mn discuss
Office: MPX
FXUS63 KMPX 021138
AFDMPX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
638 AM CDT Thu May 2 2024
.KEY MESSAGES...
- Widespread rain returns to the today. Most areas will see a quarter
to half inch of rainfall, though amounts closer to an inch
are possible across SE MN and W WI.
- Unsettled weather pattern brings additional rain chances this
weekend and early next week.
&&
.DISCUSSION...
Issued at 300 AM CDT Thu May 2 2024
Hopefully folks got a chance to get some fresh air during the mild
and sunny Wednesday afternoon, as today's weather will take a full
turn in the other direction. No major changes were made to the going
forecast, as widespread rain is on track to arrive this morning,
resulting in a cool, breezy, and soggy Thursday. We've knocked highs
down into the low to mid 50s given the expected conditions. The 2 AM
view from the KMPX 88D depicts scattered echoes across much of south
central Minnesota and western Wisconsin. The majority of this early
morning activity is not reaching the surface, given notable low-
level dry air sampled on the 00z MPX RAOB. Latest ACARS data from
MSP Airport reveals that the dry layer is still very much present
over the TC metro, such that it will be another couple of hours
before the atmosphere saturates and raindrops begin to reach the
surface. Observations reflect this idea in west/southwest MN, as a
few hundredths of QPF have been reported thus far. Regional radar
depicts a well defined, expansive precipitation shield lifting to
the north through Iowa at this hour. The shield of rain has
developed ahead of an northward surging warm front, within a region
of broad ascent east of an upper level trough. The combination of
synoptic scale lift and moisture advection into the region will
ultimately be the key players for rain to win out across much of the
area through the morning and start of the afternoon. At the surface,
low pressure is forecast to track from central Iowa towards western
Wisconsin through the course of the day. This storm track will mean
two things for the local forecast: First, thunderstorm chances will
be on the lower side for much of the area, since we'll be on the
"cooler" side of the storm system. We can't rule out isolated
thunderstorms in far southern Minnesota and portions of western
Wisconsin, given the potential for a couple hundred joules of MLCAPE
and a plume of steeper lapse rates (7-7.5 C/km) forecast to slide
through this afternoon. Second, the track of the low will mean that
the heaviest rainfall will setup along and southeast of a line from
Fairmont, MN - SE Twin Cities Metro - Barron, WI. In terms of
rainfall amounts, most areas are forecast to observe between a
quarter to half inch, with lower amounts in western Minnesota and
the chance for higher amounts (~1.00"+) along and southeast of the
line mentioned above (due to chance for thunderstorms in this
area). Once the widespread rain ends, we'll likely have patchy
fog and pockets of drizzle linger for a couple of hours given
saturation in the lower levels captured on forecast soundings.
The upper-level system will lift into southern Canada Friday, which
which will promote broad southwesterly flow into the Upper Midwest.
Though it will be breezy at times, the sunny skies and highs in the
60s to low 70s should make for a nice outdoor day. A quick moving
shortwave will lift through the region early Saturday, which will
bring scattered shower chances for the start of the weekend. This
will not be the same sort of "widespread soaking rain" that is
expected today (and that we've seen a few times lately!), rather a
few hundredths to a tenth or so of QPF is expected for the first
half of the day. Dry weather will return from Saturday afternoon
through the end of the weekend, which will set the stage for great
outdoor weather on Sunday, as highs climb back towards 70 degrees
under mostly sunny skies.
Believe it or not, our recent weather rollercoaster takes yet
another dip early next week, as more widespread rainfall is
expected. An upper trough is forecast to become negatively tilted as
it digs into the western CONUS Sunday into Monday. Large scale warm
advection will increase across the Great Plains in response and it's
likely that temperatures will surge into the mid, perhaps upper 70s
locally on Monday afternoon. The warmth will precede the return of
likely chances for rain and thunderstorms. The period of greatest
potential for rain/stormy activity appears to be later Monday into
early Tuesday morning, ahead of a cold front. While a plume of steep
lapse rates & favorable dynamics will work together to produce the
chance for thunderstorms, the amount of instability will be a key
player in the overall potential for severe weather. Nonetheless,
it's appearing likely that another round of soaking rain will move
through the region early next week.
The forecast tends to vary a bit more in the extended period given
differences in how models are resolving the progression of the upper-
level low across the northern CONUS through the middle to end of
next week. Given the uncertainty, slight chance to chance PoPs from
the NBM seem reasonable for the middle to end of next week.
&&
.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 627 AM CDT Thu May 2 2024
An area of rain is advancing northward across Minnesota and
western Wisconsin this morning. The rain is dropping
visibilities, but ceilings remain VFR. Based on current and
upstream obs, decided to bump up ceilings throughout the day
overall, despite guidance saying everything should be IFR later
this morning. Still expecting ceilings to lower a bit through
this morning and into the afternoon with lingering drizzle
through much of the day. Winds will become southwesterly this
evening with VFR conditions returning by the end of the period.
KMSP...As mentioned above, removed IFR conditions for late this
morning/early this afternoon. Heaviest rain is expected now
through 15z. Left out any thunder mention as it seems to be
confined to far southern Minnesota. Southwesterly winds 5-10kts
are expected from this evening through the end of the period.
/OUTLOOK FOR KMSP/
FRI...VFR. Wind W at 15G25kts.
SAT...MVFR/-RA. Wind NW at 10G15kts.
SUN...VFR. Wind S at 5-10kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Strus
AVIATION...Dye
Office: DLH
FXUS63 KDLH 021131
AFDDLH
Area Forecast Discussion
National Weather Service Duluth MN
631 AM CDT Thu May 2 2024
.KEY MESSAGES...
- Another round of precipitation to affect the area today and
tonight with total QPF amounts of between 0.2" and 0.5"
- Saturday to be cool and showery followed by warmer and drier
conditions for Sunday.
- Active pattern returns to our region beginning early next week
and continuing through much of the work week with multiple
chances for precipitation
&&
.DISCUSSION...
Issued at 427 AM CDT Thu May 2 2024
Our next wave of precipitation is approaching the Northland
this morning as a surface low over southeast Nebraska moves
across Iowa into southern Wisconsin by this evening, then
continuing to the northeast and weakening. There is a secondary
low that develops over North Dakota today, and as the first
feature weakens, strengthens and moves slowly northeast tonight
and Friday. There is also a strong upper level shortwave that
pushes out of Wyoming today and moves northeast across Minnesota
tonight. This will produce a healthy round of rainfall that
pushes across the forecast area today and tonight, with
lingering showers into Friday. The current radar imagery shows
the main band of rainfall associated with the southern surface
low now moving across southern Minnesota, with a second area
over North Dakota, with the developing low. These areas bot will
spread northeast across the forecast area today and tonight,
with a high probability (>90%) of bringing at least a tenth of
an inch to a large portion of the area. However, only parts of
northwest Wisconsin have a 50 percent chance of getting a half
inch of rainfall by Friday morning. These higher rainfall
probabilities are associated with some elevated instability that
may produce some rumbles of embedded thunder this evening
there. We are also in a general thunder category in the SPC day
1 outlook, and northwest Wisconsin is in a marginal risk of
excessive rainfall. It will be a chilly, blustery day with highs
down in the mid 40s to mid 50s, with the coolest conditions
around Lake Superior. We will have wrap-around shower activity
along the US/Canada border on Friday, along with a weak mid
level baroclinic zone that slides through the area and may bring
another period of light rainfall into the area on Friday night
into Saturday. Rainfall amounts with this system will be
considerably lighter with much less potential for convective
elements that could increase rainfall amounts. Friday will be
warmer than today with southwest winds instead of the easterlies
we expect today, and high temperatures should get into the 60s
for a large portion of the area. Saturday to have slightly
cooler temperatures. Sunday to be warmer and drier with highs
rising into the 60s nearly everywhere, with west to southwest
winds.
Early next week it appears we will have another fairly potent
spring storm system that moves across the central CONUS for much
of the upcoming work week. The operational models are keeping
Monday daytime mostly dry, though the ensembles are showing some
faster members that push precipitation in here earlier, so we
have some low confidence pops in for Monday. The large cut off
low associated with this system spins over the northern Plains
for the early part of the week, but the evolution after that is
rather unclear at this point, but we are carrying pops for much
of the Monday through Thursday time frame. Temperatures should
be on the warmer side for Monday and Tuesday, but then cool off
later in the week.
&&
.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 630 AM CDT Thu May 2 2024
An approaching low pressure system will cause the current VFR
conditions to deteriorate this morning. Rain spreading in from
the south will cause ceilings and visibilities to be reduced to
MVFR initially for most locations, with further lowering
expected later in the day to IFR or even LIFR, mainly for
ceilings. KDLH to get the lowest conditions, with LIFR
visibilities and ceilings. The lowest conditions are expected in
the 23z - 05z time frame. Improvement is expected after 05z as
the rain lifts out of the area to the north, causing improving
conditions from south to north overnight.
&&
.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 630 AM CDT Thu May 2 2024
Northeast winds to gradually increase this morning, with gusts
of over 20kts beginning later this morning and continuing into
the evening before diminishing once again overnight. As this
will create conditions hazardous to small craft, have issued a
Small Craft Advisory for the southwest arm, North Shore and
around the Apostle Islands for late morning through early
evening. A trough axis moving across the area will cause these
northeast winds to switch to southwest overnight tonight and
early Friday as well. On Friday these southwest winds will ramp
up again from mid morning until late afternoon, perhaps causing
another period of hazardous conditions for small craft. Once the
winds decrease on Friday evening, winds will remain less than
15 knots Friday night and Saturday.
For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 4 AM CDT
Friday for LSZ140>142-147-150.
Small Craft Advisory from 10 AM this morning to 4 AM CDT
Friday for LSZ143>146.
&&
$$
DISCUSSION...LE
AVIATION...LE
MARINE...LE
