[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 142327
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON AUG 14 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE 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.

...SPECIAL FEATURE...
A 1009 MB BROAD SURFACE LOW PRESSURE AREA EMERGED OFF AFRICA
EARLY THIS MORNING. SHOWERS AND TSTMS HAVE WEAKENED AND BECOME
LESS ORGANIZED OVER THE PAST SEVERAL HOURS. HOWEVER...SOME SLOW
DEVELOPMENT IS STILL POSSIBLE OVER THE NEXT DAY OR SO AS THE
SYSTEM MOVES WNWWARD NEAR 15 KT. BASED ON SATELLITE HOVMOLLER
DIAGRAMS...THIS WAVE/LOW HAS BEEN FAIRLY CONVECTIVE OVER AFRICA
DURING THE PAST FEW DAYS AND IS ONE OF THE MORE VIGOROUS WAVES
TO MOVE OFF THE COAST OVER THE LAST COUPLE OF WEEKS. REGARDLESS
OF TROPICAL CYCLONE FORMATION...SHOWERS AND THUNDERSTORMS WITH
STRONG GUSTY WINDS ARE LIKELY TO SPREAD OVER THE CAPE VERDE
ISLANDS LATER TONIGHT AND TUESDAY.

...TROPICAL WAVES...
TROPICAL WAVE IN THE E ATLC IS ALONG 30W S OF 18N MOVING W NEAR
15 KT. BROAD LOW-MID LEVEL CYCLONIC TURNING WITH AN INVERTED
V-PATTERN REMAINS EVIDENT ON SATELLITE IMAGERY.
HOWEVER...DESPITE THE CONTINUED FAIR STRUCTURE OF THIS WAVE...
DEEP MOISTURE REMAINS VERY LIMITED AS ONLY ISOLATED SHOWERS ARE
FOUND NEAR THE AXIS.

TROPICAL WAVE IS IN THE ERN CARIBBEAN ALONG 62W/63W S OF 20N
MOVING W 10-15 KT. OVER THE WEEKEND THIS WAVE BECAME SLIGHTLY
BETTER ORGANIZED WITH A WEAK SFC LOW DEVELOPING ON THE WAVE.
HOWEVER...IT HAS BECOME MUCH MORE DISORGANIZED TODAY WITH THE
LOW LEVEL CIRCULATION FIZZLING AND DEEP MOISTURE BEING VERY
MINIMAL AS THE WAVE IS EMBEDDED IN A DRY ENVIRONMENT. THE WAVE
STILL HAS SOME STRUCTURE WITH CYCLONIC TURNING EVIDENT ABOUT THE
AXIS ON VISIBLE SATELLITE IMAGERY.

TROPICAL WAVE EXTENDING THROUGH SRN MEXICO IS ALONG 92W S OF 20N
MOVING W NEAR 15 KT. THIS WAVE HAS BECOME DIFFICULT TO LOCATE AS
IT APPEARS TO BE GETTING MASKED BY THE CLOUDINESS IN THE WAKE OF
THE EPAC WAVE AND SFC LOW SEVERAL HUNDRED MILES TO THE W.
OVERALL VERY LITTLE SHOWER/TSTM ACTIVITY IS NOTED WITHIN 200 NM
EITHER SIDE OF THE WAVE AXIS.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 12N21W 8N37W 9N50W 12N61W. BESIDES
FOR CONVECTION ASSOCIATED WITH THE SPECIAL FEATURE...SCATTERED
SHOWERS AND ISOLATED TSTMS ARE WITHIN 120 NM EITHER SIDE OF THE
AXIS BETWEEN 31W-41W AND WITHIN 180 NM N OF THE AXIS BETWEEN
46W-56W ENHANCED BY A LARGE UPPER LOW TO THE N.

...DISCUSSION...
GULF OF MEXICO...
THE MAIN FEATURE IN THE GULF OF MEXICO IS AN UNUSUALLY FAR S OLD
FRONTAL BOUNDARY DRAPED ACROSS THE ERN PORTION. AS OF 18
UTC...THE BOUNDARY APPEARS TO BE LOSING A TEMP AND HUMIDITY GRAD
IN THE GULF SO IT WAS ANALYZED AS A TROF WHICH EXTENDS FROM THE
ATLC TO A 1014 MB LOW IN THE BAHAMAS NEAR 27N78W ACROSS S
FLORIDA NWWARD TO THE FL/AL LINE NEAR 30N87.5W. THIS TROF IS
ENHANCING SHOWERS AND TSTMS APPROXIMATELY WITHIN 150 NM OF THE
BOUNDARY. THE STRONGEST STORMS ARE OVER S FLORIDA WHERE NUMEROUS
TSTMS ARE PUSHING SWARD TO THE FL KEYS. A PATCH OF MODERATE
CONVECTION HAS BLOSSOMED OVER THE YUCATAN PENINSULA FROM 20N-22N
BETWEEN 88W-91W MOVING WSWWARD INTO THE BAY OF CAMPECHE. THE
REMAINDER OF THE AREA HAS FAIR WEATHER AND LIGHT WINDS FLOWING
CLOCKWISE AROUND A 1019 MB HIGH IN THE CNTRL/WRN GULF NEAR
25N91W. IN THE UPPER LEVELS...VERY DRY AIR IS SURGING DOWN THE
FL PENINSULA ON THE SE SIDE OF AN OHIO VALLEY UPPER HIGH. AN
UPPER LOW IS OVER SRN TEXAS BRINGING MID-HIGH LEVEL CLOUDINESS
AND SOME ISOLATED SHOWERS N OF 24N W OF 95W. ELSEWHERE...FAIRLY
DRY AIR COVERS MUCH OF THE AREA. MOISTURE IS LIKELY TO HANG
AROUND IN THE ERN GULF TOMORROW AS THE SFC TROF REMAINS IN THE
VICINITY.

CARIBBEAN SEA...
AN UPPER LEVEL TROUGH/RIDGE PATTERN REMAINS ESTABLISHED ACROSS
THE CARIBBEAN. THE UPPER TROUGH EXTENDS FROM AN UPPER LOW N OF
THE BAHAMAS ACROSS CNTRL CUBA TO THE WRN CARIBBEAN NEAR 18N86W.
THE UPPER RIDGE LIES TO THE E OF THE TROF WITH THE HIGH CENTER
OVER THE ERN DOMINICAN REPUBLIC. OVERALL...DRY AIR ALOFT LIES
ABOVE MUCH OF THE AREA. THERE ARE TWO AREAS OF SOME ORGANIZED
WEATHER IN THE REGION. ONE IS IN THE ERN CARIBBEAN ASSOCIATED
WITH A TROPICAL WAVE...BUT THERE ARE ONLY ISOLATED TO
SCATTERED SHOWERS FROM 13N-18N BETWEEN 62W-68W AS THE WAVE
REMAINS EMBEDDED IN A DRY ENVIRONMENT. THE OTHER AREA IS IN THE
NW CARIBBEAN WHERE THEY ARE PATCHES OF MODERATE CONVECTION OVER
CUBA AND THE YUCATAN PENINSULA MAINLY CONTRIBUTED TO UPPER
DIFFLUENCE BETWEEN THE CARIBBEAN TROF AND SE U.S. RIDGE. MOSTLY
FAIR WEATHER COVERS THE REMAINDER OF THE REGION. TRADE WINDS
REMAIN MODERATE GENERALLY IN THE 15-25 KT RANGE. SOME MOISTURE
ASSOCIATED WITH THE ERN CARIBBEAN WAVE WILL SPREAD INTO THE
CNTRL CARIBBEAN TOMORROW. ELSEWHERE LITTLE CHANGE IS EXPECTED.

ATLANTIC OCEAN...
A STATIONARY FRONT STRETCHES ACROSS THE NRN PORTION OF THE
DISCUSSION AREA ALONG 32N52W 29N67W 29N74W THEN AS A SFC TROF TO
S FLORIDA. THREE SFC LOWS ARE ANALYZED ALONG THE FRONT. THE
ERN-MOST LOW IS 1014 MB CENTERED NEAR 29N61W. THIS LOW IS VERY
WEAK AS IT IS MAINLY A SMALL LOW CLOUD SWIRL WITH SCATTERED
SHOWERS MORE ORGANIZED TO THE E OF THE LOW ALONG THE FRONT. A
1012 MB LOW IS LOCATED NEAR 29N74W AND A 1013 MB LOW IS ANALYZED
NEAR GRAND BAHAMA ISLAND. THESE SYSTEMS ARE MORE ACTIVE
PRODUCING SCATTERED SHOWERS AND TSTMS FROM 24N-30N W OF 73W TO
S FLORIDA. AT THE MOMENT...THE 1012 MB LOW HAS A MORE
DISCERNIBLE LOW-MID LEVEL CIRCULATION. MODELS KEEP THIS AREA
RATHER STATIONARY OR DRIFT IT NWARD OVER THE NEXT DAY OR SO.
SOME SLOW DEVELOPMENT IS POSSIBLE WITH THIS BROAD LOW PRES AREA
AS UPPER LEVEL WINDS BECOME GRADUALLY MORE FAVORABLE.  ELSEWHERE
AT THE SFC...A LINGERING WEAK SFC TROUGH DRAPED FROM A
STATIONARY 1010 MB LOW S OF THE AZORES EXTENDS ALONG 32N26W
28N33W. THIS BOUNDARY IS ONLY SPARKING A LINE OF CLOUDS AND
ISOLATED SHOWERS WITHIN 60 NM OF THE BOUNDARY. BESIDES FOR THE
WAVES AND SPECIAL FEATURE...WEAK HIGH PRES RIDGING CONTROLS MUCH
OF THE AREA ANCHORED BY A 1019 MB HIGH IN THE CENTRAL ATLC NEAR
27N47W. IN THE UPPER LEVELS...A SMALL UPPER LEVEL LOW IS SEEN ON
WATER VAPOR SPINNING NEAR 26N72W. AN UPPER HIGH IS EXTENDING
NORTH FROM HISPANIOLA INTO THE ADJACENT ATLC WATERS. A LARGE
DISTINCT UPPER LOW IS CENTERED NEAR 23N52W. THIS LOW IS
GENERATED SCATTERED SHOWERS ON THE S SIDE OF THE LOW FROM 16N TO
22N BETWEEN 50W-60W. ANOTHER WEAKER DRIER UPPER LOW IS CENTERED
NEAR 26N37W. AN UPPER HIGH REMAINS CENTERED JUST OFF THE COAST
OF AFRICA NEAR 20N19W AND EXTENDS W TO NEAR 40W.

$$
CANGIALOSI




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