July 22: The Wet Pattern Begins

Jonathan Carr
By July 22, 2018 09:16

July 22: The Wet Pattern Begins

Discussion: Last night’s synoptic rain storm has passed through and is now absorbing into the upper-level low to our W. This upper-level low will fizzle into nothing as the SW US ridge teams up with the W Atlantic ridge to help break down the lower 500mb height anomalies. The newly-emerging pattern should mostly be driven by a very prolonged and stubborn Bermuda High. I’ve plotted the surface high on the following upper-level GFS map to show the converging return flow (with approaching warm sector flow from the W) that will generally drive the wetter pattern over the next 7+ days:

gfs_z500a_atl_19

I don’t think any of the next 7+ days are complete washouts. Each day, rather, looks to feature isolated-to-scattered showers and thunderstorms especially during afternoon-evening hours. While convergence will drive, maybe assist is a better word, most convection…diurnal heating will have a big stake as well. The more sunlight that hits the surface cloud free, the easier the convergence will lift moist surface air into the atmosphere and spark the expected shower/storm activity. It obviously won’t take much lifting assistance with most model guidance suggesting 2-5+ inches of rainfall between now and next Sunday:

gfs_apcpn_neus_30

In English: Most areas should stay dry for the first half of today. Afternoon-evening hours today could feature isolated-to-scattered showers and thunderstorms moving from S to N. The next 7 days+ look to feature a lot of rainfall. However, the rainfall shouldn’t produce continuous 24/7 washout days. I would generally expect dry, maybe even sunny at times, morning to early afternoon hours for most days. Most rainfall should fall during afternoon-evening hours in the form of shower and thunderstorms that vary in nature from isolated-to-scattered. You might have a few days that are mostly cloudy but still not 24-hour washout days—a late-day shower/thunderstorm pattern (for the most part). I’ll have the detailed Monday-Friday outlook posted this evening. Everyone enjoy the rest of your Sunday and please be safe! JC

Model Image Source: Tropical Tidbits

Jonathan Carr
By July 22, 2018 09:16