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Area forecast discussion 
National Weather Service Grand Forks ND
1144 PM CDT Friday Aug 29 2014

Update...
issued at 1140 PM CDT Friday Aug 29 2014

No additional changes needed from previous update.

Update issued at 1008 PM CDT Friday Aug 29 2014

Not unexpected...but clearing has slowed a bit just a tad slower
than earlier rap model indicated. Thus backed off a little in the
grids with timing. Aviation tafs appear OK. Did add patchy fog to
dvl region as good radiational cooling will occur there.
Surrounding offices have fog mentioned and dont see enough of an
in issue as clearing will only slowly progress south overnight.
Temperatures OK. Radar shows a few sprinkles leftover around Bemidji-
Fosston so kept isolated -rw until 05z in that area.

&&

Short term...(this evening through Saturday night)
issued at 255 PM CDT Friday Aug 29 2014

Current metars show the surface boundary moving across ND today is
located roughly over the Red River vally from hco (mn) to far.
Sat continuing to show skies over the upper Sheyenne basin and
James Valley region break up. Current radar shows a small cluster
of rain showers/virga over central ND. Immediate short term models
appear to be overdoing precipitation...so will go mostly with
continuity/weather trends vs any model choice. Later in the period a
front moves into western ND...with GFS faster than the European model (ecmwf) on
timing. Will use a forecast blend for this period.

This afternoon and tonight....sfc boundary now east of area of clearing
and moving into Minnesota...where skies have been cloudy all day and
region has not heated out. Overall not an impressive situation and
will keep in the low chance probability of precipitation with rain showers and isolated thunderstorms
the main threat. Coolest areas tonight will be across eastern ND
and into far northwestern Minnesota where skies will likely clear and temperatures could
drop into upper 40s across this region.

Tomorrow and tomorrow night...short wave ridge aloft will bring dry
weather to the region...however a strong upper wave over Pacific northwest
will move into Montana while low pressure develops over the plains. An
open Gulf will allow strong h850 moisture flux into the region by
Saturday night. Expect some elevated convection to pick up by late
Sat evening and increase after midnight. Have likely probability of precipitation into the
western zones after 06z...however main show will be drg the day Sunday
(see long range discussion) as surface front moves across Dakotas and
into Minnesota.

Long term...(sunday through friday)
issued at 255 PM CDT Friday Aug 29 2014

Sun and Sun night...models indicating extended area of surface
troughing/front from eastern Dakotas down through South Dakota/NE and into
northwest Kansas. Short wave prognosticated to be entering western Dakotas from eastern
Montana at 12z Sunday. GFS is faster with the upper wave entering the
Dakotas than is the European model (ecmwf)...and its timing will be critical on severe
potential for Sun afternoon. Gulf moisture should be readily available
with both models showing strong h850 moisture flux into the
central and eastern Dakotas Sat night coupled with 35 to 45 kts of
0-6 km bulk shear. Associated surface front prognosticated to enter the
eastern Dakotas (western cwa) late Sun morning and move across the
valley in the early afternoon hours...extending across northwest and west central
Minnesota by middle afternoon. Bulk shear by Sun afternoon expected to increase to 40
kts to 50 kts. With these ingredients in place...there is
certainly a potential for severe across Minnesota on Sun afternoon. Storm Prediction Center
has issued a slight risk for day 3. Convection should begin
tapering off by midnight Sun night and Monday will be dry across
majority of the area.

For Monday night through Friday...the period should start out mainly
dry. The chances for showers and some storms could increase by the
middle to end of next week...with more cyclonic flow aloft
transitioning to potential SW flow aloft. The exact timing of
shortwaves is tough...but will leave in mention of mainly chance
type probability of precipitation for the end of next week...with the deeper moisture and
some instability confined mainly to the southern 2/3 of the forecast
area.

&&

Aviation...(for the 06z tafs through 06z Saturday night)
issued at 1140 PM CDT Friday Aug 29 2014

Initial issue will be timing of clearing of the IFR/MVFR clouds at
Fargo and Bemidji taf sites. Clearing making its way into tvf/gfk
sites at this time and will be scattered-broken at times 06z-10z period. Went a bit
more pessimistic at Fargo-Bemidji and kept in MVFR ceilings at Fargo
until just past daybreak and kept IFR at Bemidji until past daybreak
as well as cool north winds move into the moist airmass and main
drying stays further north and west of this region. Otherwise
light north winds becoming southeast Saturday aftn-eve.
&&

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

$$

Update...Riddle
short term...speicher
long term...dk/speicher
aviation...Riddle

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