[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161726
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI MAR 16 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
1715 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N11W 2N22W CROSSING THE EQUATOR AT
32W AND INTO NE BRAZIL NEAR 3S42W. SCATTERED MODERATE TO
ISOLATED STRONG CONVECTION IS WITHIN 120 NM N OF THE AXIS
BETWEEN 14W-22W AND N OF 3N E OF 6W. SCATTERED MODERATE IS
WITHIN 150 NM N OF THE AXIS BETWEEN 25W-39W.

...DISCUSSION...

GULF OF MEXICO AND EXTREME WESTERN ATLANTIC...
A PRONOUNCED SHORTWAVE TROUGH STRETCHES FROM THE EASTERN U.S.
ACROSS THE BAHAMAS AND INTO THE CARIB. A RELATED SFC TROUGH
EXTENDS FROM NE FLORIDA TO THE BAY OF CAMPECHE. UPPER DIFFLUENCE
E OF THE SHORTWAVE AXIS ALONG WITH LOW-LEVEL LIFT/MOIST INFLOW
IS GENERATING SHOWERS AND TSTMS WITHIN 30-60 NM OF A LINE
EXTENDING FROM 32N78W ACROSS DAYTONA BEACH TO JUST S OF TAMPA TO
25N86W. A FEW OTHER CLUSTERS OF SHOWERS AND TSTMS ARE AHEAD OF
THE MAIN LINE...ALL OF THESE ARE PUSHING TO THE SE AHEAD OF A
COLD FRONT THAT IS DRAPED ACROSS THE NRN GULF COAST. ELSEWHERE
IN THE GULF...QUIET WEATHER IS THE RULE UNDER A FAIR AMOUNT OF
DRY STABLE AIR IN THE MID AND UPPER LEVELS. THE FRONT IN THE NRN
GULF IS ANTICIPATED TO PUSH SE AND MERGE WITH THE TROUGH ACROSS
FLORIDA TONIGHT AND INTO THE ATLC BY SAT MORNING. IT WILL THEN
PUSH THRU THE BAHAMAS BY LATE SAT/EARLY SUN. BEHIND THE
FRONT...HIGH PRES WILL SETTLE IN SUPPLYING COOLER AND DRIER
WEATHER.

CARIBBEAN...
BROAD MID AND UPPER LEVEL TROUGHING NOW COVERS MUCH OF THE
CENTRAL AND WRN PORTIONS WHILE THE WRN PERIPHERY OF THE BROAD
RIDGE IS HANGING ON ACROSS THE LESSER ANTILLES. UPPER
DIFFLUENCE...ALONG AND TO THE E OF THE SHORTWAVE TROUGH AXIS...
ALONG WITH MOIST S-SELY LOW-LEVEL FLOW IS PRODUCING SCATTERED
SHOWERS AND TSTMS OVER CENTRAL/WRN CUBA AND THE COASTAL WATERS
FROM 21N-23N BETWEEN 78W-82W AS INDICATED BY DOPPLER RADAR FROM
CUBA. THE REMAINDER OF THE REGION IS FREE OF CONVECTIVE ACTIVITY
SUPPRESSED BY MODERATE TO STRONG SUBSIDENT FLOW. THE DRIEST AIR
ALOFT IS JUST TO THE W OF THE TROUGH AXIS OVER THE NW CARIB. THE
TAIL END OF A WEAKENING STUBBORN SFC TROUGH EXTENDS ACROSS THE
VIRGIN ISLANDS. THE ASSOCIATED SHALLOW CLOUD COVER IS MUCH
THINNER THAN PREVIOUS DAYS BUT THERE STILL IS SCATTERED PATCHES
ALONG THE TROUGH PUSHING W TOWARD PUERTO RICO...LIKELY PRODUCING
SCATTERED SHOWERS. TRADE WINDS HAVE SLACKEN IN THE WRN CARIB AS
LOW PRES IS LOCATED N OF THE AREA BUT REMAIN MODERATE TO FRESH
ACROSS THE CENTRAL AND ERN PARTS. LOOKING AHEAD...A COLD FRONT
IS EXPECTED TO PUSH INTO THE REGION TONIGHT INCREASING THE
CHANCE OF SHOWERS AS IT PROGRESSES EWD AND WEAKENS. DRIER AND
SLIGHTLY COOLER WEATHER WILL FOLLOW ADVECTED BY MODERATE TO
STRONG NLY WINDS.

WESTERN AND CENTRAL ATLANTIC...
THE MAIN FEATURE IS A SLOW MOVING VERTICALLY STACKED LOW N OF
THE AREA NEAR 38N49W. A COLD FRONT ENTERS THE REGION NEAR 32N45W
AND EXTENDS TO 25N49W THEN CONTINUES AS A SFC TROUGH TO THE
VIRGIN ISLANDS. SCATTERED SHOWERS ARE WITHIN 120 NM AHEAD OF THE
COLD FRONT. ELSEWHERE ZONAL FLOW ALOFT AND SCATTERED HIGH CLOUDS
IS THE THEME IN THE MID AND UPPER LEVELS.  AT THE SFC...A 1025
MB HIGH IS LOCATED JUST E OF BERMUDA. PATCHY LOW CLOUDS ARE
BEING STEERED ACROSS THE REGION BY MODERATE ANTICYCLONIC FLOW.
OVER THE NEXT COUPLE OF DAYS...A STRONG UPPER TROUGH AND
ASSOCIATED COLD FRONT WILL ENTER THE REGION BRINGING A GOOD
CHANCE OF ORGANIZED PRECIP FOR A PORTION OF THE AREA THIS
WEEKEND AND INTO EARLY NEXT WEEK.

EASTERN ATLANTIC...
THIS PART OF THE ATLC...E OF 40W...REMAINS QUIET WITH STRONG
RIDGING BOTH AT THE SFC AND ALOFT DOMINATING THE PATTERN. THE
UPPER AXIS IS ALIGNED FAIRLY N-S ALONG 33W/34W. THERE ARE SOME
HIGH CLOUDS...DEBRIS MOISTURE FROM THE COLD FRONT IN THE CENTRAL
ATLC...STREAMING ACROSS THE RIDGE AXIS BUT MUCH OF THE AREA IS
VOID OF PRECIP. THE MOST STABLE CONDITIONS ALOFT ARE CONFINED TO
THE ERN MOST PORTION E OF 27N FROM 12N-25N...WHICH INCLUDES THE
CAPE VERDE ISLANDS...AS UPPER CONFLUENCE IS QUITE STRONG BETWEEN
THE RIDGE...A SHARPING TROUGH OVER THE WRN MEDITERRANEAN AND
EXTREME E ATLC AND A SUBTROPICAL JET OVER AFRICA. THE SFC RIDGE
IS PRODUCING A LARGE AREA OF MODERATE TO STRONG WINDS ACROSS THE
REGION. THIS RIDGE IS EXPECTED TO SHIFT SWD TIGHTENING THE GRAD
WHICH WILL INCREASE THE WINDS FURTHER ESPECIALLY N OF 22N LATE
THIS WEEKEND.

$$
CANGIALOSI/CASTILLO




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