[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 240544
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI JUN 24 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...

FAR E ATLC TROPICAL WAVE WAS INTRODUCED ALONG 19W S OF 16W
MOVING W 10-15 KT BASED ON THE UPPER AIR SOUNDING FROM DAKAR.
ASSOCIATED DEEP CONVECTION CONFINED WITHIN THE ITCZ.

TROPICAL WAVE MOVING INTO THE CENTRAL ATLC IS ALONG 31W S OF 14N
MOVING W 15-20 KT. WEAK WAVE WITH A SLIGHT V-SHAPED CURVATURE
OBSERVED IN THE CONVECTION...BUT CONFINED WITHIN THE ITCZ.

W ATLC TROPICAL WAVE IS ALONG 51W S OF 14N MOVING W 10 KT. THE
WAVE IS W OF THE LEADING EDGE OF A UPPER LEVEL MOISTURE SURGE
WITHIN THE ITCZ WITH RELATIVELY DRIER AIR W OF THE WAVE AXIS TO
THE LESSER ANTILLES. WEAK LOW LEVEL V-SHAPED CURVATURE IS
OBSERVED ON INFRARED SATELLITE IMAGERY. NO ASSOCIATED SHOWERS OR
CONVECTION.

E CARIBBEAN TROPICAL WAVE IS ALONG 68W S OF 19N MOVING W 15-20
KT. UPPER LEVEL N FLOW IS OBSCURING THE WAVE. ISOLATED SHOWERS
MOVING WITH THE EASTERLY TRADES ARE FROM 15N-21N BETWEEN
64W-71W.

STRONG TROPICAL WAVE IN THE CENTRAL CARIBBEAN IS ALONG 78W/79W S
OF 20N MOVING W 15-20 KT AS OF 24/0300 UTC. THE N PORTION OF
THIS WAVE IS NOW ANALYZED AS A SURFACE TROUGH FROM CUBA
NORTHWARD. THE WAVE IS INTERACTING WITH A LARGE MID/UPPER
LOW/TROUGH THAT EXTENDS FROM S FLORIDA INTO THE CARIBBEAN
PRODUCING AN AREA OF SCATTERED STRONG CONVECTION FROM 14N-18N
BETWEEN 75W-79W INCLUDING MOST OF JAMAICA. ALTHOUGH THE N
PORTION HAS SPLIT FROM THE WAVE AND THE UPPER LEVEL WINDS ARE
UNFAVORABLE FOR FURTHER DEVELOPMENT...THIS IS REMAINS A STRONG
WAVE CAPABLE OF PRODUCING HEAVY RAINS AND GUSTY WINDS.

TROPICAL WAVE OVER CENTRAL AMERICA IS ALONG 86W/87W S OF 18N
MOVING W 5-10 KT. WAVE IS MOSTLY OVER LAND...THUS CONVECTION IS
INLAND OVER PORTIONS OF CENTRAL AMERICA.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 12N13W 10N24W 7N40W 8N50W. THE ITCZ
IS ILL-DEFINED W OF 50W. SCATTERED MODERATE/STRONG CONVECTION IS
WITHIN 120 NM OF THE AXIS FROM 18W-22W. SCATTERED MODERATE/
ISOLATED STRONG CONVECTION IS WITHIN 120/150 NM OF THE AXIS FROM
22W-34W.

...DISCUSSION...

GULF OF MEXICO...
MID/UPPER LEVEL RIDGE EXTENDING FROM TEXAS NORTHWARD IS FORCING
STRONG SUBSIDENCE AND DRY CONTINENTAL AIR OVER THE N GULF N OF
26N W OF 83W. A SECOND RIDGE AXIS EXTENDS W/E FROM AN UPPER HIGH
OVER SW MEXICO TO OVER THE YUCATAN PENINSULA S OF 20N. THIS IS
ADVECTING PACIFIC TROPICAL MOISTURE ACROSS THE SW GULF...
ALTHOUGH THE CONVECTION IS CONFINED TO INLAND AREAS. THE MAIN
FOCUS IS OVER THE E GULF AND THE W ATLC WHERE A DEEP LAYERED
TROUGH COVERS THE AREA W OF 85W. THIS MID/UPPER LEVEL TROUGH IS
EXPECTED TO MOVE W INTO THE GULF OVER THE THE NEXT DAY OR TWO.
THE ASSOCIATED DEEP CONVECTION IS CONFINED OVER THE E COAST OF
FLORIDA AND IN THE W ATLC. HOWEVER...OVER-RIDING ISOLATED
THUNDERSTORMS ARE ALONG THE NE GULF COAST N OF 28N TO INLAND
OVER THE FLORIDA PANHANDLE BETWEEN 83W-88W.

CARIBBEAN...
MID/UPPER LEVEL TROUGH EXTENDS ACROSS CUBA FROM THE W ATLC INTO
THE W CARIBBEAN N OF 17N FROM 75W-86W. THIS HAS LEFT THE FAR NW
CARIBBEAN CLOUD AND SHOWER FREE. INTERACTION OF THE TROPICAL
WAVE IN THE CENTRAL CARIBBEAN AND THE UPPER LEVEL TROUGH IS
GENERATING A LARGE AREA OF OVERALL CLOUDINESS WITH SHOWERS TO
HEAVY RAINS ACROSS THE CARIBBEAN W OF 72W. THE REMAINDER OF THE
CARIBBEAN IS MOISTURE LADEN EXCEPT THE LEEWARD ISLANDS WHERE
UPPER LEVEL MOISTURE IS PRESENT BUT IS RELATIVELY CLOUD FREE.
UPPER RIDGING IS BUILDING IN THE CENTRAL AND NE CARIBBEAN WITH
ANOTHER UPPER LEVEL HIGH CENTER FORMING CLOSE TO PUERTO RICO.

ATLANTIC...
CUT-OFF MID/UPPER LOW OVER THE FLORIDA STRAITS NEAR 25N80W IS
THE MAIN FOCUS OF WEATHER TONIGHT. THE UPPER LEVEL TROUGH
EXTENDS S INTO THE CARIBBEAN AND ALSO COVERS A PORTION OF THE E
GULF. A SURFACE TROUGH...PREVIOUSLY A PORTION OF A TROPICAL
WAVE...EXTENDS ALONG 78W/79W FROM CENTRAL CUBA TO 30N.
DIFFLUENCE E OF THE TROUGH IS GENERATING A LARGE AREA OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION S OF 30N FROM 70W
TO THE SURFACE TROUGH A MUCH SMALLER AREA OF SIMILAR CONVECTION
IS FROM 25N-29N W OF THE SURFACE TO JUST INLAND ALONG THE E
COAST OF FLORIDA WITH THE HEAVIER SHOWERS/THUNDERSTORMS
OFFSHORE. THE UPPER TROUGH IS EXPECTED TO MOVE W INTO THE GULF
OVER THE NEXT DAY OR TWO HOWEVER THE SURFACE FEATURE IS EXPECTED
TO LAG BEHIND. A SURFACE LOW IS ALSO EXPECTED TO DEVELOP BY THE
END OF THE WEEKEND. TROPICAL FORMATION IS NOT FAVORABLE AT THIS
TIME BUT THE AREA HAS THE POTENTIAL FOR HEAVY RAINS AND GUSTY
WINDS FOR CUBA...THE BAHAMA ISLANDS...AND THE E COAST OF
FLORIDA. FARTHER E...AN AMPLIFIED MID/UPPER RIDGE EXTENDS FROM
ACROSS PUERTO RICO NE TO BEYOND 32N57W WITH A WEAK SURFACE 1021
MB HIGH CENTERED NEAR 30N65W. MODERATE/STRONG SUBSIDENCE IS
BETWEEN THE THIS RIDGE AND A DEEP-LAYERED CENTRAL ATLC TROUGH
THAT EXTENDS FROM BEYOND 32N47W S THROUGH AN UPPER LOW NEAR
30N47W TO 15N51W. A SURFACE TROUGH EXTENDS INTO THE AREA THROUGH
32N45W TO 21N51W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE
FROM 25N-30N BETWEEN 44W-49W AND A SMALLER AREA WITHIN 60 NM OF
30W FROM 27N-30N. TO THE E A BROAD MID/UPPER LEVEL RIDGE COVERS
THE THE REMAINDER OF THE ATLC  S OF 25N WITH A MID/UPPER HIGH
LOCATED SE OF THE CAPE VERDE ISLANDS NEAR 14N29W. A SECOND UPPER
LEVEL LOW IS OVER THE NE ATLC NEAR 30N29W. A SURFACE RIDGE
EXTENDS FROM A 1026 MB HIGH NEAR 34N27W SW TO 17N42W.

$$
WALLACE




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