558
FXUS63 KFGF 041758
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1258 PM CDT Sat May 4 2024

.KEY MESSAGES...

- First chance of the season for organized thunderstorms arrives
  Monday/Tuesday.

&&

.UPDATE...
Issued at 1258 PM CDT Sat May 4 2024

Continue to see isolated to scattered showers across the
northern third of the forecast area. A few reports of pea to
isolated dime size hail with the strongest cells in the far
east/central MN near Beltrami/Hubbard Counties. Soundings
indicate some weak instability aloft with tops just above the
-10 to -20 layer suggesting that potential for small hail to
 continue into with the stronger cells through the afternoon
 hours. Radar tops have shown strongest cells developing to
 around 15-16kft.


PREVIOUS UPDATE
Issued at 1020 AM CDT Sat May 4 2024

Area of showers holding steady translating southeastward across
northeast ND this morning, therefore increased pops in the
northern RRV associated near and south of these showers through
mid-day. Also increased cloud cover some through this morning in
the north, with mostly cloudy conditions across the northern
third. Still expect clouds to become more cellular in nature
this afternoon with isolated to scattered shower development as
the upper wave continued to move east through the region. With
the thicker low clouds and showers this AM, did drop max temps a
few degrees in the north/west for the day. Otherwise overall
forecast remains on track.


PREVIOUS UPDATE
Issued at 559 AM CDT Sat May 4 2024

Some spots around Roseau and Thief River Falls showing some
drops in visibility, but short lived as more stratus has been
moving in and web cams do not show any widespread fog problems.
Put in some patchy fog mention and adjusted cloud cover a bit,
but otherwise a pretty quiet morning with only a few rain
showers expected.

&&

.DISCUSSION...
Issued at 321 AM CDT Sat May 4 2024

Shortwave trough rotating around the bottom of the Hudson Bay
low through ND will swing further east into MN, bringing some
scattered rain showers mostly to our northern counties today.
Instability looks lower than yesterday so think our chances for
pea hail and lightning are less. Upper ridging will briefly move
into the region for tomorrow, bringing our break in the active
pattern. Sunday should see increasing southeasterly winds as a
surface low develops to our west, along with sunshine and
temperatures climbing into the 60s.

The ridge will be short lived as a strong negatively tilted
trough starts to move into the Plains on Monday. The main upper
low will be over eastern MT/western ND into Tuesday, but there
is good agreement in the ensemble members in the lead shortwave
ejecting out Monday night. While timing is less than ideal for
severe convection over our CWA as there will be very little
instability to work with as the main forcing comes out, CIPS
analogs do show some isolated severe reports possible as far
north as our southern counties in these type of patterns.
Ensemble means have instability improving a little bit to around
500 J/kg by Tuesday afternoon, although deep layer bulk shear
goes down. Confidence is not high enough to start messaging
severe at this point, but could see some organized storms early
next week, and we will definitely see more rainfall with the wet
signal in the R and M climate continuing.

Predictability goes downhill for the end of the week with models
struggling with how to handle the exiting of the upper low off
to the east. Most show some sort of split flow at least in the
short term, with cool and wet pattern continuing.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1258 PM CDT Sat May 4 2024

Isolated to scattered showers across the northern/eastern sites
this afternoon. CIGS in the MVFR range and expect to lift to low
VFR through the afternoon before clearing this evening
especially in the west/southern TAF sites. CIGS could hold a bit
longer in the east/north into the evening. Winds to be northwest
to north, then light and variable overnight shifting to the
south for Sunday with mainly clear skies. Any showers to
dissipate by early evening with sunset.

&&

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

&&

$$

UPDATE...MJB/JR
DISCUSSION...JR
AVIATION...MJB/JR