|WPC Met Watch|
Mesoscale Precipitation Discussion: #0045 |
(Issued at 221 PM EST Mon Feb 10 2020
Mesoscale Precipitation Discussion 0045
NWS Weather Prediction Center College Park MD
221 PM EST Mon Feb 10 2020
Areas affected...portions of the interior Southeast
Concerning...Heavy rainfall...Flash flooding possible
Valid 101921Z - 110121Z
Summary...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.
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.
LAT...LON 35648225 35108165 34218259 33518522 33978645
34758688 35258539 35628344
Last Updated: 221 PM EST Mon Feb 10 2020