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AXNT20 KNHC 122332
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 8N12W 3N30W CROSSING THE EQUATOR
ALONG 47W TO NORTHEASTERN BRAZIL NEAR 1S50W. ISOLATED MODERATE
CONVECTION IS FROM 2N-5N BETWEEN 31W-38W...AND FROM 3N-5N
BETWEEN 43W-45W.
...DISCUSSION...
THE GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT EXTENDS FROM THE FLORIDA PANHANDLE
TO THE YUCATAN PENINSULA ALONG 30N85W 20N88W. RADAR IMAGERY
SHOWS CONVECTION WITHIN 60 NM OF THE FRONT OVER THE FLORIDA
PANHANDLE AND THE NE GULF OF MEXICO. MORE CONVECTION IS NOTED
OVER CENTRAL AND SOUTH FLORIDA AND THE E GULF E OF 84W.
ELSEWHERE...MOSTLY FAIR WEATHER IS OVER THE NW GULF W OF 86W AND
N OF 25N. 20-25 KT NW WINDS ARE W OF THE FRONT WHILE 15-20 KT S
WINDS ARE E OF THE FRONT. IN THE UPPER LEVELS...ZONAL FLOW
PREVAILS WITH A 130-150 KT JETSTREAM OVER THE N GULF N OF 25N. A
BAND OF BROKEN HIGH CLOUDS EXTENDS FROM THE BAY OF CAMPECHE TO
CENTRAL FLORIDA. STRONG SUBSIDENCE IS OVER THE NW GULF.
EXPECT...THE COLD FRONT TO MOVE RAPIDLY E AND EXTEND FROM THE
CENTRAL BAHAMAS TO HONDURAS IN 24 HOURS WITH CONVECTION. FAIR
WEATHER WITH W TO NW WINDS WILL THEN DOMINATED THE ENTIRE
GULF.
THE CARIBBEAN SEA...
AS OF 2100 UTC...A PREFRONTAL TROUGH IS OVER THE NW CARIBBEAN
FROM THE YUCATAN CHANNEL TO CENTRAL HONDURAS. WESTERLY WINDS ARE
W OF THE TROUGH WHILE SOUTHERLY WINDS ARE E OF THE TROUGH. 15-20
KT TRADEWINDS ARE OVER THE CENTRAL AND EASTERN CARIBBEAN E OF
80W. BROKEN TO OVERCAST HIGH CLOUDS ARE OVER THE YUCATAN CHANNEL
AND W CUBA. MOSTLY FAIR WEATHER IS OVER THE REMAINDER OF THE
CARIBBEAN. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER
THE CARIBBEAN WITH AXIS ALONG 80W. STRONG SUBSIDENCE IS OVER THE
MAJORITY OF THE CARIBBEAN SEA AND CENTRAL AMERICA S OF 20N.
EXPECT OVER THE NEXT 24 HOURS...FOR THE COLD FRONT TO COME OVER
THE NW CARIBBEAN WITH CONVECTION.
THE ATLANTIC OCEAN...
A 999 MB LOW IS CENTERED OFF THE COAST OF SOUTH CAROLINA NEAR
33N78W. A COLD FRONT EXTENDS S TO 28N75W WITH CONVECTION WITHIN
90 NM E OF THE FRONT. FURTHER EAST A 1023 MB HIGH IS CENTERED
NEAR 34N57W. A 1012 MB LOW IS CENTERED OVER THE E ATLANTIC NEAR
35N32W. A COLD FRONT EXTENDS S ALONG 32N28W 21N40W 17N50W.
SCATTERED SHOWERS ARE WITHIN 120 NM N OF THE FRONT. 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 IN 24
HOURS FOR...THE GULF OF MEXICO COLD FRONT TO EXTEND FROM 32N71W
TO THE CENTRAL BAHAMAS AND CENTRAL CUBA WITH CONVECTION. ALSO
EXPECT THE E ATLANTIC FRONT TO BECOME QUASI-STATIONARY WITH
SHOWERS.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE


forecast by FORMOSA
updated at 705 PM EST FRI MAR 12 2010

AXPZ20 KNHC 122154
TWDEP
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI MAR 12 2010
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM
THE EQUATOR TO 32N...EAST OF 140W.
BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2030 UTC.
...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED FROM 06N77W TO
04N95W TO 05N110W TO 04N125W TO 04N140W. SCATTERED MODERATE WITH
ISOLATED STRONG CONVECTION WAS WITHIN 240 NM S OF THE ITCZ AXIS
BETWEEN 89W AND 97W. SCATTERED MODERATE CONVECTION WAS WITHIN
120 NM N OF THE ITCZ AXIS W OF 133W AND WITHIN 90 NM S OF THE
ITCZ AXIS BETWEEN 133W AND 137W.
...DISCUSSION...
A PROGRESSIVE PATTERN IS IN PLACE OVER N WATERS. THE WESTERLY
UPPER JET WITH WINDS IN EXCESS OF 130 KT CENTERED ALONG 25N IS
BEGINNING TO SHIFT MORE SOUTHWESTERLY W OF 120W AS A DEEP
LAYERED TROUGH OVER NW FORECAST WATERS PUSHES EASTWARD. THE COLD
FRONT ASSOCIATED WITH THIS DEEP LAYERED TROUGH IS RELATIVELY
WEAK. THE LARGEST IMPACT FROM THIS COLD FRONT OVERNIGHT TONIGHT
IS THE NEW SURGE OF NW SWELL PUSHING SE THROUGH THE AREA...WITH
SIGNIFICANT WAVE HEIGHTS INCREASING TO 14 FT NW OF THE FRONT AS
IT TRAVERSES N WATERS. THE FRONT WILL DISSIPATE AS IT MOVES INTO
NORTHERN BAJA CALIFORNIA AND NE WATERS SAT...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 AND INTO THE NORTHERN GULF OF CALIFORNIA OVER
THE WEEKEND.
A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR
07N105W HAS A RIDGE AXIS THAT EXTENDS FROM ITS CENTER NE INTO
THE GULF OF FONSECA WHILE A SECOND RIDGE AXIS EXTENDS W OF THE
ANTICYCLONE TO 02N128W. JUST TO THE W LIES AN UPPER LOW NEAR
01N134W. SCATTERED MODERATE CONVECTION CAN BE FOUND NEAR THE
ITCZ W OF 133W IN THE DIFFLUENT REGION N OF THE LOW BETWEEN IT
AND SW FLOW ALOFT ASSOCIATED WITH THE AFOREMENTIONED JET.
SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS OBSERVED
S OF THE ITCZ BETWEEN 89W AND 97W. THIS AREA LIES IN A POOL OF
2.25 TO 2.50 INCH PRECIPITABLE WATER VALUES AND UNDER WEAK UPPER
LEVEL DIFFLUENCE. THIS DIFFLUENT REGION ALOFT IS EXPECTED TO
SHIFT SW TO THE EQUATOR NEAR 100W OVER THE NEXT 24 HOURS.
THEREFORE...LOOK FOR THE CONVECTION TO SHIFT W AND BECOME LESS
ORGANIZED.
AT THE SURFACE...1026 MB HIGH PRES LIES OVER NW WATERS NEAR
27N137W WITH A RIDGE AXIS EXTENDING SE TO SOCORRO ISLAND. THE
PRES GRADIENT ALONG THE MEXICAN PACIFIC COAST NEAR 20N HAS
STRENGTHENED BETWEEN THIS RIDGE AND TROUGHING INDUCED BY A COLD
FRONT PASSING THROUGH EASTERN MEXICO AND THE WESTERN GULF OF
MEXICO AS WELL AS THE INVERTED TROUGHING ON THE WESTERN SLOPES
OF THE SIERRA MADRE OCCIDENTAL. NW TO N WINDS ARE CURRENTLY IN
PLACE FROM 18N TO 28N W OF 115W...INCLUDING IN THE GULF OF
CALIFORNIA. THERE ARE SEVERAL OBSERVATIONS TO CONFIRM THESE
CONDITIONS INCLUDING THE 20 TO 25 KT WINDS SEEN IN THE 1748 UTC
ASCAT PASS OVER THE CENTRAL GULF OF CALIFORNIA...4XFX WHICH
REPORTED 20 KT NEAR 24N114W AT 1200 UTC...AND C6FR3 WHICH
REPORTED 24 KT NEAR 27N115W AT 1200 UTC. THE PRES GRADIENT HERE
WILL BREAK DOWN OVERNIGHT AS THE COLD FRONT QUICKLY PASSES SE
THROUGH EASTERN MEXICO AND THE GULF OF MEXICO. THE WINDS ARE
EXPECTED TO DIMINISH IN TURN.
SOUTH OF THE SURFACE RIDGE AXIS LIES A BROAD AREA OF STRONG NE
TRADE WINDS. THE 1934 AND 1752 UTC ASCAT PASSES IN ADDITION TO
THE 1426 UTC WINDSAT PASS SHOWED 20 TO 25 KT WINDS W OF 120W
FROM 06N TO 20N. LITTLE CHANGE IS EXPECTED IN THE AREA AND
STRENGTH OF THE TRADES THROUGH THE WEEKEND.
GAP WINDS...
THE COLD FRONT IN EASTERN MEXICO HAS PASSED INTO THE ISTHMUS OF
TEHUANTEPEC AND WINDS HAVE INCREASED TO 20 KT NEAR THE COAST.
NORTHERLY WINDS BEHIND THE COLD FRONT ARE EXPECTED TO BE SHORT
LIVED IN THIS INCREASINGLY MORE PROGRESSIVE FLOW REGIME. THE
FORECAST CALLS FOR WINDS TO PEAK JUST BELOW GALE FORCE SAT
MORNING AND QUICKLY DROP BELOW 20 KT OVERNIGHT SAT NIGHT.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE


forecast by SCHAUER