Get ready for a shocker.

The National Weather Service is expecting temperatures in Manteca, Ripon and Lathrop to flirt with the century mark today.

While 100-degree heat is old news in the San Joaquin Valley what isn’t is the severity of the temperature turnaround.

Highs today are expected to be 20 degrees above Wednesday’s mid-day high. In Manteca on Wednesday the temperature at 12:01 a.m. as recorded at the city hall weather station was 76 degrees. The mid-day high temperature was 77 degrees at 5:15 p.m. In other words it was just one degree cooler in the wee hours of the morning than in “the heat of the day.” The low instead of being shortly before sunrise was 68 degrees at 9:24 a.m. Wednesday.

The unusual weather is the direct result of the remnants of Hurricane Blanca hitting Baja California on Monday morning. That, coupled with low pressure off the California coast, spiked temperatures to 108 degrees in Manteca on Monday, brought unusually high humidity on Tuesday and the rare June light rain with tropical mugginess on Wednesday.

The National Weather Service on Tuesday issued a warning that as the system passes a quick return to heat patterns will occur creating a concern that a surge in heat-related illness may take place if people aren’t cautious.

The highs up and down the Central Valley are expected to push 100 degrees today with the highs Friday ranging from 101 to 107 degrees. In Manteca, the forecast calls for 94 degrees today, 101 degrees on Friday, 100 degrees on Saturday and then a cooling off into the low 90s on Sunday.