textproduct: Columbia

WHAT HAS CHANGED

Added mention of rain chances and cooler temperatures toward the end of this week. Aviation discussion updated for the 06z TAF issuance.

KEY MESSAGES

- 1. Seasonable temperatures and dry conditions continue today before warming into midweek. A frontal system brings increased rain chances and cooler temperatures later in the week.

DISCUSSION

Key Message 1: Seasonable temperatures and dry conditions continue today before warming into midweek. A frontal system brings increased rain chances and cooler temperatures later in the week.

Dry, cool high pressure will persist through the weekend, with high temperatures reaming near climatological normal today. Low dewpoints, light winds, and mostly clear skies will promote large diurnal temperature ranges, with below-normal overnight lows in the 40s expected this morning and again tonight. As the surface high gradually shifts southward, light southerly flow will allow temperatures to steadily rebound through midweek. Dry conditions will continue to support large diurnal temperature swings, with widespread highs in the mid to upper 70s ad overnight lows in the 40s.

Attention will then turn to a complex trough expected to dig across the eastern US late this coming week, bringing cooler temperatures in its wake. Global models continue to show disagreement regarding the placement and intensity of surface development across the southeast. Recent deterministic GFS runs have trended toward a more amplified solution with multiple shortwaves phasing together, while recent ECMWF, GEM, and ensemble guidance continues to favor a more tempered trough. Any associated frontal system is most likely to bring increased precip chances to the region Thursday into Friday, although significant rainfall is not anticipated at this time. Behind the system, much cooler conditions are expected late next week, with temperatures currently forecast to run around 5 to 10 degrees lower than normal.

AVIATION /06Z SUNDAY THROUGH THURSDAY/

Some shallow MIFG and associated restrictions possible overnight, otherwise VFR expected.

Cooler drier air has settled across the region as high pressure moves in at the surface. We are seeing some shallow ground- river fog that is currently impacting AGS-OGB; this 'fog' is pretty typical at OGB and AGS in good radiational cooling nights with light winds. It will likely only last through 09z or so. Otherwise, VFR conditions with light winds are expected from Sunday morning onward.

EXTENDED AVIATION OUTLOOK...Dry air will likely prevent widespread restrictions through the extended.

CAE WATCHES/WARNINGS/ADVISORIES

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