Severe Thunderstorm Warning 219, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
218 PM CDT THU JUL 26 2001

FORECAST CHALLENGE WILL BE LINGERING RAIN CHCS AND HIGHS FOR
FRIDAY...

WV IMAGERY INDICATES AN OPEN H5 LOW LIFTING FROM SRN UT W/ASSOC
CONVECTION. AN AREA OF INCREASING UPPER DIVERGENCE IN COLORADO AN
NORTHERN NEW MEXICO ASSOC WITH H25 JET MAX ANALYZED EXITING SRN WY.
SUBTROPICAL MOISTURE FEEDING INTO THE CENTRAL PLAINS. AT THE
SURFACE...LOW ALONG THE LEE OF THE COLORADO ROCKIES NORTHWEST INTO
NRN WYOMING. DEWPOINTS IN THE 60S OVER MUCH OF THE REGION WITH LOWER
70S POOLING IN NR KS AND SC NEBR. STATUS HAS BEEN REPLACED BY
STATOCU OVER WRN AND NC NEBR WITH MID CLOUDS MOVING INTO SWRN NEBR.

MODELS AGAIN IN GENERAL AGREEMENT FOR WIDESPREAD RAINFALL EVENT OVER
NEBRASKA TONIGHT INTO FRIDAY. TIMING OF THE SHOWERS ENDING FRIDAY
AND HIGH TEMPERATURES APPEARS TO BE THE MAIN FORECAST CONCERN. THE
ETA HAS BEEN THE MOST CONSISTENT AND WILL GENERALLY FOLLOW WITH
INPUT FROM THE AVN AND NGM.

TONIGHT...SRN STREAM H5 WAVE MOVES INTO CO AND SERN WY AS A NRN
STREAM WAVE MOVES INTO WRN SOUTH DAKOTA. THIS PHASING OF THE TWO
WAVES WILL ENHANCE LARGE-SCALE LIFT OVER NEBRASKA TONIGHT. BASES ON
CONSISTENCY OF ETA...AVN AND NGM WILL GO LIKELY POPS ALL BUT THE ERN
PANHANDLE WHERE CONVECTION MAY BEGIN MORE SCATTERED IN NATURE. HEAVY
RAINFALL IS POSSIBLE WITH THE BEST AREA INDICATED IN SOUTHWEST
NEBRASKA WHERE PRECIPITABLE WATER VALUES RISE TO NEAR 2 INCHES.
POTENTIAL MCS DEVELOPMENT FROM NERN CO INTO SWRN NEBR AND NWRN KS
WHERE HIGHEST 1000-850MB THETA-E RESIDES. WILL INCLUDE MENTION OF
HEAVY RAINFALL POSSIBLE EXTREME SOUTHWEST COUNTIES WHERE HEAVY
RAINFALL ALSO FELL EARLIER THIS WEEK.

FRIDAY...SHOWERS SHOULD END ACROSS THE WEST IN THE AM AS SUBSIDENCE
AND DRIER AIR WORK IN. THE AVN AND NGM HINT AT AFTN SHOWERS
LINGERING IN THE WEST BUT FEEL THE ETA HAS A BETTER HANDLE ON ENDING
PRECIP. BEST AREA FOR LATE AFTERNOON REDEVELOPMENT WILL BE NORTH OF
WM FRONT FROM NORTHERN KS INTO SERN NEBR AND NEAR THE FOOTHILLS
WHERE UPSLOPE FLOW AND STEEP MID LEVEL LAPSE RATES WILL OCCUR.
NOTHING MORE THAN SOME AFTERNOON CU SHOULD DEVELOP IN WRN NEBR WHILE
SHOWERS END IN THE EAST. WINDS WILL TURN TO THE NORTH FROM WEST TO
EAST AS THE SURFACE TROUGH MOVE THROUGH. WILL GO ABOVE PREVIOUS FCST
HIGHS AND GO WITH MID 80S WEST TO MID 70S FAR EAST CLOSER TO FWC
GUIDANCE.

FRIDAY NIGHT...MOSTLY CLEAR WITH WINDS RETURNING TO THE SOUTHEAST.
UPPER RIDGE BEGINS TO BUILD TO OUR WEST.

SATURDAY AND SATURDAY NIGHT...UPPER RIDGE CONTINUES TO BUILD WITH
HIGHS REACHING TO AROUND 90 WEST. CONTINUED DRY WITH VERY LITTLE
LAYER RH AND VERY WEAK WAVES THROUGH THE FLOW.

EXTENDED...UPPER RIDGE CENTER IS FORECAST TO BUILD INTO KANSAS SUN
AND MON THEN MOVES NORTHEAST TOWARD ILLINOIS BY TUESDAY. DRY SUN AND
MONDAY WITH A SLIGHT CHANCE THUNDERSTORMS TUESDAY THROUGH THURSDAY.

.LBF...NONE.

ROBERG