Area Forecast Discussion
Issued by NWS Memphis, TN

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FXUS64 KMEG 231056 AAA

Area Forecast Discussion...UPDATED
National Weather Service Memphis TN
556 AM CDT Thu Mar 23 2017

Updated for 12Z Aviation Forecast Discussion below.


.PREV DISCUSSION... /issued 458 AM CDT Thu Mar 23 2017/

DISCUSSION...Surface analysis early this morning places a warm
front from the Texas/Oklahoma Panhandle back through the Red River
Valley and southeast into Louisiana. 11-3.9 micron/IR
satellite trends over the past 1 to 2 hours have shown the
development of some mid level clouds across portions of the Mid-
South this morning with most areas remaining clear to partly
cloudy thus far. As of 4 am CDT, temperatures across the Mid-
South are predominantly in the 40s at most locations. Severe
thunderstorm potential Friday night into Saturday and again on
Monday remain the main forecast challenges in this morning`s
forecast issuance.

Short term...(Today through Saturday)...A warm front currently
over Louisiana is expected to move north across the Mid South
today. Cloud cover may increase across the forecast area this
morning in advance of the warm front but diminish in coverage this
afternoon as the front passes northeast through the area. Much
warmer temperatures are expected this afternoon with highs in the
lower 70s north of I-40, and middle 70s to approaching 80 degrees
south. Rain free weather is expected across the area tonight into
Friday morning with shortwave ridging in place.

A surface and upper level low is expected to develop in the
Rockies on Friday, move into the Southern Plains during the day,
then begin to move northeast into Missouri Friday night into
Saturday. Latest model trends suggest a slightly quicker onset of
convective activity from 24 hours ago. Increasing surface
dewpoints into the lower 60s, 0-6 km shear values increasing to
35-50 kts, moderately steep 700-500 mb layer mid-level lapse rates
between 6.5-7 C/km, 60-90 dm 500 mb mid-level height falls, and
potential for surface based CAPE values increasing to 900-1500
J/kg indicate a potential for severe thunderstorms across the Mid-
South Friday night through at least Saturday morning. Surface
based instability could become a limiting factor as convection
moves across portions of the forecast area. The greatest severe
thunderstorm threat will reside over portions of East Arkansas,
Southwest Tennessee, and North Mississippi where the best
instability is expected to reside. At this time, it appears the
mode of convection will be in the form of a line with damaging
winds and large hail as the predominant severe weather threats for
any thunderstorms that reach severe limits.

Long term...(Sunday through Wednesday)...Long term models
indicate an unsettled pattern persisting across the Mid-South next
week. A mid-level trough is expected to move across the Lower
Mississippi on Monday bringing a return of showers and
thunderstorms to the area to begin early next week. A
strong/severe thunderstorm potential will exist on Monday.
A gradual decrease in shower/thunderstorms is anticipated for
Tuesday into Wednesday.



12Z TAFs

VFR to prevail through the day. Wind will veer to the southeast
this morning, with the passage of a surface warm front. Pressure
gradient tightens sufficiently for wind gust by 03Z this evening,
with MVFR stratus a good bet thereafter with the arrival of
elevated marine layer.




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