The National Weather Service has issued a Heat Advisory for tomorrow through Sunday, with a good chance that it will be extended into next week.
Their bulletin states:
YOU ARE GETTING READY TO SEE TEMPERATURES THAT HAVE NOT BEEN SEEN IN A LONG TIME. ALL-TIME HIGH TEMPERATURES FOR THE MONTH OF JUNE ARE 104 IN EVANSVILLE (1954) AND 106 IN PADUCAH (1952). NEVER HAS IT BEEN HOTTER THAN 108 IN EITHER EVANSVILLE (1936) OR PADUCAH (1942).
The NWS doesn't reveal an all-time record high for Cape Girardeau, although Weather.com claims that the highest recorded temperature is 105°F (from the Heat Wave of 1980). It's unclear if this is an "official" or "unofficial" record, and how far their Cape Girardeau records go back.
Nevertheless, it's safe to say that the next several days are going to be ridiculously hot. The NWS forecast for Cape Girardeau features these daily temperatures:
Thursday - 103°F
Friday - 104°F
Saturday - 103°F
Sunday - 102°F
Monday - 102°F
Tuesday - 100°F
A couple of computer models actually project even hotter temperatures, as high as 108°F for Friday. In this morning's forecast discussion, the forecasters at Paducah write, "WE ARE NOT QUITE STEELEY SPINED ENOUGH TO GO COMPLETELY IN THEIR DIRECTION EITHER."
So if the temperature only reaches 104°F on Friday, we might actually be lucky.
The humidity is lower than normal, but that's not necessarily a good thing. The forecast discussion explains:
THIS WILL NOT BE THE TYPE OF HEAT TO WHICH WE ARE ACCUSTOMED. IN FACT...THE LACK OF HUMIDITY MAY BE QUITE DECEPTIVE...IN THAT DEHYDRATION WILL BE MORE LIKELY IN THE CURRENT DRY REGIME. FOR THESE REASONS...WE WILL CARRY THE HEAT ADVISORY THROUGH SUNDAY. THE ADVISORY WILL LIKELY BE EXTENDED TO LATER PERIODS AS CONDITIONS WARRANT.
The Heat Advisory bulletin doesn't spare any words about the danger of this heat wave. It says:
HEAT TOPPING THE 100 MARK SEVERAL DAYS IN A ROW WILL REALLY TAKE ITS TOLL. THE LATTER TWO DAYS WILL OCCUR OVER THE WEEKEND TOO...WHEN ALOT OF FOLKS WILL BE OUTSIDE. DEHYDRATION AND HEAT EXHAUSTION WILL BE POSSIBLE IF YOU DO NOT TAKE PRECAUTIONS. INJURY OR DEATH MAY OCCUR IF YOU DO NOT TAKE THIS HEAT SERIOUSLY AND PROTECT YOURSELF. THE ELDERLY AND VERY YOUNG ARE ESPECIALLY SUSCEPTIBLE. PETS AND LIVESTOCK WILL ALSO BE AT RISK.
To add to the mess, the threat of wildfires is quite high as we enter the July 4th fireworks season. The Weather Service has issued a Fire Weather Watch for Thursday. This bulletin states:
SEVERE TO EXTREME DROUGHT CONDITIONS...COMBINED WITH VERY HOT TEMPERATURES...AND FORECAST WINDS NEAR 15 MPH WILL CREATE HAZARDOUS FIRE WEATHER CONDITIONS THURSDAY AFTERNOON. RAPID...EXPLOSIVE FIRE GROWTH WOULD BE POSSIBLE AND A FIRE GETTING OUT OF CONTROL IS MORE LIKELY GIVEN THESE FORECAST WEATHER CONDITIONS.
I don't see any real chance of rain over the next 7 days, and I'd be surprised if the rest of July offers much improvement. We can usually count on isolated pop-up afternoon thunderstorms this time of year, but even those have been almost non-existent. The drought is going to get uglier before it gets better.