Area Forecast Discussion
Issued by NWS Topeka, KS
FXUS63 KTOP 262146
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
346 PM CST Thu Feb 26 2015
.SHORT TERM...(This Evening through Friday)
Issued at 345 PM CST THU FEB 26 2015
An upper level trough off the Vancouver, Canada coastline will dig
southeast across WA and OR during the next 24 hours. A minor
upper level trough across the four corners area will dig southeast
across northern TX and OK, bringing a chance for measurable snow
along across OK and north TX on Friday.
A broad ridge of surface high pressure will move east southeast
across the eastern half of KS into western MO Tonight and Friday.
Surface winds will diminish after sunset and skies will be clear
through 3 AM. Clear skies and light winds will allow temperatures to
drop into the single digits. High clouds will increase late tonight
and may cause temperatures to remain steady from 3 AM to 6 AM.
Friday, high and mid clouds will increase through the day as the
southern stream mid and upper level jet veers more to the
west-southwest across the southern plains. Light winds will
gradually become east-southeasterly through the afternoon hours at 5
to 10 MPH. The increased cloud cover and western edge of low-level
cold air-mass will keep highs in the low to mid 20s.
.LONG TERM...(Friday Night through Thursday)
Issued at 345 PM CST THU FEB 26 2015
Models remain in good agreement on bringing initial shortwave trough
and associated waa/isentropic lift with it into the southwestern
portions of the county warning area early Saturday...spreading
northeastward across the remainder of the cwa through the day.
Overall the track is similar with the highest qpf/snowfall amounts
across the southeast 2/3 of the cwa through the day and night.
Expect Snowfall amounts to average 1 to 3 inches across most of the
cwa Saturday...with another 1 to 3 inches Saturday night as a brief
lull in lift and snow chances is followed by a band of increasing
frontogenesis along and just south of the I 70 corridor as the
warmer air tries to nose northward into the southern cwa by Sunday
morning. This should focus the snow amounts on Sunday north and west
of the I 35 corridor where another 1 to 2 inches may
accumulate...the potential for a mixture of freezing rain and sleet
with the snow is expected to lower snowfall amounts to the south.
The band should slowly weaken and shift eastward into MO by evening
leaving the highest 36 hrs snowfall totals of 6 to 7 inches in band
along the I 70 corridor...although these totals could be locally
higher or lower and occur in a relatively narrow swath depending on
how any frontogenetical band sets up and advances during the day.
Lower amounts in the 3-6 inch range should be common elsewhere to
the northwest and southeast of this area.
Models still show a lull in precipitation Sunday night as the
northern stream shortwave pushes eastward with only slight chance
pops for snow in the north central. Then on Monday...expect the flow
aloft to back dramatically through the day and allow warmer air to
lift northward across the cwa with a morning mix of freezing
rain/sleet/snow in the morning transition to rain south and
rain/snow north as highs reach the middle 30s north to the lower 40s
far southeast. The warmer air lifts even further northward Monday
night and Tuesday with only a rain/snow mix expected in the north
central with rain elsewhere as the next stronger wave lifts out of
the desert southwest and across the cwa on Tuesday with colder air
associated with the strong cold front moving across the cwa late in
the afternoon. Light snow chances will then linger on into early
Thursday as the final piece of the western trough advances
southeastward across the cwa.
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1143 AM CST THU FEB 26 2015
Expect VFR conditions the next 24 hours. Northerly surface winds
of 12 to 15 KTS with gusts of 18 to 24 KTS will gradually diminish
late this afternoon and early this evening to 6 to 9 KTS. High and
mid level clouds will increase late Tonight with ceilings greater
than 120 KFT.