Post by T-man on Jun 14, 2007 5:34:01 GMT -6
Watching the clouds building all around me yesterday was fun. Not getting any measurable rainfall, much less hail, was not fun. Maybe it will rain here today. Too bad I have to go to town and I won't be around to see it. This morning's disco mentions yesterday's scenario, and today's chances:
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
413 AM CDT THU JUN 14 2007
.SHORT TERM...
YESTERDAY...MOISTURE PROFILES WERE ABOUT 200MB THICK FROM
800-600MB. A STRONG DRY LAYER BENEATH WARMED SUFFICIENTLY TO
CREATE STRONG THERMALS WHICH IN TURN REACHED THIS MOIST REGION AND
STARTED TS BY AFTERNOON. ANOTHER DRY LAYER EXISTED FROM 600MB
UPWARD. THIS WAS THE MOST TEXTBOOK EFFICIENT SOUNDING PROFILE I
HAVE SEEN IN A WHILE FOR DOWNBURST TS WINDS. ON A NORMAL
SOUNDING...WE SEE THIS DRY REGION AT AROUND 700MB. BUT YESTERDAYS
SOUNDING WAS AN INDICATOR OF VERY EFFICIENT THERMAL DYNAMICS
THROUGHOUT THE COLUMN. TS COULD BUILD QUICKLY INTO THE UPPER DRY
LAYER ONCE TRIGGER TEMPS WERE REACHED. AND AS RAIN AND DOWNDRAFTS
BEGAN...MORE DRY AIR ALOFT WOULD BE BROUGHT IN...FINALLY THE
STRONGLY SUBSIDENT AIR REACHED THE LOWEST DRY LAYER AND MORE DRY
AIR WAS ENTRAINED CAUSING EVEN MORE NEGATIVE BUOYANCY. THE RESULT
WAS EXTREMELY STRONG MICROBURST WINDS CREATED BY THE RAIN AND
COOL AIR HITTING THE GROUND AND SPREADING OUT IN ALL DIRECTIONS.
SUCH DRY AIR ALOFT SUPPORTS HAIL AS WELL BY NOT LETTING IT MELT AS
QUICKLY AS A MOIST ATMOSPHERE WOULD.
WHAT HAS CHANGED...WE WILL LOSE 100MB OF MOISTURE TODAY CREATING A
LESS FAVORABLE ENVIRONMENT FOR TS DEVELOPMENT. THE SFC WILL DRY A
LITTLE AS WELL CAUSING CAPE VALUES TO BE LESS. WE WILL STILL HAVE
100MB OF MOISTURE THICKNESS FROM 800-700MB. THIS WILL STILL HELP
IN SOME TS PRODUCTION BUT INSTEAD OF HAVING 8 TS DEVELOP WE MAY
ONLY SEE 5 INSTEAD. MAIN AREAS FOR TS WILL BE ALONG AND WEST OF
A LINE FROM AMITE COUNTY TO TERREBONNE PARISH WHERE AN OLD OUTFLOW
BOUNDARY CONTINUES TO EXIST FROM YESTERDAY. SLIGHTLY LESS COVERAGE
SHOULD BE FOUND TO THE EAST OF THIS LINE. WILL KEEP 30% FOR ALL
ZONES THOUGH. DON`T LET THE LOWER NUMBERS FOOL YOU THOUGH. ANY
AND ALL TS THAT DEVELOP WILL HAVE A STRONG POTENTIAL TO BECOME
SEVERE QUICKLY.
.LONG TERM...
POP NUMBERS SHOULD LOWER FOR THE WEEKEND BUT WE WILL BEGIN TO SEE
A LARGE SURGE OF DEEP TROPICAL MOISTURE MOVING TOWARD THE AREA FROM
THE CARRIBEAN STARTING SUNDAY. THE SURGE WILL NOT REACH THE AREA
UNTIL TUE. THIS MOISTURE WILL BE INDUCED BY A TROPICAL WAVE FROM
THE SOUTH ALONG WITH A STRONG COLD FRONT THAT WILL QUICKLY MOVE
IN FROM THE NORTH. THE FRONT SHOULD DRASTICALLY SLOW AS IT REACHES
THE GULF COAST CAUSING THE FRONTAL AXIS TO BECOME A MAJOR FOCUS
FOR SH/TS AS THE DEEP MOISTURE FROM THE GULF INTERACTS WITH IT.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
413 AM CDT THU JUN 14 2007
.SHORT TERM...
YESTERDAY...MOISTURE PROFILES WERE ABOUT 200MB THICK FROM
800-600MB. A STRONG DRY LAYER BENEATH WARMED SUFFICIENTLY TO
CREATE STRONG THERMALS WHICH IN TURN REACHED THIS MOIST REGION AND
STARTED TS BY AFTERNOON. ANOTHER DRY LAYER EXISTED FROM 600MB
UPWARD. THIS WAS THE MOST TEXTBOOK EFFICIENT SOUNDING PROFILE I
HAVE SEEN IN A WHILE FOR DOWNBURST TS WINDS. ON A NORMAL
SOUNDING...WE SEE THIS DRY REGION AT AROUND 700MB. BUT YESTERDAYS
SOUNDING WAS AN INDICATOR OF VERY EFFICIENT THERMAL DYNAMICS
THROUGHOUT THE COLUMN. TS COULD BUILD QUICKLY INTO THE UPPER DRY
LAYER ONCE TRIGGER TEMPS WERE REACHED. AND AS RAIN AND DOWNDRAFTS
BEGAN...MORE DRY AIR ALOFT WOULD BE BROUGHT IN...FINALLY THE
STRONGLY SUBSIDENT AIR REACHED THE LOWEST DRY LAYER AND MORE DRY
AIR WAS ENTRAINED CAUSING EVEN MORE NEGATIVE BUOYANCY. THE RESULT
WAS EXTREMELY STRONG MICROBURST WINDS CREATED BY THE RAIN AND
COOL AIR HITTING THE GROUND AND SPREADING OUT IN ALL DIRECTIONS.
SUCH DRY AIR ALOFT SUPPORTS HAIL AS WELL BY NOT LETTING IT MELT AS
QUICKLY AS A MOIST ATMOSPHERE WOULD.
WHAT HAS CHANGED...WE WILL LOSE 100MB OF MOISTURE TODAY CREATING A
LESS FAVORABLE ENVIRONMENT FOR TS DEVELOPMENT. THE SFC WILL DRY A
LITTLE AS WELL CAUSING CAPE VALUES TO BE LESS. WE WILL STILL HAVE
100MB OF MOISTURE THICKNESS FROM 800-700MB. THIS WILL STILL HELP
IN SOME TS PRODUCTION BUT INSTEAD OF HAVING 8 TS DEVELOP WE MAY
ONLY SEE 5 INSTEAD. MAIN AREAS FOR TS WILL BE ALONG AND WEST OF
A LINE FROM AMITE COUNTY TO TERREBONNE PARISH WHERE AN OLD OUTFLOW
BOUNDARY CONTINUES TO EXIST FROM YESTERDAY. SLIGHTLY LESS COVERAGE
SHOULD BE FOUND TO THE EAST OF THIS LINE. WILL KEEP 30% FOR ALL
ZONES THOUGH. DON`T LET THE LOWER NUMBERS FOOL YOU THOUGH. ANY
AND ALL TS THAT DEVELOP WILL HAVE A STRONG POTENTIAL TO BECOME
SEVERE QUICKLY.
.LONG TERM...
POP NUMBERS SHOULD LOWER FOR THE WEEKEND BUT WE WILL BEGIN TO SEE
A LARGE SURGE OF DEEP TROPICAL MOISTURE MOVING TOWARD THE AREA FROM
THE CARRIBEAN STARTING SUNDAY. THE SURGE WILL NOT REACH THE AREA
UNTIL TUE. THIS MOISTURE WILL BE INDUCED BY A TROPICAL WAVE FROM
THE SOUTH ALONG WITH A STRONG COLD FRONT THAT WILL QUICKLY MOVE
IN FROM THE NORTH. THE FRONT SHOULD DRASTICALLY SLOW AS IT REACHES
THE GULF COAST CAUSING THE FRONTAL AXIS TO BECOME A MAJOR FOCUS
FOR SH/TS AS THE DEEP MOISTURE FROM THE GULF INTERACTS WITH IT.
Need a life raft here soon. 
