[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251746
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE MAR 25 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
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.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N10W 4N20W 1N30W 1S40W EQUATOR48W.
NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS FROM THE
EQUATOR TO 1N W OF 45W. SCATTERED MODERATE CONVECTION IS WITHIN
180 NM N OF THE AXIS BETWEEN 11W-32W. SCATTERED MODERATE TO
STRONG CONVECTION IS FROM THE EQUATOR TO 4N BETWEEN 6W-13W.

...DISCUSSION...

THE GULF OF MEXICO...
STRONG SFC HIGH PRES...ANALYZED 1032 MB...OVER SW GEORGIA
CONTROLS THE PATTERN ACROSS THE REGION. THIS HIGH CONTINUES TO
BUILD EWD IN THE WAKE OF A STRONG COLD FRONT THAT SWEPT THROUGH
THE AREA SUN AND MON. COOL AND DRY AIR IS IN PLACE OVER THE E
GULF AND FLORIDA WITH TEMPS CURRENTLY IN THE 50'S AND 60'S F.
DEWPOINTS ARE IMPRESSIVELY LOW FOR LATE MARCH...NEAR 20 F OVER
PORTIONS OF THE FL PANHANDLE. THE AIRMASS MODIFIES OVER THE WRN
WATERS WHERE RETURN FLOW HAS SET UP. A LOW-LEVEL TROUGH NEAR THE
COAST OF MEXICO ALONG 24N97W 19N95W IS PRODUCING A NARROW
AREA...WITHIN 30 NM OF THE TROUGH LINE...OF LOW-LEVEL CLOUDS AND
EMBEDDED SHALLOW SHOWERS. OTHERWISE...WIDESPREAD FAIR WEATHER
DOMINATES THE REGION SUPPORTED BY VERY DRY AIR ALOFT ALONG AND
TO THE W OF A WELL DEFINED MID-UPPER TROUGH.

THE CARIBBEAN SEA...
WATER VAPOR IMAGERY DEPICTS AN AMPLIFIED MID-UPPER PATTERN
OVER THE CARIB. THE BASE OF A TROUGH EXTENDS SWD FROM THE
YUCATAN CHANNEL TO PANAMA PROVIDING SUPPORT FOR THE TAIL END OF
A COLD FRONT FROM ERN CUBA TO NICARAGUA ALONG 20N77W 15N83W.
BEHIND THE FRONT...N TO NE 20-25 KT WINDS HAVE ADVECTED MUCH
DRIER AIR INTO THE NW PORTION...INDICATED BY BUOY 42056 WHICH
HAS BEEN REPORTING DEWPOINTS IN THE UPPER 50'S F. THE FRONT WILL
LIKELY MAKE LITTLE FURTHER FORWARD PROGRESS DUE TO A LARGE
BLOCKING MID-UPPER RIDGE OVER THE WINDWARD ISLANDS. STRONG SWLY
WINDS...BETWEEN THE MID-UPPER TROUGH AND RIDGE...IS PRODUCING
AND TRANSPORTING A SWATH OF MID-HIGH LEVEL CLOUDINESS FROM
COLOMBIA TO THE DOMINICAN REPUBLIC. OTHERWISE...MODERATE TO
STRONG SUBSIDENCE IS CAPPING THE SCATTERED LOW-LEVEL CLOUD
PATCHES. THESE SHALLOW MOISTURE PATCHES ARE MOST ORGANIZED
WITHIN 180 NM W OF THE FRONT...240 NM E OF THE FRONT N OF
18N...AND OVER THE NE WATERS.

THE ATLANTIC OCEAN...
A POTENT MID-UPPER TROUGH OFF THE ERN CONUS IS SUPPORTING A
STRONG COLD FRONT THAT ENTERS THE REGION NEAR 32N65W AND EXTENDS
SW ACROSS THE BAHAMAS ALONG 26N70W 21N76W. SCATTERED SHOWERS AND
ISOLATED TSTMS ARE WITHIN 180 NM E OF THE FRONT. A SECONDARY
SURGE OR POST-FRONTAL TROUGH...ASSOCIATED WITH THE MID-UPPER
TROUGH AXIS...EXTENDS FROM 32N69W TO 27N76W. TIGHT PRES
GRADIENT...BETWEEN THE FRONT AND A 1032 MB HIGH OVER THE SE
STATES...IS PRODUCING GALE FORCE WINDS N OF 29N BETWEEN THE
FRONT AND 75W. WINDS SHOULD SUBSIDE BELOW WARNING CRITERIA BY
THIS EVENING/TONIGHT.

DEEP LAYER HIGH PRES IS WELL IN CONTROL E OF THE FRONT OVER MUCH
OF THE CENTRAL ATLC. THE UPPER AXIS EXTENDS NNE FROM A HIGH
CENTER OVER THE WINDWARD ISLANDS AND THE SFC HIGH IS ANALYZED
1035 MB NEAR 38N36W. MAINLY FAIR WEATHER IS ASSOCIATED WITH THIS
RIDGING. AN AMPLIFIED MID-UPPER TROUGH COVERS THE E ATLC
DEEPENED BY AN EMBEDDED LOW NEAR 23N27W. THE ASSOCIATED SFC LOW
HAS OPENED INTO A TROUGH FROM 27N24W TO 20N29W. SCATTERED
SHOWERS AND ISOLATED TSTMS ARE WITHIN 180 NM EITHER SIDE OF THE
TROUGH N OF 24N. STRONG S TO SW FLOW ALOFT IS SHEARING
ITCZ-CONVECTION BUT MOST OF IT IS NOT SPREADING N OF 7N.

$$
CANGIALOSI



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