FXUS63 KDLH 301143
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
643 AM CDT Tue May 30 2023

.DISCUSSION...(Today through Monday)
Issued at 409 AM CDT Tue May 30 2023

Summary: Scattered showers and thunderstorms will increase in 
coverage today. A storm or two this afternoon may become strong to 
severe, with the primary hazard being large hail up to 1" in 
diameter. Additional precip chances continue through the rest of the 
week and into this upcoming weekend with very warm temps. 

WV imagery from GOES this morning reveals a shortwave trough located 
over North Dakota. Downstream of this trough axis, scattered showers 
and thunderstorms have developed across the western half of MN. The 
00z sounding from INL shows a substantial amount of dry air in the 
lower levels and this is reflected in recent model soundings from 
the CAMs. This dry air has been inhibiting precip at the sfc as the 
showers and storms propagate into the CWA early this morning. As 
moisture advection increases later today, these showers are expected 
to increase in areal coverage. Thunderstorms are likely today, 
especially in the afternoon, as diurnal heating and enhanced low-
level moisture increases instability. A few storms this afternoon 
and early evening may become strong to severe, primarily from the 
Brainerd Lakes to the St. Croix River Valley.  

The potential for severe weather this afternoon will largely be 
dependent on how long the storm will be able to maintain cold 
pool separation. The thermodynamic environment today will be very
favorable as moisture advection from the Gulf of Mexico brings 
dewpoint temps in the mid 50s to low 60s. Instability in the CAMs 
has been on the upward trend over the past 24 hours, with the RAP 
showing MLCAPE by late this afternoon reaching 1500-2200 J/kg. 
Despite this increase in instability, the shear environment is 
still expected to be very marginal. 0-6 km bulk shear is only 
forecasted to reach 15-30 knots by the time of peak diurnal 
heating. 

CAMs are reflecting this high instability/low shear environment with 
discrete cells quickly forming and subsequently dissipating later 
today. These short-lived storms will primarily be capable of 
producing sub-severe hail and locally heavy rain. However, given the 
high instability by late afternoon, a storm or two may be capable of 
producing severe hail of 1" in diameter. Gusty winds up to 60 MPH 
may also be possible as DCAPE reaches 400-900 J/kg. However, 
damaging winds will likely be localized to dissipating cells due to 
the disorganized nature of the convection today.   

Following the first round of convection today, the remainder of the 
week will see precipitation chances continue. Additional shots of 
vorticity will enter the CWA accompanied by southerly winds 
continuing to advect moisture into the area. A diurnal trend of high 
instability and weak shear will persist for the remainder of the 
workweek. This will likely lead to scattered showers and 
thunderstorms each afternoon this week. Severe thunderstorms are 
unlikely after today, since the shear environment will become very 
weak with 0-6 km bulk shear of only 10-15 knots.   

500mb height anomalies from the global models suggest that an omega 
block pattern will potentially develop over the central CONUS this 
weekend. This omega block will differ from what we saw last weekend 
as integrated vapor transport shows plentiful moisture advection 
into the CWA. This will keep diurnal showers and thunderstorms in 
the forecast for this weekend. Temps are likely to remain very warm 
this week and into the weekend with highs in the 80s to near 90s. 

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 643 AM CDT Tue May 30 2023

Showers and thunderstorms will increase in areal coverage today as 
daytime heating occurs. Flight category is expected to remain VFR, 
with the exception being MVFR conditions in areas of locally heavy 
rainfall. An isolated strong to severe storm may be possible this 
afternoon and evening, capable of producing large hail up to 1 inch 
in diameter. If strong to severe storms develop, they will most 
likely impact BRD. Winds through the TAF period will be from the 
south, becoming gusty at times late this morning through the 
afternoon. 

&&

.MARINE...
Issued at 409 AM CDT Tue May 30 2023

Light northeast to southeast winds will occur across western Lake 
Superior today with speeds under 15 knots. Gusts in Chequamegon Bay 
and from Oak Point to Saxon Harbor may reach up to 20 knots this 
afternoon. Waves are expected to remain 2 feet or under. 
Thunderstorms will be possible this afternoon through tonight, but 
severe storms over Lake Superior are unlikely. On and off 
thunderstorm chances will persist through the remainder of the week 
with winds remaining at or below 15 knots. 

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  78  56  82  55 /  70  60  50  50 
INL  79  58  84  58 /  70  60  20  20 
BRD  84  59  88  63 /  60  40  50  50 
HYR  85  59  87  62 /  50  50  40  40 
ASX  84  56  85  57 /  40  40  40  40 

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&

$$

DISCUSSION...Unruh
AVIATION...Unruh
MARINE...Unruh