890 
FXUS63 KDTX 161919
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
320 PM EDT MON AUG 16 1999

MAIN FORECAST CONCERNS THIS FORECAST IS PRECIPITATION TIMING THROUGH 
THE PERIOD.

CURRENTLY VISIBLE SATELLITE IMAGERY INDICATES CLOUD BAND EXTENDING 
FROM NORTHEAST LOWER SOUTHWEST INTO IOWA. AREA OF CLOUDS IN RESPONSE 
TO THETA E ADVECTION IN 850 WAA PATTERN JUST AHEAD OF SURFACE 
BOUNDARY. CURRENT AIRMASS OVER SOUTHEAST LOWER VERY DRY...SO WILL BE 
TOUGH FOR ANYTHING TO FALL THROUGH THE LAYER FOR SOME TIME. THE 
THETA E RIDGE SLIDES SOUTHEAST THROUGH THE NIGHT...ALONG WITH THE 
BEST WAA. WITH THE SURFACE VERY STABLE OVERNIGHT...WEAK SURFACE 
CONVERGENCE WITH TROUGH...AND UPPER SUPPORT WELL NORTH...WILL COUNT 
ON WAA TO PROVIDE LIFTING MECHANISM TONIGHT. THIS LIFT NOT TOO 
STRONG HENCE WILL NOT MENTION THUNDERSTORMS OVERNIGHT...BUT COULD 
TAP A FEW SHOWERS ONCE THE LOWER LEVELS MOISTEN UP.

FOR TUESDAY...REMAINDER OF THE SURFACE TROUGH CROSSES EXTREME 
SOUTHERN COUNTIES DURING THE MORNING HOURS. SURFACE BASED 
INSTABILITY EXISTS IN THE MORNING WITH LIS OF -2 TO -4 AND CAPES OF 
500 TO 1000 J/KG OVER SOUTHERN HALF OF CWA. FWC TEMPERATURES LOOK 
TOO HIGH WITH TROUGH COMING THROUGH IN THE MORNING. WEAK SUBSIDENCE 
AND NVA IN THE AFTERNOON COULD LEAD TO SOME A SUNNY PERIOD THOUGH...SO 
WILL NOT GO STRAIGHT TO FAN NUMBERS...WILL LEAN TOWARD A FWC/FAN 
COMPROMISE. ANY AFTERNOON SUNNY BREAKS WILL BE TEMPERED BY CLOUDS 
AHEAD OF SECOND TROUGH. 

FOR TUESDAY NIGHT INTO WEDNESDAY...SECOND TROUGH DROPS INTO 
CWA...WITH BROAD SHORT WAVE AXIS DROPPING IN FROM THE NORTHWEST. 
WITH LITTLE FORCING...AT THIS TIME WILL FAVOR A DRY FORECAST. 
MOISTURE PROFILE WOULD FAVOR MOSTLY CLOUDY SKIES.

.DTX...NONE.

STRUBLE