Lisbon, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

845
FXUS63 KFGF 042000
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
300 PM CDT Mon May 4 2026

.KEY MESSAGES...

- Widespread showers this afternoon with mostly rain and
  occasionally graupel.

- Cooler to start the week with highs in the 40s and 50s before
  60s and 70s return Thursday onwards.

&&

.DISCUSSION...
Issued at 300 PM CDT Mon May 4 2026

...Synopsis...

Two main distinct features are present across North America
this afternoon with an upper low in western Ontario and a low
off the Baja coast with split jet flow in between. As the Baja
low comes ashore the subtropical jet becomes dominant and the
upper low in Canada is finally picked up and ejected east allow
for deamplified NW flow to return to our region. This also will
bring a downsloping airmass to the the northern plains for the
later half of the week with increasing high temps and a drier
airmass increasing the fire weather potential. Within the NW
will likley be a few subtle shortwaves but nothing noteworthy in
terms of precipitation chances.

Lapse rate driven strato-cu are leading to high probability low
qpf showers this afternoon with moderate spacing keeping the
coverage aspect on the lower side. Continuing with the 20-35%
pops this evening with a little graupel even mixing in on the
leading edge of the last shower that passed over the office. QPF
staying under 0.10" this afternoon with coverage dissipating by
midnight. Cant rule out some more shower activity tomorrow.

Additional chances for critical fire weather conditions arise
later this week. Persistent northwesterly flow continues to
contribute to downsloping and dry airmasses over our region, so
days with increasing temperatures will bring an increased risk
for critical fire conditions. The main question marks will be
wind speeds which do appear likely to meet thresholds of concern
for fire late next week with fuel status also remaining
critical. ERC percentiles are still largely high though HRB is
beginning to respond to green-up so fire spread may become
inhibited. At this time, Thursday and Friday appear to have the
greatest likelihood for critical fire weather conditions.

With ongoing green up across the region we will be planning to
start up Frost/Freeze headlines this coming weekend. Obviously
still high uncertainty with respect to exact temperatures come
this weekend along with winds but current conditions do support
at least a threat that will have to be monitored despite highs
in the 50s and 60s by the weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1217 PM CDT Mon May 4 2026

Patchy MVFR as afternoon strato-CU continually develop and drift
SE. Have seen occasional cigs as low as 2000-2500 but most are
3500+ leading to mostly VFR. These should only increase with
sustained cold air advection and increasing BL depth. Winds
gusting near 30kts but only occasionally over 30kts with the
window for any gusts over 30kts really through about 21z or so.
otherwise NW at 20kts gusting 25-28kts this afternoon. Winds die
off tonight before increasing around 15z tomorrow. Scattered
showers as well this afternoon but confidence in near zero in
timing/placement therefore went with VCSH for all sites. Would
have gone prob30 but coverage is only about 20% of the area thus
not quite high enough to do that. Just know there is a 90+ %
chance of seeing a shower at some point in the next 8 hours.

&&

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

&&

$$

DISCUSSION...TT
AVIATION...TT