[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 162359
TWDAT

TROPICAL WEATHER DISCUSSION...
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED APR 16 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...THE ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N11W 3N18W 0.5N30W CROSSING THE
EQUATOR NEAR 34W TO 1S48W. SCATTERED MODERATE TO STRONG
CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS E OF 16W.
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS
BETWEEN 24W-26W AND 35W-38W. ISOLATED MODERATE CONVECTION IS
WITHIN 240 NM N OF THE AXIS W OF 40W.

...DISCUSSION...

GULF OF MEXICO...
SFC HIGH PRES CONTINUES TO SHIFT E...CURRENTLY 1026 MB CENTERED
OVER GEORGIA...ALLOWING LOW-LEVEL RETURN FLOW TO BECOME
ESTABLISHED ACROSS THE WRN WATERS. THIS FLOW HAS GREATLY
MODIFIED THE COOL AIRMASS THAT WAS IN PLACE EARLIER THIS WEEK.
THE COOL AIRMASS IS STILL HANGING ON OVER THE ERN WATERS
ENHANCED BY LOW PRES OVER THE W ATLC. SCATTERED STRATOCUMULUS
CLOUDS ARE SLOWLY THINNING BETWEEN 86W-93W. IN THE MID AND UPPER
LEVELS...TROUGHING EXTENDS ACROSS FLORIDA AND INTO THE E GULF
WHILE A BUILDING RIDGE EXTENDS OVER MEXICO AND THE W WATERS.
THIS PATTERN IS PRODUCING A DRY STABLE ENVIRONMENT...ESPECIALLY
N OF LINE FROM CORPUS CHRISTI TO HAVANA...PROVIDING WIDESPREAD
FAIR WEATHER. THIS FAIR WEATHER REGIME WILL CONTINUE THRU
TOMORROW. THEREAFTER...THE NEXT COLD FRONT IS EXPECTED TO ENTER
THE NW WATERS ON FRI...BUT THIS ONE IS NOT EXPECTED TO BE NEARLY
AS STRONG AS THE PREVIOUS.

CARIBBEAN SEA...
THE TAIL END OF A POTENT COLD FRONT LIES OVER HISPANIOLA WITH
DENSE LOW-LEVEL CLOUDS AND SCATTERED SHOWERS ALONG AND TO THE W
OF THE BOUNDARY N OF 18N BETWEEN 70W-78W. SIMILAR CLOUDS/SHOWERS
ARE OVER THE SW WATERS S OF 12N W OF 80W AND IN THE GULF OF
HONDURAS. THIS MOISTURE IS BEING POOLED IN THESE AREAS...DRIVEN
BY N/NE WINDS...AND THEN ENHANCED BY CONVERGENCE ALONG THE COAST
AND INLAND TERRAIN. ALOFT...THE PATTERN REMAINS FAIRLY FLAT WITH
WATER VAPOR IMAGES INDICATING SLIGHT TROUGHING OVER THE NW
PORTION AND SLIGHT RIDGING OVER THE SW AND E CARIB...LEADING TO
A MODESTLY DRY ENVIRONMENT. TRADE WINDS ARE FAIRLY RELAXED E OF
THE FRONT BUT SHOULD BE ON THE INCREASE TOMORROW AND FRI AS HIGH
PRES BUILDS N OF THE REGION.

ATLANTIC OCEAN...
A VERTICALLY STACKED LOW PRES SYSTEM IS SPINNING OVER THE W ATLC
WITH SFC OBSERVATIONS INDICATING A MIN PRES OF 1001 MB NEAR
30N71W. WHILE WINDS ARE JUST BELOW GALE FORCE IN OUR FORECAST
WATERS THE TIGHT PRES GRADIENT BETWEEN THIS LOW AND HIGH PRES
OVER GEORGIA IS PRODUCING STORM FORCE WINDS N OF THE AREA. IR
IMAGES AND LIGHTNING DATA REVEAL SCATTERED SHOWERS AND TSTMS
MAINLY N OF THE LOW CENTER AND ALONG AND N OF A TRAILING TROUGH
AXIS FROM 28N-31N BETWEEN 74W-76W. THIS DEEP LAYER LOW PRES
SYSTEM HAS ALSO BEEN SUPPORTING A PAIR OF FRONTS. HOWEVER...IT
NOW APPEARS THAT THE SECOND BOUNDARY HAS MERGED WITH THE LEADING
ONE ALONG 31N64W 22N68W TO HISPANIOLA. SCATTERED TSTM ACTIVITY
IS N OF 26N BETWEEN 60W-65W ENHANCED BY UPPER DIFFLUENCE.
SCATTERED SHOWERS ARE ELSEWHERE WITHIN 120 NM E AND 180 NM W OF
THE FRONT.

THE REMAINDER OF THE ATLC BASIN IS RATHER TRANQUIL THANKS TO A
NEARLY STATIONARY SPRAWLING DEEP LAYER HIGH PRES SYSTEM CENTERED
NEAR 30N35W. THE SFC CENTER...ANALYZED 1029 MB...IS PRODUCING N
TO NE 20-25 KT WINDS NEAR THE COAST OF AFRICA FROM 19N-26N AND
MAINLY 15-20 KT NE/E WINDS ACROSS THE REMAINDER OF THE TROPICS.
AN UPPER LOW IS SPINNING NEAR 20N56W...BUT PRODUCING LITTLE
WEATHER AT THE MOMENT. A RETREATING UPPER TROUGH EXTENDS ACROSS
NW AFRICA TO 20N16W THEN WWD TO 19N37W. STRONG WLY UPPER FLOW
BETWEEN THIS TROUGH AND A FLAT UPPER RIDGE OVER THE TROPICS IS
SPREADING A PLUME OF HIGH LEVEL CLOUDINESS S OF 15N.

$$
CANGIALOSI






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