textproduct: Columbia

WHAT HAS CHANGED

Rain continues to spread into the region this morning. Aviation updated for 06Z TAFs.

KEY MESSAGES

- 1. Widespread rainfall through much of today.

- 2. Unsettled weather returns for the middle of next week.

DISCUSSION

Key Message 1: Widespread rainfall through much of today.

Deep moisture will continue to spread into the region this morning as PWAT values rise to 1-1.5 inches with the deepest moisture across the southern Midlands. Low pressure will develop along a frontal boundary to our south as a deepening trough pushes over the southeastern US. This will strengthen moisture advection over the forecast area and lead to widespread rainfall through mid-day when drier air will begin pushing in from the west. This will result in a steady, moderate rainfall event with totals expected to range from 0.5 to 1.25 inches, with isolated totals of 1.5-1.75 inches possible, especially across our southern counties. Rain will taper off this afternoon and evening. We cannot rule out a weak thunderstorm but instability, even elevated, is at a minimum.

Key Message 2: Unsettled weather returns for the middle of next week.

The next period of notable weather will be mid-week when a trough is expected to lift over the eastern US. The associated, trailing cold front may sag into the Southeast late Wednesday or Thursday. The NAEFS shows IVT near the 99th percentile of climatology and above normal atmospheric moisture. However as the stronger dynamics lift further north with the trough, we may see the convection along the front weaken with dryer westerly winds at the mid-levels accompanying the frontal passage. This typically leads to more scattered convection over our forecast area, suggesting NBM PoPs could be too high for the time period. Dry weather likely to return by late week and into the weekend.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

Conditions deteriorate overnight. Ceilings are expected to lower to IFR overnight and persist into Saturday.

Widespread rainfall is beginning to move into the forecast area and has begun falling at the Augusta area terminals. Expect this rainfall to persist for much of the day and is forecast to begin exiting around 20z-22z today. Visibilities are anticipated to gradually drop as rain intensity increases, likely reaching IFR conditions. Ceilings are currently VFR at all terminals except OGB, where IFR cigs are being observed. Those lower ceilings are forecast to move northwestward toward the Columbia and Augusta terminals in the next few hours. Then, the ceilings remain IFR into the afternoon, improving as the rain exits the region. Winds are expected to be light from the west, shifting to the north and increasing to near 10 kts for several hours beginning around 10z-12z. Winds decrease again late in the period.

EXTENDED AVIATION OUTLOOK...Drier conditions then are expected Sunday and into the early week. A midweek system brings a chance for restrictions once again.

CAE WATCHES/WARNINGS/ADVISORIES

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