031
FXUS63 KFGF 090851
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
351 AM CDT Wed Jul 9 2025

.KEY MESSAGES...

- Severe storms are possible, risk level 1 out of 5, in eastern
  North Dakota late this evening.

- Severe storms risk level 2 out of 5 will develop Thursday
  afternoon and night.

- Heat risk rises to the moderate category Thursday afternoon,
  but at this point it looks like heat index values will stay
  below 100 degrees.

&&

.DISCUSSION...
Issued at 325 AM CDT Wed Jul 9 2025

...Synopsis...

500 mb ridge is located over the Rockies and into southern
Saskatchewan. NW flow aloft presently early this morning and
satellite shows a few mid level CU in a zone from NW into
central ND. 06z NAM3k have a few showers developing in this
zone. Will monitor as we carry a dry fcst thru the morning.
Patchy fog in west central MN, very patchy, but enough risk of
fog to maintain mention past sunrise. Lots of uncertainity in
regards to thunderstorm development, intensity the next 48 hours
ahead of a 500 mb wave that passes thru Friday.

...Severe storm risk this evening...

A few cells forming from the mid level CU west of Minot at 08z.
Will monitor as NAM 3km is the only one to develop these showers
and developing them southeastward along a mid level CU early
this morning. Otherwise looking at a mainly sunny day today
with winds becoming more south- southeast and increasing to
15-20 kts sustained in E ND this aftn. Lower winds farther east
into MN. An area of 70+ dew pts will advect north thru central
ND into western Manitoba this aftn. Sfc CAPE well over 3000 j/kg
develops in that narrow zone as sfc temps reach around 90 or
higher. One would think just looking at instability, severe
storms would develop in the instability axis in far western MB
into ND. CAMs are having a tough time doing so though as forcing
appears weak and may not be able to break a cap, though the cap
seems rather small. Soundings in SW MB via HRRR shows MUCAPE
near 4000 j/kg and -25 j/kg cin. So given any forcing cap would
be broken. But models do want to keep main 500 mb short wave
activity more south across southwest ND into SD and another
short wave farther north closer to main 500 mb low in NW
Manitoba. Will have to watch but at this time areas favored for
convection late aftn/eve is southwest or south central SD into
parts of northern SD and well north of the border by Flin Flon
MB. Any storms that fire in the 22-03z period could be severe.
There is an area of 20-25 kt 0-6 bulk shear also in SW MB and
north central ND that doesnt aid in development. It does appear
though 850 mb warm advection, moist advection with a southwest
850 mb jet of 35 kts will likely be the cause for elevated
convection development in central or eastern ND late evening and
pushing east into MN late tonight. 850 mb jet not terribly
strong, so uncertain of severe chances overnight with this.

...Severe storm risk Thursday...

Some AM showers or t-storms possible in areas east of the Red
River valley to start Thursday, but otherwise dry until mid
aftn. 500 mb heights remain high over the area as trough is
positively tilted from central MB into southern Saskatchewan.
Instability will be there....3500 to 4500 j/kg but lack of
short wave aloft and and still limited shear may aid in
slowering convective development or less coverage of storms than
would otherwise be. There is a weak wind shift that does exist
east of the main cold front back closer to 500 mb trough that
will lie from about Portage La Prairie MB to Bismarck at 00z
Fri. Convection shoud fire along this and as a better chance for
reaching to severe levels. Activity will progress east Thu
evening but 850 mb jet is quite weak 20 kts so how long it can
maintain severe level is uncertain. But does make sense to have
some higher pops along this boundary Thu night.

500 mb trough moves thru Friday aftn with a chance for showers
and t-storms. Severe weather is not anticipated. Then drier this
weekend, before a 500 mb wave moves thru southern Canada early
next week, with precip chances focusing on Mon night or Tuesday.

...Heat Thursday...

Temps will rise to around 90 or low 90s within the RRV Thursday
aftn combined with dew pts at least low 70s...no doubt some
AWOS`s near crops will see much higher dew pts. Thus a period of
heat indices 95-100 develop in the valley with WBGT values into
the low 80s. For heat headlines, not quite there as think period
of HI 100 or higher relatively short period, But will continue
to message this in our DSS emails to partners.


&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1130 PM CDT Tue Jul 8 2025

VFR conditions should prevail across eastern ND and northwest
MN through the TAF period for most locations, with a low chance
for radiational fog development 09-14Z Wednesday morning where
IFR (or less) visibility may occur. There has been a bit more
consistency on potential fog development over southeast ND to
the west and south of KFAR, but even then the guidance has
tended to be spotty in impacts. There are also still areas high
level smoke aloft over parts of the region. Winds increase
after sunrise Wednesday with southerly winds gusting 20kt+
mainly in eastern ND during the afternoon. CU should begin to
increase (6000-10000 ft agl) in coverage towards the end of the
TAF period with increasing chances (20-30%) for thunderstorms
Wednesday evening mainly in ND. Coverage/probability for
thunderstorms are too low at this range for TAF inclusion
Wednesday evening.

&&

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

&&

$$

DISCUSSION...Riddle
AVIATION...DJR