334
FXUS63 KFGF 021808
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
108 PM CDT Thu May 2 2024

.KEY MESSAGES...

- Rain chances continue with multiple rounds of rain through
  next week.

&&

.UPDATE...
Issued at 108 PM CDT Thu May 2 2024

Light to moderate rain continues to work northward this
afternoon. Additional rain chances are expected to persist into
the afternoon and evening hours as the upper low pushes off to
the east. Areas in southeastern North Dakota and west-central
Minnesota will see showers push back into the area this
afternoon. Slightly better forcing is noted this afternoon along
a boundary that could provide an axis for isolated thunderstorms
heading into the late afternoon and early evening.


&&

.DISCUSSION...
Issued at 249 AM CDT Thu May 2 2024

The deep troughing over the western CONUS will continue to slide
northeast into south central Canada this weekend as eastern ridging
slowly fades and flow becomes more zonal this weekend. Stronger
waves will continue to rotate around the parent trough to the north
with a brief break in the rain for the weekend as ridging moves in.
The first round of rain is just starting to move in from the
southwest as a surface low in the central plains interacts with the
upper low to the north northwest bringing broad warm air advection
into the northern plains with a developing surface low eventually
arriving tomorrow afternoon from MT/WY. Expecting the heaviest
accumluations to fall across eastern ND and far northwest MN.
Ensemble guidance is in good agreement with the 25/75 showing 0.50-
1.00" for the area and 0.25-0.50" for the rest of the area.

Steepening lapse rates under the approaching low may result in some
cape up to 500 J/kg allowing for embedded convection tomorrow
locally enhancing totals across parts of eastern ND. With this
convective potential also wouldn`t rule out a few funnels as a sfc
boundary sweeps through an airmass with good low level stretching
potential aligned with strong surface vorticity gradients but the
threat for tornados is low due to cloud cover limiting the potential
for diurnal heating and resulting SBCAPE not exceeding a few 100
j/kg. Main area of concern for any of this activity would be in
southeast ND and the southern Red River Valley but the threat
remains conditional upon afternoon heating occuring.

Ridging will follow the late week rain as cold air advection ahead
of the ridge begins to shut off the rain machine by Friday morning
behind the cold front. A seasonally nice weekend, which feels
deserved after this long stretch of dreary weather, with highs in the
60s and 70s by Sunday.

Widespread rain chances return as southwest flow brings another slow
moving upper low from the four corners region early next week.
Between clusters there is agreement on at least an 80% chance for >
0.25" of rain in a 24 hour period sometime on Monday/Tuesday though
timing and location of this rainfall varies and thus lots of
uncertainty. Upper flow looks to remain weak through the end of next
week potentially giving more prolonged rain chances and near average
temperatures.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1230 PM CDT Thu May 2 2024

MVFR conditions prevail across much of the area this afternoon,
with periods of IFR ceilings possible during light to moderate
rain. Rain continues to lift to the north at midday, with this
trend expected to continue well into the afternoon and early evening
before eventually tapering off late this evening. Low ceilings
are most likely to occur along with rain activity, with current
and upstream obs showing consistent 800 to 1200 foot ceilings.
Outside of heavier rain, Ceilings are generally in the range of
2000 to 4000 feet. Winds are expected to remain out of the
southeast this afternoon, then shift to the southwest and
eventually west during the overnight hours.

&&

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

&&

$$

UPDATE...Lynch
DISCUSSION...TT
AVIATION...Lynch