Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wichita Kansas
1138 PM CST Sat Jan 31 2015
..updated for 06z aviation discussion...
issued at 855 PM CST Sat Jan 31 2015
Concerned about strong northwesterly winds during the day Sunday.
Guidance is in fairly good agreement regarding the placement and
gradient behind the surface low that will track across the region
tonight and through Sunday. The strong gradient and some mixing
will cause northwesterly winds to be strong. Have gone ahead and
issued a Wind Advisory for the day Sunday for this threat. Expect
winds to be strong behind the front around sunrise and persist
through the afternoon. Expect winds around 30mph with gusts 40 to
45 miles per hour. With the earlier onset...wanted to get the word out
Short term...(this evening through tuesday)
issued at 300 PM CST Sat Jan 31 2015
Lots of subtropical moisture continues to push north ahead of the
main shortwave currently spinning over extreme SW portions of the
US. This has led to widespread rain across the forecast area this
afternoon as lift from this approaching wave increases. Colder air
is not that far north of the area...with some areas near the Kansas/Nebraska
border reporting a changeover to snow.
For the early evening hours...expect this widespread rainfall to
gradually begin to shift a little further east as the evening
progresses. But a northern stream shortwave currently over Wyoming will
drop southeast and help push some polar air southward into Kansas late
this evening and overnight. This colder air will gradually change
the light rain over to a mix of rain/snow and eventually to all snow
late tonight into early on sun from northwest to southeast. The
good news is...that as this subfreezing air drops south...most of
the deeper moisture and lift will begin to be shunted to the east of
the forecast area...which will only lead to light snow accumulation
amounts...mainly in central Kansas...once the cold air arrives. Could
also see a light dusting across the Flint Hills as well.
Expect the light snow to gradually end from west to east early Sun
morning...as downglide pushes across the area. But even as the snow
ends...the cold advection will be in full force on sun...with a
rather cold and raw day expected. Not expecting temperatures to move much
on Sunday...with nearly steady temperatures in the middle 20s in central Kansas
and lower 30s in southern Kansas.
Sun night-Mon: coldest portion of the airmass looks to settle over
the region Sun night into Monday morning as the polar ridge of high
pressure moves across the area. This will lead to low temperatures falling
into the single digits in central Kansas and the teens in southern Kansas.
Expect the temperatures to moderate some on Monday...as surface winds
gradually shift to the south and middle level winds shift to the west.
This will provide downslope conditions across most of the
plains....with temperatures Monday afternoon warming back towards seasonal
normals. Think temperatures may be tempered some on Monday...due to some middle
level cloud cover.
Warm advection and downslope conditions will continue for Tuesday. Which
will lead to temperatures climbing above normal...as the next shortwave
moves across the northern rockies into the plains.
Long term...(tuesday night through saturday)
issued at 300 PM CST Sat Jan 31 2015
As this shortwave drives southeast...models are fairly similar
with another shot of polar air dropping south into the plains for
late Tuesday night into Wednesday. This will lead to the temperature rollercoaster
continuing...as temperatures are expected to fall back towards normal and
eventually below normal by Wednesday.
Some uncertainty on whether there will be any precipitation that will
develop as the this colder air drops south as moisture will be
Pacific in nature. GFS is the most robust with the moisture as the
colder air drops south into the area...with a jet streak dropping
southeast out of the northern rockies increasing the lift across the
area. The GFS would suggest a chance initially of a wintry mix as
this lift increases...changing to all snow for Wednesday. The European model (ecmwf) is
alot drier...and would suggest mainly a trace event of sprinkles or
flurries. Model consensus suggests keeping a slight pop for now
and seeing how this plays out. GFS solution would suggest the
potential for a sneaky inch or two of snow accumulation on Wednesday.
Not expecting the polar air to remains around too long...as both
medium range models suggest the colder air will quickly shift to the
east of the area by the end of the week...with warmer than normal
Aviation...(for the 06z tafs through 06z Sunday night)
issued at 1138 PM CST Sat Jan 31 2015
Main area of widespread light to moderate precipitation is moving
eastward from kict and ksln. The front is knocking on krsl door as
of 06z and will move through the remainder of the forecast area
through the next 6 hours. Temperatures will cool and winds will
pick up as the front moves through. This will cause snow to mix in
as a precipitation type at krsl/ksln. Cannot rule it out at
kict/khut and have included -rasn in a tempo group during the
overnight hours as well. No accumulation expected at kict/khut.
Could be some light accumulations at krsl/ksln.
Ceilings and visibilities will stay in IFR/MVFR with some LIFR
conditions possible. Conditions are not expected to improve until
daytime Sunday and then northwest winds will be gusty with
sustained speeds of 20 to 26 kts and gusts to over 35kts possible.
Preliminary point temps/pops...
Wichita-kict 31 34 13 37 / 100 20 0 0
Hutchinson 28 31 10 38 / 100 10 0 0
Newton 29 33 11 35 / 100 20 0 0
Eldorado 32 35 12 36 / 100 30 0 0
Winfield-kwld 35 37 13 37 / 100 30 0 0
Russell 23 26 10 40 / 100 10 0 0
Great Bend 24 27 11 41 / 100 10 0 0
Salina 25 29 9 37 / 100 20 0 0
McPherson 26 30 9 36 / 100 10 0 0
Coffeyville 39 42 15 35 / 100 50 0 0
Chanute 37 40 13 34 / 100 50 10 0
Iola 37 39 13 33 / 100 60 10 0
Parsons-kppf 38 40 13 35 / 100 50 10 0
Wind Advisory from 8 am to 6 PM CST Sunday for ksz032-033-