Area forecast discussion
National Weather Service Hastings NE
428 am CDT Sat may 25 2013
Short term...(today and tonight)
issued at 423 am CDT Sat may 25 2013
Focus remains on thunderstorm potential.
Thunderstorms continue early this morning with mesoscale convective system rolling east across
central/eastern Nebraska. Main impact currently from convection is heavy
rainfall...with many locations north of Interstate 80 picking up
at least an inch of rain. We have had one report of 3.13 inches so
far at Loup City with rain still falling.
This initial round of convection will continue to move east/end this
morning then attention turns to additional chances for convection
this afternoon. Surface boundary has settled near the Nebraska/Kansas Stateline and
front is prognosticated to lift northward this afternoon into SC Nebraska...with surface
low oriented in eastern Colorado and dry line along the High Plains
region. Frontal boundary and any residual outflow boundaries will be
focus for convection again this afternoon/evening and boundary placement
will need to be monitored closely. Cap looks to hold initially
however models are indicating development along the dry line and
along/north of warm frontal boundary...and have followed closer to
rap model for potential development this afternoon. Storms for
today/tonight have the potential to be more volatile with severe
parameters indicating potential for supercells. Instability is
prognosticated around 4000 j/kg with shear of 40kts or so and storms will
be capable of producing very large hail...damaging winds and even
tornadoes in vicinity of boundaries. Heavy rainfall/flooding also
remains a concern due to the heavy overnight/early this morning
and precipitable water values are on the order of an inch to inch
and a half and are a 100 to 150 percent of normal. All of this
being said...models are not consistent in frontal position which
is key to development this afternoon. Again feel rap and latest sref
run has a better handle on the farther south warm frontal position
across our area today...and will need to monitor closely.
Otherwise...look for some warmer temperatures this afternoon and steady/gusty
winds with the highest wind speeds expected across NC Kansas/south
of warm front...where windy conditions are possible with gusts of
30+ miles per hour.
Long term...(sunday through friday)
issued at 423 am CDT Sat may 25 2013
Sunday through Friday. Main forecast concerns will be
chances for thunderstorms most every day and temperatures through
the period.
A very active weather pattern will affect the forecast area through
the period. An upper level low develops in the western Continental U.S. And
gradually moves through the northern rockies and into the northern
plains by Friday. This upper low will send waves into the forecast
area through the period. The models are similar in the main
features...but the European model (ecmwf) has a little stronger amplitude middle week.
Each of the waves will have a chance for some thunderstorms when
they move through. It certainly will not be a rain out...it will not
rain all of the time...but there will be chances for some showers
and thunderstorms at various times during the period.
The best chances for thunderstorms will be Sunday afternoon and
Sunday night...during which time the cape approaches 5000 j/kg.
Another good chance will be Monday afternoon and Monday night with
convective available potential energy over 5000 j/kg again. Beyond Monday the models have a few
timing differences with the upper level waves that move through the
area and therefore timing thunderstorms is more of a challenge.
Temperatures will be the warmest Sunday through Tuesday then slowly
cool off toward the end of the week. Temperatures should still
remain above normal for this time of year.
&&
Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 1217 am CDT Sat may 25 2013
Thunderstorms will impact the terminal into the overnight hours...with
potential for severe weather with damaging winds...large hail and
heavy rainfall. Chances for thunderstorms and severe weather return Saturday
evening.
&&
Gid watches/warnings/advisories...
NE...none.
Kansas...none.
&&
$$
Short term...Fay
long term...jcb
aviation...Fay
