Scientific Forecaster Discussion
fxus63 kgid 161127
Area forecast discussion
National Weather Service Hastings NE
527 am CST Mon Jan 16 2017
..ice storm conts in progress and the worst of it is happening
now thru 3 PM...
Short term...(today and tonight)
issued at 352 am CST Mon Jan 16 2017
A well-developed comma-shaped precip band has evolved. Nearly the
entire State of Kansas is covered with rain and frzg rain (zr) at
this hr and it will lift north thru the fcst area thru the day.
Since we arrived late last evening...freezing rain (higher returns on radar)
has been spotty...but between areas of higher reflectivity...frzg
drzl has been falling and it is much more efficient at
accumulating. Surfaces here at the office are completely glazed.
Steady frzg rain (light-moderate intensity) will lift S-north thru the
fcst area today. North-cntrl Kansas will probably be done by noon as the
dry slot moves in and shuts off the precip. The dry slot will cont
to lift north probably making it to Franklin-Hastings-York this
afternoon. Within the dry slot...mstr will still be deep enough
for drzl/frzg drzl.
Fcst soundings cont to indicate the warm nose will eventually cool
changing the freezing rain over to snow from west-east this afternoon...but not
all areas will see snow (i.E. In the dry slot).
Possible fcst weaknesses (i.E. Lower confidence elements):
1) Phillips/Rooks counties. Some models suggest the tail end of
the deformation precip band curling around the backside of this
low could make it that far S...where snow could move in. This will
need to be monitored by the day shift for possible fcst
2) the timing and duration of the changeover to snow. This
determines how much snow will fall. For now...contd with low
snowfall amounts of 1-2 inches from Beaver City-Kearney-St. Paul-
Max ice accum: we cont to expect a 1/2 to 3/4 inch S of a line
from Stockton Kansas-Clay ctr-York. 1/3 to 1/2 inch from Phillipsburg-
Hastings-Grand Island-Fullerton. 1/10 to 1/4 inch from Beaver
Wind: we have increased winds from 18z-06z based on NAM/GFS mixing
into 20-25 kts in cold air advection. This will increase stress on power lines
and tree limbs.
Use good judgement today. Do not travel unless absolutely
necessary and take it slow if you must travel.
We expect power outages to develop as icing increases loads on
power lines and trees. Be smart and be safe with alternate
sources of light and heat.
Long term...(tuesday through sunday)
issued at 352 am CST Mon Jan 16 2017
The upper system which produced the icy wintry weather
Sunday/Monday will have departed toward the Great Lakes region
early Tuesday. In the wake of this system dry weather is forecast
however the pattern aloft will be troughy with a northern stream
wave translating southeast through neb and the upper Midwest
region while another closed low begins to lift northeast out of
Mexico. In between these systems temperatures are expected to rise
above freezing for highs, allowing for some melting of the
The forecast remains dry through mid day on Friday with
moderating temperatures. The southwest conus upper low pressure
system is progged to deepen as it lifts across Kansas and reaches
Missouri by Thursday night but this system should have negligible
impact with moisture lacking. A noticeably warmer airmass will
advect into our region with temperatures in the 40s looking
The Central Plains upper low gets kicked out by an upper trough
translating east of The Rockies Friday which lifts out across our
region Friday/Friday night. Chances for precipitation return with
thermal profiles indicating rain initially, which could change to
snow overnight as cold air is drawn south on the back side of the
Over the weekend models suggest dual closed low pressure systems
across the interior conus mainly across the Dakotas and Southern
Plains but hard to get detailed this far out. We currently have
some small pops in the forecast for our southern zones more so on
the fridge/northern edge of the Southern Plains low. Confidence is
not high on the evolution of the weekend troughs/lows at this time
and did not deviate from ensembles.
Aviation...(for the 12z kgri/kear tafs through 12z tuesday)
issued at 526 am CST Mon Jan 16 2017
Signficant wx: freezing rain conts thru 21z and IFR conds.
Today: IFR in freezing rain thru 21z. Freezing rain changes to a period of -sn and
vsbys should decrease to IFR as well at that time. NE winds
become north and increase to around 15 kts...gusting to near 25 kts.
Confidence: high...except a little uncertainty on when and if
ear/gri changeover to snow.
Tonight: IFR initially with any lingering -sn ending 00z-03z. Then
clearing and becoming VFR. North-northwest winds gust up to 25 kts until 06z
then decrease to 8-14 kts. Confidence: high...except a little
uncertainty on when snow ends.
NE...Ice Storm Warning until midnight CST tonight for nez041-048-049-
Winter Storm Warning until midnight CST tonight for nez039-040-
Kansas...Ice Storm Warning until noon CST today for ksz005>007-017>019.