[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201742
TWDAT

TROPICAL WEATHER DISCUSSION...
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN APR 20 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 4N23W 3N30W 1N40W TO THE
EQUATOR AT 50W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM
4N-7N BETWEEN 13W-16W. SCATTERED MODERATE CONVECTION IS WITHIN
210 NM N OF THE AXIS W OF 33W AND WITHIN 90 NM N OF THE AXIS
BETWEEN 25W-27W.

...DISCUSSION...

GULF OF MEXICO...
A MID TO UPPER LEVEL RIDGE IS BUILDING E ACROSS THE GULF
...CURRENTLY CENTERED ALONG 93W...OVERTAKING TROUGHING OVER THE
NE WATERS AND FLORIDA. THIS TROUGHING...ASSOCIATED WITH A CUT
OFF LOW OVER THE OHIO VALLEY...IS PROVIDING LIMITED SUPPORT FOR
A NEARLY STATIONARY FRONT FROM CENTRAL FLORIDA TO 26N90W. THE
FRONT IS ONLY MARKED BY A VERY NARROW LINE OF LOW CLOUDS WITH
EMBEDDED SCATTERED SHOWERS AS INDICATED ON DOPPLER RADAR. A WEAK
1018 MB HIGH HAS BUILT BEHIND THE FRONT CENTERED OVER THE N
CENTRAL WATERS NEAR 29N89W. MAINLY FAIR WEATHER DOMINATES THE
MAJORITY OF THE REGION SUPPORTED BY A SUBSIDENT
ENVIRONMENT...ESPECIALLY OVER THE SW PORTION. THE FRONT IS
EXPECTED TO CONTINUE TO WEAKEN AND SHIFT SE ALLOWING FAIR
WEATHER TO CONTINUE INTO THE BEGINNING OF THE WORK WEEK.

CARIBBEAN SEA...
A BROAD UPPER TROUGH LIES OVER THE CARIBBEAN SEA AND FLAT
RIDGING COVERS MUCH OF THE TROPICAL ATLC AND SOUTH AMERICA. THIS
LARGE SCALE PATTERN IS PRODUCING A MODERATE TO STRONGLY
SUBSIDENT ENVIRONMENT N OF 14N. S OF 14N...THE ATMOSPHERE IS
BEING SOMEWHAT MOISTENED ALOFT BY BROKEN HIGH LEVEL CLOUDS. IN
THE LOWER LEVELS...A 1034 Z QSCAT PASS SUGGESTS 25-30 KT NE
WINDS NEAR THE COAST OF COLOMBIA AND MODERATE TRADES ELSEWHERE.
THE TYPICAL LOW-LEVEL CLOUD PATCHES APPEAR SUBDUED TODAY WITH
THE ONLY ORGANIZED PATCH OVER THE NRN LEEWARD ISLANDS. THE TRADE
WIND FLOW IS EXPECTED TO WEAKEN TOMORROW AS TROUGHING BECOMES
BETTER ESTABLISHED OVER THE W ATLC. OTHERWISE...LITTLE
SIGNIFICANT CHANGE IS EXPECTED OVER THE NEXT DAY OR SO.

ATLANTIC OCEAN...
A LARGE SCALE TROUGH...WITH A FEW EMBEDDED SHORTWAVES...COVERS
MUCH OF THE W ATLC. ONE OF THE SHORTWAVES IS SUPPORTING A COLD
FRONT FROM THE NORTH CAROLINA COAST TO NE FLORIDA. A PRE-FRONTAL
TROUGH LIES AHEAD OF IT FROM 32N78W TO 27N79W. DOPPLER RADAR AND
LIGHTNING DATA IS SHOWING QUITE A BIT OF TSTM ACTIVITY ALONG
THESE BOUNDARIES BUT MOST OF IT IS N OF 31N/32N. SCATTERED
SHOWERS AND TSTMS ARE ALSO LOCATED N OF HISPANIOLA AND PUERTO
RICO FROM 21N-24N BETWEEN 61W-72W. THIS ACTIVITY IS ASSOCIATED
WITH BASE OF THE UPPER TROUGH (VORTICITY MAX) AND LOW-LEVEL
CONVERGENCE ALONG A PAIR OF SFC TROUGHS. DEBRIS MID-HIGH LEVEL
CLOUDS COMBINED WITH LOW LEVEL CLOUDS TRIGGERED BY A LINGERING
SFC TROUGH FROM 31N54W TO 25N61W IS PRODUCING A FAIR AMOUNT OF
CLOUD COVER AND ISOLATED SHOWERS WITHIN 120 NM OF THE SFC TROUGH
LINE.

THE CENTRAL AND EASTERN ATLC IS DOMINATED BY A QUASI-STATIONARY
1025 MB HIGH NEAR 31N35W. THIS HIGH IS PRODUCING A LARGE AREA OF
15-20 KT NE/E WINDS ACROSS THE TROPICAL BELT. IN THE MID AND
UPPER LEVELS...A RIDGE AXIS EXTENDS FROM 20N40W THRU 32N35W...A
WEAK SMALL UPPER LOW IS NEAR 19N30W AND UPPER TROUGHING LIES
OVER THE FAR NE PORTION. THIS OVERALL PATTERN IS PRODUCING
LITTLE SENSIBLE WEATHER BESIDES FOR AN AREA OF POSSIBLE
SHOWERS/TSTMS FROM 8N-10N BETWEEN 33W-40W.

$$
CANGIALOSI


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