[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211734
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON 21 FEB 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN 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...

ITCZ AXIS IS CENTERED ALONG 6N0 2N10W 2N30W 3S40W. SCATTERED
MODERATE CONVECTION OVER GHANA FROM 4.5N-10N BETWEEN 0-4W. A
TROPICAL SQUALL LINE HAS CROSSED THE PRIME MERIDIAN WITH
SCATTERED MODERATE S OF 3N E OF 5W. ISOLATED MODERATE WITHIN 30
NM OF THE AXIS BETWEEN 14W-18W. A CONVERGENCE LINE IS LOCATED N
OF THE EQUATOR ALONG 4N35W 2N49W WITH WIDELY SCATTERED
SHOWERS/TSTMS WITHIN 45 NM OF THE AXIS.

...DISCUSSION...

GULF OF MEXICO...
STRONG SFC HIGH IS SLIDING SE OVER THE W ATLC WATERS NEAR
BERMUDA AND THE ASSOCIATED SFC RIDGE IS BUILDING WWD OVER FL AND
THE GULF...EXTENDING FROM ABOUT WEST PALM/FT. LAUDERDALE NWWD TO
HOUSTON TX. UPPER FLOW REMAINS SLIGHTLY SPLIT NEAR FL BUT WITH
THE DEEP LONGWAVE TROF OFF THE U.S. WEST COAST SLOWLY
PROGRESSING TO THE E...THE FLOW IS ATTAINING A GRADUAL SWLY
COMPONENT WITH AN INCREASE IN TROPICAL MOISTURE. HENCE...A
STREAM OF HIGH CIRRUS EXTENDS FROM CNTRL MEXICO TO THE FL
PANHANDLE. MOIST LOW-LEVEL AIR MOVING INLAND OVER SE TX
CONTINUES TO SUBSTANTIATE A LINGERING DECK OF EARLY MORNING LOW
CLOUDS THAT EXTEND SW ALONG THE COAST INTO NE MEXICO BUT THERE
IS NO PRECIPITATION NOTED ON RADAR IMAGERY. THERE IS A WEAK
CONVERGENCE LINE LOCATED NEAR THE BIG BEND OF FL WHICH IS
PRODUCING SCATTERED SHOWERS FROM 27N-30N BETWEEN 83W-86W MOVING
E TOWARDS SHORE. THE SFC RIDGE WILL PERSIST OVER THE GULF AT
LEAST THRU WED WITH A COLD FRONT PROGGED TO MOVE OFF THE TX
COAST WED NIGHT. SCATTERED SHOWERS/TSTMS WILL DEVELOP ALONG THE
COAST AS EARLY AS TUE NIGHT AND MOVE OUT OVER THE GULF WATERS
BUT THE FRONT ITSELF MAY HANG UP OVER THE CNTRL GULF ON THU AS
IT LOSES ITS INITIAL PUSH. THE GFS HAS BEEN SUGGESTING THE
DEVELOPMENT OF A LOW ALONG THE STALLED BOUNDARY LATER IN THE
WEEK AND COULD INCREASE THE CHANCES FOR RAIN OVER FL BY THE
WEEKEND.

CARIBBEAN...
AS STRONG HIGH PRES OVER THE W ATLC MOVES SLOWLY SE...THE PRES
GRADIENT OVER THE CARIBBEAN IS BEGINNING TO RELAX A BIT ALTHOUGH
GALE CONDITIONS STILL EXIST JUST OFFSHORE THE COLOMBIAN COAST.
THE TAIL END OF A DISSIPATING ATLC COLD FRONT IS SAGGING SWD
OVER THE E CARIBBEAN AND LIES GENERALLY BETWEEN DOMINICA AND
MARTINIQUE EXTENDING SW TO 14N68W. A BAND OF SCATTERED SHOWERS
EXTENDS UP TO 120 NM N OF THE FRONT AND WILL MOVE TOWARDS THE
ABC ISLANDS OVER THE NEXT 24 HRS...POSSIBLY PERSISTING THRU THE
WEEK AS IT GETS PICKED UP BY THE ELY TRADES. FOR NOW...A TROF IN
THE UPPER LEVELS EXTENDS FROM THE GULF OF HONDURAS SWD PAST
COSTA RICA AND IS PRODUCING MOSTLY DRY SWLY FLOW OVER THE
AREA...LIMITING ACTIVITY TO ONLY SPORADIC SHOWERS.

ATLANTIC...
1030 MB HIGH PRES WHICH WAS REFERENCED IN THE PREVIOUS SECTIONS
IS CENTERED JUST S OF BERMUDA NEAR 31N67W AND IS DRIFTING EVER
SO SLOWLY TO THE SE WITH BROKEN STRATOCUMULUS EXTENDING N OF 20N
E OF 68W IN WEAKENING COLD ADVECTION. UPPER LEVEL SPLIT FLOW
OVER FL IS RE-CONVERGING OVER THE W ATLC WATERS BUT WEAK RIDGING
IS KEEPING ALL MOISTURE N OF THE AREA. THE FLOW ACROSS THE REST
OF THE ATLC IS LARGELY ZONAL WITH THE EXCEPTION OF A NARROW
UPPER TROF N OF 28N BETWEEN 35W-50W. A SHORTWAVE IS ROUNDING THE
BASE OF THE TROF ALONG 27N32W 32N35W AND IS PRODUCING SCATTERED
MODERATE CONVECTION N OF 29N BETWEEN 30W-35W. AT THE SFC...A
DISSIPATING COLD FRONT LIES AT THE LEADING EDGE OF BUILDING HIGH
PRES ALONG 32N36W 28N37W 17N50W 16N60W WITH WIDELY SCATTERED
SHOWERS UP TO 90 NM BEHIND THE BOUNDARY. A PRE-FRONTAL TROF LIES
ALONG 20N38W 26N33W 32N34W WHERE SWLY FLOW MEETS THE E ATLC
RIDGE...AND FOCUSED LOW-LEVEL CONVERGENCE IS HELPING TO ENHANCE
THE CONVECTION AHEAD OF THE MID/UPPER LEVEL SHORTWAVE. THESE
SHOWERS/TSTMS WILL CONTINUE MOVING TO THE E...APPROACHING THE
CANARY ISLANDS WITHIN THE NEXT 48 HRS.

$$
BERG


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