[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 250554
TWDAT

TROPICAL WEATHER DISCUSSION...COR
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SAT NOV 25 2006

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...WEATHER OBSERVATIONS...RADAR...
AND METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0530 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 9N13W 5N27W 9N46W 10N58W. CLUSTERS
OF SCATTERED MODERATE CONVECTION IS WITHIN 240 NM EITHER SIDE OF
THE AXIS BETWEEN 34W-47W AND WITHIN 300 NM N OF THE AXIS BETWEEN
47W-53W. ISOLATED MODERATE IS WITHIN 180 NM N OF THE AXIS E OF
25W.

...DISCUSSION...
THE GULF OF MEXICO...
HIGH PRES RIDGING IS CENTERED BOTH AT THE SFC AND ALOFT ACROSS
THE AREA. THIS PATTERN IS PRODUCING PLENTY OF VERY STABLE/DRY
AIR AND LIGHT TO MODERATE WINDS FLOWING CLOCKWISE AROUND A 1027
MB HIGH CENTERED ACROSS THE MID-ATLANTIC STATES. THE ONLY AREA
OF MOISTURE MENTIONABLE IS ASSOCIATED WITH LOW-LEVEL NE FLOW
ACROSS THE ATLC DRAGGING LOW CLOUDS AND ISOLATED SHOWERS ON THE
BREEZE ACROSS THE FL PENINSULA. TEMPS ARE BACK TO NEAR NORMAL
VALUES...WHICH IS QUITE A RECOVERY FROM EARLIER THIS WEEK.
CONTINUED WARMING AND SOME SLIGHT MOISTENING IS EXPECTED AS THE
LAYERED RIDGE SLIDES EASTWARD.

THE CARIBBEAN SEA...
A NEARLY STATIONARY BROAD 1008 MB LOW PRES SYSTEM IS CENTERED N
OF PANAMA NEAR 11N78W. SHOWER ACTIVITY IS VERY MINIMAL NEAR THE
LOW-LEVEL CIRCULATION CENTER EXCEPT FOR ONE BURST OF MODERATE
CONVECTION IN THE NRN SEMICIRCLE FROM 12N-13N BETWEEN 77W-78W.
THIS SYSTEM IS NOW DETACHED FROM THE PERSISTENT FRONTAL BOUNDARY
IN THE AREA WHICH IS STATIONARY OR DRIFTING BACK W AS A WARM
FRONT FROM THE WINDWARD PASSAGE ACROSS JAMAICA TO NEAR 12N81W.
SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 150 NM OF THE
FRONT. THE LOW PRES SYSTEM IS BEING MONITORED AS SOME SLOW
DEVELOPMENT IS POSSIBLE OVER THE NEXT DAY OR SO. MUCH OF THE
CENTRAL AND ERN CARIBBEAN IS QUIET WITH DRY AIR ALOFT IN PLACE
ASSOCIATED UPPER LEVEL CONFLUENCE BETWEEN AN UPPER HIGH CENTERED
N OF VENEZUELA NEAR 13N68W AND UPPER LOW/TROUGH JUST E OF THE
WINDWARD ISLANDS. MOISTURE ASSOCIATED WITH THE UPPER LOW/SFC
TROUGH IS LOCATED JUST E OF THE AREA BUT SOME OF THIS MAY MOVE
INTO THE AREA LATER WEEKEND AS THE SFC TROUGH MOVES WESTWARD.

THE ATLANTIC OCEAN...
VERY DRY STABLE AIR ALOFT COVERS THE SW ATLC FROM BERMUDA TO THE
BAHAMAS. THIS AREA IS W OF A PERSISTENT STALLED FRONTAL BOUNDARY
WHICH EXTENDS FROM 32N63W TO 25N68W TO THE WINDWARD PASSAGE.
MOISTURE DOES NOT APPEAR VERY DEEP ALONG THE FRONT...BASED ON IR
IMAGERY...AS THERE IS LIKELY ONLY SCATTERED SHOWERS WITHIN 240
NM OF THE SFC BOUNDARY. A LARGE AMPLIFIED LONGWAVE RIDGE LIES E
OF THE UPPER TROUGH/FRONTAL BOUNDARY AND COVERS A LARGE PORTION
OF THE CENTRAL AND ERN ATLC BETWEEN 25W-60W ANCHORED BY A HIGH
CENTER NEAR 24N36W. THE WRN EXTENSION OF THIS RIDGE IS BEING
ERODED BY A NARROW UPPER TROUGH WHICH EXTENDS FROM AN UPPER LOW
NEAR 26N55W TO ANOTHER UPPER LOW DEEP IN THE TROPICS NEAR
12N57W. THIS DIFFLUENT PATTERN IS ENHANCING A LARGE AREA OF
CONVECTION EMBEDDED IN THE ITCZ...REFER TO THAT SECTION FOR
DETAILS. SCATTERED SHOWERS ALSO EXIST ON THE MOIST E SIDE OF THE
NRN UPPER LOW FROM 20N-30N BETWEEN 47W-54W. A STRONG MID/UPPER
LEVEL TROUGH COVERS THE ERN-MOST ATLC JUST W OF THE IBERIAN
PENINSULA ACROSS THE CANARY ISLANDS TO NEAR 12N21W. THE
ASSOCIATED COLD FRONT JUST CLIPS THE NE PORTION OF THE AREA WITH
LIMITED LOW-LEVEL MOISTURE. AT THE SFC...HIGH PRES RIDGING
DOMINATES THE NEARLY THE ENTIRE ATLC SUPPORTED BY A 1025 MB HIGH
NEAR 36N40W AND A 1022 MB HIGH NEAR 27N34W. THIS RIDGING IS
BROKEN BY THE FRONTAL BOUNDARY MENTIONED IN THE CNTRL/WRN ATLC
WITH RIDGING CONTINUING IN THE THE GULF AND EXTREME WRN ATLC.

$$
CANGIALOSI




This weather bulletin was brought to you by:
www.nashvilleweather.net