[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 092321
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST FRI FEB 09 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N10W 4N20W 1N30W 1N40W...CROSSING
THE EQUATOR AT 44W...TO 1S50W INTO NORTHEASTERN BRAZIL.
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS
BETWEEN 30W-35W. ISOLATED MODERATE IS WITHIN 180 NM N OF THE
AXIS E OF 16W...BETWEEN 25W-28W AND W OF 45W.

...DISCUSSION...
THE GULF OF MEXICO...
A COMPLEX FRONTAL SYSTEM IS JUST N OF THE AREA DRAPED ACROSS
MUCH OF THE GULF COAST...EXCEPT FOR THE TAIL END WHICH HAS
ENTERED THE NW GULF FROM CENTRAL LA TO S TEXAS ALONG 30N91W
27N97W. THE FRONT CONTINUES STATIONARY NW ACROSS MEXICO AND INTO
WRN TEXAS. MOSAIC DOPPLER RADAR INDICATES SCATTERED SHOWERS
ACROSS A PORTION OF THE SE COAST ALONG OR N OF THE FRONT. THIS
BOUNDARY IS EXPECTED TO PUSH S INTO THE AREA LATER TONIGHT.
FURTHER S...A WEAK SFC TROUGH IS BECOMING MORE ELONGATED
ANALYZED ALONG 21N88W 28N84W. THE ASSOCIATED WEATHER IS MINIMAL
WITH ONLY BROKEN LOW TO MID LEVEL CLOUDS AND ISOLATED SHOWERS
WITHIN 120 NM OF ITS AXIS. WINDS ARE LIGHT ACROSS MOST OF THE
AREA...EXCEPT BEHIND THE FRONT WHERE NLY ARE INCREASING TO 15-20
KT. ALOFT...A STREAM OF BROKEN HIGH LEVEL CLOUDS ARE RACING
ACROSS THE AREA DRIVEN BY STRONG SW-WLY FLOW BETWEEN A SHORTWAVE
TROUGH OVER CENTRAL MEXICO AND W-NWLY FLOW ABOVE THE ERN HALF OF
THE U.S.

THE CARIBBEAN SEA...
NOT MUCH NEW TO MENTION IN THE CARIB SEA. ABUNDANT DRY AIR IN
THE MID AND UPPER LEVELS CONTINUES TO DOMINATE SUPPORTED BY
UPPER LEVEL RIDGING CENTERED IN THE TROPICAL ATLC EXTENDING
NEWARD ACROSS THE REGION. THE DRY AIR/STRONG SUBSIDENCE IS
SUPPRESSING ANY SIGNIFICANT CONVECTION FROM FORMING. IN THE LOW
LEVELS...PATCHES OF MOISTURE ARE BEING DRIVEN WWD BY MODERATE
TRADES. THE PATCHES APPEAR THICKEST IN THE SE CARIB/THE WINDWARD
ISLANDS AS WELL AS THE YUCATAN PENINSULA AND CHANNEL WHERE THERE
IS SOME INFLUENCE FROM A SFC TROUGH IN THE GULF. LITTLE CHANGE
IN THE WEATHER PATTERN IS EXPECTED OVER THE NEXT COUPLE DAYS.

THE ATLANTIC OCEAN...
THE SFC PATTERN HAS BEEN SOMEWHAT COMPLEX IN THE W ATLC WITH
SEVERAL FAST MOVING FRONTAL BOUNDARIES CLIPPING THE NRN PORTION
OF THE AREA OVER THE LAST COUPLE OF DAYS. AS OF 21Z...A COLD
FRONT EXTENDS FROM A 1013 MB LOW E OF BERMUDA NEAR 32N74W ALONG
29N79W TO A LOW OFF THE COAST OF SE GEORGIA. THE TAIL END OF
ANOTHER COLD FRONT ENTERS THE AREA NEAR 32N52W AND EXTENDS TO
27N68W. NEITHER OF THESE BOUNDARIES ARE PRODUCING MUCH DEEP
CLOUDINESS/PRECIP...HOWEVER DIRECTIONAL AND MAGNITUDE WIND
CHANGES ARE EVIDENT NEAR BOTH. THESE BOUNDARIES ARE ASSOCIATED
WITH DEEPENING FAST MOVING SFC LOWS ENERGIZED BY A STRONG
JETSTREAM TO THE SE OF A LARGE SLOW MOVING POLAR VORTEX. S OF
THE FRONTS DESCRIBED IS A PERSISTENT NE-SW ELONGATED SFC TROUGH
ANALYZED FROM THE TURKS AND CAICOS TO 28N60W. SCATTERED SHOWERS
ARE POSSIBLE WITHIN 60 NM EITHER SIDE OF THE AXIS. SOME NWP
MODELS SHOW THIS TROUGH MERGING WITH THE FRONT TO THE N LATER
TONIGHT OR TOMORROW. A STRONG UPPER LEVEL RIDGE IS
CENTERED IN THE TROPICAL ATLC NEAR 9N56W. THIS RIDGE HAS
FLATTENED SLIGHTLY TODAY BUT ITS STILL SUPPLYING AND ADVECTING
PLENTY OF STABLE AIR ALOFT ACROSS MOST OF THE ATLC W OF 30W S OF
26N. IN THE E ATLC...AN UPPER LOW HAS BEEN SLOW MOVING OVER THE
PAST 48 HOURS CENTERED NEAR 14N30W. SWLY UPPER LEVEL FLOW/UPPER
DIFFLUENCE IS GENERATING AND SPREADING MID-HIGH LEVEL MOISTURE E
OF THE LOW S OF 14N. THE SFC PATTERN IN THE E ATLC REMAINS
DOMINATED BY A 1028 MB HIGH CENTERED 180 NM W OF THE CANARY
ISLANDS NEAR 29N21W HELPING TO KEEP THE WEATHER RATHER TRANQUIL
ACROSS THE MAJORITY OF THE SUBTROPICS E OF 40W.

$$
CANGIALOSI




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