Mesoscale Precipitation Discussion 0722
NWS Weather Prediction Center College Park MD
1224 AM EDT Mon Aug 27 2018
Areas affected...Northern Minnesota
Concerning...Heavy rainfall...Flash flooding possible
Valid 270423Z - 270923Z
Summary...Heavy thunderstorms ahead of low pressure will continue
across northern Minnesota through the early morning hours.
Discussion...A frontal and prefrontal line of thunderstorms are
congealing just east of the Red River of the North. These will
continue to move east-northeast across northern Minnesota over the
next few hours. 1.6" PW will continue to advect north into this
area ahead of the surface low that was along the ND/MN border at
04Z. This moisture, the lift from the low, and 1500-2000 J/Kg
MLCAPE moving in will allow heavy thunderstorms to continue
overnight. Rain rates of 1.5 to 2" have been recently sampled over
northwestern MN and can be expected to continue.
Recent HRRR runs (including the 03Z) depict the threat continues
through about 09Z before the activity lifts into Ontario or
dissipates. Rain this week has generally been over north-central
MN and south, so this threat area in far northern MN has drier
antecedent conditions. One hour FFG is generally 2" or higher.
However, the expectation for localized repeating heavy cells
warrants a possible flash flood threat.
Jackson
ATTN...WFO...DLH...FGF...
ATTN...RFC...NCRFC...
LAT...LON 49279487 48779265 47879256 47249367 46999668
47869663 49069606
Last Updated: 1224 AM EDT Mon Aug 27 2018