textproduct: Columbia

WHAT HAS CHANGED

Significant rainfall unlikely through early next week. Aviation updated for 12z.

KEY MESSAGES

- 1. Rain chances continue to trend down for this weekend, with higher chances now falling to mid or late next week.

DISCUSSION

Key Message 1: Rain chances continue to trend down for this weekend, with higher chances now falling to mid or late next week.

Ridging over the forecast area is expected to remain in place through the weekend. Models have continued to delay the onset of moisture advection over the area as the jet streak to our west stretches out and orients north-south. Breezy northeast winds and dry high pressure will continue through Sunday with near normal temperatures.

Surface high pressure will slip offshore next week promoting some weak isentropic lift into the Southeast. The shortwave trough may allow for coastal low pressure to develop on Monday or Tuesday bringing additional moisture back into the region but confidence is low at this time. Ultimately any rainfall that does occur early next week would likely only yield light amounts. Even the 90th percentile of the NBM QMD only a few hundredths through early next week.

Model solutions diverge through the remainder of the week. Although there is a large spread in guidance, the majority of deterministic models depict a more amplified synoptic pattern from mid to late next week. This will at least support a chance of rain in the extended despite the uncertainty in the exact timing of frontal passages and rainfall.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

Mainly VFR conditions, with brief mvfr/ifr visibility restrictions through sunrise.

Limited moisture should hinder the threat of widespread fog or stratus, guidance is indicating at least some patchy mvfr/ifr visibility restrictions becoming possible through sunrise. Metars do show a few locations dropping already, but satellite loops not showing anything widespread over the cwa. Better likelihood for fg remains well east of the Midlands near the coastal plain, and near area lakes and rivers. Will continue with mention of a tempo ground at all sites for visibility restrictions to account for the possibility of brief br/fg formation. After 13z, any restrictions should quickly burn off and a return to vfr is expected then for the remainder of the taf period. Light NE winds continue through the daytime, with speeds from 5 to 8 kts and a few cumulus through the afternoon.

EXTENDED AVIATION OUTLOOK...The chance of restrictions increases this weekend however model trends have favored lower rain chances and weaker moisture advection.

CAE WATCHES/WARNINGS/ADVISORIES

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