textproduct: Columbia

WHAT HAS CHANGED

Diurnal shower and thunderstorm coverage appears isolated over the next few days. However there is a chance for more organized convection and severe weather to enter the northern FA late today and Wednesday.

KEY MESSAGES

- 1. Storms with strong downburst winds possible through Thu - 2. Above normal temperatures likely, Heat Advisory possible, through early next week.

DISCUSSION

- 1. Storms with strong downburst winds possible through Thu

Upper level ridging to our west will allow several disturbances to dig into the Carolinas today through early Thursday. In addition to typical diurnally driven storms, there is some potential for organized convection from decaying MCSs upstream. Mid-level dry air will allow for DCAPE values in excess of 1000 J/kg today and Wednesday so any diurnally driven pulse- convection will pose a threat of isolated downburst winds.

In terms of a more widespread wind threat, MCSs are expected to develop in the Midwest and dig into the Mid Atlantic States by the late evening time frame. In this setup, we typically see a decaying MCSs digging into the northern FA well after peak heating. However, there are times when convection persists longer than models anticipate leading to a cold pool driven line of storms causing scattered power outages and wind damage. These lines of storms will be possible this evening and again Wednesday morning or mid-day.

- 2. Above normal temperatures likely, Heat Advisory possible, through early next week.

Northwest, downslope flow and rising heights favor above normal temperatures through much of the 7 day forecast period. If convection does not hamper heating, we will likely have highs in the mid 90s to upper 90s. The NBM may be too warm given its verification through the spring/summer season however highs of around 100 degrees can't be ruled out late this week and early next week as ridging builds overhead. Heat Index values should range from 100 to 105 through Friday with values in the 105 to 110 range possible Thursday and Friday. That said with convection possible both days confidence in reaching Heat Advisory is low at this time.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

Relatively high confidence in VFR conditions through much of the TAF forecast period.

Showers and thunderstorms have begun to develop in portions of GA at the time of this update. Confidence has increased that this activity could affect AGS, DNL, and/or AIK this afternoon. Expect gusty and erratic winds and typical restrictions should a storm affect these terminals. The probability of CAE, CUB, and OGB being affected by showers and storms this afternoon and evening remains low at this time. There is some guidance suggesting additional activity overnight, but confidence is too low to include in the TAFs at this time. Outside of shower and thunderstorm activity, generally west winds 5 to 10 kts can be expected this afternoon and after about 15z tomorrow, with lighter winds overnight. Additionally, VFR conditions are also anticipated through the TAF period.

EXTENDED AVIATION OUTLOOK...A hot and drier weather pattern develops through the week. Convective coverage will likely be low and restrictions likely minimal as highs push into the upper 90s.

CAE WATCHES/WARNINGS/ADVISORIES

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