[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 230529
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST WED 23 MAR 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
0345 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N10W 3N15W 2N28W ACROSS THE EQUATOR
NEAR 36W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG
CONVECTION ARE WITHIN 120 NM OF THE AXIS FROM 10W-42W.

...DISCUSSION...

GULF OF MEXICO...
POTENT DEEP LAYERED...CUTOFF LOW IS MOVING INTO THE UPPER
MISSISSIPPI VALLEY AND CONTINUES TO BE THE MAIN WEATHER TODAY AS
IT MOVES SLOWLY E TO OVER THE E UNITED STATES. ATTENDANT 100 KT
SUBTROPICAL JET ROUNDS THE BASE OF THE UPPER LOW FROM NE MEXICO
E OVER THE S UNITED STATES. AT THE SURFACE...A 1001 MB SURFACE
LOW RESIDES N OF THE AREA IN ARKANSAS WITH TRAILING COLD FRONT
ENTERING THE GULF OVER E LOUISIANA NEAR 29N91W EXTENDING S TO
26N92W THEN SW TO 23N96W. THE COLD FRONT IS THE LEADING EDGE OF
THE DRY AIR ALOFT. SURFACE TROUGH E OF THE FRONT EXTENDS FROM
THE NE GULF NEAR 29N86W SW ALONG 25N90W TO A 1006 MB LOW IN THE
BAY OF CAMPECHE NEAR 20N94W. SHOWERS AND STRONG THUNDERSTORMS
ACCOMPANY THE TROUGH WITHIN 90 NM EITHER SIDE E OF 90W TO OVER
FLORIDA WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS EXTENDING
NE COVERING THE S TWO THIRDS OF THE EASTERN UNITED STATES.
GUIDANCE INDICATES THE STRONGEST LIFT/DYNAMICS WILL BE MAINLY
FOCUSED ACROSS THE NE GULF AND FLORIDA N OF THE LAKE OKEECHOBEE
LATER TODAY PRODUCING A GOOD CHANCE OF STRONG THUNDERSTORMS OVER
THOSE AREAS. HOWEVER...AMPLE LOW LEVEL MOISTURE POOLING ALONG
THE REMAINDER OF THE FRONT SHOULD BE ENOUGH TO SQUEEZE OUT SOME
WIDELY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE SE GULF
AND S FLORIDA AS THE FRONT MOVES THROUGH LATE TODAY.

CARIBBEAN...
PERSISTENT MID/UPPER LEVEL RIDGE WILL REMAIN ANCHORED E/W ACROSS
THE AREA ALONG 17N THROUGH THE NEXT FEW DAYS WITH LITTLE CHANGE.
THE COLD FRONT CURRENTLY MOVING THROUGH THE GULF WILL APPROACH
THE EXTREME NW PORTION OF THE CARIBBEAN BY TOMORROW BUT IS
EXPECTED TO BECOME STATIONARY OVER THE YUCATAN CHANNEL. INCREASE
IN MOISTURE AND SHOWER ACTIVITY IS PRECEDING THE BOUNDARY
ESPECIALLY OVER THE YUCATAN PENINSULA INTO THE YUCATAN CHANNEL
WHERE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 19N-22N
W OF 86W. OTHERWISE...VERY DRY CONDITIONS THROUGHOUT THE ENTIRE
ATMOSPHERE SHOULD CONTINUE TO RESTRICT SHOWER ACTIVITY ACROSS
THE REMAINDER OF THE AREA.

ATLANTIC...
A FAIRLY FLAT ZONAL FLOW PATTERN PREVAILS OVER THE ATLC WATERS
WITH THE CORE OF THE STRONG UPPER LEVEL WESTERLIES AND
MID-LATITUDE AIR JUST N OF THE AREA. DIFFLUENCE IN THE W ATLC
FROM THE DEEP LAYERED LOW OVER THE UNITED STATES IS PRODUCING
SCATTERED MODERATE TO STRONG CONVECTION N OF 29N W OF 75W TO
INLAND OVER THE EASTERN STATES. WEAK MID/UPPER LEVEL SHORTWAVE
CLIPS THE N PORTION OF THE CENTRAL ATLC NEAR 48W WITH THE
ATTENDANT COLD FRONT ENTERING THE AREA NEAR 32N50W EXTENDING SW
TO 28N59W AND PRE-FRONTAL TROUGH EXTENDING FROM 30N42W SW TO
25N56W. LOW LEVEL CLOUDINESS WITH ISOLATED SHOWERS ARE WITHIN
60/90 NM E OF THE FRONT. ELSEWHERE...STRONG MID/UPPER LEVEL
RIDGING ALONG 17N PREVAILS WITH MODERATE/STRONG SUBSIDENCE
PRODUCING DRY/STABLE CONDITIONS ALOFT. OVER THE E ATLC...
MODERATE/STRONG SUBSIDENCE ALSO PREVAILS IN THE UPPER LEVELS AND
VERY DRY AIR IN THE LOWER LEVELS MOVING OFF W AFRICA ARE LARGELY
SUPPRESSING CLOUDS AND PRECIPITATION OVER THE AREA EXCEPT IN THE
VICINITY OF THE ITCZ AXIS.

$$
WALLACE



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