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Area forecast discussion 
National Weather Service Grand Forks ND
302 PM CDT Tuesday Jun 2 2015

Short term...(this evening through Wednesday night)
issued at 302 PM CDT Tuesday Jun 2 2015

Severe thunderstorm chances and heavy rain will be the main
headache for the short term.

Southwesterly flow aloft with several weak shortwaves coming
through the region as seen on WV loop. The strongest circulation
is currently lifting from eastern Montana into Canada...but there are
additional shortwaves entering central ND and another in eastern
Wyoming that will be of concern for US tonight. The surface low has set up
over north central South Dakota...but short range models persist in an
inverted trough or even a more northern surface low coming into our
southern counties later tonight. There has finally been some
clearing in the southwestern counties...and with dew points in the
60s in that region there should be continuing destabilization.
Some towering cumulus and cells on radar have already started to
develop over central ND south of Bismarck...and storm scale models
continue to develop storms from that area into our southeastern
counties later this evening. Will continue to keep high probability of precipitation and a
severe mention mainly in the southwestern counties. And a Tornado
Watch for Cooperstown south has just been issued.

The other issue will be heavy rainfall. Persistant rain along the
warm front in our northern counties has brought a half an inch to
an inch to the far north. With precipitable water values near 1.5 inches...there
will be continued threat for heavy rainfall in any additional
development tonight. Think that the storms should move at a fairly
decent clip and do not think there will be a lot of training cells at
this point. Will not include any watches at this point...but will
have some heavy rain mention in the grids.

By tomorrow...the models all have the shortwave over Wyoming moving off
into Minnesota...with the surface low heading east and a cold front pushing
into the County Warning Area. There will be some lingering precipitation activity near
and even behind the cold front. Will continue to keep probability of precipitation
tapering off from west to east throughout the day GOES on on
Wednesday. Temperatures in the western counties will also will be
affected by some decent warm air advection...so even with some
decreasing clouds think that highs will stay in the 60s. Wednesday
night...there will be another weak shortwave moving towards the
western Dakotas...although surface high pressure will remain over the
plains. The NAM and European model (ecmwf) have some precipitation lingering into
Wednesday night over the eastern counties so will keep some low
probability of precipitation going for a bit longer. There could be some clearing over the
eastern counties and temperatures overnight could dip down into the 40s.

Long term...(thursday through tuesday)
issued at 302 PM CDT Tuesday Jun 2 2015

Thursday and Friday...various shortwaves continue to move through
on Thursday...but at this point it seems that the main ones will
move either into Canada or south into Minnesota/Iowa border region. Kept
some low probability of precipitation in the far south for Thursday and Thursday night in
case anything from the southern shortwave strays into our
area...but think we should have a short break in activity. The
break will be more pronouced on Friday as upper ridging builds
into the area so kept US dry. Temperatures should be near seasonal averages.

For Friday night through Tuesday...models show surface high pressure
sliding off to the east Friday night with approaching low pressure.
Models differ on precipitation placement and timing at this point but do
agree on a decent short wave moving through. This would give better
precipitation chances for Sat into Sat night across the entire forecast area. By Sunday
the precipitation chances linger along and east of the Red River valley as
another weaker short wave may rotate down the back side of the main
wave. As this feature slides off to the east it will slowly be
replaced by ridging and mainly dry weather for Mon/Tue. Temperatures that
start off cool for Sat into Sunday should warm up more by Monday
into Tuesday.

&&

Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 1235 PM CDT Tuesday Jun 2 2015

Tricky aviation forecast due to the lingering questions surrounding
convection later this afternoon. At this point it appears that kdvl
may be socked in with lower clouds and east-NE winds. Kgfk/ktvf
still have S-south-southeast winds but lower clouds are not that far away...so
will tempo in some of them for the afternoon just in case. There are
also lower clouds just west of kfar. Will keep thunderstorms mentioned by
late afternoon at all taf sites...although current indications are
that they may mainly affect the kfar area and southward. Rest of the
area may see more of a shower/thunderstorm combination. However lots of
uncertainty...so as a better picture of this afternoon emerges will
updates tafs as needed. Will keep the lower clouds in for the
duration once they appear. Wind directions will also be tricky.
Kdvl/kgfk/ktvf will keep or be near the northeast winds while
kfar/kbji will stay with S-south-southeast winds much longer. By later tonight
into Wednesday the entire area should switch to the north.



&&

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

$$

Short term...Jr
long term...Jr/godon
aviation...godon

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