[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 272353
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT DEC 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH CROSSES THE AFRICAN COAST NEAR 07N12W AND
CONTINUES TO 07N22W WHERE THE ITCZ BEGINS AND CONTINUES ALONG
06N38W TO THE COAST OF FRENCH GUIANA NEAR 04N51W. A DIFFLUENT
ENVIRONMENT AT THE MIDDLE-LEVELS ENHANCES SCATTERED MODERATE
CONVECTION FROM 03N-10N BETWEEN 27W AND 48W.

...DISCUSSION...

GULF OF MEXICO...

A SURFACE RIDGE OVER THE WESTERN ATLC ANCHORED BY A 1026 MB HIGH
NEAR 34N72W CONTINUES TO PROVIDE E-SE FLOW OF 10-15 KT...WHICH
IS ADVECTING MOISTURE ACROSS THE NORTHERN BASIN. A STATIONARY
FRONT EXTENDS FROM THE SW N ATLC ACROSS NORTHERN FLORIDA TO
SOUTHERN ALABAMA WHERE IT TRANSITIONS TO A WARM FRONT ACROSS
SOUTHERN MISSISSIPPI. RADAR IMAGERY AND LIGHTING DATA INDICATE
SCATTERED SHOWERS AND TSTMS ARE N OF 28N BETWEEN 87W-90W.
FARTHER WEST...A COLD FRONT STARTS TO EMERGE FROM THE COAST OF
TEXAS EXTENDING FROM A 1013 MB LOW NEAR 31N94W. LOW-LEVEL
MOISTURE CONVERGENCE ENHANCES ISOLATED SHOWERS OVER THE NW GULF N
OF 25N W OF 91W. MIDDLE- TO UPPER-LEVEL RIDGING ALONG WITH DEEP
LAYER DRY AIR SUPPORT FAIR WEATHER ELSEWHERE. THE COLD FRONT
WILL CONTINUE TO DRIFT EASTWARD AND START MOVING ACROSS FLORIDA
TUE MORNING. NO MAJOR CONVECTION IS ANTICIPATED.

CARIBBEAN SEA...

A VERY STABLE ENVIRONMENT ALOFT CONSISTING OF RIDGING AND DRY
AIR SUBSIDENCE CONTINUES TO SUSTAIN CLEAR SKIES AND FAIR WEATHER
ACROSS THE BASIN. IN TERMS OF WIND...A SURFACE RIDGE ANCHORED
OVER THE W ATLC EXTENDS INTO THE NORTHERN CARIBBEAN AND TIGHTENS
THE PRESSURE GRADIENT OVER THE CENTRAL BASIN TO SUPPORT TRADES
OF 20-25 KT BETWEEN 65W-82W. TRADES OF 15 KT DOMINATE ELSEWHERE.
HIGH PRESSURE WILL CONTINUE TO DOMINATE OVER THE NORTHERN
CARIBBEAN THROUGH TUE MORNING...THUS SUPPORTING THE CONTINUATION
OF 20 KT WINDS FORECAST TO EXTEND TO THE EASTERN BASIN AS THE
HIGH PRESSURE CENTER DRIFT E-SE OVER THE ATLC WATERS.

HISPANIOLA...

CURRENTLY...MIDDLE- TO UPPER-LEVEL RIDGING AND DRY AIR
SUBSIDENCE FROM ALOFT SUPPORT FAIR WEATHER ACROSS THE ISLAND.
HOWEVER...A COLD FRONT OVER THE SW N ATLC WATERS IS STARTING TO
PUSH A SHALLOW MOIST AIRMASS ACROSS THE NORTHERN ISLAND WHICH
MAY ENHANCE ISOLATED SHOWERS LATER TONIGHT. AS THE COLD FRONT
CONTINUES TO SINK IN THE ATLC WATERS...MOISTURE WILL
INCREASE...THUS INCREASING THE CHANCES FOR SCATTERED SHOWERS
STARTING SUNDAY MORNING.

ATLANTIC OCEAN...

A BROAD AND ELONGATED TROUGH ALOFT OVER THE CENTRAL ATLC
CONTINUES TO SUPPORT A COLD FRONT EXTENDING FROM A 1005 MB LOW
NEAR 30N45W AND CONTINUING SW ALONG 22N51W 21N63W TO 27N77W
WHERE IT TRANSITIONS TO A STATIONARY FRONT ACROSS NORTHERN
FLORIDA. SCATTERED MODERATE CONVECTION AND TSTMS ARE AHEAD OF
THE FRONT N OF 25N BETWEEN 30W-43W. SURFACE RIDGING DOMINATES
ELSEWHERE W AND E OF THE FRONT. THE SURFACE HIGH CENTER OVER
MID-ATLC WATERS WILL DRIFT E-SE OVER THE NEXT TWO DAYS ALLOWING
FOR A NEW COLD FRONT TO ENTER THE SW N ATLC ON TUE MORNING.

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

$$
NR


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