U.S. Severe Weather Forecast (Convective Outlook)

Day Three

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Storm Prediction Center ac 050037 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0737 PM CDT sun Oct 04 2015 

Valid 050100z - 051200z 

..there is a marginal risk of severe thunderstorms across the southern Great Basin... 

isolated strong thunderstorms...a few possibly producing gusty winds 
and hail...will continue across the southern Great Basin this 

..Great Basin... 

Early evening WV imagery suggests a well-defined region of ascent is 
sagging southeastward across central California/Nevada into the southern Great Basin. 
Considerable amount of convection is noted within exit region of jet 
as it translates through the base of the trough toward the southern Colorado 
River valley. 00z sounding from vef exhibits very steep lapse 
rates...near dry adiabatic through 4km...with substantial 
veering/speed shear with height. For this reason it appears ongoing 
convection may linger for several hours as ample buoyancy exists for 
organized updrafts. Gusty winds/hail are the primary threats with 
convection from southeastern California into northwestern Arizona until boundary-layer cools and 
small pocket of instability wanes. 

..Carolina coast... 

Upper low is progressing off the northern Florida coast and strongest corridor 
of ascent/buoyancy should encourage more robust convection to remain 
well east of Continental U.S.. while an isolated lightning strike can not be 
ruled out within conveyor of precipitation that is wrapping inland 
north of ejecting low...primary threat of thunderstorms should be east of 
the coast. 

.Darrow.. 10/05/2015 

Mesoscale Discussion

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sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 030731 cor 

Mesoscale discussion 1838 
National Weather Service Storm Prediction Center Norman OK 
0231 am CDT Sat Oct 03 2015 

Areas affected...coastal SC 

Concerning...severe potential...watch unlikely 

Valid 030731z - 031000z 

Corrected geographic wording in first paragraph. 

Probability of watch issuance...5 percent 

Summary...a low probability tornado risk will exist for the next 
couple of hours along the immediate coast of SC...primarily from the 
Charleston area to south of Myrtle Beach. While the probability of 
a tornado is non-zero it is far exceeded by hazards associated with 
the continuing potential for widespread flooding. 

Discussion...latest surface analysis depicts a 995mb sub-synoptic scale 
low pressure center moving toward coastal SC between Edisto Beach 
and Folly Beach. This circulation is embedded within an extensive 
band of deep training convection extending from the southern and central 
Appalachians southeast across the coastal waters to where it 
intercepts a decaying feeder band associated with Hurricane Joaquin. 
Intense moisture flux and pronounced dynamic ascent will continue 
across SC ahead of a slow moving large-scale middle/upper low...a 
blocking ridge off the middle Atlantic coast...and the tropical 
moisture plume associated with Joaquin. Stronger convective cells 
within the broader convective plume have occasionally exhibited weak 
but transient updraft rotation offshore. Lightning activity has also 
persisted offshore but decreases as convection spreads inland and 
across a sharp coastal baroclinic zone where surface-based 
instability lessens but intense large scale ascent continues. 

Present indications suggest that true maritime tropical warm sector 
may spread slightly inland with as sub-synoptic low crosses the 
coast in the next hour or so. This low may be followed by other weak 
waves as suggested by some hi-rez guidance. Each circulation will 
bring with it a chance for a waterspout/tornado or stronger gusts. 
Overall areal extent of the threat will likely remain quite confined 
as coastal baroclinic zone oscillates between the immediate coast 
and offshore with the passage of each perturbation. Given the 
limited spatial/temporal risk...a watch is unlikely. 

.Carbin/Mead.. 10/03/2015 

..please see www.Spc.NOAA.Gov for graphic product... 


Latitude...Lon 33137929 33187990 32838036 32568032 32508016 32547986 
32797942 32897923 33137929