000
FXUS63 KTOP 041138
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
538 AM CST Wed Mar 4 2015

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 325 AM CST WED MAR 4 2015

Latest water vapor imagery showing deeper moisture aloft surging
northeast from the Baja upper low across the southeast half of KS
and into the OH river valley. At the same time the southern
portion of a shortwave trough continues to support a weakening
band of snow near the NE border with a stronger upstream wave in
the Dakotas. The area of snow across the far northern CWA is
expected to diminish through sunrise as the better and stronger
focus for a band of snow sets up across the southern portions of
the CWA through 15Z. The better forcing from mid level
frontogenesis will be along and south of I 35 before slowly
shifting southward through midday. Expect Lyon...Coffey and
Anderson counties to be most affected through mid morning with an
inch or two possible before snow decreases and shifts southward.
With thicker clouds and precipitation across the east
central...highs today will be coldest in that area in the middle
to upper 20s...with readings closer to 30 north of I 70 where some
afternoon sunshine is expected.

Tonight should be dry...cold and mostly clear with decreasing winds.
Lows should range from 6 to 11 degrees...although the lows across
the east central counties may need to be lowered with any
significant snowcover.

.LONG TERM...(Thursday through Tuesday)
Issued at 325 AM CST WED MAR 4 2015

Models remain consistent in a dry northwest flow setting up for
Thursday through Tuesday. In this pattern, low level trajectories
are typically from the southwest and low level moisture advection
is hard to come by. This is the case in the latest model guidance
showing 850 MB winds retaining some westerly component through the
period. Additionally models have backed off on any potential low
amplitude shortwave moving across northeast KS, trending to track
these waves further north during the weekend. So with limited
moisture and no organized forcing anticipated by the models, the
forecast calls for dry weather with temps trending warmer.

Thursday should be the coldest day in the period as the surface
ridge axis begins the day over eastern KS. However with good
insolation think most areas will warm above freezing with some
spots in central KS reaching 40 where mixing may end up being a
little deeper. The warming trend should kick off for Friday as
warm air advects in from the southwest. There is the potential for
some weak Pacific fronts to move through the area over the
weekend per the 12Z ECMWF. Because of this have not gotten carried
away with the temps opting to keep highs in the upper 50s to
around 60. Lows should be around 30, which is close to normal for
this time of year, since much of the cold air should be bottled
up well northeast. Think early next week will be the warmest
period as the GFS and ECMWF show 925 temps warming to between 10C
and 15C. With this in mind, have highs is the middle 60s by
Tuesday.

&&

.AVIATION...(For the 12Z TAFs through 12Z Thursday Morning)
Issued at 532 AM CST WED MAR 4 2015

Will continue with a VFR forecast at all terminals as MVFR cigs
and IFR vsbys in snow remain south of the TAF sites thru the
period. Ceilings around 6 kft will steadily improve beyond 15z.
Gusty north winds will gradually decrease aft 15z with speeds
under 6 kts by 00z/05.

&&

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

$$

SHORT TERM...63
LONG TERM...Wolters
AVIATION...63