[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161722
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN 16 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
1645 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 5N0 3N30W 10N65W 6N80W. SCATTERED
MODERATE FROM 3N-5N BETWEEN 20W-40W AND FROM 9N-12N BETWEEN
50W-57W.

...DISCUSSION...

GULF OF MEXICO AND W ATLC...
STRONG MIDDLE TO UPPER UPPER LEVEL TROF SPANS A GOOD PORTION OF
THE E UNITED STATES NOW MOVING INTO THE EXTREME W ATLC. WATER
VAPOR IMAGERY SHOWS A VIGOROUS SHORTWAVE DISTURBANCE ROUNDING
THE BASE OVER THE S UNITED STATES AND N GLFMEX. THE SHORTWAVE IS
PRODUCING AN AMPLIFICATION OF THE OVERALL PATTERN AND GENERATING
STRONG MIDDLE TO UPPER LEVEL DYNAMICS/LIFT TO THE NE OVER THE W
ATLC WATERS. AS A RESULT...CYCLOGENESIS IS NOW OCCURRING ALONG
THE ATTENDANT FRONTAL BOUNDARY APPROXIMATELY HALFWAY IN BETWEEN
THE SE UNITED STATES COAST AND BERMUDA. THE FORMING LOW IS
SWEEPING THE PREVIOUSLY STATIONARY FRONT EWD AWAY FROM FLORIDA
THROUGH THE BAHAMAS TO CENTRAL CUBA. WIDESPREAD CLOUDINESS AND
SCATTERED TO NUMEROUS CONVECTION HAS FORMED NE OF THE DEVELOPING
SURFACE LOW OR BETWEEN 70W-80W N OF 30N.  WIDELY SCATTERED
SHOWERS AND A FEW ISOLATED THUNDERSTORMS ARE NOTED WITHIN 120 NM
E OF THE TRAILING COLD FRONT S OF 30N. BEHIND THE FRONT...STRONG
HIGH PRESSURE IS BUILDING SWD OVER THE GLFMEX FROM THE CENTRAL
UNITED STATES REINFORCING THE POST-FRONTAL NORTHERLIES AND
ASSOCIATED COLD AIR ADVECTION.  WHILE BROKEN COLD AIR
STRATOCUMULUS CLOUDS REMAIN...SIGNIFICANT DRYING IN THE MIDDLE
TO UPPER LEVELS IS PRODUCING RAPIDLY CLEARING SKIES FROM N TO S
OVER FLORIDA.  OVERCAST CLOUDINESS AND SHOWERS CONTINUE ALONG
THE WINDWARD FACING SLOPES OF THE SIERRA MADRES OF MEXICO WHERE
THE FRONT HANGS UP OVER THE HIGHER TERRAIN.

CARIBBEAN...
AFOREMENTIONED UPPER LEVEL TROUGH AND ATTENDANT COLD FRONT OVER
THE W ATLC EXTENDS ACROSS CENTRAL CUBA AND THE NW CARIBBEAN TO E
HONDURAS. MIDDLE TO UPPER LEVEL DYNAMICS/LIFT ARE PRIMARILY
CONFINED N OF THE CARIBBEAN WITH ONLY WIDELY SCATTERED SHOWERS
ALONG THE COLD FRONT. CLOUDINESS AND SHOWERS BECOME MORE
NUMEROUS OVER HONDURAS AND GUATEMALA WHERE THE FRONT BECOMES
STATIONARY ALONG THE HIGHER TERRAIN.  ELSEWHERE OVER THE
CARIBBEAN...NARROW MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM THE
ATLC WATERS OVER HISPANIOLA TO CENTRAL AMERICA NEAR HONDURAS.
THIS UPPER FEATURE COUPLED WITH AN UPPER LOW OVER THE CENTRAL
ATLC IS PRODUCING SIGNIFICANT DRYING IN THE MIDDLE AND UPPER
LEVELS OVER THE CENTRAL AND E CARIBBEAN WITH LIMITED SHOWER
ACTIVITY.  A FEW SHOWERS ASSOCIATED WITH DISTURBED WEATHER E OF
THE AREA ARE AFFECTING THE LEEWARD/WINDWARD ISLANDS.

CENTRAL AND E ATLANTIC...
A MIDDLE TO UPPER LEVEL LOW OVER THE CENTRAL ATLC NEAR 23N61W
REMAINS TRAPPED BENEATH A LARGE ANTICYCLONE FURTHER N NEAR
35N42W.  DIFFLUENT UPPER LEVEL FLOW E OF THE LOW CONTINUES TO
PRODUCE AN AREA OF CLOUDINESS AND SCATTERED SHOWERS/
THUNDERSTORMS FROM 16N-26N BETWEEN 50W-65W WHILE CONFLUENT FLOW
AND SUBSIDENCE OVER THE W SEMICIRCLE OF THE UPPER LOW PREVAILS
TO THE S BAHAMAS.  OVER THE E ATLC...STRONG DEEP LAYERED LOW IS
LOCATED APPROXIMATELY 200-300 NM NW OF THE CANARY ISLANDS NEAR
29N22W. ATTENDANT 1008 MB SURFACE LOW IS NEAR 29N20W WITH COLD
FRONT TRAILING SWD ALONG 25N26W 30N37W.  THE LOW IS EXPECTED TO
CONTINUE SLOWLY SWD OVER THE NEXT 24 HOURS AND DEEPEN. THE SLOW
MOTION OF THE LOW WILL MAINTAIN THE WET PATTERN CURRENTLY OVER
THE CANARY ISLANDS WITH LOCALLY HEAVY RAINFALL POSSIBLE OVER THE
NEXT DAY OR SO.  ALSO...STRONG NLY FLOW AND COLD AIR WILL SURGE
SWD BETWEEN LOW CENTER AND 40W. OVER THE TROPICS...ITCZ
CONVECTION IS MOST ACTIVE BETWEEN 50W-60W AND 20W-40W.  AT THE
SURFACE...A STRONG 1038 MB HIGH OVER THE CENTRAL SUBTROPICAL
ATLC NEAR 36N50W MAINTAINS ITS GRIP OVER THE AREA PRODUCING AN
UNUSUALLY LARGE SWATH OF STRONG...20-30 KT...ELY FLOW.

$$
RHOME


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