ATL: LISA - Advisories

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000
WTNT44 KNHC 260843
TCDAT4
TROPICAL DEPRESSION LISA DISCUSSION NUMBER 23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL142010
500 AM AST SUN SEP 26 2010

STRONG SOUTHWESTERLY SHEAR CONTINUES TO TAKE A TOLL ON LISA AS THE
CENTER OF THE CYCLONE IS EXPOSED TO THE SOUTHWEST OF A SMALL AREA
OF REMAINING THUNDERSTORM ACTIVITY. THE INITIAL INTENSITY IS
LOWERED TO 30 KT...BASED ON A BLEND OF DVORAK SATELLITE ESTIMATES
AND AN EARLIER ASCAT PASS. THE SHEAR...ALONG WITH DRY AIR AND COOL
SSTS...SHOULD CAUSE CONTINUED WEAKENING...AND LISA IS FORECAST TO
DEGENERATE TO A REMNANT LOW IN 12-24 HOURS.

THE INITIAL MOTION ESTIMATE IS 345/8. A NORTH-NORTHWESTWARD MOTION
IS EXPECTED DURING THE NEXT FEW DAYS AS THE CYCLONE MOVES BETWEEN A
TROUGH OVER THE EASTERN ATLANTIC AND A RIDGE NEAR NORTHWESTERN
AFRICA. THE GUIDANCE HAS GENERALLY SHIFTED WESTWARD THIS CYCLE...
AND THE OFFICIAL FORECAST HAS BEEN ADJUSTED IN THAT DIRECTION.
LATE IN THE FORECAST PERIOD...A SURFACE HIGH IS EXPECTED TO BUILD
NORTHWEST OF THE AZORES WHICH WILL LIKELY CAUSE THE REMNANT LOW TO
SLOW DOWN AND TURN NORTHWESTWARD BEFORE IT DISSIPATES.


FORECAST POSITIONS AND MAX WINDS

INITIAL 26/0900Z 25.1N 29.0W 30 KT
12HR VT 26/1800Z 26.0N 29.5W 25 KT
24HR VT 27/0600Z 27.2N 30.2W 25 KT...POST-TROP/REMNT LOW
36HR VT 27/1800Z 28.5N 30.9W 25 KT...POST-TROP/REMNT LOW
48HR VT 28/0600Z 29.8N 31.3W 25 KT...POST-TROP/REMNT LOW
72HR VT 29/0600Z 31.5N 31.3W 25 KT...POST-TROP/REMNT LOW
96HR VT 30/0600Z 32.0N 31.5W 20 KT...POST-TROP/REMNT LOW
120HR VT 01/0600Z...DISSIPATED

$$
FORECASTER BROWN

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000
WTNT44 KNHC 261431
TCDAT4
TROPICAL DEPRESSION LISA DISCUSSION NUMBER 24
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL142010
1100 AM AST SUN SEP 26 2010

LISA HAS LOST NEARLY ALL OF ITS DEEP CONVECTION AND NOW CONSISTS
PRIMARILY OF A TIGHT SWIRL OF LOW-LEVEL CLOUDS. AN 1104 UTC ASCAT
OVERPASS CAPTURED THE EASTERN PORTION OF THE CIRCULATION AND SHOWED
A SMALL AREA OF 25 TO 30 KT WINDS. BASED ON THIS DATA AND
SATELLITE INTENSITY ESTIMATES...THE INITIAL INTENSITY IS HELD AT 30
KT FOR THIS ADVISORY. THE COMBINATION OF CONTINUED STRONG
SOUTHWESTERLY SHEAR...SEA SURFACE TEMPERATURES OF AROUND 25 C...AND
A STABLE ATMOSPHERE SHOULD PREVENT THE FORMATION OF SIGNIFICANT
CONVECTION NEAR THE CENTER OF LISA...THEREFORE...DEGENERATION TO A
REMNANT LOW IS FORECAST TO OCCUR WITHIN THE NEXT 12 HOURS. THE
REMNANT LOW WILL LIKELY PERSIST FOR A FEW DAYS.

THE DEPRESSION IS MOVING TOWARD THE NORTH-NORTHWEST AT 6 KT.
LISA...OR ITS REMNANT LOW...IS EXPECTED TO CONTINUE MOVING
NORTH-NORTHWESTWARD TO NORTHWARD FOR THE NEXT FEW DAYS STEERED
BETWEEN A RIDGE OVER WESTERN AFRICA AND A TROUGH TO THE WEST OF THE
CYCLONE OVER THE EASTERN ATLANTIC. THE OFFICIAL TRACK FORECAST IS
AGAIN NUDGED SLIGHTLY TO THE WEST...TRENDING TOWARD THE MULTI-MODEL
CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/1500Z 25.6N 29.1W 30 KT
12HR VT 27/0000Z 26.4N 29.8W 25 KT...POST-TROP/REMNT LOW
24HR VT 27/1200Z 27.5N 30.6W 25 KT...POST-TROP/REMNT LOW
36HR VT 28/0000Z 28.7N 31.3W 25 KT...POST-TROP/REMNT LOW
48HR VT 28/1200Z 29.8N 31.5W 25 KT...POST-TROP/REMNT LOW
72HR VT 29/1200Z 31.3N 31.3W 20 KT...POST-TROP/REMNT LOW
96HR VT 30/1200Z...DISSIPATED

$$
FORECASTER CANGIALOSI

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WTNT44 KNHC 262038
TCDAT4
TROPICAL DEPRESSION LISA DISCUSSION NUMBER 25
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL142010
500 PM AST SUN SEP 26 2010

A SMALL AREA OF DEEP CONVECTION IS LINGERING OVER THE NORTHEASTERN
PORTION OF THE CIRCULATION OF LISA. THIS CONVECTION...HOWEVER...IS
LOCATED OVER 100 N MI FROM THE LOW-LEVEL CENTER. IN FACT...DEEP
CONVECTION HAS NOT BEEN WITHIN 100 N MI OF THE CENTER FOR ABOUT THE
LAST 11 HOURS. THEREFORE...LISA NO LONGER QUALIFIES AS A TROPICAL
CYCLONE AND THIS IS THE LAST ADVISORY ISSUED BY THE NATIONAL
HURRICANE CENTER. SOUTHWESTERLY SHEAR OF AT LEAST 30 KT IS
EXPECTED TO CONTINUE FOR THE NEXT DAY OR SO. THIS...COUPLED WITH A
STABLE ATMOSPHERE AND A RELATIVELY COOL OCEAN SHOULD PREVENT
REGENERATION.

THE INITIAL MOTION ESTIMATE IS 335/6. THE REMNANT LOW IS EXPECTED
TO CONTINUE MOVING NORTH-NORTHWESTWARD TO NORTHWARD FOR THE NEXT
FEW DAYS WITHIN THE LOW-LEVEL FLOW.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/2100Z 26.1N 29.4W 25 KT...POST-TROP/REMNT LOW
12HR VT 27/0600Z 26.8N 30.1W 25 KT...POST-TROP/REMNT LOW
24HR VT 27/1800Z 27.9N 31.0W 25 KT...POST-TROP/REMNT LOW
36HR VT 28/0600Z 29.1N 31.4W 25 KT...POST-TROP/REMNT LOW
48HR VT 28/1800Z 30.2N 31.4W 20 KT...POST-TROP/REMNT LOW
72HR VT 29/1800Z 31.4N 31.1W 20 KT...POST-TROP/REMNT LOW
96HR VT 30/1800Z...DISSIPATED

$$
FORECASTER CANGIALOSI