000 
FXUS63 KLBF 151924
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
224 PM CDT SUN AUG 15 2004

...FORECAST CHALLENGE IS POPS...

.DISCUSSION...
AT 18Z SURFACE FRONT WAS SOUTH OF THE BLACK HILLS WITH MODELS
CONTINUING TO SLOW FEATURE DOWN WHILE MOVING SOUTHEAST. LAPS DATA
SHOWS CAPE VALUES TO 2400 J/KG OVER THE CENTRAL NEB PANHANDLE WITH
AXIS OF GREATEST INSTABILITY NORTHEAST ACROSS THE PANHANDLE. VISIBLE
SATELLITE SHOW CU FORMING IN ADVANCE OF THE FRONT AS SURFACE HEATING
HAS HELPED FURTHER DESTABILIZE THE ATMOSPHERE...AND WV IMAGERY SHOWS
WAVE DROPPING SE ACROSS WESTERN SD MORE IN LINE WITH ETA SOLUTION
WITH STORMS IN THE NEAR TERM. RADAR MOSAIC HAS ISOLATED CELLS FROM
SOUTH CENTRAL SOUTH DAKOTA INTO THE NORTHWEST PANHANDLE ATTM.

ISOLATED THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP ACROSS THE
WEST THIS EVENING THEN WITH THE LOSS OF HEATING STORMS WEAKENING AND
DISSIPATING ACROSS THE WEST WHILE SCATTERED SHOWERS/THUNDERSTORMS
MOVE INTO THE NORTH CENTRAL OVERNIGHT. FRONT BECOMES ILL-DEFINED AS
IT MOVES SOUTHEAST OVERNIGHT INTO MONDAY WITH INCREASING ANTICYCLONIC
FLOW ALOFT ACROSS THE WEST. WITH NO SIGNIFICANT WAVE TO MOVING
SOUTHEAST ON MONDAY REMOVED ALL PRECIP EXCEPT EXTREME EAST IN NORTH
CENTRAL DURING THE MORNING HOURS.

MONDAY NIGHT UPSLOPE FLOW WILL BE REDIRECTED SOUTH TO ALONG
THE COLORADO HIGH PLAINS AS SURFACE HIGH RIDGES SOUTHEAST INTO
WESTERN NEBRASKA. UPPER RIDGE AXIS WILL WEAKEN OVERNIGHT AS
DISTURBANCES MOVE INTO THE RIDGE AXIS WITH CHANCE FOR THUNDERSTORMS
TUESDAY. TUESDAY MODELS IN GENERAL AGREEMENT BUT DIFFER IN
PLACEMENT OF CONVECTION AS DISTURBANCE MOVES SOUTHEAST WITH MODEL
BLEND USED.

BEYOND TUESDAY MODELS HAVING A TIME IN HOW TO HANDLE WEST
COAST UPPER RIDGE AND ENERGY TO MOVE SOUTHEAST. TRENDED WITH
PREVIOUS MODEL CONSISTENCY WHERE GFS KEEPS MAIN FORCING TO
THE SOUTHWEST. UNTIL MODEL CONSISTENCY INCREASES FOCUSING LIFTING
ENERGY TO THE NORTHEAST THURSDAY WILL GRIDS AS IS. TEMPERATURES
TO REMAIN AT OR NEAR NORMAL AS COLDEST AIR SKIRTS SOUTHEAST ACROSS
THE NORTHERN MIDWEST AND GREAT LAKES REGION.
&&

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

TLK