[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 220550
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST THU FEB 22 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N12W 3N17W 1N30W 2N40W CROSSING THE
EQUATOR NEAR 44W AND INTO NE BRAZIL. CLUSTERS OF SCATTERED
MODERATE CONVECTION ARE WITHIN 90 NM EITHER SIDE OF THE AXIS
BETWEEN 17W-20W. SCATTERED MODERATE IS FROM THE EQ TO 4N BETWEEN
46W-51W.

...DISCUSSION...
GULF OF MEXICO...
WEAK HIGH PRES RIDGING IS THE THEME ACROSS THE W ATLC AND GULF
WITH TWO EMBEDDED 1022 MB HIGH CENTERS IN THE N CENTRAL AND NE
GULF. TWO WEAK SFC TROUGHS ARE BREAKING UP THE WEAK RIDGE ONE
DEFINED BY A THIN LINE OF BROKEN CLOUDS AND AN SLIGHT INCREASE
IN WINDS FROM CENTRAL FL TO 26N89W. THE OTHER TROUGH IS VERY
DIFFUSE ALONG 89W S OF 25N. ALOFT...THE FLOW IS RATHER ZONAL TO
WNW...SANDWICHED BETWEEN A SPRAWLING RIDGE CENTERED OVER S
MEXICO AND TROUGHING ALONG THE U.S. EAST COAST. WV IMAGES SHOW A
GOOD AMOUNT OF DRY AIR ACROSS THE ENTIRE AREA...ESPECIALLY N OF
27N AND S OF 22N CLOSER TO THE UPPER CONFLUENT ZONES.
ESSENTIALLY THIS PATTERN...BOTH AND THE SFC AND ALOFT...IS
LEADING TO FAIR AND MILD WEATHER ACROSS THE REGION WITH LIGHT
WINDS. OVER THE NEXT COUPLE OF DAYS...THE SFC PATTERN IS
EXPECTED TO TIGHTEN UP AS STRONG CANADIAN HIGH PRES RIDGING
EXTENDS WELL S INTO THE AREA. AS THIS HIGH SLIDES E...SLY RETURN
FLOW IS EXPECTED TO INCREASE IN THE W GULF BEGINNING LATE FRI IN
RESPONSE TO THE NEXT COLD FRONT WHICH IS EXPECTED TO PUSH OFF
THE TX COAST ON SAT.

CARIBBEAN SEA...
HIGH PRES LOCATED JUST N OF THE AREA IS PRODUCING MODERATE TO
STRONG TRADES ACROSS THE BASIN WITH THE STRONGEST WINDS OFF THE
COAST OF COLOMBIA...AS DEPICTED WELL BY A 00Z QSCAT PASS WHICH
SHOWED NELY IN THE 20 TO 30 KT RANGE. TYPICAL PATCHES OF LOW
LEVEL MOISTURE WITH EMBEDDED SHOWERS DRIVEN BY THE TRADES ARE
AFFECTING THE AREA...PARTICULARLY THE E CARIBBEAN AND OVER THE
ISLAND OF HISPANIOLA. THE MID AND UPPER LEVEL PATTERN IS
DOMINATED BY A STRONG RIDGE CENTERED OVER S MEXICO. NEARLY ALL
OF THE REGION LIES ON THE E SIDE...DOWNWARD BRANCH...OF THE
RIDGE ENHANCING AN ABUNDANCE OF EXTREMELY DRY/STABLE AIR. THIS
STRONG CAP IS PREVENTING THE LOW LEVEL PATCHES ACQUIRE MUCH
DEPTH. OVER THE NEXT COUPLE OF DAYS...NWP MODELS SHOW LITTLE
CHANGE IN THE OVERALL PATTERN SO SIMILAR TRADES/WX CONDITIONS
ARE ANTICIPATED.

ATLANTIC OCEAN...
THE SFC PATTERN IS DOMINATED BY A LARGE FLAT RIDGE STRETCHED
ACROSS THE ENTIRE BASIN. THERE ARE TWO EMBEDDED HIGH
CENTERS...THE STRONGER IS 1026 MB LOCATED OVER THE CANARY
ISLANDS. THE OTHER IS 1023 MB LOCATED BETWEEN BERMUDA AND
HISPANIOLA NEAR 26N68W. THIS STRETCHED RIDGE IS FURTHER S THAN
WHAT IS TYPICAL. THE MID AND UPPER LEVEL PATTERN IS A LITTLE
MORE AMPLIFIED THAN THE SFC PATTERN...BUT NOT MUCH. STRONG ZONAL
FLOW ALOFT COVERS MOST OF THE AREA W OF 50W. UPPER LEVEL
DIFFLUENCE IS SUPPORTING A SWATH OF MOISTURE CONTINUED N OF 28N
BETWEEN 40W-77W. THE MOISTURE IS DEEPEST N OF 32N BETWEEN
30W-40W ENHANCED BY THE BASE OF AN UPPER TROUGH. THIS TROUGH
SUPPORTS A WEAK STATIONARY OR SLOW MOVING WARM FRONT ALONG
31N35W 31N42W 26N50W 24N56W. THE FRONT IS SLOWLY BECOMING
DIFFUSE ONLY DEFINED BY BROKEN LOW CLOUDS AND A WIND SHIFT.  IN
THE TROPICAL ATLC...A WEAK UPPER TROUGH HAS DEVELOPED ROUGHLY
ALONG 20N45W 9N60W. E OF THE TROUGH AXIS...SWLY FLOW IS
ADVECTING SOME HIGH LEVEL MOISTURE NWD BETWEEN 41W-47W S OF 19N.
THIS MOISTURE THEN GETS SUPPRESSED S AS A STRONG UPPER LEVEL
RIDGE TAKES CONTROL IN THE E ATLC CENTERED NEAR 17N29W.
OVERALL...FAIR WEATHER DOMINATES THE MAJORITY OF THE DISCUSSION
AREA WITH CLOUDS/MOISTURE MOST ORGANIZED IN THE ITCZ AND IN THE
AREA OUTLINED ABOVE.

$$
CANGIALOSI







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