[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181129
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST TUE FEB 18 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC
NEAR 8N13W AND CONTINUES TO 4N15W TO 1N20W. THE ITCZ BEGINS NEAR
1N20W AND CONTINUES TO THE EQUATOR ALONG 33W AND 50W. A CLUSTER
OF MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-7N EAST OF
14W. SCATTERED MODERATE CONVECTION AND TSTMS ARE FROM 1N-5N
BETWEEN 4W-9W. SCATTERED MODERATE IS ALSO FROM 3S-3N BETWEEN 23W-
35W AND FROM 2S-3N BETWEEN 42W-51W.

...DISCUSSION...

GULF OF MEXICO...
ZONAL WESTERLY FLOW CONTINUES TO DOMINATE THE GULF ALOFT. A
SURFACE RIDGE EXTENDS FROM THE W ATLC SW TO FLORIDA AND ACROSS
THE GULF WITH A 1025 MB HIGH NEAR 37N69W. SATELLITE WATER VAPOR
IMAGERY SHOW RELATIVELY DRY AND STABLE AIR ACROSS THE BASIN WITH
SOME UPPER LEVEL MOISTURE MOVING ACROSS THE FAR N GULF. RETURN
FLOW ALONG THE N-NW GULF COAST AND ADJACENT WATERS IS GENERATING
ADVECTION FOG N OF 27N WEST OF 89W AND IS KEEPING A FRONTAL
SYSTEM STATIONARY OVER TEXAS AND LOUISIANA. SURFACE RIDGING AND
RETURN FLOW WILL PREVAIL THROUGH THU AFTERNOON. A COLD FRONT IS
EXPECTED TO REACH THE TEXAS COAST THU NIGHT.

CARIBBEAN SEA...
ZONAL WESTERLY FLOW ALOFT CONTINUES TO DOMINATE OVER THE
CARIBBEAN SEA THIS MORNING. SATELLITE WATER VAPOR IMAGERY SHOW
DRY AND STABLE AIR IN THE MIDDLE TO UPPER LEVELS ACROSS THE
ENTIRE BASIN. A MIDDLE TO UPPER LEVEL TROUGH OVER THE WESTERN
ATLC BETWEEN 40W-70W AND WITH BASE OVER NORTHERN HISPANIOLA
SUPPORTS A FRONTAL BOUNDARY THAT TRANSITIONS INTO A SHEAR LINE
NEAR 21N70W TO NW HAITI TO THE WINDWARD PASSAGE NEAR 18N74W.
LINGERING LOW LEVEL MOISTURE ASSOCIATED WITH THE FRONTAL SYSTEM
IS WITHIN A LINE EXTENDING FROM SOUTHERN HISPANIOLA NEAR 17N71W
SW TO PANAMA NEAR 9N82W AND A LINE FROM EASTERN CUBA NEAR 20N78W
TO NW HONDURAS NEAR 15N89W. THIS MOISTURE ALONG WITH
NORTHEASTERLY SURFACE FLOW IS ENHANCING ISOLATED SHOWERS OVER NW
HONDURAS AS WELL AS SOUTHERN HAITI AND ADJACENT WATERS. EASTERLY
TRADE WINDS OF 15 KT CONTINUE DOMINATING ACROSS MUCH OF THE
BASIN EXCEPT WITHIN 200 NM OF THE NORTHERN COLOMBIA COAST WHERE
WINDS ARE UP TO 30 KT...THE CENTRAL BASIN WITH 20 KT AND THE
WINDWARD PASSAGE WITH 20-25 KT. OTHERWISE...A WESTWARD MOVING
MOIST AIRMASS ASSOCIATED WITH A SURFACE PRE-FRONTAL TROUGH NE OF
PUERTO RICO MAY BRING SHOWERS TO THE EASTERN REGION OF THE
ISLAND...THE VIRGIN ISLANDS AND THE LESSER ANTILLES. A
RELATIVELY TIGHT PRESSURE GRADIENT IS EXPECTED TO CONTINUE
THROUGH THU MORNING WHICH WILL ALLOW FOR TRADES OF 20 KT TO
PREVAIL OVER THE CENTRAL BASIN AND EXTEND FURTHER EAST TO THE
LESSER ANTILLES.

HISPANIOLA...
CURRENTLY A SHEAR LINE ACROSS THE WINDWARD PASSAGE IS PUSHING
LOW LEVEL MOISTURE AGAINST THE COAST OF HAITI TO GENERATE
SHOWERS NOW CONCENTRATED OVER SW HISPANIOLA AND ADJACENT WATERS.
WESTERLY FLOW ALOFT AS WELL AS THE PRESENCE OF DRY AIR AT THE
LOWER LEVELS IS FORECAST TO REMAIN THROUGH THU THUS INHIBITING
THE DEVELOPMENT OF DEEP CONVECTION.

ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL TROUGH COVERS PART OF THE W ATLC N OF
20N BETWEEN 40W-70W AND SUPPORTS A COLD FRONT THAT ENTERS THE
AREA OF DISCUSSION NEAR 30N51W AND CONTINUES TO 27N55W WHERE IT
TRANSITIONS TO A STATIONARY FRONT ALONG 24N63W TO 21N69W.
THEN...A SHEAR LINE CONTINUES TO NW HAITI NEAR 19N73W TO 18N74W.
ISOLATED SHOWERS ARE WITHIN 120 NM WEST OF THE FRONTAL BOUNDARY.
THE TROUGH ALOFT ALSO SUPPORTS A SURFACE TROUGH FROM 25N58W TO
20N66W WITH ISOLATED SHOWERS WITHIN 60 NM EITHER SIDE OF THE
AXIS. A SURFACE RIDGE IS BUILDING S OVER THE W ATLC W OF THE
FRONT ANCHORED BY A 1025 MB HIGH OVER THE MID ATLANTIC STATES
COASTAL WATERS. THIS RIDGE EXTENDS SW ACROSS FLORIDA INTO THE
GULF OF MEXICO. A SECOND SURFACE RIDGE DOMINATES THE REMAINDER
OF THE ATLC E OF THE FRONT ANCHORED BY A 1028 MB HIGH NEAR
33N31W. THE REMAINDER PORTION OF THE STATIONARY FRONT IS
FORECAST TO TRANSITION TO A SHEAR LINE BY TONIGHT WHILE THE COLD
PORTION PUSHES ACROSS THE CENTRAL ATLC DISSIPATING BY EARLY WED.

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

$$
NR


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