM 32N53W S-SW TO 24N60W BECOMING STATIONARY TO 20N69W THEN AS
A SHEAR LINE ACROSS HISPANIOLA AND INTO THE NW CARIBBEAN SEA.
ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 90 NM EITHER
SIDE OF THE FRONT N OF 26N AND WITHIN 90 NM NORTH OF THE FRONT W
OF 58N. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN
ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A
1037 MB HIGH CENTERED NORTH OF THE AZORES NEAR 45N32W.

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

$$
HUFFMAN


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