Area Forecast Discussion
Issued by NWS Topeka, KS
FXUS63 KTOP 091733
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1133 AM CST Mon Dec 9 2013
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 320 AM CST MON DEC 9 2013
Another surge of cold air has moves into the cwa in the wake of
exiting shortwave trough in the upper Midwest. The resulting dry air
and subsidence has led to clearing. With dry low levels...fairly
light winds and some snowcover...temperatures have cooled into the
single digits most areas except the far southeast corner where more
clouds and less snow exist are allowing temps to hold in the mid
teens. However...the next shortwave trough to the west is already
spreading high clouds back into western and portions of central
Kansas which should affect primarily the southeast 3/4 of the cwa
today. The timing of the clouds will coincide with the colder
morning lows to make way for a very cold day. Have lowered highs
across the cwa into the middle and upper teens most locations with
the lower 20s in the far south and southwest portions of the cwa.
Also...models are in agreement that the next shortwave to move
through the area will develop and keep snow slightly further south
than previous...which is a persistent trend. Have therefore edged the
snow flurry chances further south late this afternoon and early
evening to only include the far southern portions of Coffey and
Anderson counties...but this may be too far south as well if the dry
air now moving southward into that area cannot be overcome later
today. Either way...will keep the overnight periods dry with
clearing skies and lows again in the single digits...except for the
far southeast corner.
.LONG TERM...(Tuesday through Sunday)
Issued at 320 AM CST MON DEC 9 2013
Tuesday through Wednesday night, a broad longer wave length trough
will deepen across the upper Great Lakes, southward across the mid
MS river valley.
Eastern KS will be in northwesterly flow aloft. Expect dry
conditions with another surge of Arctic air moving southward across
the area on Tuesday night into Wednesday. Southwest to westerly
surface winds ahead of the surface cold front on Tuesday afternoon
will help high temperatures to warm into the lower to mid 30s.
The center of the surface ridge will move southeast across eastern
KS and northern MO during the day on Wednesday. North winds will
bring the colder airmass southward across the CWA. Highs on
Wednesday will only reach the lower 20s along the NE border with
upper 20s across the far southern counties.
Overnight lows on Wednesday will probably occur in the late evening
hours with single digits to lower teens expected. Temperatures may
remain steady or slowly rise as winds from the the south increase
through the early morning hours of Thursday, as the surface ridge
shifts eastward across MO after midnight.
Thursday and Thursday Night, a closed upper low off the CA coast
will move east across the desert southwest. A lee surface low
across the southern high plains will deepen causing southerly winds
across the state of KS. Temperatures will warm into the mid to upper
30s by Thursday Afternoon.
Friday and Friday night, The H5 trough over the southwestern US will
lift east-northeast across the southern plains. WAA will occur ahead
of the H5 trough. Residual moisture return combined with ascent
ahead of the H5 trough will cause showers to develop through the
day. At this time temperatures look warm enough that the precip
should be in the form of rain. Highs should reach the mid to upper
30s, may even have lower 40s south of I-70 during the afternoon
hours. A cold front will push southeast across the CWA Friday night
and the lingering rain showers may mix with and change to light snow
showers before ending during the early morning hours of Friday.
Saturday through Sunday, Another longer wave-length upper level
trough will develop across the Great Lakes states southward across
the mid and lower MS river Valley. The upper level flow will become
northwesterly across eastern KS. Another Arctic cold front will move
southward across the CWA on Sunday. Highs on Saturday will reach the
lower to mid 30s. Highs on Sunday may occur in the morning hours
with temperatures falling through the 20s during the afternoon,
along with a brisk north wind.
.AVIATION...(For the 18Z TAFs through 18Z Tuesday Afternoon)
Issued at 1124 AM CST MON DEC 9 2013
VFR prevails at KTOP/KFOE/KMHK. Northeast winds between 5 and 12
kts sustained begin to calm and back to the southwest aft 00Z.
Area remains dry as light snow is expected well south of terminals.