[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 162344
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST WED 16 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N10W 1N25W 3N45W 2N50W.  SCATTERED
MODERATE CONVECTION IS FROM 1N-4N BETWEEN 19W-23W.

...DISCUSSION...

GULF OF MEXICO...
IN THE UPPER LEVELS...BROAD RIDGING DOMINATES THE ENTIRE AREA
WITH UPSTREAM PACIFIC MOISTURE RIDING UP AND OVER THE RIDGE INTO
THE SW UNITED STATES AND BACK DOWN OVER FLORIDA.  AS A RESULT...
STRONG SUBSIDENCE AND DRY/STABLE AIR ALOFT PREVAILS CAPPING
SIGNIFICANT CLOUDS/CONVECTION. AT THE SURFACE...A RIDGE EXTENDS
ACROSS S FLORIDA TO THE CENTRAL GULF WITH RESULTING RETURN FLOW
OVER THE W GULF PRODUCING WARM TEMPERATURES. THE RIDGE IS
RETREATING AHEAD OF THE NEXT COLD FRONT WHICH IS PRESENTLY JUST
INLAND OVER THE TEXAS COAST.  THE FRONT IS PRIMARILY DRY AND
SHOULD ONLY BE ABLE TO PRODUCE A NARROW BAND OF CLOUDINESS AND
ISOLATED SHOWERS ALONG THE LEADING EDGE AS IT SWEEPS ACROSS THE
GULF. THE FRONT WILL ONLY BE ACCOMPANIED BY A MODERATE SURGE OF
CONTINENTAL AIR WITH POST-FRONTAL WINDS ON THE ORDER OF 15-20
KNOTS.

CARIBBEAN...
MID/UPPER LEVEL RIDGE REMAINS IN PLACE OVER CENTRAL AMERICA
WITH AXIS EXTENDING FROM COLOMBIA TO SE MEXICO.
CUBA...JAMAICA...AND HISPANIOLA IS UNDER A BROAD/FLAT TROUGH.
ZONAL FLOW IS OVER THE REMAINDER OF THE E CARIBBEAN SE OF
JAMAICA.  STRONG SUBSIDENCE AND DRY/STABLE AIR ALOFT CONTINUES
TO DOMINATE THE ENTIRE CARIBBEAN LIMITING SIGNIFICANT WEATHER TO
SHALLOW TOPPED SHOWERS WITHIN SEVERAL POCKETS OF LOW LEVEL
MOISTURE. AN AREA OF SCATTERED SHOWERS IS NOTED OVER THE LESSER
ANTILLES ALONG A LOW LEVEL TROUGH FROM 20N57W TO 11N65W.
ANOTHER AREA OF SHOWERS IS LOCATED SE OF JAMAICA FROM 12N-18N
BETWEEN 73W-80W.  NLY FLOW IS PRODUCING OVERCAST CLOUDINESS AND
SHOWERS OVER PORTIONS OF W PANAMA AND COSTA RICA EXTENDING
OUTWARD 60 NM FROM THE COAST. FINALLY...AN AREA OF WIDELY
SCATTERED SHOWERS IS OBSERVED MOVING WESTWARD OVER BELIZE...AND
PORTIONS OF THE YUCATAN PENINSULA.

ATLANTIC...
THE BULK OF THE ATLC WATERS FEATURES A FLAT UPPER LEVEL PATTERN
WITH NEAR ZONAL FLOW.  A BROAD SUBTROPICAL JET CUTS ACROSS THE
AREA BETWEEN 20N-30N PRODUCING STRONG UPPER LEVEL WINDS BETWEEN
90-110 KT.  A WEAK SHORTWAVE TROUGH MOVING OFF THE E COAST OF
THE UNITED STATES IS PRODUCING AN AREA OF MIDDLE AND HIGH
CLOUDINESS WITH ISOLATED SHOWERS N OF 25N BETWEEN 65W-75W.  THIS
ACTIVITY IS EXPECTED TO MIGRATE EWD TOWARD BERMUDA DURING THE
NEXT 12 HOURS.  AT THE SURFACE...A HIGH PRESSURE RIDGE
DOMINATES FROM BERMUDA SW OVER THE N BAHAMAS AND S FLORIDA.
OVER THE CENTRAL ATLC...A WEAKENING COLD FRONT ENTERS THE AREA
ALONG 32N35W EXTENDING SW TO 26N37W WHERE IT BECOMES STATIONARY
TO A 1010 MB LOW NEAR 20N57W. SCATTERED SHOWERS/THUNDERSTORMS
ARE OBSERVED WITHIN 120 NM OF THE TROUGH BETWEEN 45W-55W.  THE
SURFACE LOW IS EXPECTED TO LIFT NEWD ALONG THE BOUNDARY DURING
THE NEXT 24 HOURS PRODUCING INCREASING SHOWERS/THUNDERSTORMS TO
ITS EAST PRIMARILY BETWEEN 20N-30N BETWEEN 40W-50W.  OVER THE E
ATLC...A ZONALLY ELONGATED DEEP LAYERED LOW IS LOCATED NW OF THE
CANARY ISLANDS.  SHOWER ACTIVITY WITH THIS FEATURE REMAINS
MINIMAL AS IT CONTINUES TO WEAKEN.  FURTHER S...VISIBLE
SATELLITE IMAGERY STILL SHOWS AREAS OF AFRICAN DUST WITH
VISIBILITY POSSIBLY RESTRICTED BELOW 5 MILES S AND E OF THE CAPE
VERDE ISLANDS TO THE ITCZ.  OVER THE DEEP TROPICAL ATLC...THE
ITCZ HAS SHIFTED WELL S ESSENTIALLY STRADDLING THE EQUATOR W OF
25W.

$$
FORMOSA






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