AXNT20 KNHC 121144
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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.
...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N10W 4N24W 1N32W ACROSS THE EQUATOR
AND INLAND OVER SOUTH AMERICA NEAR 51W. NO SIGNIFICANT
CONVECTION IS NOTED.
...DISCUSSION...
GULF OF MEXICO...
LOW PRESSURE REMAINS IN CONTROL OF THE ENTIRE GULF WITH A COLD
FRONT ENTERING THE GULF FROM A 1004 MB LOW OFF THE GEORGIA/SOUTH
CAROLINA COAST ACROSS FLORIDA S OF JACKSONVILLE TO NEAR CEDAR
KEY TO 29N85W WHERE A DEVELOPING WARM FRONT CONTINUES TO A 998
MB LOW OVER THE CENTRAL GULF NEAR 26N90W AND A SURFACE TROUGH
EXTENDING SW ALONG 21N94W TO INLAND OVER MEXICO S OF TUXPAN.
THIS SCENARIO IS SUPPORTED BY A LARGE UPPER TROUGH/LOW CENTERED
OVER THE CENTRAL PLAIN STATES AND INCLUDES THE NW GULF. AN UPPER
RIDGE COVERS THE REMAINDER OF THE GULF ANCHORED IN THE E PACIFIC
AND CONTINUES TO DRAW TROPICAL MOISTURE ACROSS MEXICO AND THE
GULF FROM TAMPICO MEXICO TO ACROSS THE FLORIDA PENINSULA.
SCATTERED SHOWERS/THUNDERSTORMS ARE FROM 25N-29N E OF 89W TO
ACROSS THE FLORIDA PENINSULA. SCATTERED SHOWERS AND POSSIBLE
ISOLATED THUNDERSTORMS ARE WITHIN 120 NM OF A LINE FROM 26N89W
TO OVER MEXICO NEAR NEAR TAMPICO. AT 0600 UTC...A SECOND FAST
MOVING COLD FRONT HAS ENTERED THE NW GULF EXTENDING ACROSS
VERMILION BAY LOUISIANA TO THE TEXAS COAST NEAR BROWNSVILLE THEN
ALONG THE COAST OF MEXICO TO INLAND NEAR 23N98W AND AT 0900 UTC
ENTERS THE GULF ACROSS NEW ORLEANS LOUISIANA ALONG 25N95W TO
INLAND OVER MEXICO NEAR 22N98W. SKIES ARE CLEARING BEHIND THIS
COLD FRONT.
CARIBBEAN SEA...
A SURFACE TROUGH EXTENDS ACROSS THE NE CARIBBEAN FROM A
STATIONARY FRONT THAT IS E OF THE LEEWARD ISLANDS OVER DOMINICA
ALONG 15N66W TO 17N71W WITH ISOLATED SHOWERS N OF SURFACE TROUGH
TO OVER THE LEEWARD/VIRGIN ISLANDS AND THE GREATER ANTILLES. THE
BROAD UPPER RIDGE THAT DOMINATES MOST OF THE GULF OF MEXICO
COVERS THE CARIBBEAN AND COUPLED WITH DRY STABLE AIR ARE GIVING
THE REMAINDER OF THE CARIBBEAN FAIR WEATHER AGAIN THIS MORNING.
ATLANTIC OCEAN...
SURFACE RIDGE REMAINS OVER THE W ATLC ANCHORED BY A 1024 MB HIGH
ENE OF BERMUDA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N
OF 27N W OF 73W ACROSS THE FLORIDA PENINSULA INTO THE GULF OF
MEXICO. ISOLATED SHOWERS ARE OVER THE REMAINDER OF THE FAR W
ATLC S OF 27N W OF 76W. A DEEP LAYER TROUGH COVERS THE REMAINDER
OF THE W AND INTO CENTRAL ATLC N OF 18N FROM 40W-65W SUPPORTING
A COLD FRONT THAT ENTERS THE E ATLC NEAR 32N31W ALONG 21N40W TO
16N52W WHERE IT BECOMES STATIONARY TO JUST E OF THE LEEWARD
ISLANDS NEAR 15N60W THEN BECOMES A SURFACE TROUGH INTO THE NE
CARIBBEAN ACROSS DOMINICA. BROAD AREA OF SCATTERED SHOWERS AND
POSSIBLE ISOLATED THUNDERSTORMS ARE N OF THE FRONT TO 30N W OF
THE FRONT TO 47W WITH ISOLATED SHOWERS WITHIN 120 NM NW OF THE
REMAINDER OF THE FRONT CONTINUING ACROSS THE LEEWARD ISLANDS AND
INTO THE NE CARIBBEAN. A WEAK SURFACE RIDGE IS OVER THE
REMAINDER OF THE E ATLC WITH A 1020 MB HIGH SW OF THE CANARY
ISLANDS NEAR 20N17W KEEPING CONDITIONS FAIR ACROSS THE REMAINDER
OF THE E ATLC.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE


forecast by WALLACE
updated at 705 AM EST FRI MAR 12 2010

AXPZ20 KNHC 121530
TWDEP
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI MAR 12 2010
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM
THE EQUATOR TO 32N...EAST OF 140W.
BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1500 UTC.
...ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 06N77W TO 04N95W TO 05N110W TO
04N125W TO 04N140W. SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION IS WITHIN 130-150 NM S OF AXIS BETWEEN 88W AND 98W.
SCATTERED MODERATE CONVECTION WITHIN 135 NM N OF AXIS W OF 135W.
...DISCUSSION...
A DEEP LAYER TROUGH IS QUICKLY MOVING E ACROSS THE NW PORTION OF
THE AREA WHILE AMPLIFYING. THE ASSOCIATED COLD FRONT HAS ENTERED
THE NW CORNER OF THE FORECAST REGION AND STRETCHES FROM 30N138W
TO 29N140W. TO THE E OF THE TROUGH...A LARGE MID/UPPER RIDGE IS
AMPLIFYING N OF 25N AND E OF 125W WITH MEAN N TO S RIDGE AXIS
ACROSS THE WRN U.S. A JET STREAM BRANCH WITH JET CORE WINDS IN
THE RANGE OF 90-110 KT ROUNDS THE BASE OF THE TROUGH ENTERING
THE DISCUSSION AREA AT 21N140W THEN CONTINUES E-NE CROSSING
SOUTHERN BAJA CALIFORNIA AND NORTHERN MEXICO INTO THE NW GULF OF
MEXICO WHERE WINDS INCREASE TO 150 KT. A 250-300 NM WIDE SWATH
OF MODERATE SUBSIDENCE INDICATIVE OF DRY...STABLE AIR IS TO THE
SE OF THE TROUGH TO NEAR 125W...AND INCREASES TO AROUND 450 NM N
OF JET E OF 125W INCLUDING MOST OF THE BAJA PENINSULA AND
NORTHERN MEXICO N OF 24N. THE TROUGH IS FORECAST TO MOVE EWD
INLAND THE WESTERN U.S. IN ABOUT 24HOURS WHILE THE COLD FRONT
WEAKENS. THE MAIN IMPACT FROM THIS COLD FRONT WILL BE A NEW
SURGE OF NW SWELL SPREADING ACROSS THE AREA WITH SIGNIFICANT
WAVE HEIGHTS INCREASING TO 14 FT WITHIN 24 HOURS.
TO THE S OF THE JET STREAM...BROAD UPPER LEVEL ANTICYCLONIC
CIRCULATION CENTERED NEAR 7N104W EXTENDS A RIDGE E-NE TO OVER
CENTRAL AMERICA INTO THE CARIBBEAN SEA. UPPER DIFFLUENT FLOW
PATTERN TO THE SW OF THE ANTICYCLONE IS HELPING TO SUSTAIN ITCZ
CONVECTION E OF 98W. A SECOND RIDGE AXIS EXTENDS SW OF THE
ANTICYCLONE TO NEAR 3N128W. THE ANTICYCLONE IS EXPECTED TO
CHANGE LITTLE OVER THE NEXT 24 HRS...THEN BEGIN TO SHIFT E IN
36-48 HRS.
AT THE SURFACE...A 1024 MB HIGH IS ANALYZED NEAR 27N133W WITH A
RIDGE SE TO NEAR 20N110W COVERING THE AREA N OF 14N AND W OF
110W. THIS HIGH CENTER IS FORECAST TO DISSIPATE WITHIN THE NEXT
24 HRS AS ANOTHER HIGH PRES N OF THE AREA MOVES ESE. UNDER THIS
WEATHER PATTERN...EXPECT AN INCREASE IN THE AREA OF THE TRADE
WINDS AS WELL AS AN INCREASE IN WINDS AND SEAS THROUGH THE GULF
OF CALIFORNIA AND NEAR THE WEST COAST OF MEXICO PARTICULARLY
FROM 14N TO 20N E OF 107W. CURRENTLY...A BROAD AREA OF STRONG NE
TRADE WINDS FROM 06N TO 21N W OF 120W IS NOTED PER A PAIR OF
ASCAT PASSES AT 0520 UTC AND 0700 UTC AND SOME SHIP REPORTS.
GAP WINDS...
THE NEXT TEHUANTEPEC GAP WIND EVENT IS FORECAST TO BEGIN EARLY
THIS EVENING WITH N-NE WINDS OF 20 TO 25 KT...THEN INCREASE TO
POSSIBLY 30 KT IN ABOUT 24 HRS. WINDS WILL DROP TO BELOW 20 KT
IN ABOUT 36 HRS.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE


forecast by GR/JAH