Area forecast discussion...updated
National Weather Service North Platte NE
623 am CDT sun may 19 2013
Short term...(today and tonight)
issued at 353 am CDT sun may 19 2013
An upper level cold pool currently across eastern Colo will spark
scattered showers and thunderstorms today as it drifts north
through the forecast area. Southerly low level winds and moisture
advection along and east of Highway 183 look sufficient for a few
severe storms capable of large hail. Similarly the cold pool forecast
to lift north through the forecast today could produce a few storms
with marginal severe hail west of Highway 183.
It looks like highs in the lower 60s west to middle 70s east. Temperatures in
the east really depend on the ability of a warm sector to open up.
Based on current conditions...there is a chance temperatures could warm up
a bit more in the east and this would increase the threat of severe
weather. Overall.. the RUC looked like the best fit for the job as
it shows elevated instability persisting throughout the day and into
this evening. The h700 low in all models should deepen across the
Dakotas today and tonight with the h500 mb cold pool lagging south
across Nebraska. This will lift surface low across western Kansas north through eastern
Nebraska. This supports scattered showers and thunderstorms but not much
more as the better focus is across the north...presumably. There are
quite a range of model rainfall forecasts for this event. The
official forecast follows lesser quantitative precipitation forecast amounts given that the best
forcing is north of the forecast area.
Long term...(monday through saturday)
issued at 353 am CDT sun may 19 2013
On Monday morning...the low pressure system is expected to be
stacked and centered over central South Dakota with relatively dry air over
central Nebraska. However...as the drier air pushes east...showers
and possibly a few thunderstorms will develop during the afternoon
under the may sun. Temperatures will struggle to rise tomorrow...remaining
in the 60s across most of the area in the afternoon. After the
diurnally driven showers taper off during the evening hours...some
higher Theta-E air will wrap around the low to the north and
through the area in the middle levels Monday night...helping to keep
precipitation chances in the forecast. The upper low will slowly
wobble eastward Tuesday and Wednesday...with shower coverage
diminishing each day. An upper ridge will move east into the
region on Thursday. Chances for precipitation will come again
toward the end of the week as southwesterly flow aloft returns.
&&
Aviation...(for the 12z tafs through 12z Monday morning)
issued at 618 am CDT sun may 19 2013
Low confidence forecast regarding the start and stop times of The
Rounds of showers and thunderstorms which will lift north through
the forecast area today and tonight. The models are showing negative
skill with this feature so all forecasts will be based on ongoing radar
data and assume a steady state. Otherwise...some MVFR ceilings may
intrude upon northern Nebraska along and north of Highway 20. Best approach
is to use observations since high clouds are blocking The View of
the low clouds and models are showing no skill with that either.
&&
Lbf watches/warnings/advisories...
none.
&&
$$
Short term...cdc
long term...knutsvig
aviation...cdc
