[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 070607
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT MON MAY 07 2007

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0545 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N13W 4N20W 2N30W EQ35W 1S50W.
ISOLATED MODERATE CONVECTION IS FROM 1S-7N BETWEEN 16W-25W.
NUMEROUS CLUSTERS OF MODERATE WITH EMBEDDED ISOLATED STRONG
CONVECTION IS FROM 3S-2N W OF 25W.

...DISCUSSION...

GULF OF MEXICO...
A BACKDOOR COLD FRONT ASSOCIATED WITH THE DEEPENING LOW OFF THE
NORTH CAROLINA COAST IS PUSHING INTO THE NE GULF THIS EVENING. A
PREFRONTAL TROUGH IS JUST SW OF THE FRONT. SHOWER ACTIVITY
AROUND THE FRONT IS RATHER ISOLATED IN NATURE AND MAINLY LIMITED
TO WITHIN 60NM EITHER SIDE OF A BILOXI TO FT MYERS LINE.
MODERATE E TO SE WINDS DOMINATE THE REST OF THE GULF. BROKEN TO
OVERCAST LOW CLOUDS ARE AFFECTING THE NW GULF/TEXAS COAST AGAIN
TONIGHT WITH A FAIRLY SIGNIFICANT LOW LEVEL INVERSION IN PLACE.
UPPER RIDGING IS OVER THE WRN GULF WHICH IS TRANSPORTING UPPER
MOISTURE EWD...DOWNSTREAM FROM CONVECTION OVER MEXICO AND THE
EPAC. TROUGHING ASSOCIATED WITH DEEP LAYER LOW OFF HATTERS
EXTENDS INTO THE THE NE GULF. MODERATE TO STRONG NE WINDS WILL
INCREASE IN THE NE GULF BEHIND THE FRONT THROUGH THIS
MORNING...BENDING MORE E TO SE FURTHER W AROUND RIDGING
REBUILDING INTO THE AREA.

CARIBBEAN SEA...
THE SFC PRESSURE PATTERN IN THE CARIBBEAN REMAINS FAIRLY WEAK
DUE TO TROUGHING IN THE SW N ATLC. SHIPS AND BUOYS ARE MOSTLY
REPORTING E TO NELY TRADES IN THE 10-15 KT RANGE...EXCEPT
LIGHTER AND MORE VARIABLE N OF 17N WHERE THE WEAKEST GRADIENT
EXISTS. THESE LIGHT TO MODERATE WINDS SHOULD CONTINUE FOR THE
NEXT DAY OR TWO AS THE SUBTROPICAL RIDGE GIVES WAY TO
STRENGTHENING LOW PRES OVER THE W ATLC. ISOLATED CLUSTERS OF
MODERATE ITCZ CONVECTION ARE AFFECTING COLOMBIA...PANAMA...AND
COSTA RICA. THE ONLY CLUSTER AFFECTING THE CARIB IS IN THE FAR
SRN PORTION OFF THE COAST OF COLOMBIA NEAR 9N77W. UPPER SW FLOW
BETWEEN TROUGHING OVER THE NW PORTION AND RIDGING OVER THE ERN
CARIB IS SPREADING UPPER MOISTURE OVER THE CONVECTION NE THROUGH
THE BASIN...MAINLY E OF 75W.

WESTERN ATLANTIC...
THE BIG STORY IS THE STRENGTHENING LOW PRES SYSTEM OFF THE
CAROLINA COASTLINE....ANALYZED 1005 MB NEAR 34N72W. A BACK DOOR
COLD FRONT IS PROGRESSING SWD FROM THE LOW TO SOUTH CENTRAL
FLORIDA. SCATTERED SHOWERS WITH ISOLATED TSTMS WITH THE FRONT
ARE MAINLY WITHIN 120NM OF THE FRONT...THOUGH MIAMI RADAR AND
LIGHTNING DATA DEPICT TSTMS ARE MORE SCATTERED BETWEEN SFL AND
THE WRN BAHAMAS. THE MAIN IMPACT WITH THIS SYSTEM IS THE STRONG
WINDS AND LARGE SEAS AS A VERY TIGHT PRES GRADIENT HAS SET UP
BETWEEN THE LOW AND STRONG HIGH PRES OVER THE NORTHEAST STATES.
BUOY 41001 E OF HATTERAS IS REPORTING 55 KT NE WINDS WITH 36'
SEAS.  GLOBAL MODELS ARE NOW IN PRETTY GOOD AGREEMENT SHOWING
THE SYSTEM STRENGTHENING A LITTLE FURTHER AS IT GENERALLY MOVES
SSW TO A POSITION OFF NE FLORIDA BY TUE. SEVERAL MODELS ARE ALSO
SHOWING THE SYSTEM BECOMING LESS FRONTAL IN NATURE OVER THE NEXT
COUPLE OF DAYS. MARINE IMPACTS ARE EXPECTED TO BE SIGNIFICANT IN
THE NW PORTION OF THE AREA THROUGH MIDWEEK...REFER TO MIAHSFAT2
FOR DETAILS S OF 31N. FARTHER E...A WEAK 1010 MB LOW LOCATED
NEAR 28N62W ATTACHED TO A SFC TROUGH IS EXPECTED TO DISSIPATE
OVER THE NEXT 24 HOURS.

CENTRAL AND EASTERN ATLANTIC...
STRONG AZORES HIGH IS IN CONTROL OF THE PATTERN ACROSS THE ATLC
E OF 55W. THIS HIGH IS PRODUCING A LARGE AREA OF MODERATE TO
FRESH TRADES...STRONGEST E OF 25W WHERE THE PRES GRADIENT IS
TIGHTENED DUE TO LOWER PRES OVER AFRICA. SCATTERED STRATOCUMULUS
COVER MUCH OF THE REGION...EXCEPT S OF 18N E OF 28W WHERE THIS
LOW-LEVEL CLOUD DECK IS ERODED BY SAHARAN DUST. AN UPPER LOW IS
W OF THE CANARY ISLANDS NEAR 30N24W BUT DOES NOT APPEAR TO BE
GENERATING MUCH IN THE WAY OF SENSIBLE WEATHER.

$$
WILLIS



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