textproduct: Columbia

WHAT HAS CHANGED

Updated Aviation.

KEY MESSAGES

- 1) A dry airmass settles over the region to round out the work week, leading to low-end fire weather concerns.

- 2) Much-needed rainfall still appears likely Saturday night through Monday. Guidance seems locked in a general 0.5"-1.0" across the area, with higher totals more likely across the northern Midlands.

DISCUSSION

KEY MESSAGE #1: A dry airmass settles over the region to round out the work week, leading to low-end fire weather concerns.

A very dry airmass has settled into the eastern CONUS, with GOES derived PWs <0.4" across the entire forecast area. As such, we have mixed very efficiently this morning as temperatures have risen. Dewpoints have fallen well into the teens and low 20s, leading to widespread RH values <30% across the area. While high temps will be a little cooler on Friday, the core of the surface high should be passing near the area, with similarly dry air across the area. So expecting another day of RH values in the low 20% range across the area. For those planning prescribed burns (or even doing small burns in their backyards), be aware of the forecast of low RH this afternoon and again on Friday afternoon. The winds both days look light, which will keep the danger for fire spread at a minimum.

KEY MESSAGE #2: Much-needed rainfall still appears likely Saturday night through Monday. Guidance seems locked in a general 0.5"-1.0" across the area, with higher totals more likely across the northern Midlands.

Guidance is in better agreement on the specifics of the upcoming storm this weekend, with a baja low ejecting into the southwestern/southern US on Friday and Saturday. As it does so, our surface high will continue to shift eastward off the coast of the CONUS. Southeasterly flow is forecast to increase across the area and lead to a slow increase in moisture ahead of the surface low and 500 hPa trough. These features should arrive by Sunday, with a warm front lifting through the area gradually during the day. This tends to be a signal in which we would adjust the forecast for at least in-situ wedging. However, the exact details of this setup really don't favor strong wedging developing across the area. Now expecting the warm front to actually end up somewhere across the central or northern Midlands as the surface low approaches from the west. Upper level support should begin to increase Sunday morning, with isolated showers developing Sunday morning as isentropic lift increases. The heaviest rain is generally forecast across the northern Midlands and Pee Dee region, along and north of the warm front. Lift should be maximized here with strong warm and moisture advection. LREF clusters are in good agreement that this area features the highest probabilities of >1" of rain (~40-50% chance). The rest of the area should at least see a good soaking rain with the combination of isentropic lift ahead of the front and heavier rain along the front itself. Some thunder is possible within this band given we'll be south of the warm front (more than likely). So overall, this event does not look super impactful. Instead, we should see a nice, beneficial rain event that we really need.

AVIATION /16Z THURSDAY THROUGH MONDAY/

VFR conditions likely through the TAF Period.

Dry high pressure will continue to fill into the region today with only a few high cirrus expected. Winds will consequently remain light and variable. Overnight winds should drop off with a solid nocturnal inversion developing. Winds eventually strengthen slightly out of the northeast by Friday afternoon.

EXTENDED AVIATION OUTLOOK...Restrictions are likely late Saturday through Sunday with a notable rain maker moving into the area.

CAE WATCHES/WARNINGS/ADVISORIES

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