Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 242256
SPC MCD 242256
Mesoscale Discussion 0205
NWS Storm Prediction Center Norman OK
0456 PM CST Fri Feb 24 2017
Areas affected...Southern Lower MI...IN...and western OH
Concerning...Severe Thunderstorm Watch 37...
Valid 242256Z - 250030Z
The severe weather threat for Severe Thunderstorm Watch 37
SUMMARY...Mainly a large hail and damaging wind threat continues
across Severe Thunderstorm Watch 37. The prospect for a downstream
watch into western OH in the next hour or two is unclear.
DISCUSSION...Convection has recently intensified within a
pre-frontal confluence band across eastern IN and western OH
(in/near eastern portions of Severe Thunderstorm Watch 37). Farther
west, thunderstorms remain disorganized along an eastward advancing
cold front in southern Lower MI and western/central IN. With only
modest surface heating and dewpoints in the low to mid 50s,
instability remains weak (MLCAPE generally at or below 500 J/kg)
even with steep mid-level lapse rates present. Within mid-level
winds forecast to continue strengthening through the early evening
hours with the approach of an upper trough from the west, there is
some chance that the pre-frontal line may continue strengthening as
it moves into western OH even given the thermodynamic limitations.
Large hail and strong to locally damaging winds would be the main
threats. A downstream watch may need to be considered if the
pre-frontal convection continues to intensify over the next hour or
Large hail and damaging winds remain possible with thunderstorms
along the cold front within Severe Thunderstorm Watch 37, although
low-level winds ahead of the cold front have veered to
southwesterly, limiting convergence along the front. The possibility
for a tornado or two in the short term may be slightly higher near a
warm front draped southwest-northeast across southern Lower MI where
effective SRH around 250 m2/s2 resides.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 39018739 40678679 42128533 42898478 43228319 43058232
40318245 39328328 39008433 38918578 38798693 39018739