Severe Thunderstorm Warning 99, NWS Little Rock, AR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LITTLE ROCK AR
400 AM CDT MON APR 29 2002

FRONT IS NEAR THE SOUTHERN BORDER OF ARKANSAS. IT LOOKS LIKE IT MAY
MOVE A LITTLE MORE TO THE SOUTH THIS MORNING BEFORE STALLING. IT
WILL MOVE NORTH ACROSS THE AREA TUESDAY AS A WARM FRONT AS LOW
PRESSURE DEVELOPS ON THE HIGH PLAINS AND WARM ADVECTION SETS UP
ACROSS THE AREA. SOME THUNDERSTORMS HAVE DEVELOPED ALONG THE
FRONT DURING THE NIGHT AND THIS WILL LIKELY CONTINUE THROUGH TODAY
WITH THE MAIN THREAT IN THE SOUTHERN ZONES. MOISTURE INCREASES NORTH
INTO CENTRAL SECTIONS THIS AFTERNOON AND THIS ALONG WITH HEATING
AND WARM ADVECTION SHOULD EXTEND A CHANCE OF THUNDERSTORMS INTO
CENTRAL SECTIONS FOR THIS AFTERNOON. WILL GO WITH 20 PERCENT POPS
ACROSS THE SOUTH FOR THIS MORNING AND FOR CENTRAL AND SOUTHERN ZONES
THIS AFTERNOON. TEMPS STARTING OUT RATHER HIGH IN CENTRAL AND
SOUTHERN SECTIONS AND GUIDANCE DID POORLY ON MAXES YESTERDAY...SO
WILL GO ABOVE MOS FOR MAXES TODAY IN CENTRAL AND SOUTHERN ZONES.
COOLER AIR HAS A BETTER HOLD ON NORTHERN ZONES SO MOS MAXES LOOK
GOOD IN THAT AREA. AS THE FRONT BEGINS TO MOVE NORTH TONIGHT AND
TUESDAY, IT SHOULD PRODUCE A GOOD CHANCE OF RAIN ACROSS THE ENTIRE
AREA. SEVERAL WEAK SHORT WAVES MOVE ACROSS AND THIS ALONG WITH
WARM ADVECTION AND THE FRONT SHOULD DEVELOP SOME THUNDERSTORMS.
WILL HAVE CHANCE POPS ACROSS THE ENTIRE AREA WITH BETTER CHANCES
IN THE SOUTH TONIGHT AND IN THE NORTH FOR TUESDAY AS THE FRONT SLIDES
INTO THAT AREA. FAIRLY CERTAIN SOME SHOWERS WILL DEVELOP SO
FORECAST WORDING WILL BE FOR COVERAGE FOR THOSE PERIODS. THE FRONTAL
BOUNDARY BECOMES NEARLY STATIONARY NEAR THE MISSOURI BORDER OR A
LITTLE NORTH OF THERE TUESDAY NIGHT INTO WEDNESDAY. THE CWA WILL BE
IN THE WARM SECTOR AND VERY WARM 850 MB AND 700 MB TEMPS ARE PROGGED
TO MOVE INTO THE AREA ALONG WITH VERY HIGH 1000-700 MB AND 850-500
MB THICKNESSES. THIS MAY MEAN A STRONG CAP FOR THE AREA TUESDAY NIGHT
THROUGH WEDNESDAY. MEANWHILE...MODELS SHOW A 993 MB OR LESS SURFACE
LOW DEVELOPING ALONG THE FRONT. A MOISTURE AXIS DEVELOPS ACROSS
THE AREA LATE WEDNESDAY WHICH PUSHES EAST ON THURSDAY AS A COLD FRONT
MOVES ACROSS FROM THE WEST. THIS WILL MAKE FOR INTERESTING WEATHER
ON WEDNESDAY. THERE WILL EITHER BE RECORD WARMTH WITH MAXES IN THE
LOWER TO MID 90S AND NO THUNDERSTORMS DUE TO THE STRONG CAP...OR
THERE COULD BE A SERIOUS SEVERE WEATHER OUTBREAK DURING THE AFTERNOON
AND EVENING WITH THUNDERSTORMS DEVELOPING IN THE WEST DURING THE
AFTERNOON ALONG THE MOISTURE AXIS AND MOVING TO THE EAST. WILL GO
BETWEEN THOSE SCENARIOS FOR NOW WITH A CHANCE OF THUNDERSTORMS AND
MAXES IN THE MID AND UPPER 80S. DUE TO THE UNCERTAINTY FOR THUNDERSTORM
DEVELOPMENT, WILL WORD FORECASTS WITH CHANCE WORDING. UPPER RIDGE
BUILDS IN AFTER THAT WITH A SURFACE HIGH PRESSURE MOVING ACROSS
THE AREA THURSDAY THROUGH FRIDAY NIGHT. WILL GO WITH DRY AND COOLER
WEATHER FOR THOSE PERIODS.

.LZK...NONE