[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 012330
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN JUL 01 2012

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 16N36W 9N33W MOVING W NEAR 20 KT. TOTAL
PRECIPITABLE WATER IMAGERY INDICATES THAT THE WAVE LIES WITHIN A
LARGE SURGE OF DEEP LAYER MOISTURE. NO DEEP CONVECTION IS
CURRENTLY ASSOCIATED WITH THE WAVE.

LOW-AMPLITUDE TROPICAL WAVE IS ALONG 11N46W TO 4N47W MOVING W
NEAR 20 KT. THE WAVE LIES W OF AN EQUALLY LOW-AMPLITUDE SURGE IN
DEEP LAYER MOISTURE. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED
WITH THE WAVE.

TROPICAL WAVE IS ALONG 19N65W TO 12N65W MOVING W NEAR 15-20 KT.
THE WAVE COINCIDES WITH A SURGE IN DEEP LAYER MOISTURE EVIDENT
IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE
CONVECTION IS FROM 14N-16N BETWEEN 65W-69W. THE WAVE LIES WITHIN
MOIST SWLY FLOW ALOFT WHICH IS PRODUCING CIRRUS CLOUDS...WHICH
ARE MAKING IT DIFFICULT TO SEE TO THE SURFACE ON SATELLITE
IMAGERY.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF
MAURITANIA NEAR 17N16W CONTINUING ACROSS ATLC WATERS ALONG
12N22W 10N30W. THE ITCZ EXTENDS BETWEEN THE TWO EASTERNMOST
TROPICAL WAVE FROM 9N36W TO 7N46W. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS FROM 9N-11N BETWEEN 23W-26W. SCATTERED
MODERATE CONVECTION IS FROM 9N-10N BETWEEN 38W-43W.

...DISCUSSION...

GULF OF MEXICO...
SURFACE RIDGING DOMINATES THE GULF OF MEXICO TODAY CENTERED
AROUND A 1020 MB HIGH OFF THE W COAST OF FLORIDA NEAR 27N86W.
THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE OVER THE NW
CARIBBEAN AND THE BAHAMAS ACCOMPANIED BY DRY AIR...WHICH IS
HELPING MAINTAIN FAIR CONDITIONS AND MOSTLY CLEAR SKIES EXCEPT
FOR A CLUSTER OF SHOWERS/THUNDERSTORMS THAT HAS POPPED UP OVER
SW FLORIDA. AN UPPER LEVEL TROUGH COVERS THE CENTRAL GULF...BUT
IS ALSO ACCOMPANIED BY DRY AIR. THE WRN GULF IS COVERED BY A
SECOND UPPER RIDGE NEAR THE TEXAS COASTLINE. HERE...UPPER LEVEL
MOISTURE IS PRESENT AND COMBINED WITH UPPER LEVEL DIFFLUENCE
BETWEEN THE RIDGE AND UPPER LEVEL LOW OVER NRN MEXICO...A FEW
SHOWERS/THUNDERSTORMS ARE ALONG THE TEXAS COAST AND INLAND OVER
SRN TEXAS. LIGHT ANTI-CYCLONIC WINDS ARE AROUND THE SURFACE HIGH
INCREASING IN SPEED TO 20 KTS IN THE NW GULF AND ALONG THE TEXAS
COAST. EXPECT SURFACE RIDGING TO REMAIN ACROSS THE BASIN THROUGH
AT LEAST THE MIDDLE OF THE WEEK.

CARIBBEAN SEA...
MOSTLY CLEAR SKIES AND FAIR WEATHER ARE ACROSS THE CENTRAL AND
WRN CARIBBEAN DUE TO DRY AIR ALOFT AROUND BOTH A BROAD UPPER
LEVEL RIDGE OVER THE NW CARIBBEAN AND THE BAHAMAS...AND AN UPPER
LEVEL LOW OVER THE CENTRAL CARIBBEAN. A FEW WIDELY ISOLATED
SHOWERS/THUNDERSTORMS ARE WITHIN THE TRADEWIND FLOW ACROSS THE
CENTRAL AND WRN CARIBBEAN. AFTERNOON CONVECTION ACROSS THE NRN
ISLANDS IS STILL PRESENT ESPECIALLY ACROSS PORTIONS OF CUBA AND
HISPANIOLA. SHOWERS/THUNDERSTORMS ALSO DOT PORTIONS OF CENTRAL
AMERICA...ESPECIALLY OFF THE COAST OF COSTA RICA AND
PANAMA...DUE TO THE MONSOON TROUGH THAT EXTENDS FROM CENTRAL
NICARAGUA THROUGH COSTA RICA AND PANAMA. A TROPICAL WAVE IN THE
ERN CARIBBEAN IS PROVIDING A MOIST ENVIRONMENT E OF 71W.
DIFFLUENCE ALOFT AROUND THE E SIDE OF THE UPPER LOW IN THE
CENTRAL CARIBBEAN ALONG WITH THE INFLUENCE OF THE WAVE IS
HELPING PRODUCE SCATTERED SHOWERS/THUNDERSTORMS FROM 13N-16N
BETWEEN 65W-70W...AND FROM 11N-12N BETWEEN 57W-61W...WITH
ISOLATED SHOWERS POSSIBLE ACROSS THE REMAINDER OF THE ERN
CARIBBEAN. THE WAVE IS EXPECTED TO CONTINUE MOVING WWD OVER THE
NEXT FEW DAYS AND WILL BRING MOISTURE THROUGH THE CENTRAL...AND
EVENTUALLY WRN...CARIBBEAN.

ATLANTIC OCEAN...
A BROAD AND FLATTENED UPPER LEVEL RIDGE IS ACROSS THE NW
CARIBBEAN AND THE BAHAMAS SUPPORTING A 1020 MB HIGH W OF
FLORIDA...WHICH IS HELPING PROVIDE FAIR CONDITIONS ACROSS THE W
ATLC IN COMBINATION WITH DRY AIR ALOFT. A WEAK SURFACE TROUGH IS
ACROSS THE SE BAHAMAS ALONG 25N71W TO 22N74W SUPPORTING ISOLATED
SHOWERS NEAR THE AXIS. AN UPPER LEVEL LOW NEAR 33N59W IS
SUPPORTING AN AREA OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
FROM 28N-33N BETWEEN 54W-59W. ANOTHER WEAK SURFACE TROUGH IS
JUST E OF THE UPPER LOW ALONG 31N50W TO 27N52W. ISOLATED SHOWERS
ARE WITHIN 90 NM E OF THE AXIS. A SECOND UPPER LEVEL LOW IS
CENTERED NEAR 30N39W SUPPORTING A THIRD SURFACE TROUGH ALONG
32N38W TO 27N41W. ISOLATED SHOWERS ARE WITHIN 200 NM EITHER SIDE
OF THE AXIS. ALL OF THESE SURFACE TROUGHS ARE EMBEDDED WITHIN A
LARGE-SCALE RIDGE ANCHORED BY A 1030 MB HIGH JUST W OF THE
AZORES ISLANDS. THE RIDGE IS PROVIDING FAIR CONDITIONS ACROSS
MUCH OF THE ATLC. IS IT SUPPORTED BY UPPER LEVEL RIDGING N OF
THE TWO UPPER LOWS. TWO UPPER ANTI-CYCLONIC CENTERS ARE ALSO S
OF THE LOWS CENTERED NEAR 20N48W AND 21N27W. VISIBLE SATELLITE
IMAGERY ALONG WITH GOES-R DUST ENHANCEMENT IMAGERY INDICATE THAT
A LARGE AREA OF SAHARAN DUST EXTENDS FROM THE COAST OF AFRICA N
OF THE TROPICAL WAVES TO NEAR 60W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
WALTON





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