Severe Storm Outlook Narrative (AC)
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10
ACUS11 KWNS 102010
SPC MCD 102010

Mesoscale Discussion 1710
NWS Storm Prediction Center Norman OK
0310 PM CDT Tue Oct 10 2017

Areas affected...Portions of the mid Mississippi Valley

Concerning...Severe potential...Watch unlikely

Valid 102010Z - 102215Z

Probability of Watch Issuance...20 percent

SUMMARY...Storms may be capable of a few damaging gusts and
marginally severe hail through this evening. However, the threat
should remain rather limited, and watch issuance is not expected.

DISCUSSION...Scattered thunderstorms have developed south of St.
Louis along a pre-frontal trough this afternoon. MRMS CAPPI data
have illustrated relatively shallow cores with most convection --
not surprising given relatively meager mid-level lapse rates
observed in 12Z regional soundings. Nonetheless, a warm/moist
boundary layer has yielded upwards of 1000-1500 J/kg of MLCAPE.
Indeed, one cell over Jefferson Co., MO, has exhibited a deeper core
over the last 15-30 minutes, suggesting a slightly improved
thermodynamic environment. While the hail threat should remain
limited due to a lack of greater mid-level instability, surface
heating has steepened low-level lapse rates adequately to support a
marginal damaging wind threat. Additionally, straight hodographs
suggest cells may occasionally evolve into small bowing segments,
which would further enhance this threat. However, due to a lack of
greater buoyancy, watch issuance is not expected.

..Picca/Hart.. 10/10/2017

...Please see for graphic product...


LAT...LON   37849076 38689063 39278981 39028908 37668850 36748882
            35898995 35799079 36059100 36599094 37849076 is the U.S. government's official web portal to all federal, state and local government web resources and services.