Area Forecast Discussion
Issued by NWS Duluth, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
FXUS63 KDLH 221647 AAA

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
1147 AM CDT Sun May 22 2022

Issued at 1146 AM CDT Sun May 22 2022

Showers are percolating over the Northland again today. Have
raised PoPs through this evening for the areas most likely to see
showers. Cold air advection aloft continued over northwest
Wisconsin and western Lake Superior with warm air advection nosing
into north-central Minnesota. A subtle 850 mb ridge axis over the
eastern Dakotas into northwest Minnesota will gradually pivot
farther eastward this afternoon. Think that ridge axis will be the
main cutoff for showers versus sprinkles. Convection has been
slow to develop near Lake of the Woods, adjacent areas of
northwest Ontario, and southeast Manitoba. The influence of the
ridge and warm air advection aloft are the likely culprits. With
widespread cloud cover, the boundary layer will deepen gradually
today and diurnal heating will be tempered. Have lowered hourly
and max temps through this afternoon and raised dewpoints.
Yesterday`s showers yielded a few hundredths of an inch up to
around two-tenths of an inch of precip, so have added a few
hundredths to our precip forecast through this evening.


.DISCUSSION...(Today through Saturday)
Issued at 501 AM CDT Sun May 22 2022

Summary: frosty conditions are expected once again Sunday night into
Monday morning. Otherwise, quiet conditions are expected to
continue across the Northland through Tuesday night. Our next
chances of widespread precipitation is progged to return on
Wednesday, lasting into Thursday. Northwest Wisconsin appears to
be the most likely location for the heaviest rainfall amounts.

Cool and cloudy conditions will continue this morning, with some
patchy frost in some areas, particularly over the northern portions
of our region. Similar to yesterday, a diurnally-driven layer of
stratocumulus clouds are expected to develop, along with some low
chances of rain showers or sprinkles. Rainfall accumulations should
be very light, if any, thanks to very dry air in the boundary layer
progged by the RAP, NAM, and GFS model soundings. A well-defined
inverted-V sounding should support some virga as most of the rain
droplets that develop in the atmosphere will evaporate before
reaching the surface, so no impacts will be felt from this rainfall.
A large area of high pressure will slide to our south, leading to
generally light winds across the Northland. As we go into
tonight/Monday morning, another bout of frosty conditions are
expected, thanks to enhanced radiational cooling under clear skies
and light winds. Another Frost Advisory is likely, so be sure to
keep those outdoor plants protected!

More of the same is expected on Monday and Tuesday, with some
diurnal cumulus clouds expected and dry conditions. Then, the
weather pattern becomes more active for Wednesday into Thursday as
an area of low pressure forms over the southern Great Plains region
and approaches the Northland. This surface low will have plenty of
large-scale support as a longwave trough deepens across the
Intermountain West region. Moisture transport will help Pwat values
increase to around 1 inch, per the 22.00z GFS and NAM models.
Although the forcing for ascent will be pretty decent across our
region, instability will be very slim, if any, as we will be under
the inverted trough on the northern end of the low, so rain showers
will likely be common. Even most-unstable CAPE values are progged
very low, so thunderstorms are not expected.

For Thursday through next Sunday, the global models diverge a bit
regarding precipitation chances, but there is another chance for
showers and thunderstorms next weekend. Again, timing and spatial
coverage remains uncertain. Temperatures should gradually warm up
into next weekend, with more seasonal temperatures for Friday
through Sunday (normal highs are in the middle to upper 60s).
Temperatures will be cooler by Lake Superior on Wednesday due to
northeasterly on-shore flow, with highs in the lower to middle 50s,
with lower to middle 60s farther inland.


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 651 AM CDT Sun May 22 2022

VFR conditions are expected to continue through the TAF period.
Partly to mostly cloudy skies are expected to continue today as a stratus
deck lingers overhead. Some stratocumulus clouds will become more
likely during the late morning/afternoon hours, which will
support some low chances of a rain shower this afternoon. Very dry
air near the surface should inhibit most of the rain droplets
from reaching the ground, so we have used VCSH to highlight the
most likely timing of the showers. Eventually, the clouds are
expected to dissipate this evening and overnight tonight.
Northwest winds will remain through the early evening hours,
generally around 5 to 10 knots. Winds will lighten up this
evening, becoming more southerly.


Issued at 501 AM CDT Sun May 22 2022

No hazardous marine conditions are expected over the next 48 hours,
thanks to an area of high pressure that will remain in control
through the day Tuesday. Winds today will be west to southwest as
the aforementioned high pressure system remains to our south, with
winds around 5 to 10 knots for most locations, with some winds 10 to
15 knots over portions of the North Shore. Winds will turn more
south to southeasterly during the day Monday, but should remain
around 5 to 10 knots. Wave heights will remain 2 feet or less for
most locations through Tuesday, although some 2 to 3 foot waves will
be possible along the North Shore this afternoon and evening.


DLH  56  36  61  44 /  70  40  10   0
INL  57  31  63  43 /  40  10  10  10
BRD  58  37  63  45 /  30  10   0  10
HYR  57  33  62  41 /  70  50  10  10
ASX  57  33  62  43 /  70  20   0   0




MARINE...JTS is the U.S. government's official web portal to all federal, state and local government web resources and services.