Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Duluth Minnesota
903 am CDT Friday Jul 25 2014
issued at 903 am CDT Friday Jul 25 2014
The early morning showers have exited the area. Just a few
sprinkles remain. However...with the unstable airmass and cold
front in eastern ND...waa/isentropic lift ahead of said
front...showers or isolated thunderstorms may pop at any time. Have
adjusted probability of precipitation for these latest trends.
Update issued at 736 am CDT Friday Jul 25 2014
Updated to refine probability of precipitation and remove pre-first period based on
current precipitation area. The showers and thunderstorms should move
south out of the forecast area by 15z. Rest of forecast unchanged.
Update issued at 430 am CDT Friday Jul 25 2014
Updated to increase probability of precipitation across portions of the forecast area. Area
of showers and thunderstorms moving across those areas this
morning. This precipitation will end by mid-morning. Rest of forecast unchanged.
Short term...(today and tonight)
issued at 242 am CDT Friday Jul 25 2014
Short term concern is precipitation chance today and tonight.
Current surface analysis indicates rain showers north of the Iron
Range and in The Arrowhead. These showers are associated with a weak
shortwave moving through the area. They will continue move
southeast and slowly dissipate early this morning. There is an
area of thunderstorms along the ND/SD/wrn Minnesota border moving east-southeast.
The area has decreased in intensity over the past hour. The
northern edge of the precipitation may clip Cass and Crow Wing
counties this morning. A weak surface trough will move through Minnesota
today and northwest WI tonight. It will bring another round of showers
and thunderstorms. There will be some increased instability with
the trough this afternoon and evening. MUCAPES are
1500-2000...shear is 20-40...and some sun today. Storm Prediction Center has the
forecast area in a 5% probability for wind/hail with the marginal
An area of weak high pressure will build into the region from the
west late this evening. This will end the threat for precipitation
for late Friday night and Saturday. However..by the afternoon...an
area of low pressure along with a upper trough will move into
western Minnesota and will effect the region Saturday night.
Long term...(saturday night through thursday)
issued at 242 am CDT Friday Jul 25 2014
The models are in pretty good agreement through much of the
period. An upper trough over southern Manitoba Saturday evening
will drop into northern Minnesota by 12z sun...then continue into
southern Wisconsin by Sunday evening. A surface low/trough axis
will be associated with this upper wave. Showers and a few
thunderstorms will increase in coverage Saturday night into Sunday
morning...then decrease from north to south Sunday
afternoon/evening. Sunday night should be dry. We have the highest
probability of precipitation over the eastern portion of the Northland late Saturday night
into Sunday morning.
High pressure will then lead to mainly dry conditions Sunday night
into Monday night. There may be a few showers Tuesday into Wednesday
over the eastern half of the Northland with a series of shortwaves
moving through in the northerly flow aloft. We also have a small
chance for showers/storms Thursday for most areas.
The period will start out with below normal temperatures
Sunday...with highs in the middle sixties to lower seventies.
Temperatures will then moderate through the rest of the
period...reaching the upper seventies to lower eighties by Thursday.
Aviation...(for the 12z tafs through 12z Saturday morning)
issued at 632 am CDT Friday Jul 25 2014
Showers and a few thunderstorms were moving through
central/eastern portions of the Northland early this morning. We
expect a lull in coverage to develop this morning...then
additional development this afternoon ahead of the surface
boundary that will only move slowly from western Minnesota early
this afternoon toward the east.
An area of MVFR/IFR ceilings have developed over west central
Minnesota into central Minnesota. The rap is suggests these
ceilings will spread north and east today. However...the coverage
currently is not as great as the rap suggests. We feel most
confident kbrd will see the lower ceilings and added a tempo group
for the rest of the taf sites by middle to late morning.
The coverage of the precipitation will diminish this evening and
some fog will be possible.
Preliminary point temps/pops...
dlh 75 59 82 59 / 50 30 50 50
inl 76 57 81 56 / 40 50 50 60
brd 80 58 84 60 / 40 10 30 40
hyr 76 62 85 58 / 50 30 30 50
asx 77 61 81 57 / 30 40 40 50