textproduct: Columbia

SYNOPSIS

Isolated rain chances move in tonight ahead of Saturday's system with more patchy fog possible. Warm weather continues ahead of an approaching cold front tomorrow with rain chances mainly during the evening. Gusty winds are also expected Saturday and Sunday. Near to below normal temperatures will then prevail through much of next week.

NEAR TERM /THROUGH TONIGHT/

Key message(s):

- Warm with near record high temperatures - Breezy with strong wind gusts and a Lake Wind Advisory - Strong cold front pushes through the area tonight bringing scattered showers and possible isolated thunderstorms

Deep upper trough across the middle of the country is resulting in deep southwesterly flow across our area with warm moist advection off the Gulf. A cold front extends from New England back into the TN/MS Valleys and will shift slowly eastward as the upper trough axis translates eastward through the day. Regional radar showing the leading edge of a widespread area of rain extending from central NC back through southern AL. However, much of this precipitation is expected to remain in this same area off to our west through the Upstate through much of the day as shortwave energy lifts northeastward into the Great Lakes region and the upper trough deepens with another shortwave driving the front into our region this evening and pushing through overnight. Expect best chances of rain to be late afternoon through the overnight hours as the front pushes through the region but overall rainfall amounts continues to diminish with much of the forecast area likely to see less than a half inch and best chances in the western Midlands and upper CSRA. Cannot rule out an isolated thunderstorm although the HREF shows little instability with mean CAPE less than 250 J/kg.

Ahead of the approaching front, strong southwesterly winds are expected mix down by mid morning with HREF showing 850mb winds around 40 knots and probabilities of wind gusts around 70 percent. A Lake Wind Advisory is already in effect but will be extended through 00z Monday as strong winds are expected behind the front late tonight through Sunday with the cold advection. There may be a period of time where winds are not reaching criteria but cannot rule out stronger gusts. Temperatures today should be well above normal and approach record highs (daily record is 82 for Columbia, 80 for Augusta) with strong warm advection. Once the front moves through this evening and overnight, winds shift to the northwest and strong cold advection commences with overnight lows tonight falling into the mid 40s western Midlands to lower 50s eastern Midlands.

SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/

Key message(s):

- Continued breezy and much colder on Sunday with widespread subfreezing temperatures expected at night.

The cold front will be clearing the FA early in the day with skies clearing out from northwest to southeast. Winds shift northwest behind the boundary with winds quickly increasing in response to a robust low-level jet. Wind gusts of 20 to 30 mph are likely, higher on area lakes. Unlike today, these winds are driven by CAA as strong high pressure builds in from the west. Daytime temperatures are expected to be 20 to 25 degrees colder than today with highs ranging from the lower 50s northwest to the lower 60s southeast. Depending on how much rain falls, there may be fire weather concerns as relative humidity values fall into the 25 to 30 percent range for most locations in the afternoon. High pressure continues eastward Sunday night allowing surface winds to diminish. The lighter winds and clear skies should promote strong radiational cooling with lows falling into the mid to upper 20s.

LONG TERM /MONDAY THROUGH FRIDAY/

Key message(s):

- Near to below normal temperatures through the extended.

- Next chance of rain expected Wednesday into Thursday.

High pressure will be in control of the region early next week with below normal temperatures expected on Monday before more seasonal temperatures return Tuesday and Wednesday. The next storm system begins to approach on Wednesday with rain chances increasing at night. The best chance for rain appears to be on Thursday but confidence in timing remains low. The passage of a potent upper-level trough near the end of the extended should result in below normal temperatures once again.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

VFR conditions start the forecast with possible MVFR/IFR restrictions during the predawn hours.

Warm moist advection continues over the region ahead of an approaching cold front. Mixed signals in guidance suggesting possible restrictions in stratus/fog during the 08z-14z time frame, with highest confidence at OGB. Satellite imagery showing some stratus developing along the Coastal Plain already which may affect OGB but uncertain as to how far west it may reach and another area of stratus moving north through southern GA but all guidance has it dissipating before reaching AGS/DNL. Therefore will bring prevailing MVFR cigs at 07z OGB and CAE/CUB at 08z with tempo to IFR cigs 08z to 12z. Winds generally light at 5 knots or less from the south through around 14z then picking up from the south and then becoming quite gusty after 16z through the afternoon ahead of the approaching front. Cig restrictions should improve back to VFR by 14z once deeper mixing takes place. Most rain showers should remain to the west through much of the forecast period but some showers may move in just before 00z. Wind gusts should subside with sunset.

EXTENDED AVIATION OUTLOOK...A cold front will move into the area Saturday night bringing the potential for restrictions Saturday night into Sunday.

CAE WATCHES/WARNINGS/ADVISORIES

SC...Lake Wind Advisory from 10 AM this morning to 7 PM EST Sunday for SCZ016-018-020>022-025>031-035-037-038-041-115-116- 135>137. GA...Lake Wind Advisory from 10 AM this morning to 7 PM EST Sunday for GAZ040-063>065-077.