The only saving grace at the beginning of this heat wave is that the dew points are not yet high meaning the relative humidity will not be that much in the afternoon so we won’t have those extreme heat index numbers the next 5 days. However, with ample sun and temperatures 10-15 degrees above normal by the weekend and into next week we won’t need much humidity to feel heat stress and discomfort outdoors.
The prospect for rain and thunder Wednesday or Thursday is too low to plan around at only 10-20%.
Remember the pets in this heat and check the back seat for kids and pets in the car, cracked windows are NOT enough.
Make sure pets have shade and water and indoors with A/C is better and remember paws can burn on hot pavement.
It would be no surprise if the stagnant heat wave eventually leads to some of those “air quality alert code orange” ozone alerts as the sun interacts with auto exhaust and other air pollution so if you or someone you love has breathing sensitivity be ready.
The hot and mostly dry weather expected to last around 10 days or longer.
The dry spell started when we were still having mild days and cool nights and mornings.
Another effect of a long dry spell is insect trouble in the home, particularly roaches and ants. During long dry spells they are more likely to enter homes because like humans they can go longer without food than without water. So don’t leave any water in the sink or elsewhere to discourage them and lay out your traps or poison of choice ahead of time.
Energy use will be way up with air conditioners humming, I am bracing for the higher utility bill now.
Dating back to 1878 Atlanta has never had a 100 degree day in the month of May and I don’t expect that to change this year.
The highest May temperature in Atlanta has been 97 in 1914 and 1941.
Record smashing highs are most likely from around Macon South and Eastward with the best chance of triple digits in those areas.
All the tornadoes and flooding in the nations mid-section is in the boundary zone between cool weather West and Hot weather East with the jet stream storm track in-between along the baroclinic zone. This is the peak of tornado season for the country and they are occurring where they typically do this time of year.
Upper-level high pressure ridge and a “Great Smokies” surface high pressure type pattern build over the Southeast U.S. with the downward sinking air motions adding compressional heating to the hot air mass moving in on the Southerly wind flow:
ECMWF MODEL JET STREAM FORECAST SATURDAY:
ESTIMATED RAINFALL TOTALS NEXT 7-DAYS:
Farmers are taking it on the chin in the Midwest where agriculture is hurting, corn planting is at 39 year low while dry weather is hampering planting in parts of the Southeast.
We are lucky to be starting this heat wave with rivers and lakes full in much of North Georgia so no water supply issues. But our lawns and gardens and farm soils will be drying out rapidly requiring irrigation.
DROUGHT will expand across the state the next couple weeks and worsen in Central and South Georgia which has been drier than Atlanta the past two months:
ECMWF MODEL ENSEMBLE RAINFALL DEPARTURE FROM NORMAL NEXT 15-46 DAYS:
In maps above green and blues are above-normal rainfall and shades of brown and red is below-normal rainfall.
Drying spells frying in the summer because dry soil heats more rapidly than moist causing a “positive feedback loop” so the more we dry out the more likely a hot summer becomes. Heat in May does NOT have to mean a hotter than normal summer but it does tilt the odds in that direction.
Of the three main model ensembles the Canadian continues to be the coolest but still with some heat:
15-DAY MODEL ENSEMBLE TEMPERATURE OUTPUT: (Note MY forecast will vary)
Middle ground more likely. For more follow me on Twitter @MellishMeterWSB.