[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 232327
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI MAR 23 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.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N11W 4N21W 2N31W 1N45W EQ52W.
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS
WITHIN 240 NM S OF THE AXIS E OF 18W. ISOLATED SHOWERS AND TSTMS
WITHIN 150 NM EITHER SIDE OF THE AXIS ELSEWHERE.

...DISCUSSION...

GULF OF MEXICO...
AN AMPLIFIED FAIRLY NARROW MID-UPPER LEVEL RIDGE IS PUSHING
SLOWLY E WITH THE AXIS ALIGNED ALONG 91W. THIS RIDGE IS
DOWNSTREAM OF A STRONG CUT OFF LOW OVER THE SW STATES. STRONG
SWLY FLOW BETWEEN THE RIDGE AND TROUGH IS ADVECTING A PLUME OF
MOISTURE ACROSS CENTRAL MEXICO AND INTO THE SOUTH CENTRAL U.S.
SOME OF THIS MOISTURE...WHICH APPEARS TO BE MAINLY IN THE FORM
OF MID-HIGH LEVEL CLOUDS...IS SPILLING INTO THE GULF CONTAINED W
OF THE RIDGE AXIS. THE ERN HALF OF THE REGION IS VERY STABLE
WITH WIDESPREAD STRONG SUBSIDENCE NOTED E OF 88W. THIS
SUBSIDENCE IS BEING PRODUCED BY UPPER LEVEL CONFLUENCE BETWEEN
THE DOWNWARD BRANCH OF THE RIDGE AND A SHARP UPPER TROUGH ACROSS
THE BAHAMAS AND THE FL KEYS. AT THE SFC...IT'S THE SAME STORY AS
THE AREA REMAINS ON THE SW PERIPHERY OF STRONG CENTRAL ATLC HIGH
PRES. THIS IS KEEPING WINDS MODERATE OUT OF THE E-SE BLOWING IN
ISOLATED SHOWERS ACROSS S FLA...BUT FAR FEWER THAN THERE WERE
YESTERDAY AS THE UPPER DYNAMICS HAVE SHIFTED E. LOOKING AHEAD TO
THE WEEKEND...MAINLY FAIR WEATHER IS EXPECTED TO CONTINUE WITH
RIDGING BOTH AT THE SFC AND ALOFT CONTROLLING THE PATTERN.

CARIBBEAN...
A SHARP UPPER LEVEL TROUGH EXTENDS FROM THE WRN BAHAMAS ACROSS
CUBA TO HONDURAS WITH AN EMBEDDED UPPER LOW NEAR 18N83W. E OF
THIS TROUGH AXIS...UPPER LEVEL DIFFLUENCE IS FUELING SCATTERED
SHOWERS AND TSTMS WITHIN 150 NM EITHER SIDE OF A LINE ALONG
16N84W 20N73W. SIMILAR ACTIVITY IS OCCURRING OVER THE ISLAND OF
HISPANIOLA ENHANCED BY LOW-LEVEL CONVERGENCE NEAR THE TAIL END
OF A PERSISTENT SFC TROUGH...MORE ON THIS FEATURE IN THE
ATLANTIC SECTION. OUTSIDE OF THE REGION OUTLINED...RATHER
TRANQUIL CONDITIONS PREVAIL WITH FAIR SKIES AND MODERATE TRADES.
OVER THE NEXT COUPLE OF DAYS...THE AREA OF MOISTURE IS LIKELY TO
PERSIST AND SHIFT SLIGHTLY TO THE E WITH THE UPPER LOW/TROUGH.

ATLANTIC...
UNSETTLED WEATHER CONTINUES TO AFFECT PORTIONS OF THE WRN ATLC
WITH A LARGE AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS...S OF
29N BETWEEN 54W-74W. THIS ACTIVITY IS BEING PRODUCED BY TWO
ELEMENTS. ONE OF THESE IS UPPER LEVEL DIFFLUENCE TO THE E OF A
SHORTWAVE TROUGH AXIS WHICH RUNS FROM BERMUDA TO THE WRN
BAHAMAS. THE OTHER IS LOW-LEVEL CONVERGENCE NEAR A SFC TROUGH
WHICH EXTENDS FROM 27N62W TO HISPANIOLA. THIS MESSY WEATHER IS
EXPECTED TO CONTINUE FOR THE NEXT FEW DAYS AS THE SFC BOUNDARY
HANGS AROUND...POSSIBLY MERGING WITH A COLD FRONT EARLY NEXT
WEEK... AND THE UPPER TROUGH MOVES VERY SLOWLY TO THE NE.

THE UPPER LEVEL FLOW ACROSS THE REMAINDER OF THE ATLC IS FAIRLY
ZONAL WITH PATCHES OF HIGH CLOUDS SANDWICHED BETWEEN A SERIES OF
SHORTWAVES N OF THE AREA AND BROAD FLAT RIDGING ACROSS THE
EQUATORIAL ATLC. THE SFC PATTERN IS DOMINATED BY A 1033 MB HIGH
CENTERED NEAR 37N44W...PRODUCING A LARGE AREA OF MODERATE
TRADES. THIS HIGH IS EXPECTED TO CONTINUE ON IT'S SE TRACK
PROVIDING FAIR WEATHER FOR MUCH OF THE CENTRAL AND E ATLC THIS
WEEKEND.

$$
CANGIALOSI




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