textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 12z TAF.

KEY MESSAGES

- 1) Well above normal temperatures expected later this week. Highs in the 70s and 80s are expected Thursday/Friday.

- 2) Rain is expected again this weekend but the details and timing of that rain are quite uncertain.

DISCUSSION

KEY MESSAGE #1: Well above normal temperatures expected later this week. Highs in the 70s and 80s are expected Thursday/Friday.

Our warming trend is forecast to persist into the end of the week. Heights will continue to rise over the next 36-48 hours as a large, deep (and complex) upper level trough digs into the western CONUS and amplifies the overall downstream pattern. Southwesterly flow will gradually increase across the area through the end of the week, with 90th-95th percentile 850 hPa temps expected to overspread the area by Thursday and Friday. ECE EFI values suggest anomalous warmth with record temperatures possible. Thursday's record high at CAE is 80F and at AGS is 82F. Friday's record high at CAE is 84F and at AGS is 83F. For a variety of reasons, it seems like it'll be difficult to achieve that. Clouds should be too copious on Friday & we probably won't be quite warm enough yet on Thursday. However, its really not out of the question that we see low 80s either day across the area. The warmth on both days is seemingly the only part of the forecast that medium range guidance agrees on.

KEY MESSAGE #2: Rain is expected again this weekend but the details and timing of that rain are quite uncertain.

There is significant uncertainty in the forecast this weekend, driven primarily by the complexity of the western CONUS. IQR spread in the LREF for the 500 hPa heights is enormous for the medium range, with cluster analysis really not adding a ton of value to the forecast at this point. Given broad and persistent southwesterly flow for much of this week, anomalous moisture should be in place ahead of an approaching front early on Friday. Rain chances should increase on Friday ahead of this front but really don't look to increase until Saturday evening or Saturday night. We'll have access to PWs in the 80th to 90th percentile ahead of the next shortwave emerging from the western CONUS, so our best best rain chances should be Saturday afternoon through midday Sunday. Its hard to forecast more than this at this point as the spread amongst the ensemble guidance is extremely high.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

Patchy fog or stratus could impact mainly AGS/OGB for next couple hours before VFR conditions return.

Satellite imagery shows patchy fog and stratus across the southeastern Midlands and toward the CSRA, but impacts at OGB/AGS have been fairly intermittent with on and off periods of IFR to LIFR restrictions. This should continue for the next hour or two before these restrictions clear and VFR conditions move in with light winds out of the south to south- southwest much of the day. Tonight, cloud cover is expected to increase as moisture continues to ramp up but at this time, VFR conditions are expected to continue, though SCT clouds around 3500 to 5000 ft could move in near the end of the TAF period.

EXTENDED AVIATION OUTLOOK...Moisture increases through the week leading to increasing chances of morning fog/stratus. The next chance of rain is trending toward the late week and this weekend.

CAE WATCHES/WARNINGS/ADVISORIES

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