Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 kfgf 201812 
afdfgf

Area forecast discussion
National Weather Service Grand Forks ND
112 PM CDT sun Oct 20 2019

Update...
issued at 101 PM CDT sun Oct 20 2019

High clouds have spread across the majority of the region, in
advance of the approaching Colorado low. Portions of northwest Minnesota
near low and Bemidji have warmed a bit more than anticipated and
can now look to see high temperatures near 60 degrees today. Radar
data shows a few weak returns have reached southeast ND, but mid
level dry air and the weak nature of the mid level warm air
advection will likely prevent rain from reaching the ground until
at least late this afternoon.

Update issued at 1006 am CDT sun Oct 20 2019

Latest radar data shows echoes through much of South Dakota and south
central ND this morning, which will gradually progress into the
region this afternoon. Observed and model forecast soundings
indicate that broad synoptic lift will likely require support from
mid level fgen to overcome a Stout low to mid level layer of dry
air before rain is able to reach the ground this afternoon and
evening. This thinking seems to be in agreement with the latest
runs of high resolution models so delayed the start time of rain
chances back a few hours across the region to account for this.

Update issued at 635 am CDT sun Oct 20 2019

Forecast for today is on track. System continues to organize
across the Wyoming/South Dakota/Nebraska region. Latest
observations and incoming guidance arriving as expected.

&&

Short term...(today through monday)
issued at 300 am CDT sun Oct 20 2019

Main concern this period will be rainfall and wind speeds with the
system expected to affect the region. At 08z, water vapor imagery
indicated circulation (upper level low) over Wyoming with surface
analysis indicating an associated surface low developing. All
guidance is in agreement indicating this system to track due east
into Monday, and then into the northern Great Lakes by Tuesday
morning. This track is a trend slightly south and east from
previous expectations. The end result is that the potential for
2+ inch rainfall and 50+ knot wind gusts has greatly diminished.
Main rain chances will come from synoptic lift associated with
mid-level warm air advection. Deformation zone precipitation
should be mainly east of the region. Total rainfall totals will
be limited by lack of instability and somewhat limited moisture
(pwats ~0.5 inch). Taking into account ensemble guidance and
expected forcing mechanisms along with the environment, anticipate
most areas will receive 0.5 to 1.0 inch of rainfall by Tuesday
morning. Guidance indicates an area of enhanced mid-level fgen
developing by this afternoon across northwest South Dakota into
east central North Dakota. This mesoscale forcing weakens by
Monday morning. Some areas within this region should receive
higher rainfall totals, although the coverage will be limited (to
where any organized banding sets up). With the current expected
track of this system, wind potential is more limited, although
still thinking at least near advisory criteria for a portion of
the region on Monday.

Long term...(tuesday through saturday)
issued at 300 am CDT sun Oct 20 2019

A return to cooler, just below seasonal temperatures is expected
for the mid to late week period with chances for light rain
Wednesday and next weekend.

Tuesday through Wednesday...

Scattered rain showers are possible through the day Tuesday across
northern Minnesota as the Sunday/Monday low lingers across the
northern Great Lakes region. Strong pressure gradient winds
developing over the eastern Dakotas and western Minnesota will allow
gusty winds to linger into the day Tuesday. Colder air filtering
into the region will help cool temperatures to just below seasonal
averages with highs in the low to mid 40s.

Heading into Tuesday night and Wednesday, a weak upper level
shortwave is forecast to propagate southeastward from western Canada
into the northern plains within the mean northwesterly flow regime.
As this occurs, scattered rain showers developing along a low to mid
level baroclinic zone are expected to overspread western to south
central ND. While the better rain chances will remain to the west of
the region, a few showers can't be ruled out for the southern Red
River valley between Fargo and Jamestown. Otherwise, most locations
will remain dry for Wednesday.

Thursday through Friday...

Upper level ridging and surface high pressure will help keep the
region dry for Thursday and Friday. Temperatures will remain below
seasonal normals for Thursday with highs in the low 40s before
warming up to the upper 40s by Friday afternoon.

Saturday...

Ensemble guidance has come into somewhat better agreement about the
timing and evolution of the upper level pattern for the end of the
week/start of next weekend with upper level ridging giving way to an
approaching Canadian low and cold front during the Saturday period.
Although considerable model spread in the exact timing of this
wave/cold front exists, the general idea is that next weekend will
see the passage of a cold front that will bring precipitation
chances to the region.

&&

Aviation...(for the 18z tafs through 18z Monday afternoon)
issued at 101 PM CDT sun Oct 20 2019

Expect VFR conditions to prevail through early this evening. MVFR
ceilings and visibility will develop with rain tonight, gradually
overtaking all taf sites from southwest to northeast, reaching
kbji Monday morning. Winds will remain light and variable today,
increasing and backing from south to east to north overnight. On
Monday morning, north winds will ramp up quickly becoming strong
with sustained winds at 20-30 kts and up to 50 kt gusts during the
day Monday.

&&

Hydrology...
issued at 112 PM CDT sun Oct 20 2019

The system expected to bring the next widespread rainfall to eastern
North Dakota and the northwest quarter of Minnesota is approaching
from the southwest today. This system is expected to bring
widespread 0.50 to 1.00 inch rainfall amounts to the area, with the
potential to drop up to 1.50 in some smaller areas. At this point,
it appears the favored region for receiving totals in the 1.00 to
1.50 inch range will be over the James and Sheyenne river basins of
eastern North Dakota.

The river forecasts used these above mentioned precipitation
amounts, which brought some changes to the river forecasts today.
The biggest change was at Valley City, where the forecast is mainly
based on releases from baldhill dam. Releases from the dam will be
increased, which will bring the forecast for the Sheyenne river at
Valley City above major flood stage. It will take longer for the
releases from baldhill to affect other sites further downstream.
Other than for the Sheyenne river at Valley City, New River flood
warnings were issued for the Snake River at Alvarado, the Red Lake
river at Crookston, the Maple River at Enderlin, and the Goose River
at Hillsboro.

Elsewhere along the mainstem Red River and its other tributaries,
the main impact will be prolonged High River levels and perhaps
additional crests (mainly in minor to moderate flooding).

&&

Fgf watches/warnings/advisories...
ND...none.
Minnesota...none.
&&

$$

Update...bp

National Weather Service Glossary of Abbreviations