PITTSBURGH (KDKA) – Temperatures are heating up again today in the Pittsburgh area.

Will there be an alarm in the next few days? Wednesday is a first alert weather day. Saturday is a potential first alert weather day.

Consciously: Yesterday’s high of 91° was the 20th 90-degree day of the year. There’s a good chance that by the end of the week we’ll have seen the most 90-degree days in a year in over 20 years (2001, 24).

Yesterday we reached a high of 91 degrees and today should be a few degrees warmer. I expect a high of 93 degrees today and a high of 94 degrees on Wednesday. The wind will be from the south today but light. Skies will be mostly cloudy with only a scattered chance of rain.

After a calm period of weather over a few weeks, things will be active again from Wednesday. We have now declared a First Alert Weather Day for Wednesday, as we will see a shortwave low pass through in the afternoon hours.

The potential energy for storms will be sufficient with high head and extremely high humidity at the surface with dew points near 70°. The short wave should be sufficient to trigger conditional storm development in the afternoon.

While anything is possible (hail, wind, tornado), the most fearful thing is strong, straight-line winds. NOAA’s Storm Prediction Center also considers large hail to be almost as worrisome.

While severe weather is possible, there is a high degree of uncertainty. Most of this morning’s model data is struggling to adequately represent storm development due to a strong “cap,” which is a layer of stable air. The timing of the shortwave is also still somewhat uncertain. One of my preferred models shows the shortwave passing through in the morning hours during the morning rush hour. This could still result in some morning storms, but the likelihood of severe weather from the storms would be much lower.

In addition to the potential for storms on Wednesday, there is an additional chance for storms and heavy rainfall on Saturday as the ridge of high pressure breaks down and a cold front moves through. Temperatures will drop from highs in the 90s to highs in the 70s within a few days.

There will be severe weather on Saturday, as well as flooding and flash flooding. At this point, a lot can change on Saturday, so we’ll put the “potential” here so you know we’re keeping an eye on it.

Rain showers and some thunderstorms are also likely to continue on Sunday.

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