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FXUS64 KMEG 201931

Area Forecast Discussion
National Weather Service Memphis TN
231 PM CDT Sun Oct 20 2019


The main story this forecast continues to be the vigorous 
surface/upper system and associated hazardous weather threats late 
tonight into Monday. 12Z Short-range forecast guidance is in fairly 
good agreement and continues the timing and trends from earlier.

For tonight and Monday - upper system centered over the Midwest 
should take a slightly negative tilt as it pivots across the area. 
Scattered warm advection showers/storms are expected this evening 
and overnight. A squall line should develop along/ahead of the 
surface front. Line should approach our E AR counties by 9Z Monday, 
into west TN/NW MS by 12-14Z, and into NE MS by 16-18Z. 

Deep-layer and low-level vertical wind shear are supportive of 
organized storms/severe threat. Main question will be instability, 
which should be weakening as storms move across. Main severe threat 
should be early in the day over E AR/SW TN/NW MS. May see some
enhancement in the line around midday Monday as heating increases 
before line exits CWA.

Damaging winds should be the primary threat. Heavy rain/localized 
flooding will also be a primary threat with the line and with warm 
advection showers/storms. Can't rule out an isolated tornado, 
although relatively weak low-level instability should reduce this 

Monday Night through Thursday - relatively quiet weather expected as 
front/precip exits and high pressure moves in. No precipitation and 
fall-like temperatures are expected. Southerly return flow sets up 
Wednesday afternoon, bringing increased temps and moisture by 

Friday through Sunday - still much disagreement with next upstream 
system. GFS keeps a progressive open trough, while the 
Canadian/UKMO/ECMWF have some variation of a slower-moving closed 
low over the south central/southwestern U.S. Will broad-brush low 
POPs in the Friday-Saturday night time frame for now and reassess as 
details (and hopefully agreement) increase during the week.




Dynamic conditions over the next 24-30 hours will bring showers
and thunderstorms, LLWS, strong gradient winds and a wind shift to
the Midsouth as a cold front moves across the area. 0-2km wind
shear may exceed 45kt late tonight into early tomorrow, especially
at JBR, MKL and MEM. Showers and thunderstorms will accompany a
strong cold front with prevailing thunderstorms most likely at 
JBR 12-15z, MEM13-16Z and at MKL/TUP before 18Z. JBR and MEM 
should experience an abrupt wind shift around 17 and 12z 
respectively. Brief IFR or LIFR Vis due to heavy rain is likely 
along with gusty wind in association with on station 
thunderstorms. Timing of thunderstorms is still uncertain and 
amendments should be expected as new guidance comes in, and we 
begin to actually see storms develop to be used as a basis for 




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