825
AWUS01 KWNH 041753
FFGMPD
MNZ000-NDZ000-042100-

Mesoscale Precipitation Discussion 0396
NWS Weather Prediction Center College Park MD
152 PM EDT Tue Jun 04 2024

Areas affected...Red River Valley of Northwestern Minnesota & Adj
North Dakota...

Concerning...Heavy rainfall...Flash flooding possible

Valid 041755Z - 042100Z

SUMMARY...Short-term window for northward training/repeating of
developing thunderstorms capable of 1.5-1.75"/hr rates.  Scattered
spots up to 3" in 1-2 hours pose localized flash flooding concern
before front presses eastward more rapidly.

DISCUSSION...GOES-E WV suite depicts an anomalously deep (2-2.5
std. dev) closed low across southern Canada with a strong
110-120kt  Pacific jet diving south across the northern High
Plains supporting a secondary shortwave across central SDAK.  A
short 90kt jet south to north jet streak across NDAK supports dual
dynamic strengthening of the lower levels with DPVA and right
entrance ascent over the Red River Valley.  A strong surface wave
is analyzed along the SD/ND/MN boarder with a slow moving front
connected up to the triple point low along the Canadian boarder
(with the warm front across the northern MN toward Lake enhanced
front near DLH.  Isallobaric backing 925-850mb flow within the
warm sector is providing moisture flux convergence along the
stalled/slow moving front through the Red River Valley.  As such,
convective overturning has begun.  MLCAPE to 1500 J/kg support
strong updrafts; though that confluent low level flux north of the
inflection helps to pool moisture to near 1.5" TPW with mid to
upper 60s Tds.  This should support hourly rates of 1.5-1.75"/hr,
though updrafts/downdrafts may be narrow.

Deep layer steering is fairly parallel to the boundary and the
500-1000 thickness suggest propagation vectors to be generally
aligned at the front.  This will be short-lived as the shortwave
continues to progress and forward progression of the front will
begin in earnest over the next few hours.  This may allow for a
window of 1-3 hours of training cores in proximity of the front
and through the naturally lower FFG values near the River Valley.
As such, spots of 2-3" are possible which may result in a spot or
two of possible flash flooding conditions.  Thereafter, updrafts
should broaden/strengthen but forward (eastward) propagation may
limit totals to 1.5-2" mainly in a sub-hourly to hourly nature,
this will move into higher FFG and risk of flash flooding should
likewise decrease into the north woods of MN.

Gallina

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...FGF...

ATTN...RFC...NCRFC...NWC...

LAT...LON   49489513 48999453 48109463 47219507 46249567
            46089696 46509711 47609685 48969607 49079540