[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171141
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI JAN 17 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
1115 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM THE WEST AFRICAN COAST NEAR
07N11W TO 04N16W TO 02N22W. THE INTERTROPICAL CONVERGENCE ZONE
AXIS EXTENDS FROM 02N22W TO 01N34W TO THE COAST OF BRAZIL NEAR
0N49W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM
0N-07N EAST OF 24W. ISOLATED SHOWERS ARE WITHIN 100 NM N OF THE
ITCZ BETWEEN 36W-39W.

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES MOSTLY DRY WESTERLY FLOW ALOFT
OVER THE GULF THIS MORNING. AT THE SURFACE...COLD DRY AIR
PREVAILS OVER THE GULF AFTER THE RECENT PASSAGE OF TWO COLD
FRONTS AND FLOWS AROUND A SURFACE RIDGE ANCHORED BY A 1022 MB
HIGH CENTERED NEAR 26N89W. HIGH PRESSURE AT THE SURFACE ALONG
WITH DRY AIR AT THE LOWER AND UPPER LEVELS CONTINUE TO SUPPORT
MOSTLY CLEAR SKIES AND FAIR WEATHER ACROSS THE GULF. A BROAD
MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE CENTRAL U.S. TO
THE WESTERN N ATLC AND SUPPORTS A COLD FRONT THAT ENTERS THE NW
BASIN THIS MORNING CREATING A WEAKNESS IN THE SURFACE RIDGE. AS
OF 0900 UTC THE COLD FRONT EXTENDS FROM THE LOUISIANA COASTLINE
NEAR 29N91W SW TO 27N95W TO SOUTHERN TEXAS NEAR 26N97W. IN TERMS
OF WINDS...ANTICYCLONIC FLOW IN THE RANGE OF 10-15 KT SPREADS
OVER THE BASIN WITH LIGHTER WINDS CIRCLING AROUND THE HIGH
PRESSURE CENTER. BY TONIGHT...THE COLD FRONT IS EXPECTED TO
EXTEND FROM JACKSONVILLE FLORIDA SW TO THE NE BASIN WHERE IT IS
FORECAST TO TRANSITION TO A STATIONARY FRONT TO CENTRAL-EASTERN
MEXICO. THE HIGH PRESSURE CENTER HAS BEEN DISSIPATED BY THEN.
SURFACE RIDGING WILL BUILD BEHIND THIS FRONT WHICH IS FORECAST
TO PREVAIL THROUGHOUT SUNDAY NIGHT.

CARIBBEAN SEA...
BY 0900 UTC THE REINFORCING COLD FRONT HAS MERGED WITH A
PRECEDING STATIONARY FRONT. A BROAD MIDDLE TO UPPER LEVEL TROUGH
EXTENDING FROM THE CENTRAL U.S. TO THE WESTERN N ATLC CONTINUES
TO SUPPORT THE FRONTAL SYSTEM WHICH EXTENDS AS A STATIONARY
FRONT FROM EASTERN CUBA NEAR 20N75W TO WESTERN JAMAICA NEAR
18N78W TO 14N81W TO NORTHERN PANAMA NEAR 09N82W. LOW-LEVEL
MOISTURE CONVERGENCE IN THE VICINITY OF THE BOUNDARY IS
ENHANCING ISOLATED SHOWERS WITHIN 150 NM EITHER SIDE OF THE
FRONT. WATER VAPOR IMAGERY INDICATE THAT AN UPPER LEVEL RIDGE
DOMINATE THE CENTRAL AND EASTERN BASIN WITH RELATIVELY DRY AND
STABLE AIR WHICH CONTINUE TO SUPPORT FAIR WEATHER THIS MORNING.
IN TERMS OF WIND...NORTHEASTERLY FLOW IN THE RANGE OF 15-20 KT
SPREADS WEST OF THE FRONTAL BOUNDARY. EXCEPT WITHIN 120 NM FROM
THE COAST OF COLOMBIA WHERE TRADEWINDS OF 25 KT
ABOUNDS...LIGHTER TRADES UP TO 15 KT DOMINATE ELSEWHERE. THE
FRONT IS EXPECTED TO STALL THROUGHOUT TONIGHT WHEN IT IS
FORECAST TO START DISSIPATING.

...HISPANIOLA...
WATER VAPOR IMAGERY CONTINUE TO INDICATE DRY AIR AND OVERALL
STRONG SUBSIDENCE OVER THE ISLAND...HOWEVER...THE PROXIMITY OF A
STATIONARY FRONT OVER EASTERN CUBA CONTINUE TO SUPPORT
CLOUDINESS AND POSSIBLE ISOLATED SHOWERS ACROSS THE WINDWARD
PASSAGE. EXCEPT FOR AFTERNOON SHOWERS ENHANCED BY DAYTIME
HEATING...FAIR WEATHER IS EXPECTED ACROSS THE ISLAND THROUGHOUT
SATURDAY AFTERNOON.

ATLANTIC OCEAN...
THE FORMER REINFORCING COLD FRONT HAS MERGED WITH THE PRECEDING
STATIONARY FRONT AT 0900 UTC. THE NEWLY FORMED FRONT EXTENDS AS
A COLD FRONT FROM 30N68W TO 24N71W WHERE IT TRANSITIONS TO A
STATIONARY FRONT TO THE SOUTHERN BAHAMAS NEAR 22N73W TO EASTERN
CUBA NEAR 20N74W AND THEN INTO THE SW CARIBBEAN. THIS NEW
FRONTAL BOUNDARY CONTINUE TO BE SUPPORTED BY A BROAD MIDDLE TO
UPPER LEVEL TROUGH EXTENDING FROM THE CENTRAL U.S. TO THE
WESTERN N ATLC. ISOLATED SHOWERS ARE POSSIBLE WITHIN 200 NM WEST
OF THE FRONT WHILE SCATTERED SHOWERS ARE N OF 28N BETWEEN 64W-
67W. FARTHER EAST AND WITHIN A WEAKNESS OF THE SURFACE RIDGE
THAT COVERS THE REMAINDER ATLC...A REMNANT AREA OF LOW PRESSURE
IS ANALYZED AS A SURFACE TROUGH FROM 30N52W TO 23N54W. ISOLATED
SHOWERS AND TSTMS ASSOCIATED WITH IT ARE N OF 26N BETWEEN 50W-
54W. OTHERWISE...AN UPPER LEVEL LOW NEAR 25N50W SUPPORTS
SCATTERED MODERATE CONVECTION FROM 08N-26N BETWEEN 38W-50W.

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

$$
NR


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