textproduct: Columbia

WHAT HAS CHANGED

No significant changes to the forecast.

KEY MESSAGES

- 1. Above normal temps expected today, with a backdoor front ushering in drier and slightly cooler air through the middle to end of this week.

- 2. Increasing moisture and rain chances by the end of the weekend into early next week.

DISCUSSION

KEY MESSAGE 1: Above normal temps expected today, with a backdoor front ushering in drier and slightly cooler air through the middle to end of this week.

The forecast remains largely on track over the next 7 days, with high confidence in the pattern set to unfold. Strong 500 hPa ridging is building into the southeastern CONUS, with heights above average for this time of year by Tues/Wed, which is consistent with ensemble guidance. A strong surface high is expected to push into the northeastern US and Mid-Atlantic over the next couple of days, yielding a backdoor front progged to push through the area tonight. Persistent surface ridging is forecast to hang around through the end of the week, with seasonally low PW air and very pleasant afternoon dewpoints through Friday. Combine this with strong subsidence directly beneath the upper ridge and we are looking at a nice week across the area. Today will be the last really hot day as heights rise & we experience some compressional heating ahead of the backdoor front, with highs forecast in the mid 90s. Behind this front, we should see highs in the upper 80s to around 90 Tues/Wed/Thur, with overnight lows dipping into the mid 60s given the dry airmass in place. This is near normal for this time of year, a nice reprieve from what we have seen the past few weeks. By late week, an inverted upper trough is forecast to undercut the strong ridge and move south of our forecast area. This doesn't look to yield rain across the area though, so precip chances look low through at least this upcoming weekend.

KEY MESSAGE 2: Increasing moisture and rain chances by the end of the weekend into early next week.

The persistent upper-level ridge begins to break down by the weekend as a cold front approaches the forecast area from north Saturday. This will allow for southerly flow to return and increasing moisture from the south. Seasonally high PW air will return with surface dewpoints climbing into the upper-60s to low-70s. Ahead of the front this weekend, lows in the low 70s and highs may reach the mid 90s with feels like temperatures approaching the upper 90s to near 100. There may be a slight chance of precipitation (15-30%) Saturday and Sunday, but the greatest likelihood appears early next week (30-50%).

AVIATION /18Z MONDAY THROUGH SATURDAY/

Mainly vfr through the period, although a low probability of mvfr ceilings developing across the area early Tuesday morning.

Dry backdoor cold front will be pushing through the area this evening, bringing an airmass with lower moisture to the forecast area by Tuesday. May see some scattered to broken cumulus this afternoon and evening, mainly remaining above 5kft. Winds turning more north to northeasterly as the front sags through. Average speeds between 5-10 knots, but can not rule out a few gusts up to 15 knots along and behind the front. Although vfr conditions are forecast to remain through the period, guidance does show an indication of mvfr ceiling development late tonight. With the drier air pushing in, confidence right now is lower than usual for this. However low-level winds towards morning to shift to more easterly, so not entirely out of the question that some weak upslope could still bring a narrow band of moisture inland towards Tuesday morning. For now kept vfr ceilings, with broken clouds coming in around 5kft towards 10z. Included mention of scattered 2kft to at least hint at some lower clouds at this time.

EXTENDED AVIATION OUTLOOK...Rain and restrictions unlikely for much of the week.

CAE WATCHES/WARNINGS/ADVISORIES

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