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AXNT20 KNHC 291753
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.
...TROPICAL WAVES...
TROPICAL WAVE IS MOVING OFF THE COAST OF AFRICA LOCATED FROM
16N19W TO 9N15W MOVING W NEAR 15 KT. THE DAKAR SENEGAL UPPER AIR
SOUNDING INDICATED THE WAVE RECENTLY PASSED THROUGH AT THE LOWER
LEVELS. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG
CONVECTION ARE WITHIN 150 NM W OF THE WAVE AXIS BETWEEN 10N-14N
WITH SCATTERED STRONG CONVECTION WITHIN 90/120 NM E OF THE WAVE
AXIS OVER THE SW PENINSULA OF SENEGAL.
TROPICAL WAVE IS FROM 16N51W TO 6N57W MOVING W NEAR 20 KT. WAVE
REMAINS TILTED N-NE/S-SW AND IS EMBEDDED WITHIN THE ITCZ THAT
SHIFTS N NEAR 50W. DUE TO THE ABUNDANCE OF CONVECTION ASSOCIATED
WITH THE ITCZ...THE WAVE AXIS IS NOT EASILY RECOGNIZABLE ON
SATELLITE IMAGERY.
TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN IS ALONG 74W/75W S OF
18N MOVING W NEAR 20 KT. WAVE REMAINS TO THE W OF AN UPPER RIDGE
AND COUPLED WITH DIFFLUENCE ALOFT IS ENHANCING THE ACTIVITY IN
THE VICINITY OF THE WAVE.
...THE ITCZ...
THE ITCZ AXIS IS ANALYZED ALONG 11N18W 9N25W 8N37W 12N46W 13N52W
10N62W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG
29W/30W FROM 6N-11N GENERATING SCATTERED MODERATE WITH EMBEDDED
CLUSTERS OF SCATTERED/NUMEROUS STRONG CONVECTION WITHIN 120 NM
OF LINE FROM 7N29W 6N32W TO 11N34W. SIMILAR CONVECTION IS FROM
10N-15N BETWEEN 55W-63W INCLUDING THE WINDWARD ISLANDS. CLUSTERS
OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 90 NM OF LINE
FROM 9N36W TO 7N45W AND FROM 2N TO THE EQUATOR BETWEEN 37W-40W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM N
OF THE ITCZ BETWEEN 45W-55W.
...DISCUSSION...
GULF OF MEXICO...
AN UPPER HIGH IS INLAND OVER MEXICO WITH THE UPPER RIDGE
COVERING THE W GULF W OF 94W PROVIDING DIFFLUENCE ALOFT
ENHANCING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS
N OF 26N BETWEEN 94W-96W TO JUST INLAND OVER THE TEXAS COAST. A
SECOND UPPER RIDGE IS ANCHORED ALONG THE NE COAST OF FLORIDA
COVERING THE NE GULF N OF 24N TO 90W WITH AN UPPER LOW IN THE NW
CARIBBEAN EXTENDING OVER THE FAR CLIPPING THE S GULF. A SURFACE
TROUGH EXTENDS ACROSS THE FLORIDA PENINSULA THROUGH MELBOURNE
INTO THE GULF NEAR NAPLES. THE UPPER RIDGE OVER THE NE GULF IS
PROVIDING DIFFLUENCE ALOFT TO ENHANCE CLUSTERS OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS WITHIN 75 NM OF LINE FROM 23N85W
TO THE FLORIDA COAST BETWEEN TAMPA AND FORT MYERS. A SURFACE
RIDGE DOMINATES THE N GULF WITH A 1023 MB HIGH INLAND OVER SW
LOUISIANA.
CARIBBEAN SEA...
A BROAD UPPER LOW IS THE NW CARIBBEAN CENTERED OVER HONDURAS
NEAR 15N87W COVERS THE AREA W OF 80W AND INTO THE S GULF OF
MEXICO. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM
20N-22N W OF 82W TO INLAND OVER THE YUCATAN PENINSULA WHICH IS N
OF AN AREA OF STRONG SUBSIDENCE AND DRY AIR THE COVERS THE
REMAINDER OF THE NW CARIBBEAN N OF 17N W OF THE CAYMAN ISLANDS.
SIMILAR ACTIVITY COVERS A BROADER AREA FROM 12N-18N BETWEEN
75W-80W AND FROM 13N-17N W OF 80W TO INLAND OVER CENTRAL
AMERICA. ISOLATED SHOWERS COVER THE SW CARIBBEAN S OF 13N W OF
75W AND MOST OF THE E CARIBBEAN FROM 13N-18N BETWEEN 66W-72W. A
BROAD UPPER RIDGE IS ANCHORED IN THE SE CARIBBEAN NEAR 13N66W
COVERING THE REMAINDER OF THE CARIBBEAN AND INTO THE W TROPICAL
ATLC ENHANCING THE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE.
ATLANTIC OCEAN...
A STATIONARY FRONT IS ALONG THE N PERIPHERY OF THE W ATLC
EXTENDING FROM A 1018 MB LOW NEAR 33N60W ACROSS BERMUDA TO
32N73W WITH CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
FROM 27N-33N BETWEEN 60W-78W. OTHERWISE...NO SIGNIFICANT WEATHER
IS OCCURRING ACROSS THE REMAINDER OF THE ATLC BASIN. A SURFACE
RIDGE DOMINATES THE ATLC ANCHORED BY A 1025 MB HIGH NEAR 32N46W
ALONG 26N65W TO THE N BAHAMA ISLANDS NEAR 27N78W. VISIBLE
SATELLITE IMAGERY SHOWS YET ANOTHER DRY SAHARAN AIR MASS SURGING
INTO THE FAR E ATLC AND REMAINING ACROSS PORTIONS OF THE
REMAINDER OF THE TROPICAL ATLC.
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE


forecast by PAW
updated at 205 PM EDT WED JUL 28 2010

AXPZ20 KNHC 291522
TWDEP
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU JUL 29 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 INTERTROPICAL CONVERGENCE ZONE IS ANALYZED ALONG A LINE FROM
05N77W TO 15N103W TO 10N115W TO 10N140W. SCATTERED MODERATE AND
ISOLATED STRONG CONVECTION IS FROM 06N TO 12N BETWEEN 89W AND
96W. ISOLATED MODERATE CONVECTION IS WITHIN 180 NM OF THE AXIS
BETWEEN 99W AND 107W. A TROUGH IS EMBEDDED IN THE ITCZ ALONG 89W
N OF 07N. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM E AND 120
NM W OF THE TROUGH.
...DISCUSSION...
AN UPPER LEVEL TROUGH AXIS PASSES THROUGH 32N135W TO 26N140W. A
30-50 KT UPPER LEVEL JET STREAM IS WITHIN 300 NM TO THE EAST OF
THE TROUGH AXIS FROM 25N TO 30N. UPPER LEVEL ANTICYCLONIC FLOW
COVERS THE REST OF THE AREA TO THE NORTH OF 10N TO THE EAST OF
140W. THIS PATTERN IS EXPECTED TO RETROGRADE SLIGHTLY WESTWARD
DURING THE NEXT COUPLE OF DAYS WITH AN UPPER LEVEL LOW TO
DEVELOP NW OF THE AREA NEAR 34N145W. DRY AIR IN SUBSIDENCE IS
WITHIN AT LEAST 360 NM ON EITHER SIDE OF THE LINE THAT PASSES
THROUGH 32N119W TO 18N140W. BROAD SURFACE ANTICYCLONIC FLOW
COVERS THE AREA TO THE NORTH OF 18N TO THE WEST OF 115W. A
SURFACE TROUGH IS ANALYZED FROM 14N114W TO 12N117W. SOUTHERLY
SWELLS TO 9 FEET ARE LOCATED NEAR THIS TROUGH AND IN GENERAL TO
THE SOUTH OF 15N BETWEEN 96W AND 120W AND SOUTH OF 12N TO THE
WEST OF 120W.
MODERATE EASTERLY TO NORTHEASTERLY WINDS ALOFT COVER THE EASTERN
PORTION OF THE DISCUSSION AREA. A SURFACE TROUGH IS EMBEDDED IN
THE ITCZ FROM 12N88W TO 07N89W. ANY NEARBY PRECIPITATION IS
MIXED IN WITH ITCZ PRECIPITATION. AN EARLIER ASCAT PASS AROUND
29/0406 UTC INDICATED 20 KT WINDS ON THE WESTERN SIDE OF THE
TROUGH. THIS TROUGH IS EXPECTED TO DRIFT SLOWLY WESTWARD OVER
THE NEXT TWO DAYS. SOME OF THE COMPUTER MODEL GUIDANCE SUGGESTS
THAT A LOW PRESSURE CENTER MAY DEVELOP ALONG THIS TROUGH DURING
THE NEXT 48 HOURS AS SHORTWAVE ENERGY ASSOCIATED WITH A MIDDLE
LEVEL TROUGH NEAR THE COAST OF THE BAY OF CAMPECHE SEEPS
SOUTHWARD THROUGH THE GULF OF TEHUANTEPEC INTO THE WESTERN SIDE
OF THIS PACIFIC OCEAN TROUGH. THE PASSAGE OF THE SHORTWAVE
ENERGY IS EXPECTED TO INDUCE 20 TO 25 KT WINDS FROM THE NORTH
AND NORTHEAST AT THE SURFACE...IMPACTING THE GULF OF TEHUANTEPEC
REGION LATE TONIGHT INTO EARLY FRIDAY.


forecast by HUFFMAN