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Area forecast discussion...updated
National Weather Service Grand Forks ND
704 PM CST Sat Nov 16 2019

Update...
issued at 703 PM CST Sat Nov 16 2019

Canadian radar and surface observing sites in south central
Manitoba are reporting light snow or drizzle, progressing east-southeast
along the shortwave trough axis. Some cams and deterministic
models continue to depict potential for this area of mid level
lift to dip into northwest Minnesota late tonight, producing light
freezing drizzle or light snow.

&&

Short term...(this evening through sunday)
issued at 306 PM CST Sat Nov 16 2019

Currently, a surface low is moving east across southern Manitoba. A
surface trough over central ND will push east across the area
today/tonight, shifting winds to the west/northwest. Warm air aloft
has pushed north ahead of the boundary, with cold air at the surface
lagging behind a bit. The cold front will push through the region
this evening with northwesterly winds and low clouds on the
backside. A mid level frontogenesis band is creating some light rain
over central South Dakota and far southeast ND currently, and will move east-northeast
affecting other parts of the southern Red River late this afternoon and
west-central Minnesota this evening. Believe this will all fall as rain
given temperatures staying warm into the evening.

Further north over northwest Minnesota, the low stratus moving in from the
northwest will likely have some light drizzle associated with it.
Temperatures in the saturated layer aloft are around -5 to -7c. And
given surface temperatures are expected to fall below freezing after
midnight, freezing drizzle (fzdz) is a concern. Models indicate a
relatively low chance of measurable precipitation (chance of at
least 0.01"). However, even a trace of fzdz can cause impacts on
area roadways. With this afternoon's update, will go with a slight
chance of fzdz in northwest Minnesota. Later shifts will need to monitor and
see if confidence increases...and see if a Special Weather
Statement or Winter Weather Advisory will be needed. Right now,
confidence for fzdz is not high enough to warrant a product like
that. Will continue mentioning in the hazardous weather outlook.

On Sunday, the cold air moves east and warm air begins to return
to the area as a surface high moves through the area. Highs will
be a bit cooler than today...mostly in the 30s. Sunday night
another upper wave approaches from the northwest and could bring
some snow or perhaps some mixed precip to the west late Sunday
night. Temps look warm enough aloft. Model spread on the
amount/placement/timing of precipitation is rather large, however.
Impacts to travel are possible, but confidence is low at the
present time.

Long term...(monday through saturday)
issued at 306 PM CST Sat Nov 16 2019

Main focus for impactful weather next week is wintry mix with the
accompanying chance for light icing Monday-Tuesday followed by
the chance for accumulating snow Wednesday-Thursday.

Monday-tuesday:

A couple of shortwave troughs move through from the northwest early
next week. The first weaker impulse comes early Monday dragging a
warm front eastward out of central ND into the area. There should be
enough lift aloft to promote dendrite formation above a dry, warm
layer (2-3c) near h7-h8. Surface temps are suggested to be in the
upper 20s early Monday morning. While the magnitude of dryness in
this 700 mb-800 mb layer will dictate how many hydrometeors don't reaching
the ground, thinking is that not all will succumb to evaporation
before reaching the ground. Surviving hydrometeors should acquire
enough warmth to melt and fall as liquid, at least partially. For
this reason, we've introduced the chance for light freezing rain
Monday morning, mainly for the Red River valley and west. Thus this
potential for light freezing rain brings the chance for light icing
and hazardous travel conditions, especially for the Monday morning
commute.

The second, somewhat better strengthened wave follows behind the
first late Monday into Tuesday with the majority of synoptic
forcing expected to move into northern Minnesota. The nbm ensemble system
suggests a loss of ice nuclei aloft as this lift and moisture
moves into northern Minnesota, although further examination of forecast
soundings across the deterministic suite suggests otherwise. Thus,
confidence is low in the thermodynamic profile aloft, and we've
included an equal chance of light freezing rain and snow for
northwest Minnesota late Monday into early Tuesday. If any
accumulation results, it is expected to be rather light.

Wednesday-saturday:

Focus then shifts to a system moving west through the northern
plains and its chance to bring accumulating snow across the area
Wednesday into Thursday. Confidence is quite low as spread is high
within the ensemble suite regarding focus for ascent and subsequent
quantitative precipitation forecast placement/amount. There is some suggestion of frontogenetical
forcing associated with this system's warm front, although it is
much too early to say how this would augment quantitative precipitation forecast amounts.
Regardless, potential snow accumulation is likely to be more on the
minor side, ie under 3 inches. Warm temps south of the forecast warm
front may influence precip type differences, but again it is too
early to comment on details regarding this.

Beyond Thursday the forecast looks relatively dry and a return to
colder temps is expected underneath northwest flow aloft.

&&

Aviation...(for the 00z tafs through 00z Sunday evening)
issued at 703 PM CST Sat Nov 16 2019

A weak north-south oriented cold front will continue to progress
eastward through the northwest quarter of Minnesota overnight. Winds will
turn westerly and eventually northwesterly behind the front, then gradually
weaken to 5-10 kts Sunday afternoon with surface high pressure.

MVFR ceilings will prevail overnight through Sunday morning. There
is potential for patchy fzdz or flurries to occur late tonight
through early Sunday across northwest Minnesota, mainly affecting ktvf
and kbji and areas northeast. Since coverage will be fairly low,
will leave out of taf for now and include if/when confidence
increases.

&&

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

$$

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