Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KEAX 272051

351 PM CDT Fri Mar 27 2015

Issued at 351 PM CDT FRI MAR 27 2015

Strong northwest flow aloft across the area has been the main
culprit in the cool conditions across the area. This strong
northwest flow aloft will continue to be in place tonight as a vort
max (similar to last night`s system) moves into the area. Dry air in
the low to mid level will be in place however isentropic ascent on
the 285K-295K surfaces coupled with this vort max will help to
overcome this dry air and precipitation is expected after midnight.
The main question is in what form will that precipitation fall?
Models are in good agreement the a swath of precipitation will
bisect the CWA after midnight. Interrogating model soundings shows
that there will be moisture in the snow growth zone with the whole
column below freezing with the exception of near the surface. This
will lead to a chance for snow over much of the area with the
exception of extreme western Missouri and eastern Kansas where mixed
precipitation is possible.

Precipitation will exit the area tomorrow morning and modest height
rise and southeasterly winds will help temperatures rise into the
upper 40s to lower 50s. Saturday night into Sunday morning an upper
level trough will move from northern Plains into the Upper Midwest.
This will force a cold front through the area during the morning
hours. Moisture will be meager with this front but enough forcing
will be provide to produce light rain. Conditions will improve
during the afternoon hours on Sunday as the upper trough shifts east
of the area. Downslope flow will allow highs to rise into the upper
50s to mid 60s.

Shortwave ridging will begin to impinge on the area on Monday and a
return to above normal temperatures will move back into the area.
Highs Monday will be in the mid to upper 60s. Tuesday will be even
warmer as continued height rises and further exertion of the upper
ridge on the area will allow temperatures to reach the upper 60s to
mid 70s.

Models are in agreement that a upper level trough moving through the
northern Plains and Upper Midwest will push a cold front into the
area late Wednesday afternoon/Wednesday evening. Warm air advection
out ahead of the front will help temperatures rise into the 70s out
ahead of the front. There will be modest instability across the area
which allow for the production of thunderstorms Wednesday night. The
best forcing will be well north of the area so severe weather is not
anticipated at this time. expect this system to exit the area by
Thursday morning.

Large model difference make the latter part of the extended forecast
a little more uncertain. The GFS moves to a less amplified more
zonal pattern behind the Wednesday night system and depicts a dry
forecast for the end of the work week. The ECMWF depicts another
trough digging through the Plains on Thursday night and Friday with
a more amplified pattern. The EC solution would bring active weather
for the area Thursday and Friday with continued thunderstorm
chances. As such, have kept POPs inherited from the initialization
to account for the EC solution.


.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1237 PM CDT FRI MAR 27 2015

VFR conds will cont thru tonight. However, after midnight, model
soundings indicate that a narrow band of light snow will develop. At
this time, models suggest the better chance for pcpn to remain east
of the terminals however, just a slight shift to the west and pcpn
will be poss at the terminals. Also of concern, is that sounding
profiles show moisture in the dendritic snow growth zone and the
profile below freezing with the exception of just a shallow layer
near the surface. This would for provide for pcpn to be in the form
of snow. Since the best potential for snow looks to be east of the
terminals at this time have opted for VCSH mention in the TAF btn
07Z-11Z. Otrw...expect ovc stratus around 5kft overnight. Cigs will
then sct out tomorrow morning. Winds will be out of the north this
afternoon before becmg light and vrb this evening. Winds will then
pick back up out of the SE btn 10-15kts after midnight.




AVIATION...73 is the U.S. government's official web portal to all federal, state and local government web resources and services.