[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 260558
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE JUL 26 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0445 UTC.

...SPECIAL FEATURES...

TROPICAL STORM FRANKLIN IS CENTERED NEAR 31.0N 68.0W...OR ABOUT
187 NM WSW OF BERMUDA...AT 26/0600 UTC MOVING NE AT 6 KT.
MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. THE
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. SEE LATEST NHC
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC
FOR MORE DETAILS. CONVECTION IS TO THE E OF LOW LEVEL CENTER.
THE ERRATIC MOTION OF THE PAST 24 HOURS ARE LIKELY TO CONTINUE
AS THE SYSTEM APPEARS TO HAVE HAVE MORE THAN ONE CENTER IN THIS
DISORGANIZED SYSTEM. UPPER WINDS DO NOT LOOK FAVORABLE FOR MUCH
STRENGTHENING NOW WITH AN UPPER LOW JUST TO THE W OF THE CYCLONE
PROVIDING W SHEAR. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS WITHIN 75 NM OF 31N FROM 65W-69W.

...TROPICAL WAVES...

CENTRAL ATLC TROPICAL WAVE ALONG 34W/35W S OF 23N MOVING W 10-15
KT WITH A 1014 MB LOW ALONG THE WAVE NEAR 11N. THIS WAVE IS NOT
AS WELL DEFINED AS IT WAS 24 HOURS AGO. WAVE IS ON THE W EDGE OF
AN UPPER RIDGE WHICH IS LIFTING THE SHOWER ACTIVITY TO THE N.
SCATTERED SHOWERS/THUNDERSTORMS ARE FROM 10N-14N BETWEEN
33W-38W.

E CARIBBEAN TROPICAL WAVE IS ALONG 69W S OF 16N MOVING W 15 KT.
WAVE IS ON THE W EDGE OF A SECOND UPPER RIDGE THAT IS CENTERED
OVER THE W TROPICAL ATLC. WAVE IS MUCH WEAKER SINCE THE UPPER
PORTION SPLIT OFF AND NOW REMAINS E OF THE CARIBBEAN. WAVE IS
MOVING INTO AN AREA WITH VERY FAST LOW/MID LEVEL FLOW AND WILL
PROBABLY BE DIFFICULT TO TRACK OVER THE NEXT COUPLE OF DAYS.
WITH STRONG SUBSIDENCE AND DRY AIR AT ALL LEVELS...NO ASSOCIATED
CONVECTION.

W CARIBBEAN TROPICAL WAVE ALONG 89W S OF 19N MOVING W 10-15 KT.
WAVE IS COMPLETELY INLAND OVER CENTRAL AMERICA. ASSOCIATED DEEP
CONVECTION IS INLAND OVER GUATEMALA AND HONDURAS.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 12N16W 11N21W 13N27W 9N40W 12N46W
BECOMING ILL-DEFINED ACROSS THE REMAINDER OF THE ATLC.
SCATTERED/NUMEROUS STRONG CONVECTION IS MOVING OFF THE COAST OF
SW AFRICA WITHIN 150 NM BETWEEN 11W IN LIBERIA AND 10N IN
GUINEA.  CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 2N-12N BETWEEN 36W-48W. SCATTERED MODERATE
CONVECTION IS WITHIN 150 NM S OF THE AXIS FROM 25W-28W.

...DISCUSSION...

GULF OF MEXICO...
MOSTLY CLEAR SKIES DOMINATE THE AREA WITH A FEW HIGH CLOUDS OVER
THE OPEN WATERS AND SOME LINGERING THUNDERSTORMS OVER CENTRAL
FLORIDA. SCATTERED MODERATE/STRONG CONVECTION DEVELOPING OVER S
MEXICO AND WITHIN 60 NM ALONG THE COAST FROM 94W-96W ARE ON THE
FAVORABLE E SIDE OF AN INVERTED TROUGH EXTENDING FROM THE
CENTRAL BAY OF CAMPECHE TO 25N93W. FARTHER E...A SUBTLE SURFACE
TROUGH EXTENDING AWAY FROM T.S. FRANKLIN STRETCHES ACROSS FAR S
FLORIDA INTO THE E GULF TO A WEAK 1014 MB LOW NEAR 26N84W. THE
TROUGH HAS CAUSED EXTREMELY WEAK FLOW OVER THE NE GULF AND
SERVED AS A FOCUSING MECHANISM FOR ISOLATED THUNDERSTORMS THAT
REMAIN OVER CENTRAL FLORIDA. THE ATMOSPHERE WILL REMAIN
RELATIVELY DRY OVER THE NEXT FEW DAYS WITH A LOW CHANCE OF
SHOWERS/THUNDERSTORMS OVER THE WATER. THE BULK OF THE AFRICAN
DUST IS REMAINING EITHER TO THE S OVER THE CARIBBEAN OR IS
GETTING SUCKED INTO THE CIRCULATION OF FRANKLIN...SO LITTLE
EFFECTS ARE EXPECTED OVER THE GULF REGION SAVE THE FAR S
PORTIONS NEAR THE YUCATAN. SOME INCREASE IN DUST IS POSSIBLE BY
LATE SAT AS LOW/MID LEVEL WINDS TURN MORE EASTERLY OVER THE SE
GULF INTO S FLORIDA.

CARIBBEAN...
THE SAHARAN DUST SURGE HAS SPREAD ACROSS THE ENTIRE CARIBBEAN
BASIN WITH ONLY ISOLATED SHOWERS STILL NOTED ON PUERTO RICO
RADAR. THE PLUME CONCENTRATIONS HAVE THINNED OUT CONSIDERABLY AS
IT CONTINUES TO SPREAD W. DRY AIR HAS WIPED OUT MOST CONVECTION
SAVE FOR SCATTERED MODERATE/ISOLATED STRONG CONVECTION S OF 10N
TO INLAND OVER PANAMA W OF 80W TO THE BORDER OF COSTA RICA. E
WINDS ARE ALOFT OVER THE NW CARIBBEAN W OF JAMAICA...WITH THE
MID-OCEANIC TROUGH RUNNING FROM A WEAK MID/UPPER LOW N OF
DOMINICAN REPUBLIC SW TO 15N84W IN NE NICARAGUA. VERY DRY AIR IN
THE MID/UPPER LEVELS CONTROLS THE CARIBBEAN SE OF THE TROUGH
AXIS. WEAK UPPER RIDGING HAS BUILT INTO THE E CARIBBEAN FROM AN
UPPER HIGH JUST N OF BARBADOS THRU THE ABC ISLANDS TO COSTA
RICA...THOUGH ANY SIGNIFICANT SHOWERS ARE MOSTLY OVER S AMERICA.
THE TRADEWINDS ACROSS THE REGION ARE AS STRONG AS THEY HAVE BEEN
DURING THE PAST FEW MONTHS WITH WINDS UP TO 30 KT POSSIBLE IN
THE TYPICAL ENHANCED REGION NW OF COLOMBIA.

ATLANTIC...
COMPLEX UPPER PATTERN IN THE W ATLC WITH A MID/UPPER HIGH OVER
THE CAROLINAS AND WEAK ONE NEAR 26N68W WITH A SHARP MID/UPPER
LEVEL TROUGH ALIGNED OVER T.S. FRANKLIN IN BETWEEN FROM ABOUT
BERMUDA TO 27N77W. DIFFLUENCE BETWEEN THE RIDGE AND THE CYCLONE
IS CAUSING AN ABUNDANCE OF SHOWERS TO FORM WELL TO THE SE OF
FRANKLIN FROM 25N-32N BETWEEN 58W-69W. FARTHER E...ANOTHER SHARP
UPPER TROUGH IS ALONG 31N48W THROUGH AN UPPER LOW NEAR 25N53W TO
17N56W BUT APPEARS TO BE SLOWLY LIFTING TO THE N IN WATER VAPOR
IMAGERY. SURFACE TROUGH...REFLECTION OF THE UPPER TROUGH EXTENDS
FROM 21N54W TO 13N56W WITH SCATTERED SHOWERS/THUNDERSTORMS NEAR
THE S END OF THE UPPER TROUGH AND N END OF THE SURFACE TROUGH
ARE FROM 17N-20N BETWEEN 52W-58W. STRONG UPPER RIDGING LIES
ACROSS THE EASTERN/CENTRAL ATLC ALONG 17N WHICH IS SUPPORTING
DEEP EASTERLY FLOW OVER A LARGE AREA TO ITS S. HOWEVER...
MOISTURE IS MOSTLY LIMITED AND STABLE CONDITIONS N OF THE ITCZ
ARE LIMITING CONVECTION TO THE S OF THE TROPICAL WAVE ALONG
34W/35W. VERY DRY AIR COVERS THE AREA N OF 12N. FARTHER N...A
DEEP TROUGH....MUCH DEEPER THAN AVERAGE FOR THE MIDDLE OF THE
SUMMER...EXTENDS FROM JUST E OF THE AZORES TO 30N29W THOUGH ANY
WEATHER IS N OF THE AREA. A 1025 MB HIGH IS NEAR 30N41W WITH
RIDGING EXTENDING ACROSS THE ATLC BETWEEN THE CAPE VERDE ISLANDS
AND 60W.

$$
WALLACE


WWWW
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