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Area Forecast Discussion (AFD)

Issued by Kansas City/Pleasant Hill, MO (EAX)

                            
000
FXUS63 KEAX 160528
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1128 PM CST Fri Feb 15 2019

.Discussion...
Issued at 247 PM CST FRI FEB 15 2019

Winter just refuses to loosen its grip on the lower Missouri Vly
this winter season as evidenced by yet another winter storm system
that continues to impact our region this afternoon. For winter
lovers, this has been a season to rejoice, while those who can't
stand the thought of seeing another snowflake this winter, should
probably plan on not reading the rest of this discussion. In any 
event, latest radar trends now showing the back edge of persistent
snow approaching the stateline with very light returns noted 
further west out towards TOP. So far we've had 2.3" here at the 
office, with multiple reports of 2-4" on social media. Despite the
fact that the system is moving out of the region, roadways, as 
highlighted through multiple social media posts by local law 
enforcement agencies, local DOTs, and the KC Scout network remain
very hazardous, and will remain so through the evening commute. 
Because of this, have decided to let the winter weather advisory 
proceed as scheduled with the anticipation that the afternoon crew
can cancel early if conditions improve significantly before the 9
PM expiration time. Otherwise, expect a cold overnight period 
with fresh snow cover and the possibility of clearing skies 
towards daybreak allowing many locations to fall into the single 
digits early Saturday morning. 

For Saturday, much of the day is expected to remain dry, however
conditions will again deteriorate by late afternoon as yet another
storm system approaches from the west. Quick inspection of 500-hPa
height fields reveal incoming trough will be take on a negative 
tilt as it approaches the forecast area, with its cross hairs for
max vorticity advection directly centered on northern Missouri 
and eastern Kansas. Couple that with the fact that much of our 
region will lie beneath the left exit region of a 170 kt jet 
streak, its hard to ignore the dynamics this next system will have
as it moves through our region. The forecast difficulty lies with
the fact that model RH fields through the snow growth region 
look to remain fairly dry for the southern 2/3rds of the forecast
area, suggesting that freezing rain and drizzle will be a concern
for Route 36 southward. Further north, models are in agreement 
that thermal and moisture profiles will remain saturated enough 
to keep the bulk of precipitation in the form of snow, and a 
general 2-4" will be possible up towards the Iowa line before 
activity comes to an end later Sunday morning. Right now, ice 
accumulations of several hundredths will be possible Saturday 
night/early Sunday for the southern 2/3rds of the fcst area, and 
it stands to reason that the entire forecast area will need 
another winter wx advisory for this system. Did toy with the idea 
of issuing the headline with this afternoon's package, but elected
to hold off for now with a current headline in effect. 

And as the first paragraph alluded to, another round of winter wx
looks to be on our door step early Tuesday. While its a little 
early to get into specifics with this system, model presentation 
this afternoon certainly looks interesting as a large-scale upper
trough approaches from the west and sfc low pressure develops and
moves well to our south. Models seem to agree that a large region
of QPF will extend north into the lower Missouri Vly as main sfc 
low tracks through the Deep South and into the Tennessee Rvr Vly. 
This system could obviously be the next winter wx maker following 
this weekend's system and it certainly bears watching for the 
start of the next work week. 

&&

.Aviation...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1120 PM CST FRI FEB 15 2019

VFR conditions will persist overnight as a surface ridge advances
over the area. Lingering low-level VFR stratus should partially
thin out leading into Saturday late morning, before cloud cover
builds back into the area ahead of the next storm system. By
sunset Saturday, light snow will develop across the terminal
sites, with brief periods of heavy snow possible shortly
thereafter. Will likely see MVFR, and periodic IFR conditions
between 00Z to 06Z Sunday, before precipitation quickly pushes
eastward after 06Z.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

Discussion...32
Aviation...Welsh