MD 1937 CONCERNING SEVERE POTENTIAL…TORNADO WATCH LIKELY FOR LOWER MO VALLEY TO CNTRL IA
MESOSCALE DISCUSSION 1937
NWS STORM PREDICTION CENTER NORMAN OK
1017 AM CST WED NOV 11 2015
AREAS AFFECTED...LOWER MO VALLEY TO CNTRL IA
CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY
VALID 111617Z - 111815Z
PROBABILITY OF WATCH ISSUANCE...95 PERCENT
SUMMARY...SURFACE-BASED STORMS SHOULD COMMENCE AROUND MIDDAY ALONG A
COLD FRONT ACROSS THE LOWER MISSOURI VALLEY. ALL SEVERE HAZARDS WILL
BE POSSIBLE WITH THIS ACTIVITY AS IT MOVES RAPIDLY NORTH TO EAST
THROUGH THE AFTERNOON. A MARGINAL SEVERE HAIL THREAT ALSO EXISTS
WITH ELEVATED STORMS NORTHWEST OF THE WARM SECTOR.
DISCUSSION...16Z SURFACE ANALYSIS PLACED A PAIR OF 995 MB CYCLONES
OVER N-CNTRL KS. LEADING PACIFIC COLD FRONT/EFFECTIVE DRYLINE HAS
REACHED ERN KS WITH AGITATED CU ALONG IT. THE CYCLONES SHOULD
CONSOLIDATE AS THEY TRACK NE ALONG A QUASI-STATIONARY FRONT ACROSS
FAR SERN NEB INTO SWRN AND W-CNTRL IA THIS AFTERNOON. MODEL FORECAST
SOUNDINGS SUGGEST 55-57 DEG F SURFACE DEW POINTS WILL BE THE
DELIMITER FOR MEAGER SURFACE-BASED INSTABILITY. THIS MOISTURE PLUME
SHOULD SHIFT NE FROM THE LOWER MO VALLEY ACROSS NRN MO TO CNTRL IA.
AS THE LEFT-EXIT REGION OF THE POWERFUL MID-LEVEL JET OVERSPREADS
THE NRN PERIPHERY OF THE CONFINED WARM SECTOR...COOLING ALOFT WILL
AID IN STEEPENING MID-LEVEL LAPSE RATES AND YIELD WEAKENING MLCIN
/EVIDENT IN THE 12Z TOP RAOB/ AMID ONLY WEAK DIABATIC SURFACE
HEATING. SURFACE-BASED TSTMS SHOULD INITIATE BY 18-19Z INVOF THE
NEB/KS/MO BORDER AREA. ORIENTATION OF DEEP-LAYER SHEAR TO THE FRONT
AND ENLARGED LOW-LEVEL HODOGRAPHS WILL BE FAVORABLE FOR FAST-MOVING
LOW-TOPPED SEMI-DISCRETE SUPERCELL STRUCTURES /ESPECIALLY ACROSS SRN
IA AND NRN MO/. FARTHER NW...ARCS OF ELEVATED CONVECTION WILL POSE A
MARGINALLY SEVERE HAIL RISK...BUT THIS THREAT SHOULD BE SPATIALLY
CONFINED AND DIMINISH WITH NRN EXTENT.
..GRAMS/THOMPSON.. 11/11/2015
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LSX...DVN...SGF...DMX...EAX...FSD...OAX...TOP...
LAT...LON 38389442 39589530 40039587 40249622 40429669 40679688
40959699 41339693 41649668 42079625 42919474 43039350
42679234 42349183 41729157 40969148 39739169 39149180
38779213 38399256 38259348 38389442
from SPC Mesoscale Discussions http://1.usa.gov/1zbKd0R
Be First to Comment