Overview

A very warm but wet week is in store for Galveston County. Enjoy the sunshine to start the week, but a midweek system will bring widespread rain and thunderstorms to the area.

The Forecast

Monday (Memorial Day)

It should be a beautiful holiday with mostly sunny skies and temperatures reaching the mid 80s. However, there is a 20% chance of showers and thunderstorms during the day due to daytime heating. A 5–10 mph northeast wind will transition to the southeast throughout the day. Skies will become partly cloudy overnight, with lows falling into the low-to-mid 70s. A 20% chance of showers and thunderstorms will linger into the night.

Tuesday

Tuesday will feature mostly sunny skies with another 20% chance of showers and thunderstorms during the day. Highs will climb into the mid 80s with southeast winds at 5–10 mph. Rain chances will increase Tuesday evening and overnight under mostly cloudy skies, with a 50% chance of showers and thunderstorms as an upper-level trough to the west begins ejecting shortwaves into the region. Southeast winds will increase to 10–15 mph, with overnight lows in the mid-to-upper 70s.

Wednesday

Wednesday will be the most active weather day of the week. There will be no shortage of moisture to fuel widespread rain and thunderstorms, with a 90% chance of precipitation during the day. Some storms could produce locally heavy rainfall, which is why the Weather Prediction Center has placed all of Southeast Texas under a Slight Risk (Level 2 of 4) for excessive rainfall. This means localized flooding will be possible with the strongest storms. Plan accordingly, and remember: “Turn Around, Don’t Drown!” when driving through flooded areas. Highs will still reach the mid 80s with light southeasterly winds. Rain and storm chances will remain elevated Wednesday evening and overnight, with a 70% chance as temperatures fall into the low-to-mid 70s.

Thursday

Rain chances continue Thursday as the Weather Prediction Center places Galveston County under a Marginal Risk (Level 1 of 4) for excessive rainfall. There is a 60% chance of showers and thunderstorms during the day, decreasing to 20% by the evening and overnight hours as the system begins to exit the region and the atmosphere gradually stabilizes. Highs will reach the mid 80s under partly sunny skies, while overnight lows fall into the mid-to-upper 70s.

Friday

A calmer end to the week is likely as a weak mid-level ridge builds over the area. However, there is still a 20% chance of isolated showers and thunderstorms during the day, mainly driven by daytime heating. Highs will reach the mid-to-upper 80s, with overnight lows dropping into the mid-to-upper 70s.

Summary

Galveston County will see a hot and humid week with highs mainly in the mid-to-upper 80s. Rain chances remain low early in the week before widespread showers and thunderstorms move in Tuesday night through Thursday, with Wednesday expected to bring the heaviest rainfall and the greatest flooding concern. Conditions should gradually improve heading into the weekend with lower rain chances and more sunshine returning.