151
FXUS63 KFGF 181932
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
232 PM CDT Thu Jul 18 2024

.KEY MESSAGES...

- Daily shower and thunderstorm chances through the period. No
severe weather is anticipated.

&&

.DISCUSSION...
Issued at 230 PM CDT Thu Jul 18 2024

...Synopsis...

Upper level pattern over the northern plains is north to
northwesterly flow as a ridge out in the western United States
continues to amplify. Out of the northerly to northwesterly flow
comes chances for showers, thunderstorms, and potential upper level
smoke. Canadian wild fires up in the Northwestern Territories,
Yukon, and Alberta continue to push wildfire smoke into the upper
level flow. RAP/HRRR guidance has the smoke pushing along the flow
into the northern plains later this evening and into the overnight
hours. This trend continues into the weekend. Current satellite has
smoke pushing through portions of eastern North Dakota and southern
Manitoba. Areas towards lakes country are seeing continued cumulus
development from the heating of the day.

Out of the north to northwesterly flow we get the introduction of
short waves translating along the flow. This brings chances for
precipitation almost on a daily basis. Confidence is low on the
breakdown of the north to northwesterly flow from the ridge out
west, with clusters indicating two potential scenarios. 50% of
clusters have our continued pattern through the majority of next
week, with the second scenario (50% chance) we see the ridge shift
further eastward bringing drier/warmer conditions. A strong upper
level wave in the Gulf of Alaska would be needed to have the second
scenario occur. None the less temperatures will be warmer this
weekend and into next week with the low to mid 80s expected.

...Daily shower and thunderstorm chances...

Daily chances for shower and isolated thunderstorms during the
weekend and into early next week. During daytime heating hours,
instability increase and weak synoptic forcing would allow for
isolated thunderstorms and showers to develop within the forecast
region. With shear and instability being weaker, we don`t anticipate
severe weather at this time. However, a few storms could be on the
stronger side producing frequent lightning, brief gusty winds, and
small hail. This is justified by atmospheric soundings where we have
weak instability, weak forcing in the hail growth zone, with a layer
of drier air in the mid to upper levels. This would limit the growth
of the thunderstorms and supply only quick updrafts leading to small
hail, brief gusty winds, and frequent lightning. The best chances
for these isolated thunderstorms would be over the weekend, with
confidence being lower as we start the new work week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1227 PM CDT Thu Jul 18 2024

VFR conditions through the TAF period, with brief MVFR ceilings
possible. Cumulus has continued to increase east of the Red
River Valley and has the potential to reach GFK, FAR, and TVF
this afternoon and evening. Ceilings are VFR, but may drop
briefly to MVFR at times. BJI will be under the cloud deck
through sunset. Otherwise, there is a slight chance for shower
and an isolated thunderstorm for eastern North Dakota end of the
TAF period, but confidence is on the low.

&&

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

&&

$$

DISCUSSION...Spender
AVIATION...Spender