Severe Storm Outlook Narrative (AC)
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13

000
ACUS11 KWNS 272024
SWOMCD
SPC MCD 272024
NEZ000-272230-

MESOSCALE DISCUSSION 1751
NWS STORM PREDICTION CENTER NORMAN OK
0324 PM CDT THU AUG 27 2015

AREAS AFFECTED...PARTS OF NORTH CENTRAL NEBRASKA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 272024Z - 272230Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT...INCLUDING
THE RISK FOR A COUPLE OF SUPERCELLS...IS EXPECTED WITHIN THE NEXT
FEW HOURS.  IT IS NOT CERTAIN THAT A SEVERE WEATHER WATCH WILL BE
NEEDED...BUT TRENDS WILL CONTINUE TO BE MONITORED FOR THIS
POSSIBILITY.

DISCUSSION...BENEATH WARM AND CAPPING ELEVATED MIXED LAYER AIR WHICH
HAS OVERSPREAD MUCH OF THE SOUTHERN THROUGH CENTRAL PLAINS...DEEP
BOUNDARY LAYER MIXING HAS OCCURRED WITHIN THE LEE SURFACE TROUGH
ACROSS MUCH OF WESTERN/CENTRAL KANSAS INTO SOUTHWEST NEBRASKA.
HOWEVER...NEAR SURFACE FLOW IS MAINTAINING A SOUTHEASTERLY
COMPONENT...ALONG WITH COOLER TEMPERATURES/HIGHER DEW POINTS...
ACROSS SOUTHEASTERN THROUGH NORTH CENTRAL NEBRASKA...WHERE MIXED
LAYER CAPE NEAR THE SURFACE TROUGH AXIS HAS BECOME MODERATELY LARGE
/ON THE ORDER OF 2000 J PER KG/.

ALTHOUGH IT APPEARS UNLIKELY THAT CONVECTIVE TEMPERATURES WILL BE
APPROACHED THROUGH FURTHER LATE AFTERNOON BOUNDARY LAYER
WARMING...MID-LEVEL COOLING ASSOCIATED WITH ONE SHORT WAVE IMPULSE
NOW PROGRESSING THROUGH CENTRAL NEBRASKA MAY BE SUFFICIENT TO
CONTRIBUTE TO STORM INITIATION WITHIN THE NEXT FEW HOURS.  THIS MAY
BE AIDED BY FORCING WITH ANOTHER WEAK IMPULSE DIGGING EAST
SOUTHEASTWARD OUT OF WYOMING THROUGH THE 22-00Z TIME FRAME.

ON THE EASTERN FRINGE OF 30+ SOUTHERLY 850 MB FLOW...LOW-LEVEL SHEAR
APPEARS FAVORABLE FOR SUBSTANTIVE UPDRAFT ROTATION...AND SHOULD
BECOME INCREASINGLY SO THROUGH EARLY EVENING...PERHAPS ENHANCED BY A
BELT OF 30 KT SOUTHWESTERLY 500 MB FLOW CURRENTLY OVERSPREADING THE
REGION.  STORM COVERAGE REMAINS A BIT IN QUESTION...BUT AT LEAST
ISOLATED SUPERCELLS APPEAR POSSIBLE...PERHAPS HAS EARLY AS 21-22Z
TIME FRAME.

..KERR/CORFIDI.. 08/27/2015

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OAX...GID...LBF...

LAT...LON   42580095 42939889 41359792 40819929 41619979 42580095



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.