Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 292020
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
220 PM CST Thu Jan 29 2015
.SHORT TERM...(This Evening through Sunday Afternoon)
Issued at 220 PM CST THU JAN 29 2015
For tonight, cold temperatures are anticipated as skies gradually
clear from west to east and surface high pressure drifts into the
region. Near to slightly above normal temperatures in the lower to
mid 40s are expected again tomorrow as southerly winds return but
temperatures aloft remain cool.
The main focus in the short term will be snowfall potential this
weekend. Models have started to come into better alignment with both
precipitation amounts and timing for the changeover to snow, thus
confidence is starting to increase for snowfall amounts.
Precipitation is still expected to start out as rain or a non-snow-
accumulating mix on Saturday, and will transition to all rain by
noon throughout the majority of the region. Temperature profiles
aloft are supportive of snow the entire duration of the event with
no discernible warm nose present, so the determining factor in
precipitation type will be the depth and strength of the near-
surface warm layer and the speed of the cold front that will sweep
through with a northern clipper system late Saturday night into
early Sunday. Due to preexisting warm air, southerly winds, and warm
ground temperatures, do not expect any snowfall accumulation until
around 8 PM in far northern Missouri, around 10 PM along/near Hwy
36, and after midnight elsewhere as colder air starts to build in.
The changeover will happen at the same time that the heaviest
precipitation is also lifting northeast through the forecast area,
resulting in a relative snowfall minimum over our southwestern CWA,
and a relative maximum across the northeast where snowfall duration
will be the longest from the southern-stream system and additional
snowfall is possible from the clipper. The system will also begin to
strengthen over our northeastern forecast area as the southern wave
tightens up, the surface low deepens, and the two systems phase,
helping support the higher snowfall amounts across northeast MO.
However, it is important to note that although models have seemingly
settled on the timing and position of colder air and the changeover
to snow, a small deviation in this will spell a significant change
in snowfall amounts. It is possible that too much initial warm air
and delayed colder air on Sunday morning could result in little to
no snow accumulation for the KC metro area and points southwestward.
Do not think this is the likely scenario at this point, but it also
cannot be ruled out.
Snow is expected to taper off Sunday afternoon/evening from west to
east, and no additional snowfall accumulation is anticipated after
sunset Sunday evening.
.LONG TERM...(Sunday Evening through Thursday)
Issued at 220 PM CST THU JAN 29 2015
Broad northwest upper flow looks to continue through most of the
extended which will maintain seasonably cool temperatures into next
week. Sunday night will be the coldest temperatures we`ve seen in a
few weeks with temperatures likely to drop into the single digits
especially for areas with any snow cover. Light winds should prevent
wind chills from being much of an issue. A slight warming trend will
bring temperatures back into the 40s for Tuesday before another
front drops through Tuesday night. Could see a few rain or snow
showers with the front but the better chances for any precip will be
closer to the primary upper wave over the Great Lakes.
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1153 AM CST THU JAN 29 2015
Ceilings are expected to remain around or slightly above 3 kft
through the next several hours as stratus continues to sit over the
region, then gradual scattering from west to east will occur between
22z and 02z, impacting all TAF sites. Gusty northwest winds will also
gradually diminish late this afternoon, then should become light this
evening and remain less than 5 kts during the overnight hours. Skies
will become and remain clear overnight into tomorrow.