Mesoscale Discussion 1749

Issued

Nov 3, 2017, 2:11 PM CDT (19:11 UTC)

Expired

Nov 3, 2017, 4:15 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

40%

The Little Rock radar (KLZK), 100 km from the middle of the area, began a volume at 19:11 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

• Severe Thunderstorm Watch 510Nov 3, 3:50 PM CDT

854 
ACUS11 KWNS 031911
SWOMCD
SPC MCD 031911 
MSZ000-ARZ000-032115-

Mesoscale Discussion 1749
NWS Storm Prediction Center Norman OK
0211 PM CDT Fri Nov 03 2017

Areas affected...Portions of the Lower Mississippi Valley

Concerning...Severe potential...Watch possible 

Valid 031911Z - 032115Z

Probability of Watch Issuance...40 percent

SUMMARY...Thunderstorms will continue to develop this afternoon
across central/eastern Arkansas. A few storms may be capable of
large hail and damaging winds. While widespread severe weather is
not likely, conditions will be monitored for possible watch
issuance.

DISCUSSION...Evident in water-vapor imagery, the arrival of ascent
associated with a shortwave trough (moving east from OK into AR) is
fostering initial thunderstorm development across parts of Arkansas
this afternoon. Ample insolation across the open warm sector and
surface dew points in the upper 60s/lower 70s have promoted moderate
buoyancy, characterized by MLCAPE values upwards of 1500 J/kg. While
low-level flow remains weak with a lack of a stronger synoptic
response, KLZK VWP data sampled modest mid-level westerlies around
30-35 kt. Combined with a veering profile with height, effective
shear will be marginally favorable for occasional updraft
organization, enabling isolated large hail. Additionally, dry
mid-level air and propagation focused along an
east/southeastward-extending front may yield sufficient upscale
growth for a few damaging gusts, as storms head towards the
Mississippi River. If storms exhibit adequate organization later
this afternoon, a watch may be considered.

..Picca/Hart.. 11/03/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...MEG...JAN...LZK...

LAT...LON   34309025 33929027 33239063 33119120 33329194 33549254
            34229284 34849279 34949275 34959245 34909167 34579047
            34309025

Mesoscale Discussions in Arkansas, 2017Mesoscale Discussions in Mississippi, 2017Every mesoscale discussion in 2017

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.