Storm Prediction Center Update: 7/29/20

The Storm Prediction Center (SPC) Outlook shows a little activity today, but then storm coverage tapers off as we drift into the doldrums of summer.

Day 1:  Slight Risk

The SPC has issued a Slight Risk for the Central High Plains today:

Associated with the Slight Risk is a 2% Tornado Threat Ring:

A small, shortwave trough will move southeast from Wyoming into this region.  The dryline is holding near the CO/KS border.  Afternoon thunderstorms may become severe, as there will be adequate CAPE and deep-layer shear, though they are expected to evolve quickly into storm clusters.


Day 2:  Marginal Risk

The SPC has issued three Marginal Risk regions:  one over the Ozarks and into north Texas, one over the South, and one from New Jersey to Massachusetts.

A mid-level trough will enhance storm probabilities and severity ahead of a frontal boundary that is moving southward.  Diurnal heating ahead of the front will be the main driver of storm development.

In New England, diurnal heating ahead of a weak surface front will also drive storm development.  Ample deep-layer shear will provide venting of the stronger storms.  Wind damage will be the primary threat.

Day 3:  Marginal Risk

The SPC has issued a Marginal Risk over the Southern Great Plains and into the Ozarks.

A good combination of deep-layer shear and CAPE is possible in this region.  There is potential for severe thunderstorms, with large hail, damaging winds and a few tornadoes possible.

The biggest problem is that outflow from the first storms to fire may stabilize the air, killing the potential for new storms.  The SPC mentions a rapidly-moving outflow/cold front boundary having an adverse affect on future storms.


Day 4-5  Predictability Too Low

Overall, the potential is low, due to the zonal flow pattern that will emerge later this week.  However, the jet is expected to split, and there may be a low-amplitude shortwave or two that could lead to severe weather.  Also, a tropical storm may impact Florida, which would increase the potential for severe weather.

Day 6-8 Potential Too Low

Once the threat of the tropical storm has passed, the pattern should settle back into a zonal flow regime, limiting severe potential.


Thank you for reading this post.

All data and images are from the Storm Prediction Center Website, accessed 7/1/20.

About highplainschasing

This blog is about my tales in storm chasing. My name is Seth Price and I am an instrumentation instructor at New Mexico Tech. My amateur radio call sign is N3MRA.
This entry was posted in Models, Practicing Concepts, Predictions, Severe Weather, SPC 1-7 day and tagged , , . Bookmark the permalink.

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