Severe Thunderstorm Warning 140, NWS Hastings, NE

CENTRAL NEBRASKA/NORTH CENTRAL KANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
238 PM CDT THU AUG 21 1997

THUNDERSTORMS MAIN CONCERN AGAIN THIS PACKAGE IN NW FLOW ALOFT.

WILL BEGIN FORECAST DISCUSSION WITH YESTERDAYS MODEL RUNS.  THEY INDCTD
IMPRESSIVE ISENT LIFT OVER SW FA BY THU MORNING.  1.25 IN PCPTBL H2O
VALUES WERE LIFTED TO SATURATION ALONG FAVORED 570 THICKNESS CONTOUR
WHICH RUNS RIGHT THROUGH SVR WX AREA THIS MORNING AS PER K0K.

ON GOING ELEVATED CONVECTION ATTM ALSO NEAR 570 TKNS CONTOUR AS PER K1K
AS 1.25 IN CONTS TO BE LIFTED AS PER P03.  ALSO COMING INTO PLAY TAFTN
IS A JET MAX RIDING NW-SE ACROSS MN/IA AD H7 S/W BOTH PER 12Z UA/PROFS.
THESE FEATURES HARD TO DISCERN ON WV IMGRY.  THESE STORMS SHOULD CONT
INTO EARLY EVENING GRADUALLY SINKING SWD.

WHAT IS MORE EVIDENT ON SATELLITE ARE OUTFLOW BNDRIES FROM MORNING TRWS
AND NW NEBR S/W WITH IMPRESSIVE DRYING AS PER GLD AFD.  THESE SHUD
COMBINE WITH MST/UNSTABLE AIR FOR TSTMS THIS EVENING NEBR AND INTO THE
NIGHT KS.  ALTHOUGH CELL MOVEMENTS QUICK...SOME TRAINING AS OCCURRED
THIS MORNING...COULD PRODUCE HEAVY AMOUNTS AND WILL MENTION IN KS TNGT.
WILL ALSO MENTION PSBLTY OF SVR WX OVER WRN SECTIONS OF FA CLOSER
WHERE SHEAR PROFILES AND HIGHER INSTABILITIES WARRANT HIGHER SVR WX
THREAT.

MODELS HAVE A TOUGH TIME WITH THIS NW FLOW SO CANT SAY THAT ANY DO A
FANTASTIC JOB.  NGM DID INITIALIZE VVEL FAIRLY WELL THIS MORNING.
WILL GO WITH TYPICAL BLEND OF MODELS USING WV IMGRY EXTRAPOLATION TO
GET SOME SEMBLANCE OF TIMING OF PSBL TSTMS FOR OUT PDS.

IT APPEARS THAT AFTER TNGT...NEXT CHC COMES AGAIN FRI AND INTO THE
EVENING AS A PORTION OF IGNACIO COMES DOWN FRONT SIDE OF UPPER RIDGE.
NGM HINTS AT THE RESULTING PRECIP BEST BUT MAY BE A LITTLE SLOW WITH
TIMING.  WILL GO WITH SMALL POPS FRI/FRI NGT AND LEAVE SAT DRY ATTM
AS THERE SHOULD BE SOME BREAK BETWEEN WAVES AFTER TROP SYS REMNANT
PASSES.

TEMPS FRIDAY PROBABLY A TAD WARMER THAN TODAY WITH ERLY AM TSTMS NOT
FCST.  SATURDAY REMAINS UP IN THE AIR BUT WILL GO EVEN A LITTLE MORE
WARMER AS UPPER RIDGE BUILDS/SHIFTS SLGTLY EWD.  FWC/FAN BLEND RSNBL
EXCEPT THAT MINS ARE A LITTLE ON THE COOL SIDE GIVEN CURRENT DEW POINTS.
.
GRI BB 064/082/064/085 4331
ODX BB 061/083/063/085 3331
LXN BB 063/084/062/086 4331
HBR BB 065/083/065/085 4331
BEL BB 067/084/066/086 5331

DROZD