Area Forecast Discussion
Issued by NWS Duluth, MN
FXUS63 KDLH 240551
Area Forecast Discussion
National Weather Service Duluth MN
1251 AM CDT SUN JUL 24 2016
Issued at 1100 PM CDT Sat Jul 23 2016
Overall, only a few showers and isolated thunderstorms were over
the Northland as of 04Z. However, stronger thunderstorms were
occurring just west of our CWA and ahead of the frontal boundary
over the Red River Valley. We expect showers and storms to
continue along and ahead of the frontal boundary as it moves east.
Storms may also develop out ahead of the front in an area of WAA.
The severe threat is low but an isolated severe storm will be
possible into the early morning hours mainly south of highway 2.
We did trim back on the Flash Flood Watch earlier this evening
cancelling northwest Wisconsin into far east central/northeast
Minnesota. Although the risk is not all that high under the
current watch, we kept it going as the storms just off to the west
will be capable of some heavy rain, but generally less than 2" as
they are moving at a decent clip.
UPDATE Issued at 648 PM CDT Sat Jul 23 2016
Convection continues to struggle to get going this evening. There
was an area of light rain moving through portions of northwest
Wisconsin and scattered showers and storms from north central
Minnesota back into eastern North Dakota along the frontal
boundary. CAPE continues to increase over the western half of
Minnesota with 3 hourly increase of 500-1000 J/KG. Visible imagery
showed an expanding area of stratocu indicative of increasing
moisture/lift. The models were not doing a real good job this
evening depicting the state of convection through 23Z, although
the latest runs of the HRRR seem to be doing better. The best
surface convergence was occurring in the Red River Valley just
ahead of the cold front and we expect the best chance for strong
to severe storms to occur over the western half/third of the CWA
between about 02Z and 07Z. The threat for flash flooding has
diminished and we may be able to cancel portions of the watch
early. Area VWPs showed veering 925-850MB across most of the
region with speeds of 15 to 25 knots. Due to the limited
instability over northwest Wisconsin, it may be tough to get
stronger storms capable of heavy rain to occur there. We will
continue to monitor how convection develops through 01Z or 02Z
before making any adjustments to the watch.
.SHORT TERM...(This evening through Sunday)
Issued at 316 PM CDT Sat Jul 23 2016
At 330 PM, it was relatively quiet across the Northland. Earlier
convection that was moving rapidly northeastward has started to
move more eastward into northwestern Wisconsin and EC Minnesota.
Other thunderstorms were developing just west of the CWA.
Temperatures were generally in the 70s across the CWA, kept cooler
by abundant cloud cover and advancing precipitation.
The big focus for tonight will be the threat of severe storms, as
well as the potential for flash flooding. The CAM solutions are
pretty much all over the place, as has been the case for many of
the big events this summer. So we will need to focus more on the
surface and upper level forcing features. Things were starting to
destabilize across NW and WC MN, with extreme instability now over
southwest Minnesota. Our CWA has been pretty worked over, so
storms will likely need to develop west of here, and move
eastward into our area.
High precipitable water, on the order of 2.2 inches, was poised
just south of our CWA, but it was less than an inch across the
Arrowhead. PWAT was also building across the eastern Dakotas,
reaching 1.8 inches west of the Minnesota border. SPC continues to
call for an Enhanced Risk of severe storms late this afternoon and
tonight, across central MN and portions of northwest Wisconsin
based on the potential for development in the area of heating just
west and southwest of the CWA. Still some opportunity for storms
to develop and move into the area tonight. Have also continued the
Flash Flood Watch for the southern half of the CWA based on the
.LONG TERM...(Sunday through Saturday)
Issued at 316 PM CDT Sat Jul 23 2016
The Northland can expect another seasonably warm week with highs
generally in the upper 70s and lower 80s. Drier weather will keep
showers and storms primarily at bay for the early part of the week,
but more humid weather (and accompanying chances of showers and
storms) will return for the middle of the week.
The Northland will find itself Sunday in the wake of tonight`s cold
front, with warm, but drier, gusty westerly flow through the day.
The well mixed model soundings support gusts of 20 to 25 mph. A
passing upper level trough will provide the synoptic lift to develop
widespread scattered/broken cumulus, as well as scattered showers
and isolated weak storms across Northern Minnesota.
High pressure will shift from the Northern Plains to the Upper
Midwest Sunday night and Monday, leading to clearing skies across
the Northland. Quasi-zonal flow will begin to set up Monday night
and Tuesday in the wake of the passing surface high pressure. The
models are not in good agreement, but shortwaves could pass through
or near the Northland through the middle of the week, maybe even the
through the rest of the week, and could be the catalyst to fire off
showers and storms.
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1251 AM CDT Sun Jul 24 2016
A frontal boundary in far western Minnesota will continue east
overnight with showers and storms occurring along and ahead of it.
Plenty of moisture and lift has led to MVFR and some IFR ceilings
over portions of the Northland and that will continue until
frontal passage. Gusty westerly winds will develop late tonight
into Sunday morning as the front passes and will cause the lower
ceilings to lift. However...an upper trough will be over northern
Minnesota through the day and will lead to some additional
cumulus development through the day. The best chance for ceilings
will be over northern Minnesota with heights in the low VFR to
MVFR range, rising through the afternoon. A few showers or storms
may also occur over far northern Minnesota in the afternoon and
early evening hours.
.PRELIMINARY POINT TEMPS/POPS...
DLH 61 81 60 82 / 60 10 0 0
INL 61 74 57 81 / 50 30 30 0
BRD 64 82 61 85 / 70 0 0 0
HYR 65 83 60 82 / 50 10 0 0
ASX 64 83 62 82 / 70 10 0 0
MN...Flash Flood Watch until 7 AM CDT this morning for MNZ025-026-