[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221744
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT MAR 22 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.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 05N09W TO
03N13W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
03N13W TO 02N23W TO THE EQUATOR NEAR 30W. ISOLATED MODERATE
CONVECTION IS FROM 01N-04N BETWEEN 04W-16W...AND FROM 01N-03N
BETWEEN 25W-32W. SCATTERED MODERATE CONVECTION IS S OF 04N
BETWEEN 40W-50W.

...DISCUSSION...

GULF OF MEXICO...
WESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY OVER MUCH OF
THE GULF BASIN THIS AFTERNOON AS BROAD MIDDLE TO UPPER LEVEL
RIDGING REMAINS ANCHORED OVER SOUTHERN MEXICO AND CENTRAL
AMERICA NEAR 17N91W. WHILE ZONAL...GLOBAL MODEL GUIDANCE
INDICATES A NARROW EAST-WEST RIBBON OF MID-LEVEL VORTICITY
STRETCHING FROM WEST TEXAS TO THE MISSISSIPPI RIVER DELTA. THIS
AREA OF VORTICITY...AS OF 22/2100 UTC...SUPPORTS A SURFACE
TROUGH OR MOISTURE CONVERGENCE BOUNDARY EXTENDING FROM 27N87W TO
THE TEXAS COAST NEAR GALVESTON BAY. WIDELY SCATTERED SHOWERS AND
ISOLATED TSTMS ARE OCCURRING FROM 26N-30N BETWEEN 86W-94W...
MOSTLY WITHIN 75 NM NORTH OF THE SURFACE TROUGH AXIS. THE
REMAINDER OF THE GULF GENERALLY S OF 28N IS UNDER THE INFLUENCE
OF SOUTHERLY RETURN FLOW ON THE WESTERN PERIPHERY OF WEAK
RIDGING ANCHORED ALONG THE WESTERN COAST OF THE FLORIDA
PENINSULA. THE SURFACE TROUGH IS EXPECTED TO GRADUALLY BECOME
DIFFUSE BY EARLY SUNDAY AS THE NEXT FRONTAL BOUNDARY APPROACHES
THE TEXAS AND LOUISIANA COAST...AND IS FORECAST TO EMERGE OFF
THE COAST SUNDAY AFTERNOON INTO THE EVENING HOURS. WINDS BEHIND
THE FRONT WILL SHIFT NORTHEASTERLY AND REMAIN IN THE RANGE OF 15
TO 20 KT DUE TO THE OVERALL LACK OF MIDDLE TO UPPER LEVEL
FORCING DYNAMICS. A STRONGER SECONDARY COLD FRONT IS EXPECTED
EARLY TUESDAY.

CARIBBEAN SEA...
WEST TO NORTHWEST UPPER LEVEL WINDS PREVAIL OVER MUCH OF THE
CARIBBEAN BASIN THIS AFTERNOON WITH WATER VAPOR IMAGERY
INDICATING VERY DRY AND STABLE AIR OVER THE REGION. THE OVERALL
STABILITY AND LACK OF ANY SIGNIFICANT MOISTURE IS RESULTING IN
MOSTLY CLEAR SKIES AND FAIR CONDITIONS. HOWEVER...A SMALL
PORTION OF THE NORTH-CENTRAL CARIBBEAN...INCLUDING NW
HISPANIOLA...THE WINDWARD PASSAGE...AND JAMAICA IS UNDER THE
INFLUENCE OF A REMNANT FRONTAL BOUNDARY NOW ANALYZED AS A
SURFACE TROUGH EXTENDING FROM THE CENTRAL ATLC TO 21N70W TO
20N73W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM EITHER SIDE
OF A LINE FROM 21N72W TO 18N78W. THE BOUNDARY IS EXPECTED TO
BECOME DIFFUSE DURING THE NEXT 24 HOURS. FINALLY...THE OTHER
SIGNIFICANT IMPACT IS STRONG TRADE WINDS OCCURRING ACROSS THE
SOUTH-CENTRAL CARIBBEAN S OF 15N BETWEEN 67W-78W. THESE TRADES
RANGE FROM 20 TO 25 KT AND ARE EXPECTED TO PERSIST THROUGH
TUESDAY.

...HISPANIOLA...
A SURFACE TROUGH EXTENDS FROM THE CENTRAL ATLC TO THE NORTHWEST
TIP OF THE ISLAND NEAR 20N73W. ISOLATED SHOWERS ARE OCCURRING N
OF 19N W OF 72W INCLUDING THE ADJACENT COASTAL WATERS TO THE
NORTHWEST AND PORTIONS OF THE WINDWARD PASSAGE. OTHERWISE...
NORTHWESTERLY WINDS ALOFT PREVAIL AND WILL MAINTAIN A FAIRLY DRY
AND STABLE ENVIRONMENT ALOFT OVER THE NEXT FEW DAYS. WITH THE
BOUNDARY IN PLACE AND TRENDING TOWARD BECOMING DIFFUSE...HIGHER
PROBABILITIES OF PRECIPITATION ARE FORECAST THROUGH THE
AFTERNOON AND EVENING HOURS...WITH THE THREAT OF PRECIPITATION
GRADUALLY BECOMING LESS THROUGH THE OVERNIGHT HOURS INTO SUNDAY.

ATLANTIC OCEAN...
WEST-NORTHWESTERLY FLOW ALOFT IS NOTED OVER THE SW NORTH ATLC
WITH WATER VAPOR IMAGERY INDICATING A FAIR AMOUNT OF PROGRESSIVE
MIDDLE TO UPPER LEVEL CLOUDINESS AND MOISTURE CONTINUING TO MOVE
EAST N OF 28N. MOST OF THIS MOISTURE IS ABOVE A FAIRLY BROAD
SURFACE RIDGE ANCHORED BY A 1024 MB HIGH CENTERED W-NW OF
BERMUDA NEAR 33N67W. WITH RETURN FLOW ON THE WESTERN PERIPHERY
OF THE RIDGING...LOW-LEVEL MOISTURE CONVERGENCE AND AID FROM
MARGINAL MID-LEVEL DYNAMICS ARE GENERATING WIDELY SCATTERED
SHOWERS AND ISOLATED TSTMS N OF 29N BETWEEN 67W-78W...AND N OF
25N W OF 78W. FARTHER EAST...A MIDDLE TO UPPER LEVEL TROUGH AXIS
EXTENDS SOUTHWARD ALONG 55W TO A BASE NEAR 23N. THIS TROUGHING
SUPPORTS A COLD FRONT ANALYZED FROM 32N55W TO 29N61W AND A PRE-
FRONTAL SURFACE TROUGH FROM 31N53W SW TO 26N57W TO 24N66W TO
20N72W. ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE
OF BOTH THE COLD FRONT AND SURFACE TROUGH BOUNDARIES.
FINALLY...THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE
RIDGE ANCHORED BY A 1030 MB HIGH CENTERED S OF THE AZORES NEAR
32N29W.

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

$$
HUFFMAN


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