Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
1224 am CDT Sat Jul 4 2015
Updated for 06z aviation discussion.
Previous discussion... /issued 903 PM CDT Friday Jul 3 2015/
Skies are mostly cloudy across the forecast area this evening with
temperatures mainly in the low to middle 70s. Some showers and
thunderstorms continue to move across mainly eastern sections of
the forecast area this evening. Overall coverage of precipitation
is much less than earlier today. While some additional
thunderstorms are expected overnight most of this activity should
be confined to north Mississippi. Will lower probability of precipitation for the
overnight hours over northern sections of the forecast area.
Previous discussion... /issued 645 PM CDT Friday Jul 3 2015/
Significant flash flood event well underway over the
midsouth...with numerous pictures and rainfall reports arriving by
social media in the office. Thank you. Heaviest activity has
fallen in a zone from southern Marshall through Union and Pontotoc
counties in north Mississippi...where 7 plus inches have been
reported. Radar continues to show backbuilding of storms capable
of producing 1 to 3 inch rain rates per hour training over this
region...with ongoing storms in northeast Arkansas and west
Short term through tomorrow...have extended the flash Flood Advisory to include
the entire midsouth through early Saturday evening. The
combination of an upstream mvc in southeast Kansas pivoting around
a closed 500mb low in Indiana...and abundant low level moisture
pooling south of a stationary front will produce multiple rounds
of storms...and areas of moderate rain...from late this afternoon
through tomorrow. Already airmass is becoming unstable over
southern Missouri through central Arkansas just ahead of mesoscale convective vortex.
This activity is expected to Blossom further east and rotate
into the midsouth this evening and overnight...while convergent
band from southern Arkansas into north Mississippi remains active
with training convection.
Convection should begin to dwindle tomorrow from the northwest
counties around midday to the southeast counties by evening as
upper level low sharpens in the Tennessee Valley. This will
provide a period of subsidence on the low's backside to slide
over the area. Have further reduced high temperatures for today
and lowered them a degree or so for tomorrow.
Sunday through Friday...a weaker northwest upper flow will begin
to take shape starting Sunday as the aforementioned low center
opens and begins to slowly fill to our east. Low level moisture
will remain fairly high over the area so rain chances will
continue each day...but more diurnally driven in the afternoon/early
evening. Lowered temperatures a degree or two...leading to
slightly cooler than normal readings from the middle 80s to near 90.
06z taf cycle
Showers and thunderstorms will become widespread from east central
Arkansas into north MS overnight into Saturday morning affecting ktup.
Otherwise conditions lowering to IFR areawide...possibly LIFR in
some locations. Conditions improving to MVFR late Saturday
morning...then mostly VFR Saturday afternoon. However...lowering
conditions will occur in scattered showers and thunderstorms
developing areawide Saturday afternoon and continuing into Saturday
Winds tonight SW 4-8 kts. Winds Saturday S-SW 7-9 kts.
Arkansas...Flash Flood Watch through this evening for Clay-Craighead-
MO...Flash Flood Watch through this evening for Dunklin-Pemiscot.
MS...Flash Flood Watch through this evening for Alcorn-Benton MS-
Tennessee...Flash Flood Watch through this evening for Benton Tennessee-Carroll-