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000
FXUS63 KTOP 060539
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1139 PM CST Wed Mar 5 2014

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Thursday)
Issued at 254 PM CST WED MAR 5 2014

Another round of light precipitation moving across the forecast area
today as an upper longwave trof moves through the central and high
plains along with another low moving across Texas at this time.

For tonight, current band of precipitation is forecast to weaken
through the late afternoon and early evening hours and should leave
dry air and clearing skies in its wake. Winds at the surface lighten
towards morning, and low levels of the atmosphere remain saturated
from todays precipitation and melting snow from previous days.  May
have some haze or even fog in low lying spots depending on how fast
skies can clear and winds go calm.  Not a strong enough signal to
put in the forecast at this time but worth noting here.  Lows should
fall toward 20 by early morning.  Tomorrow marked by mostly clear
skies and increasing southerly winds and a rise in 850mb
temperatures to 8-12C should bring highs into the upper 40s to lower
50s west by mid to late afternoon.

.LONG TERM...(Thursday Night through Wednesday)
Issued at 254 PM CST WED MAR 5 2014

Southerly flow returns Thursday evening into Friday as a h85
trough develops over eastern Colorado. Within the thermal ridge axis
at 850 hpa, temperatures maximize from 10-13C at 12Z. As the trough
shifts and deepens southward, south winds increase between 10 and 15
mph sustained with gusts near 20 mph through the afternoon. A cold
front approaches far north central Kansas by the afternoon period,
shifting winds to the north between 10 and 20 mph sustained during
the early evening. Good surface heating with some compressional
warming along and ahead of the boundary results in a much warmer day
across most of the area ranging highs near 60 degrees over far east
central Kansas, to around 50 degrees over far north central Kansas.
Along and just behind the boundary, introduced a slight chance for
rain near the Nebraska border as the upper trough approaches.

The cold front is expected to sweep through the area Friday evening
while the trailing upper trough brings additional forcing across
Kansas. There still exists some timing discrepancies of the trough
axis, resulting in a variance in QPF totals for the event. Overall
believe QPF totals remain on the light side (near a tenth of an inch
or less) due to the weak nature of this system. Sounding profilers
suggest temps aloft hover at or just below the freezing mark. Could
possibly see a brief period of sleet, before the wintry mix Friday
evening gradually becomes all snow or a mix of rain and snow towards
sunrise Saturday. Recent runs from the NAM and GFS try to clear this
system out by late Saturday morning while the ECMWF/GEM are slower
in keeping precip falling through the afternoon. Lack of strong cold
advection behind the departing wave Saturday should bring highs in
the 30s for far northeast Kansas to near 40 degrees elsewhere,
transitioning the lingering precip from snow back to rain over east
central Kansas. Any snowfall accumulations remain minimal at this point.

Conditions quickly recover Sunday through at least Wednesday as the
exiting trough becomes elongated across the southern Conus with
southerly flow returning at the surface. The thermal ridge axis
builds Sunday and especially on Monday as highs peak in the 50s
Sunday, to the 60s and perhaps 70 degrees on Monday. Timing of the
cold front on Tuesday afternoon will dictate on how warm
temperatures can reach in advance of the boundary. Ample mixing at h85
through the day may raise highs to the low 60s over far east central
Kansas while cooler readings in the mid 50s reside over north
central Kansas. Once the front passes, temperatures cool down
slightly with lows in the 30s and highs in the 40s on Wednesday.
Sided closer to the ECMWF on the next system arriving Tuesday
evening into Wednesday as the previous runs of the GFS are much
slower and inconsistent. A deepening PV anomaly in the wake of the
front warrants a chance for light rain or snow Tuesday evening,
transitioning to all rain Wednesday afternoon. Does not appear to be
a particularly strong system so do not foresee high amounts of precip
at this present time.

&&

.AVIATION...(For the 06Z TAFs through 06Z Thursday Night)
Issued at 1132 PM CST WED MAR 5 2014

Expect stratus ceilings that will vary between MVFR and VFR
through the night. KFOE may see periods of IFR ceilings.
Visibilities should be around 4SM, though if skies clear for a
while later tonight then patchy ground fog may develop. Model
forecast soundings show the boundary layer mixing deep enough for
scattered stratus by the mid and late morning hours. Expect VFR
conditions through the afternoon and evening.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...67
LONG TERM...Bowen
AVIATION...Gargan