textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 12z TAFs.

DISCUSSION

KEY MESSAGE #1: Showers and an isolated storm moving into western FA early this morning.

An MCS continues to move east southeastward through the region, which has brought rain showers and some embedded thunderstorms to the CSRA doorstep. IR satellite imagery, radar reflectivity, and lightning activity all suggest this activity is weakening as it moves into the forecast area. That said, some brief downpours and some rumbles of thunder remain possible in the CSRA very early this morning. With the weakening of this activity, there is question of how far east showers will make it before dissipating. Latest hi-res guidance indicates that this activity should die out quickly over the next couple of hours. Additional isolated activity is possible this afternoon as well.

KEY MESSAGE #2: Well above normal temperatures continue today and tomorrow with near record highs possible tomorrow.

The upper low over the Baja California region continues to drift eastward today and tomorrow. As it does, ridging over the Southeast is expected to strengthen in response. Additionally, high pressure offshore brings southwest winds to the region, ushering in some warmer temperatures. As a result, abnormally high temps continue today and tomorrow, with tomorrow being the warmest day. Near record to potentially record highs for Columbia (CAE) and Augusta (AGS) remain possible for tomorrow. Taking a look at ensemble probabilities, there is a moderately high chance (60-80%) of temps greater than 85F from the I-20 corridor to locations south and east. However, there is more uncertainty among the different guidance about highs reaching at least record highs (88F at both CAE and AGS), confidence is on the low to moderate range (30-50%). Temperatures then drop for Thursday and especially Friday before rebounding again.

KEY MESSAGE #3: The next storm system expected Thursday bringing breezy conditions along with showers and potentially thunderstorms.

As mentioned in Key Message #2, the upper low is forecast to track eastward for the next couple of days. It is then anticipated to get swept up by a northern stream trough moving across the CONUS. Guidance continues to slow the timing of when the closed low opens up with this trough, however. This trough tracks eastward through the rest of the week, leading to the development of a surface cold front. There continues to be discrepancies with the timing of when the trough and attendant front arrive to the area among model solutions. However, it appears the front passes through Thursday afternoon at this time. Showers and potentially thunderstorms are expected to move through the area with this front. Depending on how early (or late) this activity moves through will play a role in the thunderstorm coverage as well as the strength of the thunderstorms. In addition to the showers/storms, confidence is increasing in breezy winds ahead of, and especially behind the front. We'll continue to monitor trends for the need of a Lake Wind Advisory on Thursday.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

VFR conditions generally expected through the forecast period.

A shortwave driving earlier showers across parts of the forecast area continues to move offshore. Expect improving skies through this morning and winds picking back up from the west-southwest around 10 knots. There is a slight chance for a shower or thunderstorm this afternoon, but confidence is too low to include in the TAFs. Winds then decouple again tonight, variable at less than 5 kts with mainly high clouds moving through the area.

EXTENDED AVIATION OUTLOOK...The next chance of significant rain is expected Wednesday night into Thursday with a cold front. Some restrictions will be possible.

CAE WATCHES/WARNINGS/ADVISORIES

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