textproduct: Columbia

WHAT HAS CHANGED

Separated the original key message into two while making marginal changes. Aviation discussion updated.

KEY MESSAGES

- 1. Drier conditions through the end of the week will provide a break from the oppressive heat and humidity.

- 2. Rain chances ramp back up this weekend into early next week as a more typical summertime pattern returns.

DISCUSSION

- 1. Drier conditions through the end of the week will provide a break from the oppressive heat and humidity.

Surface high pressure just south of the Great Lakes will maintain a light, dry northerly breeze over the area. Aloft, northwest flow on the back side of the cold front will continue to support dry conditions and lower dewpoints, giving us a much deserved two-day break from heat/humidity today and tomorrow. Temperatures are running a couple of degrees below normal, with dewpoints falling into the low 60s and mid to upper 50s. The forecast tomorrow is largely a repeat as the high shifts over the Appalachians tonight. While high temperatures will be near normal (90-94F) both days, the noticeably lower humidity will make for much more comfortable conditions.

- 2. Rain chances ramp back up this weekend into early next week as a more typical summertime pattern returns.

As we head into the weekend, the synoptic pattern becomes more favorable for rainfall across the region. High pressure retreats, allowing southwesterly flow to return and bring an increase in moisture beginning Saturday. The overall pattern supports scattered to numerous showers and thunderstorms, although recent rainfall trends suggest caution is warranted regrading coverage. Even so, the large-scale setup appears favorable for numerous, efficient showers and storms beginning Saturday evening and continuing into Monday.

A maturing low pressure system is forecast to develop over the OH Valley and occlude as it tracks southeastward through the weekend. Moisture transport increases ahead of the system, with PWs climbing back to around 2" and remaining elevated into next week. Rain chances will increase from west to east, with the best overall chance for widespread precip arriving on Sunday. Daily shower and thunderstorm chances will persist into early next week, with the moist environment supporting lower max temperatures due to increased cloud cover and convection during peak heating. Widespread severe weather currently appears unlikely given the very moist atmospheric profile with potential flash flooding being the main threat.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

VFR conditions expected over the next 24 hours.

With the drier air in place across the region, expecting vfr conditions will prevail at all locations. Should only see a few afternoon and early evening mid-level cumulus, then skies return to clear overnight and into Friday. Winds generally variable around 5 knots through sunset, then either calm or very light overnight.

EXTENDED AVIATION OUTLOOK...Rain and restrictions become increasingly likely this weekend and into early next week.

CAE WATCHES/WARNINGS/ADVISORIES

SC...None. GA...None.