Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Memphis Tennessee
716 PM CDT Sat Mar 28 2015


Updated for the 00z aviation discussion.


Previous discussion... /issued 453 PM CDT Sat Mar 28 2015/

updated to add slight chance of snow in for this afternoon for
portions of the area.


Still getting plenty of reports across north Mississippi of snow
in the past hour. Either light rain or snow will be possible
through 7 PM this evening. For this evening monitoring a good
thermal gradient between US and the arklatex...and strengthening
warm air advection. So existing middle level cloud cover may persist deep into the
night which would throw a monkey wrench in the current freeze and
frost headlines.



Previous discussion... /issued 315 PM CDT Sat Mar 28 2015/


Active weather will continue across the middle-south for the majority
of this forecast cycle. Large-scale pattern will evolve from a
trough over the eastern U.S. To a more zonal pattern by midweek.

For tonight...main focus will be on minimum temperatures. Latest guidance
suggests temperatures in some areas a degree or so cooler than previous
forecast. Will convert the freeze watch area into a freeze
warning through 14z Sunday. Additionally...will issue a frost
advisory for 1-2 tiers of zones south of the freeze warning.

On Sunday...shortwave ridging and southerly surface winds will allow
for a sizable rebound in temperatures. Surface trajectories aren/T ideal
for moisture return...but we should see some surface moisture
increase through the day.

Next upper system drives a front toward the middle-south Sunday
evening. Showers should spread across the area along and ahead of
the front Sunday night. Some MUCAPE is forecast...especially over
Mississippi will include isolated thunder in our
southern zones.

Surface ridging to build into the area on Monday...but may see
lingering showers/thunder over our far southern zones. As surface
ridge builds east Monday night/early Tuesday...warm advection
pattern sets up across the area. Ripples in the quasi-zonal upper
flow will assist with lift and development of precipitation. Cape
forecasts suggest some thunder may be possible Tuesday into
Tuesday night.

A slightly stronger wave should move across the lower MS valley
Wednesday. This will continue the threat of precipitation...with cape
forecasts again suggesting some thunder may occur. Zonal upper flow
with embedded ripples will continue the unsettled pattern through
Thursday night.

Another more substantial upper system will approach the MS valley
area on Friday. This far out...there is quite a disagreement in the
guidance with the GFS showing a surface low near the MO bootheel at
00z Saturday...while the Euro has this feature near the Great Lakes.
At this time will broad-brush probability of precipitation on Friday...drying out Friday
night into Saturday. Details should come into better focus as the
week progresses.




00z taf cycle

A band of middle level clouds continue to bisect the middle south this
evening and will continue to effect kmem...kjbr...and ktup through
the evening hours. VFR ceilings will be the rule though through much
of the overnight hours. Winds will remain light southeasterly at 6
kts or less.

Late tonight...moisture will increase with a quick increase in
lower level clouds at all sites with low end VFR ceilings expected.
These clouds should lower further Sunday morning with widespread
MVFR ceilings developing. These should mix out by afternoon as deeper
mixing occurs as a warm front lifts north of the taf sites. Winds
will increase from the south and become strong and gusty through
the afternoon at all sites.



Meg watches/warnings/advisories...
Arkansas...freeze warning from 1 am to 9 am CDT Sunday for Clay-Craighead-

Frost advisory from 1 am to 9 am CDT Sunday for Crittenden-cross-
Lee AR-Poinsett-St. Francis.

MO...freeze warning from 1 am to 9 am CDT Sunday for Dunklin-Pemiscot.

MS...freeze warning from 1 am to 9 am CDT Sunday for Alcorn-Prentiss-

Frost advisory from 1 am to 9 am CDT Sunday for Benton MS-DeSoto-
Itawamba-Lafayette-Lee MS-Marshall-Monroe-Panola-Pontotoc-

Tennessee...freeze warning from 1 am to 9 am CDT Sunday for Benton Tennessee-

Frost advisory from 1 am to 9 am CDT Sunday for Shelby.



National Weather Service Glossary of Abbreviations