AXNT20 KNHC 131714
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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.
...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N12W 3N30W 3N40W EQ50W. WIDELY
SCATTERED MODERATE CONVECTION IS FROM 3N-7N BETWEEN 13W-17W...
AND FROM 1N-5N BETWEEN 33W-40W.
...DISCUSSION...
GULF OF MEXICO...
A 1017 MB HIGH IS CENTERED OVER THE SW GULF OF MEXICO NEAR
23N93W. ANTICYCLONIC WINDS WITH MOSTLY FAIR WEATHER COVERS THE
AREA. THE SURFACE PRESSURE GRADIENT REMAINS TIGHT OVER THE NE
GULF...FLORIDA...AND THE STRAITS OF FLORIDA WHERE 20-25 KT
SURFACE WINDS ARE NOTED. IN THE UPPER LEVELS...ZONAL FLOW
PREVAILS WITH A 130-150 KT JETSTREAM OVER THE N GULF N OF 23N.
STRONG SUBSIDENCE IS OVER THE ENTIRE AREA. EXPECT...THE SURFACE
HIGH TO DOMINATE THE GULF FOR THE NEXT 24 HOURS WITH FAIR
WEATHER.
CARIBBEAN SEA...
A COLD FRONT EXTENDS FROM CENTRAL CUBA TO THE COAST OF NICARAGUA
ALONG 23N78W 18N81W 12N83W. NW WINDS ARE W OF THE FRONT WHILE S
WINDS ARE E OF THE FRONT. 15-20 KT TRADEWINDS ARE OVER THE
CENTRAL AND EASTERN CARIBBEAN E OF 75W. BROKEN TO OVERCAST
MULTILAYERED CLOUDS WITH SCATTERED SHOWERS ARE OVER CENTRAL CUBA
ALONG THE FRONT. BROKEN TO OVERCAST LOW CLOUDS WITH SCATTERED
SHOWERS ARE ALSO ALONG THE N COAST OF HONDURAS FROM 15N-17N
BETWEEN 84W-89W. 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 13N. STRONG SUBSIDENCE IS
OVER THE ENTIRE CARIBBEAN SEA AND CENTRAL AMERICA. EXPECT OVER
THE NEXT 24 HOURS...FOR THE COLD FRONT TO DRIFT E AND EXTEND
FROM E CUBA TO COSTA RICA WITH SHOWERS.
ATLANTIC OCEAN...
A COLD FRONT IS OVER THE W ATLANTIC FROM 32N74W TO CENTRAL CUBA
NEAR 23N78W. SCATTERED SHOWERS ARE WITHIN 30 NM OF THE FRONT.
PATCHES OF WIDELY SCATTERED MODERATE CONVECTION ARE E OF THE
FRONT FROM 25N-32N BETWEEN 65W-74W. FURTHER EAST A 1023 MB HIGH
IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 33N51W. A STATIONARY
FRONT IS OVER THE E ATLANTIC ALONG 32N29W 18N43W. SCATTERED
SHOWERS ARE WITHIN 90 NM OF THE FRONT. IN ADDITION SCATTERED
MODERATE CONVECTION IS FROM 28N-32N BETWEEN 29W-33W. IN THE
UPPER LEVELS...A RIDGE IS OVER THE W ATLANTIC W OF 50W. AN UPPER
LEVEL TROUGH IS OVER THE CENTRAL ATLANTIC N OF 10N BETWEEN
30W-50W. AN UPPER LEVEL RIDGE IS OVER THE E ATLANTIC E OF 30W.
EXPECT IN 24 HOURS FOR...THE W ATLANTIC COLD FRONT TO EXTEND
FROM 32N63W TO E CUBA WITH CONVECTION. ALSO EXPECT THE E
ATLANTIC FRONT TO MOVE E AGAIN TO 32N23W WITH SHOWERS.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE
forecast by FORMOSA
updated at 105 PM EST SAT MAR 13 2010
AXPZ20 KNHC 131604
TWDEP
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAR 13 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
1545 UTC.
...ITCZ...
THE ITCZ AXIS WAS CENTERED ALONG 08N77W TO 04N90W TO 05N120W TO
06N140W.
...DISCUSSION...
MOST SIGNIFICANT FEATURE TODAY IS THE TEHUANTEPEC GAP WIND EVENT
ONGOING THIS MORNING. AN EARLIER 0318 UTC ASCAT PASS SHOWED A
FEW N 35 KT WIND VECTORS. GIVEN THE UNSTABLE SST-BOUNDARY LAYER
CONDITIONS...ALL MODELS...GFS...ECMWF...AND NAM...ARE SHOWING
JUST BELOW GALE FORCE...AND THE TYPICAL DIURNAL CYCLE OF THESE
EVENTS PEAKING LATE NIGHT-EARLY MORNING...I ADDED THIS AS A GALE
WARNING FOR 12 UTC. FORCING FOR THE EVENT COLLAPSES IMMEDIATELY
AND ALONG WITH THE TYPICAL DIURNAL WEAKENING DURING THE DAY
MEANS THAT IT SHOULD DROP BELOW GALE FORCE BY THIS AFTERNOON AND
BELOW OUR 20 KT THRESHOLD BY TOMORROW MORNING. NO OTHER GAP
WIND EVENTS ARE ONGOING OR ANTICIPATED TO OCCUR UNTIL TUESDAY
NIGHT WHEN THE NEXT TEHUANTEPEC EVENT IS LIKELY TO BEGIN.
MODERATE NW TO N WINDS IN THE GULF OF CALIFORNIA ARE ANTICIPATED
TO WEAKEN TODAY AS THE PRESSURE GRADIENT FORCING SLACKENS. BUT
THIS IS SHORT-LIVED AS HIGH PRESSURE REBUILDS JUST WEST OF
CALIFORNIA AND CYCLOGENESIS OCCURS OVER NORTHERN MEXICO...NEW
MEXICO AND TEXAS. NW TO NW 20 TO 25 KT WINDS PARALLELING THE
GULF SHOULD CONTINUE OVER AT LEAST THE NEXT TWO DAYS. WEST OF
BAJA NW TO N 20 TO 25 KT WINDS SHOULD GENERALLY CONTINUE FOR THE
NEXT DAY BEFORE WEAKENING.
A LARGE AREA OF NE MODERATE TRADEWINDS ARE OCCURRING GENERALLY
BETWEEN 07N AND 20N W OF 120W THAT WILL CONTINUE WITH LITTLE
CHANGE FOR THE NEXT COUPLE OF DAYS.
MOST OF OUR AREA OF RESPONSIBILITY IS COVERED BY SEAS OF AT
LEAST 8 FT WITH THE HIGHEST UP TO 13 FT OCCURRING W OF BAJA AND
UP TO 14 FT IN MIXED NW SWELL AND NE WIND WAVES IN THE TRADEWIND
BELT. MODERATE NW SWELL WILL CONTINUE TO IMPACT THE WESTERN
HALF OF OUR AREA OVER THE NEXT FEW DAYS.
IN THE UPPER LEVELS...A SHARP ENE-WSW ORIENTED TROUGH STRETCHES
FROM 30N118W TO 23N140W AND IS ASSOCIATED WITH A STATIONARY
SURFACE FRONT ALONG OUR NORTHERN BOUNDARY NEAR 130W. FARTHER
SOUTH...AN UPPER HIGH IS CENTERED NEAR 09N104W. A MODERATE
UPPER LEVEL JET IS SITUATED A COUPLE HUNDRED NM SOUTH OF THE
UPPER TROUGH AXIS AND IS ASSOCIATED WITH UPPER LEVEL MOISTURE
AND SOME HIGH CLOUDINESS BEGIN ADVECTED OVER SOUTHERN BAJA
CALIFORNIA AND MAINLAND MEXICO.
ONE CURIOUS NOTE IS THE LACK OF SIGNIFICANT ORGANIZED DEEP
CONVECTION ANYWHERE IN OUR AREA OF RESPONSIBILITY. EVEN THE
ITCZ IS SUPPRESSED SUCH THAT NO DEEP CONVECTION BEYOND
SMALL...TRANSIENT THUNDERSTORMS ARE TO BE SEEN TODAY. THIS IS
NOT...HOWEVER...COMPLETELY ATYPICAL OF SPRING CONDITIONS.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE
forecast by LANDSEA
