textproduct: Columbia

WHAT HAS CHANGED

Drier air than expected has moved into the western half of the forecast area. Meanwhile, the frontal boundary that brought rain earlier today has stalled over the eastern portions of the forecast area. Aviation discussion updated for 00z TAF.

KEY MESSAGES

- 1) Rain chances increase again for the weekend, with a few thunderstorms possible on Saturday.

- 2) Cold temperatures return behind this system, with well below normal temps expected Monday and Tuesday.

DISCUSSION

KEY MESSAGE #1: Rain chances increase again for the weekend, with a few thunderstorms possible on Saturday.

The front that brought rain through the area this afternoon seems to have stalled somewhere in the eastern Midlands as noted by the differences in wind direction and dew points. East of the front, winds are generally from the southwest while winds west of the front are generally more westerly. Dew points range from the 60s in the east to 40s in the west. The dew points on the drier side of the front are lower than previously thought, so have adjusted them to account for this into tonight.

This front is forecast to generally remain in the area into the weekend before a stronger trough is able to help push the front out of the area by the end of the weekend. With this front hanging out for the next couple of days, rain chances return for Saturday and into Sunday. Lingering moisture is forecast to lead to moderate amounts of rain, with amounts of a half inch or more possible, with higher amounts the further east you go. Latest guidance does show instability creeping into the forecast area on Saturday, leading to the potential for a few thunderstorms. The highest instability is expected to be in the lower CSRA. Shear should be sufficient enough for the potential of a stronger storm, but it depends on how far north the stronger instability gets in the afternoon on Saturday. Showers linger into Sunday as the frontal boundary gradually moves eastward.

KEY MESSAGE #2: Cold temperatures return behind this system, with well below normal temps expected Monday and Tuesday.

A large scale trough is expected to dig into the Southeast to begin the week as surface high pressure builds into the region. As a result, temperatures are expected to be much below average Monday and Tuesday. Confidence is also moderately high that lows will be below freezing Sunday and Monday nights.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

VFR conditions expected most of tonight, with a few MVFR restrictions returning Saturday as rain moves into the area.

VFR conditions prevail this evening as SCT mid-level cloud decks around 10k ft MSL are starting to return to the area. Rain chances are expected to increase into Saturday morning, with MVFR ceilings redeveloping, especially at AGS/DNL/OGB. Less confidence in MVFR CIGs at CAE/CUB during the current TAF period, but more likely during the next forecast period. For now, have kept conditions at MVFR but there is the potential for lowering to IFR with the heavier rain, especially moving into Saturday evening. Winds should be light and variable between WLY tonight and NLY/NELY on Saturday.

EXTENDED AVIATION OUTLOOK...Abundant low level moisture will bring chances for morning fog/low stratus this weekend, likely resulting in restrictions. Chances of rain continue on Saturday with some thunderstorms possible. Conditions improve Sunday into early next week with predominantly VFR returning.

CAE WATCHES/WARNINGS/ADVISORIES

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