Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Hastings NE
548 am CDT Sat Aug 1 2015
Short term...(today and tonight)
issued at 403 am CDT Sat Aug 1 2015
A fairly challenging forecast this morning as convection has
continued and actually enhanced across portions of the local
forecast area overnight. With the training of this convection over
the same areas the past few hours...could eventually see some
minor flooding in spots if additional activity develops.
In the meantime...expect an upper level disturbance stretching
from western South Dakota across the local forecast area this
morning to continue to spark shower and thunderstorm activity
across the local area through the remainder of the morning hours.
While most guidance is doing a very poor job with the ongoing
convection...08z hrrr seems fairly well initialized...and have
leaned towards this solution in the morning forecast. As a
result...expect ongoing convection to continue across the
northeastern quadrant of the local area through the late morning
hours before dissipating...with the focus then turning to the
next disturbance...which is expected to drop towards the local
area from South Dakota during the middle to late afternoon hours.
While the coverage and timing from this disturbance is
still a bit uncertain...several models are picking up on this
feature...brining confidence that at least the northern portions
of the forecast area will see another round of showers and
thunderstorms this evening. With cape building ahead of this
disturbance and ample shear in place...in part due to the
presence of a near stationary frontal boundary across this
area...expect the potential for a few strong to marginally severe
storms developing during the late afternoon and evening hours.
Temperature wise...expect another seasonably warm afternoon across
the region with most locations that are able to clear out by
afternoon expected to see temperatures climb into the lower to
middles 90s...with the best chance for more widespread convection
also expected during the late afternoon through early evening
hours. With the right parameters in place...a few strong to severe
storms appear likely...especially for the northeastern portions of
the forecast area.
Long term...(sunday through friday)
issued at 403 am CDT Sat Aug 1 2015
Biggest concerns for the forecast period...chances of thunderstorms
Monday night through Tuesday night then again middle week.
Models in relative agreement with large scale features so will use
blend. Generally in a northwest flow pattern through the period.
This type pattern typically makes it tough to forecast the speed and
strength of systems moving through. So...confidence is not the
highest in timing...coverage or even chances of rain until we get 12
to 24 hours away from any rain event.
None the less...the models are fairly consistent in forecasting a
nearly stationary boundary over the forecast area from Monday on.
Also...models suggest a short wave and associated jet streak will
top the ridge and move over an area between the Dakotas and Kansas
on Monday night or Tuesday. Thus...will leave chances for
thunderstorms in forecast. If storms develop they appear to have
enough instability and weak shear that a few could produce some near
severe hail stones and perhaps some gusty winds.
In between any storms that develop...dry and warm weather is
expected. Temperatures should be near normal through the period.
Aviation...(for the 12z kgri/kear tafs through 12z Sunday morning)
issued at 540 am CDT Sat Aug 1 2015
An area of showers and thunderstorms is expected to impact the
terminals during the early morning hours...albeit with high
bases...ceilings are expected to remain VFR with only temporary MVFR
visibilities expected. Otherwise...middle level clouds will likely stream
across the terminals through the afternoon hours accompanied by
light southerly breezes. Another round of showers and
thunderstorms will then be possible during the late afternoon or
evening hours...but due to uncertainties in timing and
coverage...opted to keep only a thunderstorms in the vicinity mention for the time being.