MD 1158 CONCERNING SEVERE THUNDERSTORM WATCH 328…330… FOR A LARGE PART OF KS…FAR SRN NEB…NRN OK
MESOSCALE DISCUSSION 1158
NWS STORM PREDICTION CENTER NORMAN OK
1120 PM CDT TUE JUL 05 2016
AREAS AFFECTED...A LARGE PART OF KS...FAR SRN NEB...NRN OK
CONCERNING...SEVERE THUNDERSTORM WATCH 328...330...
VALID 060420Z - 060615Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
328...330...CONTINUES.
SUMMARY...THE SVR-TSTM RISK IS SPREADING SWD/SEWD ACROSS PORTIONS OF
WRN/CNTRL KS...AND THE SVR RISK SHOULD SPREAD FARTHER S -- PERHAPS
AS FAR SOUTH AS NRN OK -- DURING THE OVERNIGHT HOURS.
DISCUSSION...CONGEALING CONVECTIVE CLUSTERS OVER PARTS OF WRN KS
HAVE EVOLVED INTO A MORE ORGANIZED SYSTEM SURGING SWD IN PARTS OF
NESS AND LANE COUNTIES KS. THIS IS CONSISTENT WITH THE NOCTURNAL
INCREASE IN LOW-LEVEL SLYS DRIVING CONVECTIVE PROPAGATION SWD INTO
THE STRENGTHENING LLJ. THE DDC VWP INDICATES 0.5-KM-AGL SLY FLOW
HAVING INCREASED FROM 20 TO 30 KT DURING THE PAST FEW
HOURS...RESULTING IN STRENGTHENING INFLOW FOR THE ONGOING
CONVECTION. FURTHER STRENGTHENING OF THE NOCTURNAL BOUNDARY-LAYER
WIND-SPEED MAXIMUM SHOULD FOSTER STRENGTHENING INFLOW ON THE SRN
FLANK OF THE ONGOING CONVECTION DURING THE OVERNIGHT HOURS...WHILE
WLY/NWLY MID-LEVEL FLOW YIELDS EWD/SEWD CELL ADVECTION. AS A
RESULT...LOCALLY UPSCALE-GROWING CONVECTIVE CLUSTERS WILL CONTINUE
SPREADING SWD/SEWD DURING THE NEXT SEVERAL HOURS.
THE EARLIER 00Z DDC RAOB SUGGESTS THAT AMPLE BUOYANCY WILL EMANATE
FROM BASE OF THE RESIDUAL MIXED LAYER...WITH MUCAPE ON THE ORDER OF
3000-4000 J/KG FOSTERING INTENSE UPDRAFTS AMIDST 35-50 KT OF
EFFECTIVE BULK SHEAR. THIS WILL ALLOW SOME SVR RISK TO EXTEND S OF
WW 330 INTO THE OVERNIGHT HOURS...AND LOCAL EXTENSION OF THE WW MAY
BE NEEDED. FURTHERMORE...SOME ISOLATED SVR RISK CANNOT BE RULED OUT
AS FAR S AS NRN OK LATER TONIGHT AS THE LLJ ENHANCES INFLOW.
HOWEVER...GROWING NOCTURNAL MLCINH MAY BE DETRIMENTAL TO DOWNDRAFTS
PENETRATING THE SFC-BASED NOCTURNAL STABLE LAYER. AS SUCH...THE
ISSUANCE OF AN ENTIRELY NEW WW IS UNLIKELY.
OTHER ISOLATED INTENSE CONVECTION CONTINUES DEVELOPING ACROSS PARTS
OF N-CNTRL KS AT THE TERMINUS OF THE STRENGTHENING LLJ. IT IS
POSSIBLE THAT THIS ACTIVITY MAY SUPPORT AN ISOLATED SVR RISK AS IT
SPREADS ACROSS PARTS OF CNTRL/NRN KS.
FARTHER N INTO FAR SRN NEB...THE SVR RISK ACROSS REMAINING-VALID
PORTIONS OF WW 328 HAS LARGELY DIMINISHED OWING TO STABILIZATION
ASSOCIATED WITH NOCTURNAL COOLING OF THE SFC LAYER...AS WELL AS
PRIOR CONVECTIVE PROCESSING.
..COHEN/GUYER.. 07/06/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...TSA...TOP...ICT...OUN...GID...DDC...GLD...
LAT...LON 36719932 37480025 38340067 39100062 39779974 40229815
39259719 37079658 36639747 36719932
from SPC Mesoscale Discussions http://bit.ly/29moVuR
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