Scientific Forecaster Discussion
fxus64 kmeg 211722
Area forecast discussion
National Weather Service Memphis Tennessee
1122 am CST Thu Nov 21 2019
Previous discussion... /issued 956 am CST Thu Nov 21 2019/
Skies are cloudy across much of the mid-south this morning with
temperatures mainly in the 50s. A large area of light rain covers
much of the southern half of the region. As this area of rain
exits the mid-south this afternoon more scattered showers are
expected to develop. Temperatures are not warming up as much as
expected so have lowered forecasted highs for this afternoon.
Previous discussion... /issued 434 am CST Thu Nov 21 2019/
Currently the ridge that has been sitting over the mid-south is
now downstream of the area with a pre-frontal mid-level trough
situated over MO and Arkansas. The trough is helping produce numerous
showers across the area - upstream of the County Warning Area.
Clouds are increasing across the mid-south as the disturbance
moves through. Temperatures are currently in mid 40s to mid 50s
with the cooler temperatures unusually in MS due to much less
Scattered-to-numerous showers will persist for much of the day
for most areas in the mid-south. However, the chance of rain is
much less in MS as the trough is expected to stay far enough north
that the rain will mostly hold off until the evening and
overnight hours for the southern portions of the County Warning Area. Temperatures
will be in the mid 60s with a southerly flow over the region.
The chance of rain will greatly increase as we head into the
overnight hours through Saturday morning as a cold front moves
through. The front is expected to slowly drag through the region
with a blocking ridge east of the area that will be reluctant to
break down in this meridional pattern. Friday looks like it will
be a wet day with persistent rain over the area as the upper-level
ridge slowly fills with an approaching upper-level trough
upstream. Severe weather is not expected, but with an upper-level
jet upwards of 120kts, a 35-45kt llj, high bulk shear, and weak
elevated instability, the possibility for isolated thunderstorms
is there, especially over northern MS. Temperatures will fall
throughout the day with highs in the upper 40s to upper 60s.
The rain will move out as the cold front exits the region Saturday
morning and a ridge begins to build over the area. Temperatures
will be much below normal with north-northwesterly flow and highs
in the upper 40s to upper 50s.
High pressure will remain over the area through Tuesday which is
when our next system is expected to move through the mid-south.
It's difficult to pinpoint the timing of the system at this time
and the coverage of precipitation as models are all over the
place. Guidance does point to a potentially potent storm system
with the possibility of seeing some strong storms.
Rain showers are expected to continue for the next 24-30 hours as
a cold front moves across the midsouth. MVFR vis is expected to
prevail for much of the night into tomorrow. Cigs are expected to
steadily lower to IFR then LIFR levels overnight, with no
significant improvement tomorrow. Winds will shift from the north
around 10 kt behind the cold front.