textproduct: Columbia

WHAT HAS CHANGED

No major forecast changes. Rainfall amounts remain uncertain for this coming week. Updated aviation discussion for 06z TAF.

KEY MESSAGES

- 1. High pressure and a cooler, drier air mass settles over the area today.

- 2. Showers and thunderstorms possible mid-week and this weekend.

DISCUSSION

Key Message 1: High pressure and a cooler and drier air mass settles over the area today.

High pressure over the eastern seaboard continues to ridge down the coast early this morning. Northeast flow has ushered in some low level moisture resulting in stratus, and also drier surface air with dewpoints beginning to fall into the 40s. Generally expecting this trend to continue through the day, though the stratus deck should clear out by mid to late morning. PWAT should continue to drop as well, ending up below 0.5" by this afternoon. No precip expected today with the ridge building overhead and temps reaching the mid 70s. The SCFC Burn Ban remains in effect with daytime RH values likely falling into the low 30s, and northeast winds may be breezy at times.

Key Message 2: Showers and thunderstorms possible mid-week and this weekend.

PWATs increase again tonight into Tuesday to above 1", with surface high pressure generally remaining in place. However, a shortwave passing through the area may fire off a few morning showers or thunderstorms. At this point, the overall severe threat is low and the bulk of the rain should be confined to the western and northern Midlands. Additional energy is progged to move through the region Wednesday as the synoptic pattern shifts and ridging overhead begins to flatten out. Moderate wind shear coupled with sufficient instability hints at the potential for low-end storm organization, with an overall decent chance of rainfall Wednesday into Wednesday night. Rainfall amounts between one third and one half inch are looking more likely, with the NAEFS IVT remaining around the 90th percentile of climatology. Additional shortwaves are then forecast to move through periodically into this weekend, continuing at least slight chances for rain. The next big slug of moisture doesn't arrive until Saturday, so accumulations until then will likely be meager.

AVIATION /06Z MONDAY THROUGH FRIDAY/

Periods of MVFR ceilings are spreading into the TAF sites and should continue this morning before giving way to VFR conditions by the late morning to early afternoon.

There has not been significant change as LAMP/NBM guidance attempts to play catch up with the stratus deck that currently is pushing into the FA with MVFR cigs already seen at CAE/CUB/OGB/AIK. Winds remain out of the northeast around 6-10 kts with spotty gusts to 15-18 kts noted. These restrictions should continue to push southward toward the Augusta terminals in the coming hours and should be more widespread across the area by 08-09z, as indicated in the latest HRRR which continues to have the best handle of this deck (though even it is a bit underdone). These restrictions are expected to continue into the late morning before mixing out with scattered cumulus remaining. Skies then are expected to gradually clear through the afternoon with passing cirrus expected the remainder of the TAF period. Winds generally remain out of the northeast around 6-10 kts through the TAF period, but do become a bit lighter and easterly this evening into tonight.

EXTENDED AVIATION OUTLOOK... Another round of stratus/restrictions could be possible Tuesday morning, mainly toward the CSRA. This comes ahead of a line of showers that moves in during the late morning to early afternoon. Periods of restrictions then possible into the mid to late week with a more unsettled pattern continuing.

CAE WATCHES/WARNINGS/ADVISORIES

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