MD 0254 CONCERNING SEVERE POTENTIAL…TORNADO WATCH LIKELY FOR EAST-CENTRAL INTO NORTHEASTERN KS…FAR SOUTHEASTERN NE…NORTHWESTERN INTO CENTRAL PARTS OF MO
Mesoscale Discussion 0254
NWS Storm Prediction Center Norman OK
0148 PM CST Mon Mar 06 2017
Areas affected...east-central into northeastern KS...far
southeastern NE...northwestern into central parts of MO
Concerning...Severe potential...Tornado Watch likely
Valid 061948Z - 062145Z
Probability of Watch Issuance...95 percent
SUMMARY...A couple of supercells are forecast to develop over
eastern KS during the 22-00 UTC period. An attendant risk for very
large hail (2 inches or greater in diameter) and some tornado
potential will seemingly accompany this activity. Upscale
convective growth will eventually lead to an increased risk for 50+
kt gusts later this evening, along with some lingering tornado
potential, and a decrease in the large-hail threat.
DISCUSSION...Visible-satellite imagery shows a swelling cumulus
field from the eastern half of OK north-northeastward into northeast
KS to the east of a dryline. Surface analysis indicates
temperatures are warming into the mid 70s with dewpoints in the
mid-upper 50s. A strong capping inversion will likely inhibit
convective initiation for a few more hours until the cap locally
erodes over east-central and northeast KS during the 21-23 UTC
period.
Additional surface heating and some slight increase in low-level
moisture (boundary-layer dewpoints in the upper 50s) will yield
moderate buoyancy (1000-1500 J/kg MLCAPE). Strong effective shear
(60-kt) coupled with the magnitude of buoyancy ---owing in part to a
steep lapse rate profile--- will promote an initial discrete mode
and the likely development of a couple of supercells. Large to very
large hail will probably be the predominant risk but a
window-of-opportunity for a tornado or two may develop during the
1-3 hour period after convective initiation as storms intensify as
hodographs enlarge by early evening (300-450 m2/s2 0-1 km SRH).
Upscale growth is likely to occur this evening ---supported by a
plethora of CAM guidance--- as a 100-kt 500-mb speed max moves
rapidly from the central High Plains into the lower MO Valley by mid
evening. An increasing risk for damaging winds will probably
develop and spread downstream across central and northern portions
of MO later this evening.
..Smith/Grams.. 03/06/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LSX...DVN...SGF...EAX...OAX...TOP...ICT...
LAT...LON 38179668 39579621 40499526 40569242 40139220 39149231
38429284 38089408 38039601 38179668
from SPC Mesoscale Discussions http://bit.ly/1pTcJjZ
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