[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221759
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST THU FEB 22 2007

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...
METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N11W 2N25W EQ35W EQ48W. SCATTERED
MODERATE CONVECTION IS WITHIN 120 NM OF THE AXIS BETWEEN THE
COAST OF AFRICA AND 15W. CLUSTERS OF SCATTERED MODERATE ALSO
SEEN WITHIN 150 NM S OF THE AXIS BETWEEN 34W-50W. SIMILAR
ACTIVITY IS FROM EQ-5N BETWEEN 48W-52W.

...DISCUSSION...
GULF OF MEXICO...
WEAK SFC RIDGING AND LIGHT WINDS DOMINATE THE NRN GULF FROM A
1021 MB HIGH PRES CENTER OVER SRN LOUISIANA. A TROUGH IS
ANALYZED IN THE SW GULF ALONG 25N91W 18N93W...AND WAS DEPICTED
WELL BY THIS MORNINGS QUIKSCAT PASS. SCATTERED TO BROKEN LOW TO
MID CLOUDS WITH POSSIBLE EMBEDDED SHOWERS ARE WITHIN 120 NM OF
THE TROUGH AXIS. SIMILAR CLOUDS WITH POSSIBLE SHOWERS ARE WITHIN
60 NM OF A LINE BETWEEN KEY WEST AND 25N90W. AREAS OF DENSE FOG
ALONG THE TEXAS...LOUISIANA...AND MEXICO COASTS HAVE BEEN SLOW
TO BURN OFF THIS AFTERNOON. THE REMAINDER OF THE GULF HAS LITTLE
CLOUD COVER WITH FAIR WEATHER. ALOFT...THE FLOW IS PREDOMINATELY
WNW...SANDWICHED BETWEEN A SPRAWLING RIDGE CENTERED OVER SE
MEXICO AND TROUGHING PUSHING OFFSHORE OF THE U.S. EAST COAST. WV
IMAGES SHOW A GOOD AMOUNT OF DRY AIR ACROSS THE ENTIRE
AREA...ESPECIALLY N OF 25N AND E OF 88N.  AS THE SFC HIGH SLIDES
E...SLY RETURN FLOW IS EXPECTED TO INCREASE IN THE W GULF
BEGINNING LATE FRI IN RESPONSE TO THE NEXT COLD FRONT FORECAST
TO PUSH OFF THE TX COAST DURING SAT.

CARIBBEAN SEA...
HIGH PRES N OF THE AREA IS PRODUCING MODERATE TO STRONG TRADES
ACROSS THE CARIB. TYPICAL PATCHES OF LOW LEVEL MOISTURE WITH
EMBEDDED SHOWERS DRIVEN BY THE TRADES ARE AFFECTING THE
AREA...PARTICULARLY THE E CARIBBEAN AND OVER HISPANIOLA. THE MID
AND UPPER LEVEL PATTERN IS DOMINATED BY A STRONG RIDGE CENTERED
OVER SE MEXICO AND EXTREMELY DRY/STABLE AIR. THIS STRONG CAP IS
SUPPLYING THE AREA WITH FAIR WEATHER...PREVENTING THE LOW LEVEL
MOISTURE PATCHES FROM ACQUIRING MUCH DEPTH. OVER THE NEXT COUPLE
OF DAYS...MODELS SHOW LITTLE CHANGE IN THE OVERALL PATTERN SO
SIMILAR TRADES AND WEATHER CONDITIONS ARE ANTICIPATED.

ATLANTIC OCEAN...
A WEAK SFC TROUGH MARKED MAINLY BY THE PRESSURE PATTERN IS IN
THE WRN ATLC ALONG 30N73W 26N78W. A 1010 MB SFC LOW ATTACHED TO
A COLD FRONT IS JUST N OF THE AREA NEAR 33N63W. THIS...ALONG
WITH UPPER DIFFLUENCE/DYNAMICS AHEAD OF UPPER TROUGH OFF THE
EAST COAST IS SUPPORTING THE SWATH OF MOISTURE WITH EMBEDDED
SHOWERS N OF 24N BETWEEN 40W-68W...AND IS BEING TRANSPORTED E BY
WIDESPREAD ZONAL UPPER FLOW OVER THE AREA. VERY DRY MID TO UPPER
AIR IS FILTERING IN THE WRN ATLC BEHIND THE UPPER TROF WITH NW
FLOW. A LINE OF LOW CLOUDS/SHOWERS IS SEEN BETWEEN THE SE
BAHAMAS AND 27N66W. A DISSIPATING 1018 MB SFC HIGH IS NNE OF
PUERTO RICO NEAR 24N65W. A DISSIPATING STATIONARY FRONT ENTERS
THE AREA AT 32N39W AND CONTINUES SW TO 22N60W. E ATLC SFC
PATTERN IS DOMINATED BY A 1028 MB HIGH PRES CENTERED NEAR
20N25W. FAIRLY COMPLEX/HIGH WAVE NUMBER UPPER PATTERN PERSISTS
OVER THE DEEP TROPICS...WITH A TROUGH JUST E OF THE WINDWARD
ISLANDS FOLLOWED BY RIDGE/TROUGH/RIDGE/TROUGH. NONE OF THESE
APPEAR TO BE GENERATING SIGNIFICANT WEATHER...THOUGH ARE
TRANSPORTING NARROW REGIONS OF UPPER MOISTURE IN THE ASSOCIATED
UPPER DIFFLUENT ZONES.

$$
WILLIS




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