[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 071054
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT 07 MAY 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1030 UTC.

...TROPICAL WAVES...

WEAK TROPICAL WAVE ALONG 68W S OF PUERTO RICO MOVING WEST 15 KT.
A WIND SHIFT OCCURRED AT SAN JUAN IN THE MID-LEVELS BETWEEN 800
AND 650 MB ABOUT 12 HRS BEFORE THE LOW-LEVEL WIND SHIFT BETWEEN
THE SFC AND 850 MB...SUGGESTING THAT THE WAVE IS FORWARD TILTED
WITH HEIGHT. SATELLITE IMAGERY SHOWS THE GREATEST CURVATURE NEAR
68W WITH ISOLATED SHOWERS/TSTMS DEVELOPING S OF PUERTO RICO FROM
14.5N-18N BETWEEN 64W-68W. NUMEROUS MODERATE/STRONG CONVECTION
IS ALSO MOVING W ACROSS VENEZUELA FROM 6N-10N BETWEEN 66W-69W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N10W 6N20W 2N40W 2N52W. SCATTERED
MODERATE WITHIN 120 NM N AND 90 NM S OF THE AXIS BETWEEN
11W-15W. SCATTERED MODERATE WITHIN 45 NM OF LINE 5N3W 5N11W
2N17W. NUMEROUS MODERATE/STRONG WITHIN 100 NM OF THE AXIS
BETWEEN 22W-37W. SCATTERED MODERATE FROM 2N-7N BETWEEN 45W-53W
INCLUDING ALONG THE COASTS OF FRENCH GUIANA AND EXTREME NRN
BRAZIL.

...DISCUSSION...

GULF OF MEXICO INTO THE W ATLANTIC...
MID/UPPER TROUGH HAS PUSHED ACROSS FLORIDA TO THE W ATLC WATERS
WITH ATTENDANT LATE SEASON COLD FRONT EXTENDING FROM A 995 MB
STORM CENTER N OF THE REGION THROUGH 32N70W ACROSS CAT AND GREAT
EXUMA ISLANDS IN THE BAHAMAS THEN TO CNTRL CUBA. THE FRONT IS
ASSOCIATED WITH AN UNUSUAL SOUTHWARD PUSH OF CONTINENTAL AIR
WITH DEWPOINTS DROPPING INTO THE 50'S INTO SW FL AND TO THE
LOWER 60'S ACROSS SE FL AND THE NRN BAHAMAS. PRECIPITATION
WISE...DIFFLUENT FLOW ALOFT IS OVER THE W ATLC E OF THE TROF
WITH WIDELY SCATTERED MODERATE CONVECTION N OF 26N BETWEEN
63W-68W. ADDITIONALLY...CONFLUENT FLOW ON THE BACKSIDE OF THE
UPPER TROUGH IS PRODUCING STRONG SUBSIDENCE AND DRY AIR ALOFT
OVER THE ENTIRE E GULF INTO THE W ATLC BETWEEN 69W-86W. COLD
FRONT WILL CONTINUE TO MOVE E ACROSS THE W ATLC WITH THE FRONTAL
BOUNDARY WEAKENING S OF THE BAHAMAS DURING THE DAY. HIGH
PRESSURE CONTINUES TO BUILD S ACROSS THE GULF RESULTING IN
VEERING OF THE LOW LEVEL WINDS. OVER THE REMAINDER OF THE
AREA...WEAK MID/UPPER LEVEL RIDGING OVER MEXICO HAS SHIFTED INTO
THE W GULF AND WILL BEGIN TO BUILD ACROSS THE GULF DURING THE
NEXT 24 TO 48 HOURS. THIS SHOULD PRODUCE GENERALLY DRY/TRANQUIL
CONDITIONS THROUGH THE WEEKEND. OVER MEXICO ITSELF...20-25 KT
WESTERLY FLOW AT ABOUT 850 MB IS IMPINGING ON THE MOUNTAINS JUST
N OF CHIHUAHUA AND PRODUCING SCATTERED MODERATE CONVECTION UP TO
120 NM N OF THE CITY BETWEEN 104W-106W. IN ADDITION...A MOIST
LOW-LEVEL SLY JET IS PRODUCING LOW CLOUDS AND FOG E OF THE
SIERRA MADRES EXTENDING FROM ABOUT VERACRUZ NWD INTO S/CNTRL
TEXAS...BUT THIS AREA SHOULD BREAK UP DURING THE HEATING OF THE
DAY.

CARIBBEAN SEA...
BROAD MID/UPPER LEVEL RIDGE COVERS THE CARIBBEAN SEA WITH MEAN
AXIS EXTENDING FROM E VENEZUELA NWD OVER THE VIRGIN ISLANDS INTO
THE W/CNTRL ATLC. THE MID/UPPER LEVELS REMAIN RELATIVELY
DRY WITH WEAK/MODERATE SUBSIDENCE COVERING MOST OF THE
CARIBBEAN...BUT IT IS MOISTENING UP AS TROPICAL MOISTURE IS
ADVECTED ACROSS THE CENTRAL CARIBBEAN WITH A LARGE CLUSTER OF
NUMEROUS MODERATE/STRONG CONVECTION BEING GENERATED FROM 8N-13N
BETWEEN 76W-82W. EXPECT HEAVY SHOWERS/TSTMS TO MOVE INLAND
ACROSS PANAMA...COSTA RICA...AND NICARAGUA OVER THE NEXT 24 HRS
AS THIS CLUSTER MOVES TO THE W. AT THE SURFACE...COLD FRONT OVER
THE W ATLC IS DISSIPATING OVER CUBA WITH ONLY ISOLATED SHOWERS
REMAINING ALONG THE N COAST OF THAT ISLAND. ELSEWHERE...TROPICAL
WAVE CONTINUES TO PUSH WESTWARD ACROSS THE E/CNTRL CARIBBEAN
WITH ASSOCIATED AREA OF ISOLATED SHOWERS/TSTMS UP TO 150 NM E OF
THE AXIS. MINIMAL SHOWER/TSTM ACTIVITY IS EXPECTED JUST TO THE E
OF THE WAVE AS IT TREKS ACROSS THE CARIBBEAN DURING THE NEXT
SEVERAL DAYS.

CENTRAL/EASTERN ATLANTIC...
HIGHLY AMPLIFIED UPPER PATTERN OVER THE ATLC WATERS WITH A SHARP
MID/UPPER LEVEL TROUGH ALONG THE UNITED STATES E COAST...BROAD
AMPLIFYING RIDGE OVER THE W/CNTRL ATLC BETWEEN 50W-65W...AND
TROUGH OVER THE CNTRL/ERN ATLC FROM 32N32W THROUGH 20N36W TO
14N46W. MID/UPPER LEVEL SUBSIDENCE AND DRY AIR ALOFT EXISTS
ACROSS THE AREA FROM 25W-54W PRODUCING DRY AND STABLE
CONDITIONS...HIGHLIGHTED BY SCATTERED STRATOCUMULUS N OF 18N.
OVER THE E ATLC...THE NEAR PERSISTENT LOW IS NOW N OF THE REGION
NEAR 35N28W HEADING TOWARDS THE AZORES. TRAILING SURFACE TROUGH
HAS ALSO LIFTED N BUT ISOLATED SHOWERS/DRIZZLE ARE POSSIBLE IN
THE STRATOCU TO THE S. A SWATH OF SAHARAN DUST EXTENDS ACROSS
THE ATLC S OF A LINE 30N20W 20N34W 16N50W TO THE ITCZ.

$$
WALLACE/BERG




This weather bulletin was brought to you by:
www.nashvilleweather.net