[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251805
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN DEC 25 2011

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
1745 UTC.

...ITCZ/MONSOON TROUGH...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N14W TO
07N20W TO 04N30W TO 04N40W TO 04N52W. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN
34W-40W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM N OF
THE AXIS BETWEEN 24W-26W.

A SURFACE TROUGH IS ANALYZED N OF THE WESTERN EXTENT OF THE ITCZ
AXIS FROM 18N41W TO 08N46W LARGELY A REFLECTION OF AN UPPER
LEVEL LOW CENTERED NEAR 20N45W. LOW-LEVEL CONVERGENCE EAST OF
THE SURFACE TROUGH AND STRONG UPPER LEVEL DIFFLUENCE EAST OF THE
UPPER LEVEL LOW IS GENERATING A LARGE AREA OF WIDELY SCATTERED
MODERATE CONVECTION NORTH OF THE ITCZ FROM 11N-18N BETWEEN
30W-40W.

...DISCUSSION...

GULF OF MEXICO...
A WARM FRONT STRADDLES THE NORTHERN PORTION OF THE GULF FROM
NEAR THE FLORIDA BIG BEND AREA TO 29N88W TO A WEAK 1020 MB
LOW AT 27.5N93W. A COLD FRONT THEN EXTENDS FROM THE LOW S TO
23N93W WHERE IT BECOMES STATIONARY S TO INLAND MEXICO AT
VERACRUZ. SATELLITE IMAGERY SHOWS EXTENSIVE OVERCAST LOW CLOUDINESS
WITH EMBEDDED AREAS OF LIGHT RAIN AND DRIZZLE TO W OF THE LOW AND
COLD/STATIONARY FRONTS FRONTS...WHILE PATCHES OF BROKEN TO
BROKEN TO SCATTERED LOW CLOUDS WITH SCATTERED SHOWERS AND A
FEW LIGHT PATCHES ARE ALONG AND N OF THE WARM FRONT BETWEEN 86W
AND 93W. WATER VAPOR IMAGERY SHOWS AN EXTENSIVE SWATH OF MID/UPPER
LEVEL MOISTURE STREAMING NORTHEASTWARD FROM THE EASTERN
PACIFIC TO OVER EASTERN TEXAS AHEAD OF AN UPPER LEVEL LOW
PRES SYSTEM OVER THE NW TEXAS PANHANDLE. THIS MOISTURE FEED THEN
TURNS MORE TO THE E AS IT GETS CAUGHT IN THE UPPER ZONAL FLOW
PATTERN ACROSS THE SE U.S. THE UPPER LOW WILL ADVANCE LITTLE TO THE
E THROUGH MON...THEN BEGIN TO ADVANCE E LATE MON AND TUE IN RESPONSE
TO A DEEP LAYER TROUGH THAT CATCHES UP WITH IT...ABSORBING IT
EARLY ON TUE. THIS TROUGH WILL DRIVE A COLD FRONT ACROSS
THE WESTERN AND CENTRAL SECTIONS OF THE GULF TUE. PRIOR TO THE
FRONT MOVING INTO THE AREA...EXPECT LOW LEVEL MOIST SOUTHERLY
FLOW TO ADVECT MOISTURE NWD OVER THE MIDDLE AND EASTERN GULF
SECTIONS RESULTING IN SCATTERED SHOWERS AND TSTMS TO TRACK NWD
TO ACROSS THE SE U.S. WITH POSSIBLE LOCALLY HEAVY RAIN.

IN THE MEANTIME...STRONG HIGH PRES SURGING SWD INTO THE WESTERN
GULF BEHIND THE LOW AND FRONTS IS RESULTING IN STRONG TO MODERATE
NW-N WINDS TO FUNNEL INTO THE GULF. A GALE WARNING REMAINS IN EFFECT
FOR THE SW GULF THROUGH THIS AFTERNOON. WINDS DIMINISH LATE THIS
AFTERNOON AND TONIGHT AS THE LOW PULLS TO N OF THE GULF OVER
LOUISIANA ALLOWING FOR THE PRES GRADIENT TO SLACKEN.
 EXPECT THE FRONTAL SYSTEMS TO BECOME STATIONARY OVER THE NEXT
24 HOURS WITH CONVECTION. ALSO EXPECT THE GALE TO WEAKEN TO 30
KT IN 18 HOURS.

CARIBBEAN SEA...
STRONG HIGH PRES JUST N OF THE AREA IS MAINTAINING A RATHER
TIGHT SURFACE PRESSURE GRADIENT OVER MUCH OF THE CARIBBEAN SEA.
SCATTERED TO BROKEN LOW CLOUDS WITH ISOLATED SHOWERS DUE TO
THE MOIST DEEP ELY FLOW ARE NOTED MOVING QUICKLY WESTWARD FROM
12N TO 17N TO INLAND HONDURAS AND NICARAGUA...AND ALSO N OF 19N W OF 80W.

A MONSOON TROUGH EXTENDS FROM N COLOMBIA TO COSTA RICA. ISOLATED
SHOWERS AND POSSIBLE WEAK TSTMS ARE S OF 12N W OF 79W. LITTLE
CHANGE IN THE PRESENT WEATHER CONDITIONS ARE EXPECTED OVER THE
NEXT 24 HOURS.

ATLANTIC OCEAN...
A COLD FRONT EXTENDS FROM 32N60W TO 29N70W...THEN BECOMES A
DISSIPATIONG STATIONARY FRONT TO INLAND NE FLORIDA. SCATTERED
SHOWERS ARE WITHIN 60 NM OF THE FRONT. A SURFACE TROUGH IS OVER
THE CENTRAL ATLANTIC FROM 32N46W TO 22N47W. ISOALTED SHOWERS ARE
WITHIN 30 NM OF THE TROUGH. AN UPPER LEVEL LOW IS CENTERED NEAR
21N42W PRODUCING ISOLATED MODERATE CONVECTION FROM 20N-28N
BETWEEN 35W-40W. A HIGH PRES RIDGE AXIS EXTENDS FROM 32N34W
TO 20N32W. EXPECT OVER THE NEXT 24 HOURS FOR THE FRONTAL SYSTEM
TO MOVE E WITH SHOWERS WHILE THE CENTRAL ATLANTIC TROUGH REMAINS
QUASI-STATIONARY.

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

$$
AGUIRRE







This weather bulletin was brought to you by:
www.nashvilleweather.net