[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181731
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE 18 JAN 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 4N0 5N10W 4N25W 5N35W EQ52W. WIDELY
SCATTERED MODERATE CONVECTION WITHIN 130 NM OF THE AXIS BETWEEN
19W-26W. SCATTERED MODERATE WITHIN 90 NM OF THE AXIS BETWEEN
30W-40W. NUMEROUS MODERATE EXTENDING WITHIN 100 NM OF THE
SURINAME/GUYANA BORDER S OF 8N.

...DISCUSSION...

GULF OF MEXICO...
A STRONG 1045 MB HIGH PRES CENTER CONTINUES TO SHIFT EWD OVER
THE OHIO VALLEY AND SFC WINDS OVER THE GULF WATERS HAVE
RESPONDED BY VEERING TO THE NE/E. TEMPERATURES HAVE MODERATED
NICELY OVER THE WARMER WATERS OF THE W GULF NOW THAT THE
STRONGEST COLD ADVECTION EXTENDS FROM THE CAROLINAS SWD TO
FLORIDA AND THE E GULF...SUPPORTING BROKEN STRATOCU BEYOND 200
NM SW OF THE FLORIDA COAST. THE E SLOPES OF THE SIERRA MADRE IN
MEXICO REMAIN SOCKED IN WITH LOW CLOUDS AND SHOWERS BUT TODAY
THIS ACTIVITY ALSO EXTENDS 200 NM E OF THE COAST ADJACENT TO A
LOW-LEVEL COASTAL TROF. THE UPPER LEVEL PATTERN IS DOMINATED BY
A BROAD RIDGE ALIGNED ALONG THE E COAST OF MEXICO WITH A
110-130W KT SUBTROPICAL JET RIDING FROM E TEXAS TO CNTRL
FLORIDA. UPPER LEVEL MOISTURE IS MOVING IN BEHIND THE JET ACROSS
N MEXICO AND THE TX/LA COAST TO THE E OF AN UPPER TROF OVER THE
BAJA PENINSULA.

CARIBBEAN...
A COLD FRONT IS SLOWLY MAKING ITS WAY ACROSS THE CARIBBEAN BASIN
AND EXTENDS FROM THE DOMINICAN REPUBLIC SW TO 12N78W THEN AS A
STATIONARY FRONT ALONG THE MTN RIDGES OF W PANAMA AND COSTA
RICA. STRONG HIGH PRES CONTINUES TO BUILD IN BEHIND THE
FRONT...EFFECTIVELY BEING BLOCKED BY CNTRL AMERICA AND SLIDING
TO THE S. BROKEN STRATUS/STRATOCU WITH EMBEDDED SHOWERS EXTEND
OVER THE ENTIRE W CARIBBEAN BEHIND THE FRONT AND BANKING UP
AGAINST THE CNTRL AMERICAN MTNS. E OF THE FRONT...SKIES ARE MUCH
CLEARER BUT A FEW SHOWERS ARE AFFECTING THE WINDWARD/LEEWARD
ISLANDS ALONG A SFC TROF WHICH EXTENDS ALONG 21N63W 9N59W. THIS
FEATURE IS WELL-OBSERVED IN SFC OBSERVATIONS AND SATELLITE
IMAGERY...MOVING W/NW TOWARDS THE APPROACHING COLD FRONT. THE
UPPER LEVELS CONTINUE TO BE OVERWHELMINGLY DRY DUE TO CONFLUENT
FLOW EXTENDING FROM THE CAYMAN ISLANDS TO THE NORTHERN LEEWARD
ISLANDS.

WEST ATLANTIC...
THE CARIBBEAN COLD FRONT ORIGINATES FROM OVER THE W ATLC
WATERS...EXTENDING ALONG 32N58W 25N66W TO THE DOMINICAN
REPUBLIC. SCATTERED MODERATE CONVECTION EXTENDS SE OF THE FRONT
N OF 24N BETWEEN 56W-62W...SOMEWHAT ENHANCED BY CONVERGENCE AT
THE NRN END OF THE SFC TROF NEAR THE LESSER ANTILLES. A
BROKEN/OVERCAST BAND OF LOW CLOUDS AND EMBEDDED SHOWERS EXTENDS
UP TO 120 NM W OF THE FRONT...THEN TRANSITIONS TO BROKEN
STRATOCU BACK TO THE U.S. COAST. THE FRONT IS BEING SUPPORTED BY
A FLAT UPPER TROF WHICH IS MOVING OFF THE NEW ENGLAND/MID-ATLC
COAST...AND ALL THE DEEP CONVECTION IS ORIENTED WITHIN A ZONE OF
DIFFLUENCE E OF A SHORTWAVE ALONG 61W.

CENTRAL AND EAST ATLANTIC...
THE UPPER LEVEL PATTERN OVER THE SUBTROPICAL E ATLC IS DOMINATED
BY A LARGE AND ELONGATED CYCLONIC CIRCULATION CENTERED NEAR
27N28W AND ALIGNED ALONG AN AXIS FROM MADEIRA ISLAND SW TO
24N43W. THE SFC LOW IS CENTERED ABOUT 520 NM WSW OF THE CANARY
ISLANDS NEAR 26N27W WITH A TROF ALONG 26N26W 21N32W. SCATTERED
MODERATE CONVECTION IS LOCATED N OF THE LOW FROM 26N-31N BETWEEN
23W-35W. FARTHER S...AN ACTIVE SUBTROPICAL JET EXTENDS ACROSS
THE TROPICAL ATLC FROM 16N50W TO THE CAPE VERDE ISLANDS AND NE
TO MOROCCO WITH CORE SPEEDS NEAR 110 KT AT 250 MB. THE JET IS
ADVECTING A LARGE SWATH OF MOISTURE FROM THE ITCZ NEWD TO W
AFRICA...AND IS EXPANDING N/NW AS A STRONG RIDGE BUILDS ALONG
7W. MOISTURE WILL CONTINUE FEEDING UP TO THE NE THROUGH THE REST
OF THE WEEK UNTIL THE DEEP-LAYERED LOW DISSOLVES AND THE RIDGE
BREAKS DOWN.

$$
BERG



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