[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 192330
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI MAR 19 2010

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND 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
2300 UTC...

...SPECIAL FEATURE...

A STATIONARY FRONT REMAINS OVER HAITI AND EXTENDS S TO PANAMA
ALONG 19N72W 15N78W 9N80W. TOTAL PRECIPITABLE WATER IMAGERY
INDICATES SIGNIFICANT MOISTURE ACROSS THE CENTRAL CARIBBEAN
ASSOCIATED WITH THIS FRONT. THE SYSTEM BRINGS CONTINUED SHOWERS
TO HISPANIOLA AND SURROUNDING WATERS N OF 18N BETWEEN 68W-75W.
RAIN MAY BE HEAVIER OVER HIGHER ELEVATIONS. EXPECT RAIN TO
CONTINUE OVER THE SAME AREA FOR THE NEXT 24 HOURS.

...ITCZ...

ITCZ AXIS IS CENTERED FROM SIERRA LEONE NEAR 7N12W ALONG 5N20W
3N30W 2N40W TO THE NE BRAZIL COAST NEAR EQ50W. SCATTERED
MODERATE/STRONG CONVECTION IS FROM 2N-7N BETWEEN 12W-16W.
SIMILAR ACTIVITY IS FROM 4N-7N BETWEEN 18W-26W. ISOLATED
MODERATE CONVECTION IS FROM 1N-3N BETWEEN 37W-40W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE DOMINATES THE GULF OF MEXICO ANCHORED BY A 1020
MB HIGH S OF ALABAMA NEAR 29N87W BRINGING GENERALLY FAIR WEATHER
ACROSS THE BASIN. LIGHT ANTI-CYCLONIC SURFACE FLOW IS AROUND THE
RIDGE WITH INCREASING SE-S WINDS UP TO 20 KT OVER THE WRN GULF.
SKIES ARE MAINLY CLEAR EXCEPT FOR AN AREA ALONG THE NE MEXICO
AND S TEXAS COAST N OF 21N W OF 95W WHERE BROKEN TO OVERCAST
SKIES PREVAIL. ALOFT...MAINLY ZONAL WLY FLOW IN A 90-110 KT
JETSTREAM N OF 25N COVERS THE BASIN ACCOMPANIED BY DRY AIR AND
SUBSIDENCE. EXPECT THE SURFACE RIDGE TO SHIFT EWD ALLOWING SLY
RETURN FLOW TO INCREASE ACROSS THE WRN GULF AND SPREAD E AHEAD
OF A COLD FRONT FORECAST TO MOVE OFF THE TEXAS COAST SAT.

CARIBBEAN SEA...
A STATIONARY FRONT CONTINUES TO IMPACT THE CENTRAL CARIBBEAN
EXTENDING FROM THE W ATLC ACROSS HAITI TO PANAMA ALONG 19N72W
15N78W 9N80W. SCATTERED SHOWERS ARE N OF 18N BETWEEN 68W-75W
AFFECTING MUCH OF HISPANIOLA...SEE SPECIAL FEATURES ABOVE.
ISOLATED SHOWERS AREA WITHIN 45 NM OF THE FRONT ELSEWHERE. A
SURFACE TROUGH IS AHEAD OF THE FRONT ALONG 18N73W 14N74W TO
INLAND COLOMBIA. ISOLATED SHOWERS ARE N OF 15N BETWEEN 70W-73W.
THIS FRONT IS SUPPORTED BY A BROAD UPPER LEVEL TROUGH OVER THE W
ATLC THAT EXTENDS TO THE CENTRAL ATLC ACROSS THE WINDWARD
PASSAGE TO NEAR 12N76W. SIGNIFICANT DRY AIR AND SUBSIDENCE
BUILDS BEHIND THE UPPER TROUGH OVER THE NW CARIBBEAN KEEPING
CONDITIONS CLEAR. ACROSS THE ERN CARIBBEAN...MODERATE TO FRESH
TRADEWINDS PREVAIL ALONG WITH GENERALLY FAIR WEATHER. ALOFT...AN
UPPER LEVEL RIDGE EXTENDS FROM NRN COLOMBIA TO THE CENTRAL ATLC.
EXPECT THE FRONTAL SYSTEM TO BRING CONTINUED SHOWER ACTIVITY TO
THE N CENTRAL CARIBBEAN ISLANDS OVER THE NEXT 24 HRS.

ATLANTIC OCEAN...
A DEEP LAYER TROUGH REMAINS OVER THE W ATLC SUPPORTING A COLD
FRONT ENTERING THE DISCUSSION AREA NEAR 32N62W ALONG 26N65W
22N69W BECOMING STATIONARY TO HAITI. NUMEROUS SHOWERS WITH
EMBEDDED THUNDERSTORMS ARE WITHIN 90 NM BEHIND...AND 150 NM
AHEAD OF THE FRONT. THIS AREA OF SHOWERS ACTIVITY IS ENHANCED BY
UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER TROUGH OVER THE W ATLC
AND AN UPPER LEVEL RIDGE EXTENDING FROM THE E CARIBBEAN TO NEAR
40N49W. THIS UPPER RIDGE IS SUPPORTING A SURFACE RIDGE OVER THE
CENTRAL AND E ATLC ANCHORED BY A 1026 MB HIGH NEAR 33N41W WHICH
IS KEEPING CONDITIONS GENERALLY FAIR. HOWEVER...A SECOND COLD
FRONT PROTRUDES INTO THE SURFACE RIDGE FROM E OF THE CANARY
ISLANDS NEAR 31N18W ALONG 25N25W 21N37W DISSIPATING TO NEAR
20N41W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE FRONT N OF
26N. ISOLATED SHOWERS ARE WITHIN 30 NM OF THE FRONT ELSEWHERE.
THIS FRONTAL BOUNDARY IS SUPPORTED BY AN UPPER LEVEL TROUGH
EXTENDING FROM THE AZORES ISLANDS TO THE CANARY ISLANDS TO THE
CAPE VERDE ISLANDS TO NEAR 2N34W. THIS UPPER LEVEL TROUGH IS
ALSO MOST LIKELY ENHANCING THE CONVECTION ALONG THE ERN HALF OF
THE ITCZ.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
WALTON




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