A Mesodiscussion is issued by the National Weather Service's Storm Prediction Center when there is a chance of a significant weather event impacting an area. These are routinely issued before weather watches or as updated to weather watches.

SPC MD 787

MD 0787 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN NEW MEXICO AND WEST TEXAS
MD 0787 Image

Mesoscale Discussion 0787
NWS Storm Prediction Center Norman OK
1212 PM CDT Sat May 25 2019

Areas affected...Eastern New Mexico and west Texas

Concerning...Severe potential...Watch possible 

Valid 251712Z - 251915Z

Probability of Watch Issuance...60 percent

SUMMARY...Storms are developing along the dryline in eastern NM/west
TX with storm coverage increasing throughout the afternoon. Severe
hail/wind are the main threats.

DISCUSSION...Storms will continue to initiate along the dryline this
afternoon with a moist airmass in place (60-70 F surface dewpoints)
and strong insolation. Per water vapor imagery, a mid-level
shortwave trough is also likely contributing to storm initiation
along the dryline. Storms will be developing in a conducive severe
environment characterized by 2000-3000+ J/kg of MLCAPE and 40-45
knots of effective bulk shear. Large hail and damaging winds will be
the primary threats given the high/strong CAPE/shear, although the
tornado risk will increase this afternoon/evening as the LLJ
strengthens and storms move into an environment with better
low-level veering wind profiles.

..Nauslar/Hart.. 05/25/2019

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

ATTN...WFO...LUB...AMA...MAF...ABQ...

LAT...LON   32020288 32660227 33320195 34210193 35260197 36140210
            36470227 36570255 36150329 35160385 34020414 32860408
            32120381 32060358 32020288 

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SPC MD 786

MD 0786 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF IN INTO WESTERN OH
MD 0786 Image

Mesoscale Discussion 0786
NWS Storm Prediction Center Norman OK
1207 PM CDT Sat May 25 2019

Areas affected...portions of IN into western OH

Concerning...Severe potential...Watch possible 

Valid 251707Z - 251830Z

Probability of Watch Issuance...60 percent

SUMMARY...Thunderstorms will increase this afternoon across parts of
Indiana into Ohio. Damaging wind gusts will be the main concern, but
hail is also possible with the strongest cells.

DISCUSSION...Thunderstorms were increasing early this afternoon
across central IN ahead of an eastward advancing MCV. A very moist
airmass with dewpoints in the mid 60s to near 70 F and strong
heating with temperatures already in the low to mid 80s has resulted
in MLCAPE in the 500-1500 J/kg range. Some additional
destabilization is possible into the afternoon hours, but in the
absence of steeper midlevel lapse rates, instability will generally
be weak to moderate. Nevertheless, strong vertical shear will
support organized, intense convection. Damaging wind gusts will be
the main concern given the steep low level lapse rates, high PW
values and rather quick storm motion. Deep layer flow will remain
generally unidirectional, but speed shear could be adequate for some
supercell structures with an attendant hail risk, in addition to
bowing segments. A watch may be needed shortly for the MCD area.

..Leitman/Hart.. 05/25/2019

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

ATTN...WFO...PBZ...RLX...CLE...ILN...IWX...IND...LOT...

LAT...LON   40508713 40628677 41088483 41468315 41678115 41138079
            40278111 39548173 39098251 39078449 39188582 39288676
            39518733 39908737 40508713 

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SPC MD 785

MD 0785 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR WESTERN NY...WESTERN PA...FAR EASTERN OH...NORTHERN WV AND WESTERN MD
MD 0785 Image

Mesoscale Discussion 0785
NWS Storm Prediction Center Norman OK
1153 AM CDT Sat May 25 2019

Areas affected...western NY...western PA...far eastern OH...northern
WV and western MD

Concerning...Severe potential...Watch possible 

Valid 251653Z - 251900Z

Probability of Watch Issuance...40 percent

SUMMARY...Thunderstorms will increase in coverage and intensity over
the next couple of hours. Strong to locally damaging wind gusts are
possible with the strongest storms, though hail is also possible. A
watch may be needed in the next few hours across this region.

DISCUSSION...Widely scattered thunderstorms were developing early
this afternoon on the nose of eastward surging boundary layer
moisture from northwest PA/eastern OH into WV. A warm front was
lifting northeast across NY/PA/VA just ahead of this convection.
Dewpoints in the mid 60s to near 70 F will spread eastward with time
today and convection should increase in coverage and intensity as
continued strong heating and destabilization occurs in strong deep
layer west/southwesterly flow. Forecast RAP soundings indicated
steepening low level lapse rates, with 30-40 kt southwest winds
around 760-700 mb at the top of the mixed boundary layer, suggesting
strong to locally damaging wind gusts will be possible. While
midlevel lapse rates are unimpressive, around 6.5-7 C/km at best,
vertical shear will support rotating updrafts and a few supercell
structures are possible. This will bring an attendant risk for
severe hail with the strongest storms. While forecast LCLs are
relatively high at around 3kft, any storm that interacts with the
warm front or through favorable cell/outflow interactions, could
produce a tornado or two given modestly favorable low level
hodographs and effective SRH around 150-200 m2/s2. Convective trends
will continue to be monitored and a watch may be needed in the next
few hours.

..Leitman/Hart.. 05/25/2019

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

ATTN...WFO...BUF...CTP...LWX...PBZ...RLX...CLE...

LAT...LON   42268012 43077936 43237887 43127821 42657783 41637782
            40377808 38997901 38537950 38408048 38818177 39208192
            39778157 40878088 41848039 42268012 

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