157
FXUS63 KFGF 131144
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
644 AM CDT Thu Jun 13 2024

.KEY MESSAGES...

- Unsettled period heading into next week with 500 mb trough
  west and ridge east and area in southwest flow aloft.

- There is a 15 percent probability of another round of severe
  thunderstorms on Monday.

&&

.UPDATE...
Issued at 642 AM CDT Thu Jun 13 2024

Skies clear over the fcst area as we approach 12z. Upper wave is
north and northwest of area and approaching Brandon MB. It will
move southeast and generate isold-scat t-storms midday and aftn
in far NE ND and NW MN per forecast.


&&

.DISCUSSION...
Issued at 234 AM CDT Thu Jun 13 2024

...Synopsis...

For today, we will be dealing with a 500 mb low over the
Manitoba lakes and a short wave which is well seen moving on the
south side of the upper low near Yorkton SK. This wave will move
east-southeast toward toward Lake of the Woods region. 500 mb
temps in the -17/-18C range near the ND/MB border and into NW MN
along with daytime heating into the 70-75 range will create MU
CAPES in the 500-800 j/kg range, with 20 pct chance of MU CAPE
in the 1000-1100 j/kg range near Roseau and Baudette. Bukfit
sounding profile for BDE shows that steep lapse rate 7.5 C/km.
All of this is sufficient for scattered thunderstorms to develop
today Langdon to Thief River Falls to Bemidji area north. Pea
size hail wouldnt be out of the question from some storms, but
expect non-severe. This follows Day 1 SPC outlook as well.

Scattered storms diminish early this evening and tonight into
most of Friday look dry with clear to partly cloudy sky as the
colder air aloft move east.

...Unsettled period into next week...

500 mb ridging builds into the northern Plains Friday night but
the building ridge quickly shifts east toward the Ohio Valley
and Mid Atlantic region Sunday and holds there thru most of the
next week. This will set the region up in a southwest flow
aloft with periodic short waves moving northeast in the flow
through the area giving chances for showers and thunderstorms.
Position of front will be critical to where any severe threat
lies with ECMWF remaining slower to advance 500 mb trough to our
west east vs GFS. Per SPC discussion on days 4-5 severe threat
will side more toward a slower ECMWF progression. That would
leave south/east half of the fcst area in some strong/severe
threat early next week, while significantly cooler air and more
showery weather occurs west central/northwest into north
central ND incl Devils Lake region. From Grand Ensemble in DESI
the probs for more than 1.5 inch of rain Sun-Wed next week is
highest in warm sector due to more convective nature of the
rainfall...roughly over the southeast fcst area and southeast
from there toward the Twin Cities and up toward Duluth.

...15 pct probability of severe weather next Monday...

SPC in its Thu AM update kept a 15 pct prob of severe in the RRV
and MN for Monday. Uncertainity on frontal location means no
outlook for Tuesday. But there will be sufficient instability
in the warm sector Monday with ECMWF maintaining a stormier
outlook vs GFS which pushes warm unstable airmass far south and
east.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 642 AM CDT Thu Jun 13 2024

Clear sky at 12z but expect some CU to form near the 4-6k ft agl
level by late morning and thru the aftn, esp north. Few scat
t-storms as well but timing and location uncertain enough to
avoid putting any in TAF site (esp TVF) which would have a
higher chance than the rest. West-northwest winds increase to
12-20 kts today with gusts 25 kts .


&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.

&&

$$

UPDATE...Riddle
DISCUSSION...Riddle
AVIATION...Riddle