[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 122342
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SUN MAR 12 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE 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
2314 UTC.

...THE ITCZ...
ITCZ IS CENTERED ALONG 7N5W 1N35W INTO S AMERICA NEAR 2N51W.
SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 100 NM EITHER SIDE
OF THE ENTIRE ITCZ.

...DISCUSSION...

GULF OF MEXICO...
STRONG MIDDLE TO UPPER LEVEL RIDGE DOMINATES THE GLFMEX
EXTENDING FROM A ANTICYCLONE OVER THE YUCATAN PENINSULA NEWD
ALONG THE E COAST OF THE UNITED STATES. AS A RESULT...THE CORE
OF THE STRONGEST WESTERLIES AND ASSOCIATED DYNAMICS/LIFT REMAIN
N OF THE AREA OVER THE CENTRAL UNITED STATES.  AT THE
SURFACE...THE COMBINATION OF BROAD LOW PRES OVER THE CENTRAL
U.S. AND A 1025 HIGH NEAR BERMUDA IS MAINTAINING BRISK SE FLOW
ACROSS THE ENTIRE GULF.  THIS PATTERN IS CREATING AN ALMOST
SUMMER-LIKE AIRMASS IN THE LOWER LEVELS WITH DEWPOINTS IN THE
60S TO 70S ACROSS THE REGION.  LOOKING UPSTREAM...A BROAD MIDDLE
TO UPPER LEVEL TROUGH CURRENTLY OVER THE W UNITED STATES WILL
PROGRESS EWD INTO THE CENTRAL U.S. MON THEN TO THE E U.S. BY
LATE TUE.  THIS WILL IGNITE LEE-CYCLOGENESIS ALONG E SLOPES OF
THE ROCKIES TONIGHT WHICH WILL SEND A COLD FRONT SWD REACHING
THE NW GULF MON AFTERNOON. WITH THE UPPER FLOW EXPECTED TO
REMAIN NEARLY ZONAL OVER THE GULF...THE FRONT WILL BECOME
INCREASING WEAK AS IT PUSHES SWD THROUGH FLORIDA LATE TUE
CLEARING THE S PENINSULA LATE WED.  STILL...LOW LEVEL MOISTURE
POOLING ALONG THE BOUNDARY WILL LIKELY PRODUCE SOME SCATTERED
SHOWERS AND ISOLATED TSTMS RIGHT ALONG THE LEADING EDGE OF THE
FRONT.  THE MOST WIDESPREAD OF THIS ACTIVITY IS CURRENTLY
EXPECTED OVER THE NE GULF AND N FLORIDA TUE.  ELSEWHERE...A WEAK
LOW-LEVEL ELY DISTURBANCE OVER THE BAHAMAS MAY CAUSE SOME
SHOWERS OVER S FLORIDA TONIGHT AND MON AS IT CONTINUES WNW
AROUND THE W PERIPHERY OF THE SUBTROPICAL RIDGE. N

CARIBBEAN SEA...
THE AFOREMENTIONED ANTICYCLONE OVER THE YUCATAN PENINSULA NOSES
SEWD ACROSS THE N CARIBBEAN WITH A WEAK MIDDLE TO UPPER LEVEL
TROUGH OVER N PORTIONS OF S AMERICA.  THE RESULTING UPPER-LEVEL
FLOW BETWEEN THESE FEATURES IS STRONGLY CONFLUENT PRODUCING
MODERATE TO STRONG SUBSIDENCE AND VERY DRY/STABLE CONDITIONS
ALOFT ACROSS THE ENTIRE CARIBBEAN AND CENTRAL AMERICA.  AT THE
LOWER LEVELS...THE W EXTENT OF AN OLD REMNANT FRONTAL TROUGH
OVER THE CENTRAL TO E ATLANTIC HAS FRAGMENTED FORMING A
SCREAMING EAGLE OVER THE E CARIBBEAN. THE FEATURE IS PRODUCING
SCATTERED SHOWERS AND TSTMS FROM 13.5N TO 16.5N E OF 67W. THIS
ACTIVITY WILL SPREAD WESTWARD TONIGHT REACHING THE CENTRAL
CARIBBEAN BY EARLY MON AND THE W CARIBBEAN LATE TUE. ASSOCIATED
SHOWERS/TSTMS ARE EXPECTED TO REMAIN PRIMARILY S OF THE GREATER
ANTILLES AND N OF S AMERICA. ELSEWHERE...BRISK TRADES ON THE
ORDER OF 20-30 KT WILL CONTINUE ACROSS MUCH OF THE CARIBBEAN SEA
THROUGH MON THEN GRADUALLY WEAKEN TUE AND WED AS THE ATLANTIC
SUBTROPICAL RIDGE SHIFTS EWD.

ATLANTIC OCEAN...
A LARGE-SCALE RIDGE-TROUGH PATTERN PREVAILS IN THE MIDDLE TO
UPPER LEVELS WITH A RIDGE OVER THE W ATLANTIS BETWEEN BERMUDA
AND THE E COAST OF THE U.S. AND A BROAD/FLAT TROUGH OVER THE
CENTRAL TO E ATLANTIC.  THE CENTRAL TO E ATLANTIC TROUGH IS
COMPRISED OF MULTIPLE SHORT-WAVE DISTURBANCES...THE MOST NOTABLE
CURRENTLY DROPPING SEWD OVER THE CENTRAL ATLC.  THIS FEATURE IS
DRAGGING A MODERATELY STRONG COLD FRONT SWD INTO THE DISCUSSION
AREA...CURRENTLY ALONG 32N42W 29N55W 32N69W. MOST OF THE UPPER
DYNAMICS ALONG THE FRONT REMAIN JUST N OF THE AREA WITH ONLY A
150 NM WIDE BAND OF BROKEN/OVERCAST LOW/MID CLOUDINESS AND
SCATTERED SHOWERS NOTED AHEAD OF THE FRONT.  ELSEWHERE...
GENERALLY TRANQUIL WEATHER PREVAILS ESPECIALLY OVER THE FAR E
ATLANTIC WHERE EARLIER VISIBLE SATELLITE IMAGERY SHOWS A STRONG
SAHARAN AIR LAYER OUTBREAK EQUATORWARD OF A LINE FROM 32N28W
18N50W.  THE HIGHEST CONCENTRATION OF DUST APPEARS TO BE S OF
20N E OF 50W WITH VERY HIGH CONCENTRATIONS NOTED OVER AND JUST
SE OF THE CAPE VERDE ISLANDS.  AVAILABLE OBSERVATIONS INDICATE
OCCASIONAL VISIBILITIES BELOW 5 SM WITHIN THIS AREA.  AT THE
SURFACE...THE SUBTROPICAL RIDGE EXTENDS FROM A 1027 MB HIGH NEAR
31N70W ESE ALONG 26N55W THEN NE TO 31N37W.

$$
RHOME



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