RSS Mesoscale Discussions from Storm Prediction Center

SPC MD 1339

MD 1339 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR WESTERN AND CENTRAL NORTH CAROLINA...UPSTATE SOUTH CAROLINA
MD 1339 Image


Mesoscale Discussion 1339
NWS Storm Prediction Center Norman OK
0120 PM CDT Sun Jul 03 2022

Areas affected...Western and Central North Carolina...Upstate South
Carolina

Concerning...Severe potential...Watch unlikely 

Valid 031820Z - 032045Z

Probability of Watch Issuance...5 percent

SUMMARY...Thunderstorms developing over the mountains of western NC
will spread east-southeastward into the Piedmont region.  The
stronger cells will produce brief gusty/damaging winds.  A watch is
not anticipated at this time.

DISCUSSION...Visible satellite and radar imagery show increasing
thunderstorms  over the mountains of western NC.  This activity is
expected to increase in coverage through the afternoon as strong
heating and dewpoints in around 70F yield MLCAPE values of ~2000
J/kg.  Low-level lapse rates will be rather steep today as
temperatures ahead of the convection rise into the 90s.  However,
mid-level lapse rates are weak, and winds through the cloud-bearing
layer are generally below 20 knots.  Isolated cells across the
Piedmont region will pose a risk of locally gusty/damaging winds
this afternoon, but the risk of a more organized severe threat
appears limited.

..Hart/Grams.. 07/03/2022

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

ATTN...WFO...RAH...RNK...CAE...GSP...

LAT...LON   35188265 36228110 36527980 36087945 35587996 35018092
            34678216 34618277 34828308 35188265 

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SPC MD 1338

MD 1338 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR SOUTHWEST MONTANA
MD 1338 Image


Mesoscale Discussion 1338
NWS Storm Prediction Center Norman OK
0109 PM CDT Sun Jul 03 2022

Areas affected...Southwest Montana

Concerning...Severe potential...Severe Thunderstorm Watch likely 

Valid 031809Z - 031915Z

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorms are expected to intensify across southwest
Montana this afternoon, with a risk of a few supercells capable of
large hail and damaging winds.  A severe thunderstorm watch is
likely.

DISCUSSION...Radar/satellite imagery show a small cluster of
thunderstorms over southern Lemhi county ID, along with increasing
towering cumulus clouds over the Sawtooth mountains of central ID. 
This activity is ahead of a shortwave trough over eastern WA/OR that
will track northeastward across the region this afternoon and
evening.  Mid and high clouds are slowly clearing to the east of
this activity, which should allow strong heating and destabilization
to occur.  Rather cool temperatures aloft (-13 to -14C at 500mb)
coupled with dewpoints in the low-mid 50s will aid in MLCAPE values
over 1000 J/kg in the mountains of southwest MT.  Sufficient
effective shear values suggest a risk of a rotating storms capable
of large hail and damaging wind gusts.  Trends are being monitored
for watch issuance in parts of the discussion area.

..Hart/Grams.. 07/03/2022

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

ATTN...WFO...BYZ...RIW...TFX...PIH...MSO...

LAT...LON   44601356 45701425 46221340 46791181 47011035 46110973
            45171061 44241237 44601356 

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SPC MD 1337

MD 1337 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST SD
        
MD 1337 Image

Mesoscale Discussion 1337
NWS Storm Prediction Center Norman OK
1224 PM CDT Sun Jul 03 2022

Areas affected...Southeast SD

Concerning...Severe potential...Watch unlikely 

Valid 031724Z - 031900Z

Probability of Watch Issuance...20 percent

SUMMARY...Some threat for localized hail and damaging wind gusts may
persist through early afternoon.

DISCUSSION...An isolated strong thunderstorm has recently evolved
along the southern periphery of an elevated storm cluster that
developed overnight and moved eastward across SD. It appears that
this new cell is being sustained along the eastern edge of a
buoyancy gradient, in conjunction with steepening midlevel lapse
rates and favorable low-level moisture. Recent intensification
trends and weakening MLCINH suggest that this storm may be becoming
surface based. Modest midlevel westerly flow is supporting effective
shear for a surface-based storm of 30-40 kt, so evolution into a
supercell appears possible in the short term, with an attendant risk
of hail and locally damaging wind gusts. 

The longevity of this cell remains somewhat uncertain, with rather
weak large-scale ascent and most short-term guidance struggling to
maintain convection in this area, but the environment is not
prohibitive for sustained convection, and this storm may persist
into the mid afternoon. Given the isolated nature of the threat and
uncertainty regarding storm longevity, watch issuance is considered
unlikely in the short term.

..Dean/Grams.. 07/03/2022

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

ATTN...WFO...FSD...ABR...

LAT...LON   44079912 44259806 44319759 44249707 43629689 43269705
            43189764 43309817 43729912 44079912 

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