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Area forecast discussion 
National Weather Service Grand Forks ND
645 am CDT Sat Aug 30 2014

Update...
issued at 645 am CDT Sat Aug 30 2014

Extended patchy fog mention in the northwestern counties for a few
more hours as observation and web cams show some sites still with lower
visible. Clouds have hung on in the south and east...but think they
will start to dissipate after sunrise. Temperatures have dropped into the
upper 30s in some spots in the northwestern counties but think
they should recover quickly this morning under sunny skies.

&&

Short term...(today through sunday)
issued at 343 am CDT Sat Aug 30 2014

Precipitation timing tonight and Sunday will be the main forecast
problem for the short term.

Today will be fairly quiet between systems as the shortwave that
brought the cold front moves off into WI and the next shortwave
heads into Montana. The weak surface high over the region weakens further
and moves off to the east as a trough develops over the northern
rockies. Some clouds may linger in the southeastern counties as
the surface low slowly pulls further away...but the northwestern
counties should be pretty sunny. Continued to keep highs getting
into the 70s...although will have to watch the southeast if the
clouds do not clear out as much as expected it could be a bit
cooler.

Tonight...the next shortwave will come off the main trough and
into the northern plains...with a surface low beginning to enter the
western County Warning Area. There seems to be a bit slower trend with the precipitation
arriving in our western counties...with most of the activity after
06z and may even be closer to 12z. Went a bit slower with probability of precipitation but
continued to keep likely values coming into our far west by late
tonight. Increasing clouds and south wind will keep temperatures in the
50s to low 60s. The main upper trough begins to move into the
Western Plains Sunday...with the models all in fairly decent
agreement on taking the surface low northeastward into Canada. There
is less model agreement on how much storms develop along a weak
frontal boundary that moves into our eastern counties by
afternoon. Models show some cape values over 2000 j/kg by
afternoon ahead of the front...and with the fairly strong flow
aloft...shear will be good enough for severe storms. However...if
clouds hang around a bit more than expected into Sunday afternoon
the instability will be quite a bit lower. Will mention
possibility of severe in severe weather potential statement but will keep it out of grids for
now. Highs on Sunday should again by in the 70s.

Long term...(sunday night through friday)
issued at 343 am CDT Sat Aug 30 2014

Sunday night through Monday night...the upper trough axis moves
off to the east...but a broad trough remains over the region into
the early part of the work week. The surface trough will move off to
the east leaving the County Warning Area in southwest to west winds. Showers and
thunderstorms will linger in the eastern tier through Sunday
night and even into Monday in the Lake of The Woods area. Some
additional precipitation development is not out of the question into
Monday night as a models show weak shortwaves embedded in the main
trough although they cannot agree on exact placement. Will
continue to keep low probability of precipitation going for Monday night. Temperatures will be
just slightly below seasonal averages.

Tuesday through Friday...this particular run of the various models
are in fair agreement through this period. A flat northwest flow
early quickly transitions to a flat southwest flow Thursday as
moderately strong 500mb short wave moves into Pacific northwest. Thunderstorms and rain/rash near intnl
border early in period along baroclinic ribbon and upper divergence
under exit region of lifting jet. Temperatures should warm to near
early September values Tuesday and Wednesday.

The European model (ecmwf) [low-res] and Gem-New Hampshire are about 12-18hrs faster than the
GFS with frontal passage. Ec/Gem have the wind shift moving across the County warning forecast area
early Thursday while GFS has it exiting eastern County warning forecast area 00z Friday. Dgex
is even faster with surface high squarely over County warning forecast area 00z Friday...so have
discounted that model beyond 00z Thursday. If slower model solutions are
correct high temperatures Thursday could be well above median values.

With departing jet/right rear entrance region...cooling aloft and
different vorticity like the idea of low probability of precipitation into Friday. Temperatures
drop back to or below normal at the end of the period.

&&

Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 645 am CDT Sat Aug 30 2014

VFR conditions at all taf sites but kdvl which has been going in
and out of 1sm with patchy shallow fog in the area. Winds will
shift around to the south by this afternoon. Clouds will increase
overnight but think that most sites should be VFR except kbji
which may drop to MVFR. Some storms will begin to move into the
west towards the end of the period. Included some thunderstorms in the vicinity mention at
kdvl but a bit soon for the further east sites.

&&

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

$$

Update...Jr
short term...Jr
long term...Jr/ewens
aviation...Jr

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