357
FXUS63 KFGF 071448
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
948 AM CDT Sun Jul 7 2024

.KEY MESSAGES...

- Scattered thunderstorms today into this evening. Main hazard
  is lightning along with brief very heavy rainfall rates.

- Warming up late week with highs Friday-Saturday in the upper
  80s to lower 90s.

&&

.UPDATE...
Issued at 948 AM CDT Sun Jul 7 2024

Tweaked POPs for current trends as showers continue to rotate
around the upper low in central MN. Should still see some
additional activity later this afternoon as we destabilize, but
again not much shear to work with. Main threat still look to be
lightning and brief heavy rain.

&&

.DISCUSSION...
Issued at 327 AM CDT Sun Jul 7 2024

...Synopsis...
500 mb low at 08z near Fargo and it will be near Duluth by late
this afternoon. This will continue the broad area of convection
into this evening, most numerous coverage in the afternoon.

Lingering weak 500 mb troughiness to continue Monday and Tuesday
giving isolated afternoon thunderstorms.

We will transition to a drier pattern mid to late week as 500
mb ridging that is building into Alberta moves east into the
northern Plains.

...Today...

Continued scattered convection near the 500 mb low and to the
west as 500 mb temps though not as cool as Saturday still
remain low enough so that MU CAPE in the 1500 j/kg are generated
in North Dakota. Cloud cover and cooler temps at the sfc keep
mean MU CAPE values closer to 1000 j/kg in northern Minnesota.
Brief localized heavy rainfall rates and lightning are the main
hazards. As we have seen cannot rule out a brief funnel cloud,
small hail or wind gusts 30 mph or higher from any storm. NAM12
forecast of non supercell tornado parameter shows some risk of
funnels in eastern ND west of the Red River valley this
afternoon. Funnels did occur in an area west of the upper low in
western ND Saturday so it would make sense that it will be
possible west of the upper low in our area today.

...Late Week Heat...

Continuing past Wednesday the western ridging finally progress far
enough east to build low level thermal ridging over us and push
sfc temps into the 80s. Building southerly 850mb flow Thursday
into next weekend on the eastern periphery of this thermal ridge
will promote increased mixing. This is reflected by the low
spread in NBM maxT through the week with <7 degree spread between the
10th and 90th percentile any given day between now and Friday
at a given point. Area highs climbing from the 70s and 80s today
to upper 80s and even a few low 90s for some by the end of the
week. HeatRisk (found at wpc.ncep.noaa.gov/heatrisk) is already
showing a broad chunk of the area under a moderate risk of
health related impacts for Friday and Saturday due to these warm
temps.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 632 AM CDT Sun Jul 7 2024

VFR conditions predominately throughout the day. An upper level
low is slowly moving east creating scattered showers this
morning and will persist through the evening. Timing these
showers are extremely difficult due the weak forcing created by
the upper level low. Winds are expected to be under 10kts
through this evening.

&&

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

&&

$$

UPDATE...JR
DISCUSSION...Riddle
AVIATION...MM