PLEASE SEE THE PUBLIC INFORMATION STATEMENT...NEWPNSLCH OR WMO
HEADER NOUS44 KLCH...FOR INFORMATION ON TODAYS RECORD HEAT.

PREV DISCUSSION... /ISSUED 407 PM CDT WED JUN 24 2009/

DISCUSSION...
AN ABSOLUTE SCORCHER THIS AFTERNOON WITH HIGH TEMPERATURE RECORDS
BROKEN AT EVERY CLIMATE OBSERVING SITE. HEAT INDEX VALUES HAVE
CLIMBED TO OVER 108 DEGREES AT MOST OBSERVING SITES IN
LOUISIANA...WITH SOUTHEAST TEXAS SPARED THANKS TO LOWER SURFACE
DEWPOINTS. ISOLATED SHOWERS AND A THUNDERSTORM OR TWO HAVE
DEVELOPED OVER MAINLY EAST TEXAS AND CENTRAL LOUISIANA...WITH
THE SURFACE HEATING PERMITTING THE CAP TO BE OVERCOME. INVERTED-V
SIGNATURES ON LAPS SOUNDINGS...ALONG WITH VERY HIGH FREEZING
LEVELS AND LITTLE 0-6KM BULK SHEAR...POINT TO PRIMARILY A
DOWNBURST WIND THREAT WITH THE STRONGEST THUNDERSTORMS. THE AREA
IS IN A SLIGHT RISK FOR THIS THREAT INTO EARLY EVENING.

ASIDE FROM ISOLATED AND PRIMARILY DIURNALLY DRIVEN CONVECTIVE
ACTIVITY...NO SIGNIFICANT RELIEF FROM THE HEAT AND LACK OF
RAINFALL IS ON THE HORIZON IN THE SHORT TERM. IN THE NORTHERLY
FLOW ALOFT AROUND THE MID/UPPER LEVEL RIDGE CENTERED TO OUR
NORTHWEST...FORECAST MODELS SHOW DRIER AIR ADVECTING INTO THE AREA
TOMORROW. THERE IS SOME UNCERTAINTY REGARDING HOW FAR SOUTH THIS
DRY AIR WILL GET...AND THIS IS CHIEFLY THE REASON FOR HOLDING OFF
ON ISSUING ANOTHER HEAT ADVISORY FOR TOMORROW AFTERNOON. BEST
ESTIMATE AT THIS POINT IS THAT CENTRAL LOUISIANA AND THE EAST
TEXAS LAKES...ALTHOUGH HOT...WILL REMAIN BELOW ADVISORY CRITERIA
WITH AFTERNOON DEWPOINTS IN THE MID 60S. THE I-10 CORRIDOR...ON
THE OTHER HAND...MAY VERY WELL NEED ONE WITH DEWPOINTS PROGGED
AROUND 70. WILL LET THE MID SHIFT FURTHER EVALUATE THE PROGRESSION
OF THE DRY AIR OVERNIGHT AND MAKE THE CALL.

THE MID/UPPER RIDGE IS FORECAST TO REMAIN QUASI-STATIONARY THROUGH
FRIDAY...BEFORE STARTING TO FLATTEN OUT AND STRETCH EAST OVER US ON
SATURDAY AS A MID/UPPER TROF ROUNDS THE RIDGE THROUGH THE
NORTHERN/CENTRAL PLAINS. MEANWHILE...AT THE SURFACE THE BERMUDA HIGH
WILL BECOME DOMINANT OVER THE GULF...WITH A PERSISTENT
SOUTH/SOUTHWESTERLY FLOW PREVAILING AT THE SURFACE. THIS SHOULD
START TO MODERATE TEMPERATURES NEAR THE COAST...WHILE INTERIOR
LOCATIONS CONTINUE TO BAKE. THE TROF IS FORECAST TO CLOSE OFF AND
STALL OVER THE GREAT LAKES...WITH THE RIDGE RETROGRADING TO THE
SOUTHWEST CONUS...RESULTING IN NORTHWEST FLOW OVERHEAD. THE GFS
AND ECMWF SHOW A FRONT SAGGING TO THE COAST BY THE EARLY TO MID
PART OF NEXT WEEK...AND WITH THE LOW LEVEL INFLUX OF MOISTURE...WE
MAY FINALLY SEE MORE THAN JUST ISOLATED CONVECTION.

MARINE...
HIGH PRESSURE ACROSS SOUTH CENTRAL TEXAS RIDGES SOUTHEAST INTO
THE NORTHWEST GULF OF MEXICO. THIS SYSTEM WILL MOVE LITTLE OVER
THE NEXT COUPLE OF DAYS.  THE BERMUDA HIGH WILL RE-ESTABLISH
ITSELF ACROSS THE GULF OF MEXICO ON FRIDAY...WITH THE RETURN OF
THE MORE TYPICAL SOUTHERLY WINDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
KLCH  77  99  76  97  78 /  20  20  10  20  10
KBPT  77 100  76  98  77 /  20  20  10  20  10
KAEX  73 101  72 100  75 /  20  20  10  20  10
KLFT  79  99  78  97  78 /  20  20  10  20  10

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&

$$