textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 00z TAF issuance.

KEY MESSAGES

- 1. Light rainfall amounts possible late this week.

DISCUSSION

Key Message 1: Light rainfall amounts possible late this week.

Throughout the week, an upper level trough will traverse the central CONUS with a trailing cold front slowly approaching the Southeast. As the trough approaches the region mid-week, much of the associated energy lifts well north of the forecast area. This will limit the amount of moisture advection into the forecast area ahead of the front. PWAT values still rise to near 1.5 inches as the front approaches late Wednesday and Thursday, which should support some shower activity. However with upper dynamics quickly pulling further away from the region and weak IVT, we usually do not receive much rainfall from this type of setup. NBM QMD probabilities of receiving greater than half an inch are low (20 to 30 percent) mainly limited to the western FA. A few thunderstorms could be possible with weak instability over the forecast area, particularly on Thursday afternoon. Weak instability and weak shear should limit any threat of severe weather. Showers may linger into Friday as the front stalls in over the region. It may not push through the forecast until the weekend when a stronger trough is progged to dig into the eastern US. This will keep at least a chance of rain in the forecast through the end of the forecast period.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

VFR conditions should prevail through most of the TAF period except for possible brief MVFR cigs in the Augusta area Tuesday morning.

Low level easterly flow continues to bring moisture into the region and satellite imagery shows BKN/OVC VFR cigs impacting the CSRA and parts of the Midlands. These clouds likely will be intermittent through the night but should remain VFR. MOS guidance with some support from SREF indicates a brief period of MVFR cigs at AGS/DNL during the 11z-15z time frame so included a TEMPO group for now given a bit of lower confidence. Later forecasts can move it into the prevailing group if confidence increases.

Winds should remain around 3 to 6 knots from the east-northeast overnight before picking up to around 7 to 10 knots from the east after 15z.

EXTENDED AVIATION OUTLOOK...Increasing chances for rain during the mid to late week may lead to some lower CIGS or VSBY restrictions, but confidence remains low.

CAE WATCHES/WARNINGS/ADVISORIES

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