As Allentown prepares for its annual St. Patrick’s Parade on Sunday, the chance that showers and thunderstorms could affect the festivities has increased.

There’s a 40% chance that Allentown will see precipitation Sunday afternoon, with the odds of showers and thunderstorms increasing to 90% in the evening hours, according to the latest National Weather Service forecast. Saturday is expected to remain dry.

The Sunday forecast calls for a chance of showers between 2 and 5 p.m., with thunderstorms possible after 5 p.m.

Total new rainfall is expected to be low Sunday afternoon, with a forecasted amount of less than a tenth of an inch that could rise if thunderstorms materialize.

Sunday temperatures are expected to approach a high of 71 degrees, with low winds between 5 and 10 mph.

Sunday evening, the chance of showers and thunderstorms will rise to 90%, with forecasted new precipitation between a tenth and a quarter of an inch. The weather service expects the thunderstorm risk to dissipate by 11 p.m., but rain showers could continue.

Here’s the extended weather service forecast for next week:

Monday: A chance of showers before 2pm. Partly sunny, with a high near 50. North wind 10 to 15 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.

Monday Night: Mostly clear, with a low around 29.

Tuesday: Sunny, with a high near 49.

Tuesday Night: Mostly cloudy, with a low around 34.

Wednesday: Partly sunny, with a high near 53.

Wednesday Night: Mostly cloudy, with a low around 35.

Thursday: Mostly cloudy, with a high near 56.

Thursday Night: Rain likely. Mostly cloudy, with a low around 40. Chance of precipitation is 60%.

Friday: A chance of rain. Partly sunny, with a high near 52. Chance of precipitation is 30%.