textproduct: Columbia

WHAT HAS CHANGED

Updated discussion about the precipitation overnight into Thursday morning. Aviation discussion for the 00z TAF issuance.

KEY MESSAGES

- 1) Light rain showers continue, with some scattered snow showers or brief freezing drizzle possible Thursday morning.

- 2) Temperatures near to slightly below average through the weekend followed by a significant warmup next week.

DISCUSSION

KEY MESSAGE #1: Light rain showers continue, with some scattered snow showers or brief freezing drizzle possible Thursday morning.

Light rain associated with a prefrontal surface trough continues to move through the area this evening. That said, radar trends have shown this activity is becoming more scattered in nature. Expect this trend to continue overnight. An upper trough to our west pushes eastward overnight into Thursday. As we get toward daybreak, forecast soundings show the potential for a few light snow showers or freezing drizzle, generally north of I-20. Temperatures are forecast to be near the freezing/thawing mark before warming back up, so impacts due to any wintry precipitation is expected to be minimal.

KEY MESSAGE #2: Temperatures near to slightly below average through the weekend followed by a significant warmup next week.

No notable changes made to the previous forecast. Overall expect temperatures to be near average through the weekend, quite the change from the significant cold spell for the Midlands and CSRA over the last week or so. The exception will be behind the front Thursday which likely be colder with an upper trough over the forecast area, with NAEFS mean indicating 500mb heights will be below the climatological 10th percentile. Upper ridging late this weekend will begin to build over the central US with blended guidance favoring a quick return to above average temperatures by the middle of next week.

AVIATION /00Z THURSDAY THROUGH MONDAY/

Restrictions expected to persist through the 24 hour TAF period.

Rain continues to push northeastward across the forecast area as a trough axis and associated moisture moves eastward. Low clouds have developed along with this as IFR ceilings are noted everywhere. Rain is generally forecast to decrease in coverage and intensity over the next couple of hours as the low pressure system pushes to the east of our area. However, as it does so, a secondary trough is forecast to develop in the lee of the Appalachians, forcing some in-situ wedge conditions overnight tonight and into the day tomorrow. LIFR and IFR ceilings and visibilities are expected at all sites for the majority of the period, maybe only lifting by 19z-21z tomorrow. Drizzle is also expected as forecast soundings show a picture perfect setup for widespread drizzle overnight tonight and into tomorrow morning, so have that in the forecast as well. Winds are generally expected to be southerly until the secondary surface trough develops & then the winds will shift to northeasterly for the bulk of the period. Expect winds around 5-10 knots.

EXTENDED AVIATION OUTLOOK...Restrictions should finally end on Thursday night as drier air and northwesterly surface flow scour out remaining ceiling restrictions.

CAE WATCHES/WARNINGS/ADVISORIES

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