U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus01 kwns 171224 
Storm Prediction Center ac 171223 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0623 am CST Fri Nov 17 2017 

Valid 171300z - 181200z 

..no severe thunderstorm areas forecast... 

thunderstorms are expected tonight across much of the Midwest from 
Missouri to Ohio, with more isolated afternoon and evening 
thunderstorms possible across parts of the central rockies. 

..central rockies area this afternoon/evening... 
A pronounced positive-tilt midlevel trough will progress eastward 
from the northern Great Basin this morning to the Central Plains by 
Saturday morning. Steepening low-midlevel lapse rates and ascent 
focused along an associated baroclinic zone will support weak 
buoyancy and the threat for isolated thunderstorms this 
afternoon/evening in the area centered on western Colorado. 

..mid MS and Ohio Valley regions late this evening and overnight... 
A downstream Lee cyclone will deepen this afternoon near the Colorado/Kansas 
border, and then begin to move eastward overnight toward MO with the 
approach of the midlevel trough. A Reservoir of boundary-layer 
dewpoints in the 60s across the Southern Plains will be drawn 
northeastward in a strengthening warm advection regime through 
tonight, when elevated convection will become more probable across 
parts of the mid MS and Ohio Valley regions. MUCAPE could increase to 
the 500-1000 j/kg range from 06-12z from central MO to 
central/southern IL, where midlevel lapse rates will be steeper 
above the returning low-level moisture. Thermodynamic profiles 
appear sufficient for a conditional threat for some hail with 
slightly elevated convection near the surface cyclone/cold front, 
though any window of opportunity will be small and near the very end 
of the forecast period, so will not introduce any hail probabilities 
at this time. 

.Thompson.. 11/17/2017 


Mesoscale Discussion

acus11 kwns 061643 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 061643 

Mesoscale discussion 1767 
National Weather Service Storm Prediction Center Norman OK 
1043 am CST Mon Nov 06 2017 

Areas affected...northern Arkansas...southern Missouri...far western 
Tennessee and Kentucky 

Concerning...severe potential...watch unlikely 

Valid 061643z - 061915z 

Probability of watch issuance...20 percent 

Summary...a smattering of thunderstorms today will have the 
capability of producing marginally severe hail. 

Discussion...a small cluster of thunderstorms persists across 
northeast Arkansas in a zone of modest instability and supported by an 
elevated warm front. Flow aloft is strong out of the west, resulting 
in favorably long hodographs for sustained cells. These cells have 
mainly shown indications of hail less than 1.00" this morning. 

Behind this activity, satellite imagery shows new elevated 
development across far northern Arkansas into southwest MO, with lighting 
recently detected. Models suggest increasing lift from warm 
advection across this area today with backed 850 mb flow. In 
addition, temperatures aloft are cooler with northward extent which 
will aid destabilization as low-level warm advection continues. The 
result should be an additional rash of strong storms with a few 
containing hail up to 1.00". 

.Jewell/Hart.. 11/06/2017 

..please see www.Spc.NOAA.Gov for graphic product... 


Latitude...Lon 35088963 35129127 35379235 35989304 36429346 36779361 
37109358 37359343 37619311 37839281 37909229 37879185 
37829038 37588974 37248921 36778887 36298871 35708880 
35348891 35088963