Horace, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

512
FXUS63 KFGF 060909
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
409 AM CDT Sun Jul 6 2025

.KEY MESSAGES...


- Isolated severe thunderstorms with a level 1 out of 5 risk is
  forecasted Monday afternoon and evening.

- The potential exists for aevere storms Thursday afternoon and
  evening and possibly again on Friday.

&&

.DISCUSSION...
Issued at 351 AM CDT Sun Jul 6 2025

...Synopsis...

In typical mid summer fashion predictability in regards to
coverage and intensity of thunderstorms will be a huge
challenge. 500 mb flow remains zonal thru the upcoming week with
several waves moving thru, namely Monday and again Thursday and
Friday. For the late week, models diverge on timing and strength
of the 500 mb wave and front.

A 500 mb wave is moving into northeast Montana early this
morning and this will move into north central North Dakota by
18z today. Area of showers with this wave to its north /east
over NW ND and SE Sakatchewan will move east slowly this
morning. So do have pops entering DVL basin for some showers by
mid to late morning. Afterwards, the wave will continue moving
east, but moisture becomes less and for now will maintain a dry
fcst for areas farther east along the border for this aftn/eve
but something to watch. I could see where sprinkles may need to
be added. Increasing clouds today into E ND and a bit cooler
than yesterday...sunny in Minnesota with increasing clouds in
the aftn.

...Monday severe potential...

As the first wave moves out a stronger 500 mb low will move from
the Edmonton area at 00z Monday to near Saskatoon 12z Monday
then toward Winnipeg/Brandon MB 00z Tues.

Questions remain in regards to instability but with upper low
moving close by a pool of cold air aloft and a nose of 63-65 dew
pts into E ND/RRV should be enough to get sfc CAPE values into
the 800 to 1200 j/kg range. Ensemble data from 00z GFS/EC/GEM
indicate probs of greater than 1000 j/kg and bulk shear of
greater than 30 kts will co-exist in the Red River valley (40
pct chance) with higher probs farther south. This matches SPC in
showing a marginal risk in our area with higher risk categories
farther south. Does appear to be more of a multi-cell event with
majority of the storms below severe limits but with a couple
getting enough sustained updrafts for large hail (up to 1.50
inches). That would seem to be favored from Winnipeg area south
along the Red after 21z and into parts of NW MN 00z or so.
Instabilty weakens considerably though farther east so would not
expect a long lived severe event.

...Thursday / Friday severe potential...

00z models have come in with a considerably stronger 500 mb wave
moving east and developing into a closed upper low Thursday
anywhere from southern Saskatchewan into southern Manitoba.
Airmass advecting northward Wednesday into Thursday ahead of
this system will bring high temps around 90 Thursday and dew pts
low 70s. Instability in eastern and central ND peak in the 4000
j/kg range. Would look like a front/boundary between humid and
drier air will advect east to the south and east of the upper
low into central and eastern ND Thursday aftn/eve. Timing is key
to where greatest severe threat is. Friday may see a severe
threat in our eastern fcst area based on GFS and ECMWF timing.
SPC added a 15 pct severe for Thursday in central ND incl DVL
basin and agree with this. It may have to be adjusted east or
west in future days due to movement of the system. But all modes
of hazards are possible.





&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1113 PM CDT Sat Jul 5 2025

Low aviation impacts are expected for the TAF period with the
exception of smoke potentially lowering visibilities. Upstream
observations indicate visibilities are remaining VFR right now,
so don`t except at this time to see MVFR conditions tomorrow,
but it is something to watch. Showers may impact DVL tomorrow
but the probability remains low to not add to the routine 06z
TAF.

&&

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

&&

$$

DISCUSSION...Riddle
AVIATION...Perroux