AXNT20 KNHC 070544
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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.
...SPECIAL FEATURES...
TROPICAL DEPRESSION IDA IS CENTERED NEAR 16.2N 84.0W AT 07/0300
UTC OR ABOUT 95 NM ENE OF LIMON HONDURAS MOVING N AT 6 KT.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED
WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/ WMO HEADERS MIATCMAT1/WTNT21 KNHC
FOR MORE DETAILS. IDA HAS RE-EMERGED INTO THE CARIBBEAN WATERS
OFF THE COAST OF HONDURAS. SCATTERED MODERATE/STRONG CONVECTION
COVERS THE AREA FROM 16N-17N BETWEEN 83W-85W AND FROM 17N-20N
BETWEEN 80W-85W.
...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 34W S OF 14N MOVING W NEAR 15 KT. WAVE
REMAINS WITHIN A BROAD AREA OF DEEP LAYERED MOISTURE ON THE
TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS JUST TO THE SE OF AN
UPPER TROUGH AND BENEATH AN UPPER RIDGE WHICH DRAWING MOISTURE
AWAY FROM THE WAVE ITSELF. ANY CONVECTION IS ASSOCIATED WITH THE
ITCZ.
TROPICAL WAVE IS ALONG 56W/57W S OF 16N MOVING W NEAR 15 KT.
WEAK LOW LEVEL CURVATURE IS OBSERVED ON SATELLITE IMAGERY AND IT
IS IN AN AREA OF SLIGHT UPPER LEVEL MOISTURE THUS NO SIGNIFICANT
DEEP CONVECTION. SCATTERED SHOWERS ARE FROM 15N-18N BETWEEN
52W-56W.
...ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 8N11W 6N22W 7N34W 6N43W 8N55W.
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE
FROM 4N-7N BETWEEN 10W-14W AND FROM 2N-10N BETWEEN 22W-33W.
...DISCUSSION...
GULF OF MEXICO...
A 1027 MB HIGH IS CENTERED OVER EASTERN NORTH CAROLINA WITH A
SURFACE RIDGE EXTENDING SW AND SE COVERING THE W ATLC AND GULF
OF MEXICO GIVING MOST OF THE GULF NE TO E FLOW. THIS FLOW
FILTERS INTO THE SW GULF AND BAY OF CAMPECHE NEAR A SURFACE
TROUGH THAT EXTENDS FROM 18N93W THROUGH A 1010 MB LOW NEAR
19N95W TO 23N96W. THE REMAINDER OF THE GULF IS DOMINATED BY AN
UPPER RIDGE ANCHORED IN THE CENTRAL CARIBBEAN. THE SURFACE
LOW/TROUGH IS SUPPORTED ALOFT BY AN UPPER LEVEL SHORTWAVE TROUGH
WITH AN AXIS EXTENDING FROM NE MEXICO NEAR TAMPICO TO 19N95W.
THE SURFACE FEATURES ALONG WITH DIFFLUENCE E OF THE UPPER LEVEL
TROUGH AXIS IS GENERATING SCATTERED SHOWERS AND POSSIBLE
ISOLATED THUNDERSTORMS S OF 27N BETWEEN 88W-97W. SCATTERED
SHOWERS/ ISOLATED THUNDERSTORMS ARE MOVING WESTWARD WITHIN 60 NM
ALONG THE N COAST OF CUBA E OF 88W.
CARIBBEAN SEA...
THE MOST SIGNIFICANT FEATURE FOR THE CARIBBEAN TONIGHT IS
TROPICAL DEPRESSION IDA. THE UPPER LEVELS OF THE CARIBBEAN ARE
DOMINATED BY A LARGE UPPER RIDGE ANCHORED IN THE CENTRAL
CARIBBEAN NEAR 14N74W AND COVERS THE GULF OF MEXICO AND THE W
ATLC AS WELL. A WEAK SURFACE TROUGH IS ANALYZED ALONG 77W/78W S
OF 13N TO INLAND OVER E PANAMA AND IS GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS S OF 13N FROM 73W-79W. THE E
CARIBBEAN IS UNDER MODERATE SUBSIDENCE AND DRIER AIR.
HOWEVER...ISOLATED LOW LEVEL FAST MOVING SHOWERS DOTS THE
REMAINDER OF THE CARIBBEAN USHERED IN ON MODERATE/STRONG
EASTERLY TRADEWINDS.
ATLANTIC OCEAN...
A SURFACE RIDGE CONTROLS THE W ATLC W OF 65W ANCHORED ON A 1027
MB HIGH CENTERED OVER EASTERN NORTH CAROLINA. SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS ARE WITHIN 60 NM OF LINE FROM 26N65W INTO
THE GULF OF MEXICO THROUGH THE STRAITS OF FLORIDA NEAR 24N80W.
FARTHER EAST...A COLD FRONT ENTERS THE DISCUSSION AREA NEAR
32N56W EXTENDING SW TO 26N63W WITH A SURFACE TROUGH EXTENDING
FROM 30N58W TO 22N60W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
ARE WITHIN 120 NM OF LINE FROM 25N62W TO BEYOND 32N54W. THE
FRONTAL SYSTEM IS SUPPORTED ALOFT BY AN UPPER LEVEL TROUGH N OF
26N W OF 52W. THE E ATLC IS UNDER THE INFLUENCE OF A SURFACE
RIDGE ANCHORED ON A 1034 MB HIGH CENTERED OVER THE AZORES. AN
UPPER LEVEL TROUGH IS OVER THE E ATLC EXTENDING AN AXIS FROM
32N30W INTO THE TROPICS TO 16N51W. UPPER LEVEL DIFFLUENCE EAST
OF THE TROUGH AXIS IS GENERATING POSSIBLE ISOLATED SHOWERS N OF
THE AREA ASSOCIATED WITH THE TROPICAL WAVE ALONG 34W COVERING
THE AREA FROM 16N-26N BETWEEN 36W-44W.


forecast by WALLACE
updated at 105 AM EST SAT NOV 07 2009

AXPZ20 KNHC 070328
TWDEP
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT NOV 07 2009
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
0315 UTC.
...TROPICAL LOWS...
.LOW PRES IS CENTERED NEAR 12N91W ESTIMATED AT 1008 MB AND IS
NOW MOVING SLOWLY N IN RESPONSE TO THE UPPER TROUGH IMMEDIATELY
TO ITS W WHICH IS ALSO CONTRIBUTING BOTH SOUTHWESTERLY WIND
SHEAR AND DRY AIR ENTRAINMENT. CURRENTLY SCATTERED MODERATE AND
ISOLATED STRONG CONVECTION IS NOTED N OF 13N BETWEEN 91W AND 93W.
.LOW PRES IS CENTERED NEAR 13N117W ESTIMATED AT 1010 MB. THE
SURFACE LOW IS UNDER AN UPPER ANTICYCLONE AND THE ASSOCIATED
UPPER DIFFLUENCE HAS BEEN ENHANCING CONVECTION...BUT OVERALL
CONVECTION HAS BEEN DECREASING THE PAST FEW HOURS. CURRENTLY
SCATTERED MODERATE TO STRONG CONVECTION IS NOTED WITHIN 30 NM OF
13N117W.
...ITCZ...
THE ITCZ AXIS EXTENDS ALONG 11N85W TO 12N91W TO 08N98W TO
13N116W TO 08N140W. SCATTERED MODERATE ISOLATED STRONG
CONVECTION IS NOTED WITHIN 90 NM EITHER SIDE OF A LINE FROM
07N105W TO 11N110W.
...DISCUSSION...
AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 11N112W WITH A SHORT
WAVE RIDGE SHIFTING NE AND NOW CRESTING NEAR 21N107W. A TROPICAL
RIDGE EXTENDS SW FROM THE ANTICYCLONE TO A SHARP CREST AT
11N127W WITH ANOTHER RIDGE EXTENDING SE FROM THE ANTICYCLONIC
CENTER TO 06N98W. UPPER LEVEL DIFFLUENCE ENHANCED ITCZ
CONVECTION EARLIER BETWEEN 132W AND 137W WITH THE DEBRIS STILL
SPREADING NE ALONG THE W PERIPHERY OF THIS TROPICAL RIDGE...
ROUGHLY WITHIN 150 NM EITHER SIDE OF LINE 08N136W TO 18N115W.
DEBRIS MOISTURE FROM EARLIER CONVECTION NEAR A SURFACE LOW UNDER
THE UPPER ANTICYCLONIC CENTER...DESCRIBED ABOVE...REMAINS WITHIN
120 NM OF 15N115W. UPPER DIFFLUENCE IS ALSO ENHANCING CONVECTION
ALONG THE ITCZ BETWEEN 104W AND 111W WITH THE DEBRIS MOISTURE
SPREADING S BUT EVAPORATING ALONG 03N.
AN UPPER RIDGE IS NOW AMPLIFYING NE INTO THE DISCUSSION AREA
ALONG 27N140W TO 32N127W. AN UPPER CYCLONE IS NEAR 30N118W WITH
A TROUGH EXTENDING SW TO 22N123W. DENSE UPPER MOISTURE IS
OBSERVED OVER THE NE SEMICIRCLE OF THIS CYCLONE AND IS SPREADING
NE ACROSS SOUTHERN CALIFORNIA AND ARIZONA AND NEW MEXICO.
ELSEWHERE THE UPPER LEVELS APPEAR DRY N OF 20N W OF 117W.
AN UPPER TROUGH EXTENDS S ALONG EASTERN OLD MEXICO INTO A SMALL
MID TO UPPER CYCLONE AT 19N96W WITH THE TROUGH CONTINUING S TO A
BASE OVER THE DEEP TROPICS AT 08N93W. THIS CYCLONE HAS DEEPENED
WITH A SURFACE LOW OVER THE SW BAY OF CAMPECHE AT 19.5N95W AND
ANALYZED AT 1010 MB. ISOLATED CONVECTION IS SLIGHTLY ENHANCED
ALONG THE ITCZ JUST S OF THIS TROUGH BASE...BETWEEN 94W AND 100W
WITH MOST OF THE DEBRIS MOISTURE EVAPORATING QUICKLY AS UPPER
DRY AIR IS SWEEPING S ACROSS OLD MEXICO AND OVER THE TROPICAL
PACIFIC N OF 09N BETWEEN 92W AND 107W.
AN UPPER ANTICYCLONE IS OVER THE CENTRAL CARIBBEAN NEAR 14N74W
WITH A RIDGE EXTENDING W TO NEAR 13N83W. SOME CONVECTION WAS
ENHANCED ALONG THE PACIFIC COAST OF COLOMBIA BUT IS DISSIPATING
AND THE DEBRIS MOISTURE IS SPREADING W AND NW ALONG THE UPPER
RIDGE.
AT THE LOW LEVELS A RIDGE IS BRIDGING SEVERAL DISSIPATING
FRONTAL TROUGHS OVER THE NW WATERS AND CRESTING NEAR 15N110W.
ALTHOUGH ASSOCIATED N WINDS ARE ONLY AT 15-20 KT IN THE WAKE OF
THE FRONTS...THE FRONTS ARE ACCOMPANIED BY NW SWELLS THAT WILL
CONTINUE TO BUILD TO NEAR 18 FT LATE SAT ALONG 30N BETWEEN 125W
AND 135W.
GAP WINDS...
GALE FORCE WINDS ARE EXPECTED TO CONTINUE THROUGH THE GULF OF
TEHUANTEPEC TONIGHT DIMINISHING BELOW GALE AFTER SUNRISE SAT
MORNING. A RECENT SHIP REPORT OF 50 KT...AND THE DEVELOPMENT OF
THE SURFACE LOW PRES IN THE BAY OF CAMPECHE...RESULTED IN
RAISING THE INITIAL CONDITIONS TO 30 TO 45 KT. UNCERTAINTY
CONTINUES IN THE FORECAST AS THE STRENGTH AND POSITION OF LOW
PRES IN THE BAY OF CAMPECHE...THE PERSISTENT LOW PRES NEAR
12N91W THAT IS NOW DRIFTING N...AND TROPICAL DEPRESSION IDA IS
NOW OVER THE EASTERN GULF OF HONDURAS AND IS FORECAST TO MOVE
NORTHWARD AND STRENGTHEN. DEPENDING ON THE ORIENTATION OF THE
LOW PRES CENTERS N OF THE AREA...ANOTHER N SURGE MAY OCCUR AS
EARLY AS SUN IN THE GULF OF TEHUANTEPEC OR THE LOW POSITIONS MAY
ACTUALLY IMPEDE THE N FLOW THROUGH THE ISTHMUS OF TEHUANTEPEC.


forecast by NELSON