textproduct: Columbia

WHAT HAS CHANGED

This afternoon's temperatures are trending downward due to extensive cloud cover. Aviation discussion updated for 18z TAF issuance.

KEY MESSAGES

- 1. Daily chances for showers and storms continue through Tuesday, with locally heavy rain possible today.

- 2. Relatively cool temps today and Tuesday, followed by a warming trend.

DISCUSSION

Key Message 1: Daily chances for showers and storms continue through Tuesday, with locally heavy rain possible today.

The cold front the moved through the area last night and this morning is roughly located generally south and west of the CSRA at the time of this writing. While there is some shower activity moving through the area at this time, the heavier rain is located closer to the front. Latest guidance suggests the heaviest rain in the afternoon stays out of the area. A shortwave is forecast to move over the area tonight, which is expected to lift the front back to the north. As a result, the chances for shower and storm activity slide northward as well. PWATs are relatively low compared to what we've seen recently, except in the CSRA where they are approaching 2". These higher PWATs are forecast to move northward this evening and tonight, bringing the potential for locally heavy rain once again. Although the threat is low, isolated flash flooding cannot be ruled out through tonight, with areas south of I-26 having a higher likelihood of such an occurrence.

The frontal boundary is then expected to waver some tomorrow and Tuesday before a sharper trough digs through the eastern US, aiding in pushing the front out of the area. With this front in place, rain chances continue through Tuesday, but PWATs are expected to be lower than they have been, so the flooding threat decreases after today. Then, mainly dry weather is forecast for the rest of the week.

Key Message 2: Relatively cool temps today and Tuesday, followed by a warming trend.

Temperatures today remain well below normal for much of the area, with most locations in the mid to upper 60s at this time. Only a few locations have reached the 70s so far. Therefore, have lowered high temps for today to generally the mid 70s. As the frontal boundary wavers north tomorrow, then south again for tomorrow night into Tuesday, temps rebound for tomorrow to near normal before dropping again on Tuesday. After Tuesday, a gradual warming trend is anticipated the rest of the week.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

A combination of mvfr/ifr ceilings and visibilities, along with periods of showers, are expected at all locations over the next 24 hours.

All sites starting off with mvfr restrictions outside of showers, and expect to have ifr restrictions at times as heavier showers move through over the next 24 hours. With lingering low level moisture and a front remaining in the area, rain showers will continue. Greatest coverage early this afternoon will be in the CSRA and southern Midlands. However this activity will expand and push northward into the central Midlands through the afternoon and into tonight. Guidance consistent with lowering ceiling to ifr/lifr after midnight, and followed that trend. Late in the taf period, sites may begin to see some improvement into mvfr as rain exits off to the east and ceilings begin to lift on the backside of the exiting rainfall.

EXTENDED AVIATION OUTLOOK...Restrictions possible into Tuesday, then drier air could begin to move into the region mid-week.

CAE WATCHES/WARNINGS/ADVISORIES

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