textproduct: Columbia

SYNOPSIS

Periods of rain remain possible today, with highest chances in the eastern Midlands and lower CSRA. Unsettled weather then continues into the weekend and potentially into early next week. Dry conditions are then anticipated for the mid to late week period while temperatures remain on the cooler side.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Rain chances continue to decrease for the rest of the day, with highest potential for rain in the eastern Midlands and lower CSRA. - Cooler temperatures than yesterday.

Today and Tonight: Scattered shower activity continues to move through the forecast area as of this writing, but there is a continued downward trend in the overall coverage. In addition, the chances for showers continue to decrease for the rest of the day due to a couple of changes in the forecast. The main shortwave that brought rain this morning has generally moved through the area, with subsidence moving in behind this activity. Latest SPC analysis shows the best isentropic lift is located near the coast, so there is a lack of support over our forecast area. Additional pulses of energy are forecast to move through the area today, which could bring additional shower activity. Hi- res guidance suggests an uptick in activity mid to late morning, but given the location of the placement of rain at the initialization being too far north of reality, I am not confident this activity will move through the Midlands. The better chances for this activity looks to be the eastern Midlands/lower CSRA to the Low Country. That said, can't rule out some shower activity as the day progresses. As a result of the latest trends, did lower PoPs by 20-40% or more from I-20 and areas north and west and lowered PoPs east of I-20, but not as much.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/

Key message(s):

- Unsettled weather continues this weekend - Rainfall totals trending lower - Continued below normal temperatures

Mid level southwesterly flow will persist through the period with a series of shortwaves moving through and keeping the weather unsettled. Guidance is showing some drier air moving into the forecast area from the northwest with a strong gradient in PWATs across the area on Saturday, which will focus the rainfall axis a bit further south than previous forecasts. PWATs range from around normal in the northwestern Midlands to around 150 percent of normal across the southeast Midlands into the Coastal Plain. Overall forcing remains weak Saturday but continued isentropic lift and a surface boundary should provide continued chances of rain, focused south of the I-20 corridor.

Widespread clouds and some precipitation will again keep temperatures below normal with highs expected around 50 to the lower 50s. The approach of another shortwave trough on Sunday with some southern stream energy is expected to result in coastal low development Sunday afternoon and evening. This will keep the chance of rain in the forecast although again focused across the southern part of the forecast area. Temperatures expected to be similar to Saturday but slightly warmer across the eastern Midlands with highs in the lower to mid 50s.

LONG TERM /MONDAY THROUGH THURSDAY/

Key message(s):

- Upper trough moves through Monday with lingering rain chances - Drier and cooler air mass settles over the region through midweek

An upper trough will move over the region on Monday keeping low chances of rain in the forecast before drier air moves into the region in the wake of a cold front crossing the area. Cold high pressure settles over the forecast area Monday night with strong radiational cooling conditions expected to result in lows in the mid to upper 20s. A return to a more dry and cool pattern returns mid week with ensemble mean PWATs around 50 percent of normal Tue/Wed with 500mb flow generally zonal across the region with upper trough across the Great Lakes and west coast ridging. EC EFI continues to highlight anomalously low temperatures and expect the below normal temperatures to persist.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

Mainly VFR conditions to start the TAF period, but gradually worsening conditions anticipated.

VFR ceilings and visibilities are being reported at all 5 TAF terminals as of this writing, but low ceilings are being reported upstream. Expect these ceilings to work their way into the forecast area through the TAF period, gradually lowering over the next several hours, with LIFR conditions remaining possible after about 00z. The chances for rain have decreased since the last TAF forecast. Therefore, have dropped the predominant -RA groups and added PROB30 groups for the CAE, CUB, AGS, and DNL. Did include a TEMPO from for rain at OGB as the chances for rain are higher there. Whatever shower activity develops is anticipated to be done by mid afternoon. Light east to northeast winds 5 kts or less expected this morning, before switching to north or northwest around 19z or so. Winds become light and variable again overnight.

EXTENDED AVIATION OUTLOOK... Restrictions are likely to continue into Saturday as low ceilings continue and another round of rain remains possible, but chances for rain have decreased. Rain chances diminish Sunday and into the early week, but ceiling restrictions may remain in place at least part of Sunday.

CAE WATCHES/WARNINGS/ADVISORIES

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