SPC MD 12



MD 0012 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF OH…FAR NORTHERN WV…AND WESTERN PA

MD 0012 Image

Mesoscale Discussion 0012
NWS Storm Prediction Center Norman OK
1254 PM CST Tue Jan 08 2019

Areas affected...Portions of OH...far northern WV...and western PA

Concerning...Severe potential...Watch unlikely 

Valid 081854Z - 082100Z

Probability of Watch Issuance...20 percent

SUMMARY...Strong/gusty downdraft winds could produce isolated damage
through the afternoon and early evening. Watch issuance will
probably not be needed, but radar trends will be closely monitored.

DISCUSSION...Large-scale ascent associated with a shortwave trough
and exit region of a 90-100+ kt mid-level jet is beginning to
overspread the OH Valley and lower Great Lakes region per water
vapor and visible satellite imagery. A recent increase in showers
and thunderstorms has occurred over northwestern OH along/near a
cold front, and this activity is expected to continue increasing in
coverage as it moves eastward around 35-40 kt through the remainder
of the afternoon and early evening. Low-level moisture observed in
the 12Z ILN and PIT soundings was quite limited, and 18Z surface
dewpoints generally remain in the mid 40s due to mixing of the
boundary layer. Still, some diurnal heating and related steepening
of low-level lapse rates has occurred. Strong flow in the
cloud-bearing layer, particularly at mid levels, could potentially
be brought to the surface in convective downdrafts. Resultant
strong/gusty surface winds may produce isolated damage, even with
the strongest observed winds probably remaining in the 35-50 kt
range. The limited low-level moisture and weak instability (MLCAPE
less than 500 J/kg) should tend to limit the strength of updrafts.
For now, watch issuance remains unlikely, but radar trends will be
closely monitored.

..Gleason/Hart.. 01/08/2019

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

ATTN...WFO...CTP...PBZ...RLX...CLE...ILN...

LAT...LON   39438171 39538244 40118343 40678379 41248373 41608346
            41598293 41438245 41588173 41808128 41998044 41787975
            41527932 41077907 40367903 39577978 39328044 39438171 

Read more



Source link

Editor

Leave a Reply

Your email address will not be published. Required fields are marked *