[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 281735
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT MAR 28 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND 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
1715 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 5N8W 1N16W CROSSING THE EQUATOR NEAR
23W TO 3S41W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS S
OF 3N BETWEEN 2W-13W. SIMILAR CONVECTION IS WITHIN 180 NM OF THE
AXIS BETWEEN 15W-25W AND S OF 4N BETWEEN 38W-49W.

...DISCUSSION...

GULF OF MEXICO...
A STRONG COLD FRONT IS MOVING ACROSS THE MID GULF FROM SRN
ALABAMA TO THE BAY OF CAMPECHE. BEHIND THE FRONT...A QSCAT PASS
AROUND 1230 Z REVEALED NLY GALE FORCE WINDS...STRONGEST OVER THE
FAVORED ZONE NEAR THE COAST OF MEXICO S OF 24N. AHEAD OF THE
FRONT...SLY WINDS ARE MAINLY 20-25 KT. WIND GENERATED WAVES
COMBINED WITH NW SWELL IS CAUSING HAZORDOUS MARINE CONDITIONS
ACROSS JUST ABOUT OVER THE ENTIRE GULF. PRECIP-WISE...DOPPLER
RADAR AND LIGHTNING DATA SHOW SCATTERED SHOWES AND TSTMS (SOME
STRONG) WITHIN 180 NM E OF THE FRONT 28N. THE REMAINDER OF THE
FRONT IS RELATIVELY INACTIVE WITH ONLY ISOLATED SHOWERS POSSIBLE
ALONG IT. THE FRONT IS FORECAST TO CONTINUE TRACKING E AND
WEAKEN...CLEARING THE ENTIRE ZONE BY SUN EVENING. WINDS ARE
EXPECTED TO QUICKLY DIMINISH FROM W TO E AS WEAK HIGH PRES
BUILDS E BEHIND THE FRONT.

CARIBBEAN SEA...
STRONG E TO SE TRADES CONTINUE ACROSS THE REGION DUE TO THE
TIGHT PRESSURE GRADIENT BETWEEN A 1024 MB HIGH CENTERED A COUPLE
HUNDRED NM S OF BERMUDA AND BROAD LOW PRES TROUGHING OVER THE
GULF OF MEXICO. THE STRONGEST FLOW...ESTIMATED TO BE JUST BELOW
GALE FORCE...IS OVER THE FAR NW CARIBBEAN. 20-25 KT EXIST
ELSEWHERE BASED ON SFC OBS AND A RECENT QSCAT PASS. TYPICAL
PATCHES OF SHALLOW CLOUDINESS WITH EMBEDDED SHOWERS ARE BEING
STEERED BY THE LOW-LEVEL FLOW...MOST ORGANIZED OVER THE SRN
WINDWARD ISLANDS AND THE SE CARIBBEAN.  ABUNDANT DRY AIR IN THE
MID AND UPPER LEVELS IS SUPPRESSING THIS MOISTURE ESPECIALLY
OVER THE WRN CARIBBEAN WITHIN AN UPPER RIDGE. TRADE WINDS ARE
FORECAST TO DIMINISH OVER THE W CARIBBEAN SUN IN RESPONSE TO A
COLD FRONT MOVING INTO THE YUCATAN CHANNEL. LITTLE CHANGE IS
ANTICIPATED OVER THE ERN CARIBBEAN THROUGH THE WEEKEND.

ATLANTIC OCEAN...
OVER THE W ATLC...DEEP LAYER RIDGING IS STILL HOLDING CONTROL
WITH THE ASSOCIATED 1023 MB SFC HIGH CENTERED A COUPLE HUNDRED
NM S OF BERMUDA. SLY WINDS ARE 20-25 KT W OF 77W DUE TO THE
TIGHT PRES GRADIENT BETWEEN THE HIGH AND A FRONT OVER THE GULF
OF MEXICO. THESE WINDS ARE EXPECTED TO EXPAND E AND INCREASE
FURTHER TONIGHT AS THE FRONT APPROACHES. SEE GULF OF MEXICO
SECTION FOR MORE DETAILS ON THE FRONT. OVER THE CENTRAL
ATLC...DEEP LAYER TROUGHING IS SLOWLY WEAKENING BUT REMAINS THE
DOMINATE PATTERN. WHILE THE SFC LOWS ARE WELL N OF THE AREA...AN
ATTENDANT COLD FRONT DOES EXTEND INTO SUBTROPICS/TROPICS FROM
32N37W TO 24N42W THEN STATIONARY TO 18N51W TO 11N59W. SCATTERED
SHOWERS AND ISOLATED TSTMS ARE WITHIN 180 NM E OF THE FRONT N OF
25N. LONG PERIOD NLY SWELL HAS SPREAD INTO THE TROPICS ELEVATING
SEAS TO 10-15 FT W OF THE FRONT TO NEAR THE BAHAMAS. ANOTHER
MID-UPPER TROUGH IS LOCATED OVER THE FAR NE PORTION OF THE AREA
WITH AN EMBEDDED UPPER LOW CENTERED OFF THE COAST OF MOROCCO.
THE ASSOCIATED SFC LOW/TROUGH HAS DISSIPATED AND MUCH OF THE
SENSIBLE WEATHER IS WELL INLAND OVER AFRICA. OVER THE DEEP
TROPICS...A LARGE SPRAWLING UPPER HIGH IS CENTERED NEAR
7N25W...ENHANCING CONVECTION WITHIN THE ITCZ.

$$
CANGIALOSI



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