580
FXUS63 KFGF 190900
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
400 AM CDT Sun Jul 19 2026

.KEY MESSAGES...

- There is a level 2 out of 5 risk for severe thunderstorms this
  evening. Hail to the size of golf balls and wind gusts to 70
  mph would be the primary threats.

- Near critical fire weather conditions are expected today
  Near critical to critical fire weather conditions may develop
  in these areas Monday and Tuesday.

&&

.UPDATE...
Issued at 354 AM CDT Sun Jul 19 2026

As anticipated a few high based showers and isolated t-storm
formed in south central ND into SD. They are slowly moving
southeast as area slides east. It does look like most will miss
our far southwest fcst area. Otherwise question will be what
happens in regards to t-storm development and severe weather
coverage that develops near and ahead of a cold front advancing
east. Timing wise would look like evening/overnight for our
area, but coverage is the big question as latest CAMs indicate
some storms in southern ND and then not much north. Net result
was keeping a broad 30 to 40 pops in the unstable airmass ahead
of the front tonight. DCAPE values in the 1300-1400 range via
soundings from HRRR in E ND would indicate as SPC noted more of
a wind threat from organized outflow ahead of a cluster of
storms.


&&

.DISCUSSION...
Issued at 352 PM CDT Sat Jul 18 2026

...Synopsis...

The upper level ridge remains centered over the central Rockies and
mean axis over the Northern Rockies in Canada. Northwest flow aloft
is in place over our region. There has been enough instability along
weak convergence this afternoon for isolated/widely scattered
thunderstorms in the Lake of the Woods Region of north central MN
(no severe threat and this should end with sunset). A stronger wave
passes through Canada Sunday through Monday, with the associated
cold front bringing a period of seasonably mild temperatures Tuesday.
On Sunday before the front passes high temperatures should increase
into the 90s, with variable Td conditions and cloud cover lowering
confidence in Heat Advisory impacts (Heat indices generally around
95 or less and Wet Bulb Globe temps generally in the High category
instead of Extreme category). The ridge starts to build back into
the region with rising heights and increasing temperatures once
again late next week into the weekend. Other than the system Sunday
night-Monday there isn`t an organized precipitation signal through
the 7 day (only smaller scale features that may bring isolated to
scattered thunderstorms to parts of the region periodically).

...Severe Risk Sunday Evening...

Initially the presence of the mid level ridge axis/thermal ridge
over our CWA should limit initiation with stronger capping locally
until closer to 00Z or even later when the main synoptic ascent/pre-
prefrontal trough moves into our CWA. Better mid level lapse rates
also arrive after 00Z which matches the timing of better instability
ahead of the frontal zone to the west/northwest. As a result better
thunderstorm chances and severe chances early on should be in
western/central ND or in southern Saskatchewan/Manitoba with activity
then spreading east. Early in the event discrete/elevated supercells
would be favored based on shear profiles, however as the deeper
layer shear increases through the evening hours mergers and one or
several linear MCS`s may develop as simulated by CAMs. Thermal
profiles and strong 0-3kt shear and DCAPE 1000+ J/KG support an
increased damaging wind threat (60-70 mph gusts). While QLCS type
features may develop, the bigger threat with mesovortex development
may be localized surges of winds greater than 70mph within the line
normal/surging segments.

There are a number of CAMs that favor earlier initiation in central
ND which would increase the risk for discrete cells entering our
west and an earlier MCS development (transition to wind risk). Other
CAMs favor upstream development more towards Canada moving into our
CWA in the mid to late evening. This matches better with timing of
the main forcing entering our CWA, and lowers the risk for discrete
cells (less of a hail risk and more of a pure wind risk). In
general, there is high variability in location of initiation, track,
and timing of thunderstorm activity, however there is a strong
general signal in environment and potential for MCS development.
Ultimately we will need to monitor the evening hours and possibly
the early overnight hours for severe thunderstorms development.

...Fire Weather...

The isolated/widely scattered storms in our northeast are less
likely to provide wetting rain and may carry a dry thunderstorm risk
before they dissipate early this evening. Fuels in the forested
regions of Lake of the Woods, Beltrami, and Hubbard counties
continue to be areas of concern for fire partners and with less
confidence in wetting rains in those areas will continue to be
locations to monitor into early next week. Today and Sunday RH
values may fall near 40% during the afternoon/early evening periods,
with breezier conditions on Sunday (gusts to 25 mph). Much windier
conditions are expected Monday and Tuesday with the potential for
post frontal wind gusts 30-35 mph in our east (around 40 mph along
and west of the Red River Valley). It is possible that grassier
areas of southeast ND may be drying out enough that near critical or
critical fire weather conditions could develop in those areas if they
remain dry from the Sunday night/Monday thunderstorm activity.
Confidence in lower RH values are lower Monday as cloud cover and
faster frontal arrivals may create a larger spread in potential RH
from the north to the south (60% in the north and 40% ahead of the
front). Tuesday may carry the better chance for 40% or lower RH
depending on how warm temperatures actually get (cloud cover and
cooler airmass).

In any case, near critical fire weather conditions are likely to
continue in north central MN each afternoon/early evening through
Tuesday, and we will continue to monitor for the potential for
critical/RFW conditions over the upcoming windier pattern.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1140 PM CDT Sat Jul 18 2026

VFR throughout the TAF period. Wind overnight will be light and
variable. However, winds will increase again on Sunday, with
gusts by the afternoon. Wind direction will be southerly.
Thunderstorms are forecast Sunday evening. At this time,
predictability in the coverage of storms is low, including which
terminals will be most at risk to see a storm. Therefore, left
out any PROB30s at this time.

&&

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

&&

$$

UPDATE...Riddle
DISCUSSION...DJR
AVIATION...Rafferty