AXNT20 KNHC 112348
TWDAT
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
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 2315 UTC.
...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 7N10W 3N20W CROSSING THE
EQUATOR ALONG 28W TO NORTHEASTERN BRAZIL NEAR 3S40W. ISOLATED
MODERATE CONVECTION IS FROM 6N-9N BETWEEN 14W-17W.
...DISCUSSION...
THE GULF OF MEXICO...
AS OF 2100 UTC...A 1000 MB LOW IS CENTERED OVER THE NW GULF OF
MEXICO NEAR 26N94W. A SURFACE TROUGH EXTENDS S FROM THE LOW TO
THE BAY OF CAMPECHE NEAR 19N95W. ANOTHER 1004 MB LOW IS CENTERED
OVER N FLORIDA NEAR 30N84W. A SMALL COLD FRONT EXTENDS W FROM
THIS LOW CENTER TO 28N90W. OVERCAST MULTILAYERED CLOUDS ARE OVER
THE GULF N OF 25N. RADAR IMAGERY SHOWS RAIN AND ISOLATED
THUNDERSTORMS OVER CENTRAL AND NORTH FLORIDA AND SURROUNDING
WATERS FROM 27N-30N BETWEEN 78W-84W. IN THE UPPER LEVELS...ZONAL
FLOW PREVAILS WITH A 130-150 KT JETSTREAM OVER THE N GULF N OF
24N. EXPECT IN 24 HOURS...FOR THE 1000 MB LOW TO MOVE E TO THE W
OF TAMPA FLORIDA. A COLD FRONT WILL EXTEND S FROM THE LOW TO THE
YUCATAN PENINSULA WITH CONVECTION. ALSO EXPECT THE 1004 MB LOW
TO MOVE NE TO THE COAST OF SOUTH CAROLINA. A COLD FRONT WILL
EXTEND S FROM THIS LOW TO CENTRAL FLORIDA WITH CONVECTION.
THE CARIBBEAN SEA...
THE TAIL END OF AN OLD STATIONARY FRONT IS OVER THE LEEWARD
ISLANDS FROM 17N60W TO 16N64W. SCATTERED SHOWERS ARE WITHIN 60
NM N OF THE FRONT. AN AREA OF BROKEN TO OVERCAST LOW CLOUDS AND
ISOLATED SHOWERS ARE ALSO OVER THE NE CARIBBEAN FROM 16N-19N E
OF 67W. ELSEWHERE...OVERCAST MULTILAYERED CLOUDS WITH RAIN IS
INLAND OVER N COLOMBIA AND N VENEZUELA FROM 4N-11N BETWEEN
67W-78W. 15-20 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH
STRONGEST WINDS ALONG THE COAST OF N COLOMBIA. WINDS ARE FROM
THE NE OVER THE LEEWARD ISLANDS...FROM THE E OVER THE CENTRAL
CARIBBEAN...AND FROM THE SE OVER THE W CARIBBEAN W OF 80W. IN
THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS PRODUCING W TO NW
UPPER LEVEL WINDS. STRONG SUBSIDENCE IS OVER THE ENTIRE
CARIBBEAN SEA AND CENTRAL AMERICA N OF 12N. EXPECT OVER THE NEXT
24 HOURS...FOR MORE SHOWERS OVER THE LEEWARD ISLANDS...AND OVER
PANAMA AND THE SW CARIBBEAN S OF 12N.
THE ATLANTIC OCEAN...
A 1023 MB HIGH IS CENTERED OVER THE W ATLANTIC NEAR 34N61W. A
1011 MB LOW IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 31N35W. A
COLD FRONT EXTENDS SW FROM THE LOW CENTER TO 24N40W 19N50W. A
STATIONARY FRONT CONTINUES TO THE LEEWARD ISLANDS AT 17N60W.
OVERCAST LOW CLOUDS AND SCATTERED SHOWERS ARE WITHIN 180 NM N OF
THE FRONTS. A WARM FRONT ALSO EXTENDS SE FROM THE LOW CENTER TO
28N26W. SCATTERED MODERATE CONVECTION IS N OF THE WARM FRONT
FROM 31N-34N BETWEEN 30W-35W. SCATTERED SHOWERS ARE ALSO WITHIN
90 NM OF THE WARM FRONT. A COLD FRONT IS OVER THE E ATLANTIC
FROM 30N10W TO 26N20W 28N26W. IN THE UPPER LEVELS...A RIDGE IS
OVER THE W ATLANTIC W OF 55W. AN UPPER LEVEL TROUGH IS OVER THE
CENTRAL ATLANTIC N OF 10N BETWEEN 35W-55W. AN UPPER LEVEL RIDGE
IS OVER THE E ATLANTIC E OF 35W. EXPECT...THE ATLANTIC SURFACE
LOW TO MOVE NE OVER THE NEXT 24 HOURS TO NEAR 34N32W WITH
ASSOCIATED COLD FRONT EXTENDING SW TO 18N50W WITH SHOWERS.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE


forecast by FORMOSA
updated at 705 PM EST THU MAR 11 2010

AXPZ20 KNHC 120334
TWDEP
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI MAR 12 2010
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM
THE EQUATOR TO 32N...EAST OF 140W.
BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0145 UTC.
...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG A LINE
FROM 04N77W TO 06N90W TO 05N105W TO 07N115W TO 02N140W.
SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN
180 NM S OF THE ITCZ AXIS BETWEEN 84W AND 96W AND WITHIN 90 NM N
OF AXIS THE ITCZ AXIS BETWEEN 83W AND 89W. SCATTERED MODERATE
CONVECTION WAS WITHIN 300 NM SW OF THE ITCZ AXIS BETWEEN 109W
AND 118W.
...DISCUSSION...
A PROGRESSIVE PATTERN OVER N WATERS WILL SEE THE BROAD UPPER
TROUGH OVER NW MEXICO FINALLY PUSH EASTWARD AS THE NEXT DEEP
LAYERED TROUGH MOVES INTO NW WATERS OVERNIGHT TONIGHT. A W-SW
UPPER JET IN EXCESS OF 130 KT WILL REMAIN CENTERED ALONG 25N E
OF 120W THROUGH FRI NIGHT WHEN THE JET WILL PUSH E ALONG THE
LEADING EDGE OF THE DEEP LAYERED TROUGH. THE W-SW UPPER LEVEL
WINDS FEEDING INTO THE JET ARE BEGINNING TO LOSE THEIR
CONNECTION TO TROPICAL MOISTURE. THIS IS EVIDENT BY THE
DISSIPATING BAND OF CIRRUS CLOUDS FOUND WITHIN 180 NM OF A LINE
FROM 23N100W TO 16N117W. THE UPPER TROUGH OVER NW MEXICO FROM
30N104W TO 23N110W WILL MOVE E TO MAKE WAY FOR THE DEEP LAYERED
TROUGH BY FRI WITH THE COLD FRONT ASSOCIATED WITH THIS NEW
TROUGH EXPECTED TO BE WEAK INITIALLY. THE LARGEST IMPACT FROM
THIS COLD FRONT OVERNIGHT TONIGHT AND ON FRI WILL BE A NEW SURGE
OF NW SWELL PUSHING INTO THE AREA WITH ITS ARRIVAL...WITH
SIGNIFICANT WAVE HEIGHTS INCREASING TO 13 FT NW OF THE FRONT.
THE FRONT WILL DISSIPATE AS IT MOVES INTO NORTHERN BAJA
CALIFORNIA AND NE WATERS BY SAT EVENING...BUT THE PRES GRADIENT
IS EXPECTED TO BUILD BETWEEN THE FRONTAL TROUGH AND HIGH PRES
FOLLOWING CLOSELY BEHIND IT AS THE NORTHERN STREAM PATTERN
BECOMES MORE AMPLIFIED. THIS WILL ALLOW FOR NW TO N WINDS TO
INCREASE ABOVE 20 KT OVER NE WATERS OFF THE W COAST OF BAJA
CALIFORNIA ON SAT.
A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR
09N107W INFLUENCES THE REMAINDER OF THE DISCUSSION AREA. A RIDGE
AXIS EXTENDS FROM THE ANTICYCLONE NE INTO THE GULF OF FONSECA
WHILE A SECOND RIDGE AXIS EXTENDS SW OF THE ANTICYCLONE TO
07N135W. SCATTERED MODERATE CONVECTION WAS OBSERVED S OF THE
ITCZ BETWEEN 109W AND 118W IN THE REGION OF MODERATE UPPER LEVEL
DIFFLUENCE ASSOCIATED WITH THE ANTICYCLONE ALOFT. PLEASE SEE THE
SECTION ABOVE FOR DETAILS. FARTHER E...SCATTERED MODERATE TO
STRONG CONVECTION WAS NEAR THE ITCZ BETWEEN 83W AND 96W. THIS
AREA LIES IN A POOL OF 2.25 TO 2.50 INCH PRECIPITABLE WATER
VALUES AND UNDER MODERATE UPPER LEVEL DIFFLUENCE. THIS DIFFLUENT
REGION ALOFT IS EXPECTED TO SHIFT W FROM 90W TO 100W PRIMARILY S
OF 05N OVER THE NEXT FEW DAYS. THEREFORE...LOOK FOR THE
STRONGEST CONVECTION TO SHIFT W AS WELL.
AT THE SURFACE...1025 MB HIGH PRES LIES OVER NW WATERS NEAR
28N132W WITH A RIDGE AXIS EXTENDING SE TO NEAR 15N105W WHILE LOW
PRES AT THE SURFACE ASSOCIATED WITH THE LEADING EDGE OF THE
BROAD TROUGH ALOFT OVER NW MEXICO HAS SHIFTED EASTWARD INTO THE
WESTERN GULF OF MEXICO WITH 1000 MB LOW PRES ANALYZED NEAR
26N94W. THE PRES GRADIENT ALONG THE MEXICAN PACIFIC COAST NEAR
20N HAS STRENGTHENED BETWEEN THIS LOW PRES TO THE E AND THE
RIDGE TO THE W. NW TO N WINDS ARE EXPECTED TO HOVER NEAR 20 KT
THERE AND INTO THE SOUTHERN GULF OF CALIFORNIA THROUGH FRI.
THERE ARE A FEW OBSERVATIONS TO CONFIRM THESE CONDITIONS WITH
SHIP ZCDF4 REPORTED 25 KT WINDS NEAR 17N100W AT 0000 UTC AND
SHIP A8EH2 REPORTED 20 KT WINDS NEAR 19N108W AT 1800 UTC.
SOUTH OF THE SURFACE RIDGE AXIS LIES A BROAD AREA OF STRONG NE
TRADE WINDS. THE 1814 ASCAT PASS SHOWED 20 TO 25 KT WINDS W OF
120W FROM 06N TO 21N. THE HIGH PRES OVER NW WATERS WILL WEAKEN
AHEAD OF THE APPROACHING COLD FRONT TONIGHT. THIS WILL SHRINK
THE AREA OF STRONG TRADE WINDS WESTWARD A FEW DEGREES FRI WITH
LITTLE CHANGE EXPECTED IN THE AREA AND STRENGTH OF THE TRADES
SAT.
GAP WINDS...
THE NEXT TEHUANTEPEC GAP WIND EVENT IS FORECAST TO BEGIN
TOMORROW EVENING AS A FAST MOVING COLD FRONT SWINGS THROUGH THE
WESTERN GULF OF MEXICO. WINDS OF 20 TO 30 KT ARE EXPECTED SAT.
THE EVENT IS EXPECTED TO BE SHORT LIVED...WITH WINDS FORECAST TO
DROP BELOW 20 KT OVERNIGHT SAT NIGHT.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE


forecast by SCHAUER