Heavy rainfall is moving into the region from the west-southwest and is expected to become more convective with time. Hourly rain totals to 1″ with local amounts of 2-3″ are expected through 8 pm EDT.
In-Depth Discussion: Moisture is streaming in from the west-southwest within an atmospheric river moving into the region. Precipitable water values are currently 0.8-1.3″. Inflow at 850 hPa is west-southwest at 30-50 knots per nearby VAD wind profiles, similar in direction and magnitude to the 850-400 hPa mean wind. MU CAPE remains under 100 J/kg for much of the area, though trends are upward across northern AL. Recent observations show hourly rain totals of 0.15-0.30″, roughly 1/5 of the current precipitable
water value, due to the lack of instability.
With time, hourly rain totals are expected to rise to 0.5-1″ as MU CAPE rises to 500+ J/kg across northeast AL and northern GA and convective elements become more common within the mostly stratiform rain areas. Mesoscale guidance generally advertises local amounts ~2″, but 3″ can’t be ruled out during the next several hours. Two-week precipitation anomalies are 150-300%+ of average, which has led to fairly saturated soils. Flash flooding is considered possible through 8 pm EDT.
