Scientific Forecaster Discussion
fxus64 kmeg 240310
Area forecast discussion
National Weather Service Memphis Tennessee
1010 PM CDT Thu Mar 23 2017
Mild night across the mid-south with mostly clear skies. Temps
range from the low 60s north to low 70s south with a southeast breeze
around 10 mph. Expect above normal low temperatures tonight as
increasing southerly winds keep mixing the boundary layer. Updated
Friday night's pops earlier this evening to reflect latest
guidance that slows the arrival of storms in the Memphis area to
mainly after midnight. No further updates needed.
Previous discussion... /issued 316 PM CDT Thu Mar 23 2017/
Currently a pleasant Spring day over the midsouth with generally
mostly sunny skies. Temperatures ranged from near 60f across the
far northeast counties where morning cloud cover lingered...to
near 80f in the southwest Delta counties. Winds were in the 5 to
15 mph range from the east through south.
Tonight through Saturday...a deep upper trough in the southern
rockies will close off at 500mb as it slides into the High Plains
early tomorrow. This deepening will trigger the intensification of
a surface low in southeast Colorado tonight while surging a warm
front north into the Midwest. South winds will increase in
response tonight across the lower Mississippi Valley with the
Delta counties likely reaching Wind Advisory criteria tomorrow.
Surface winds will remain high in the through tomorrow night as
850mb winds increase to near 60 kts ahead of the approaching
surface low/cold front. Despite warm air advection cloud cover and few pop-up
showers in the west the area should remain dry through the day
with temperatures mainly in the 70s. The first of two rounds of
storms will move into eastern Arkansas tomorrow evening at which
time the storm Mode should be mainly linear with occasional bowing
segments. Models keep hinting that a weak wave will form out
ahead of the line after midnight across eastern Arkansas...that
would back winds 10 or 20 degrees providing the best window for
low level shear and an isolated tornado threat if any storm forms
ahead of the main line. Believe convection will wane somewhat
Saturday morning before either new cells form on the cold front or
the nearly stalled line intensifies from cape increasing by midday.
This new convection will be more scattered in nature and should
pose a greater hail threat as height falls from the upper low will
be at their maximum. Where these new storms form is still
unclear, but likely the development will be close to the
Mississippi River. Temperatures will remain in the 70s for most
Saturday with rain chances ending from west to east by evening.
Sunday...a quick passing ridge will dry out the region...with mild
temperatures continuing and dewpoints dropping into the 40s/50s.
Clouds and rain chances will ramp up quickly late Sunday night
with the next approaching shortwave.
Monday...the aforementioned wave will provide another threat for
storms...of which a few could again be severe. The GFS currently
is farther north and more robust with the shortwave triggering both
better shear and cape...while European model (ecmwf) is south and more conservative.
Extended period...storms will be back in the forecast again by
next week Wednesday and Thursday as dewpoints remain mild and the
flow aloft fairly strong. A severe threat may evolve for Thursday.
It's that time of year. Temperatures will remain above average.
00z taf cycle
VFR conditions will continue for the entire forecast period over
the western half of the forecast area. Low clouds will move into
eastern sections of the forecast overnight producing a period of
IFR ceilings. These clouds will lift Friday morning with a return
to VFR conditions expected. Thunderstorms may reach far western
sections of the forecast area by late Friday afternoon but should
affect taf sites during the forecast period. Winds should be
mainly from the south at 10 to 15 knots with higher gusts starting
after midnight. Some low lever wind shear conditions may develop
over western sections of the forecast area.
Arkansas...Wind Advisory from 10 am Friday to 7 am CDT Saturday for Clay-
MO...Wind Advisory from 10 am Friday to 7 am CDT Saturday for Dunklin-
MS...Wind Advisory from 10 am Friday to 7 am CDT Saturday for Coahoma-
Tennessee...Wind Advisory from 10 am Friday to 7 am CDT Saturday for Dyer-