Area Forecast Discussion
Issued by NWS Topeka, KS
FXUS63 KTOP 171734
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1234 PM CDT Sun May 17 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 313 AM CDT SUN MAY 17 2015
Early this morning, the upper level trough, that brought
widespread thunderstorms across the CWA this evening, was located
across south central NE and was lifting northeast. A 700MB dry
slot was moving northeast across eastern KS. The deeper moisture,
stronger ascent and thunderstorms were pushing east across MO.
Today, The upper trough will continue to track north-northeast into
eastern ND by 00Z MON. Surface winds will become southwesterly
during the morning hours and will increase to 15 to 25 MPH with
gusts of 30 to 35 MPH during the late morning and afternoon hours.
Most of the day will be sunny, though a few boundary layer CU may
develop across the northern CWA during the afternoon hours.
Afternoon highs will reach the lower 80s.
Tonight, a cold front will push southward across the CWA. The
low-levels of the atmosphere look too dry for any pre or post
frontal showers to develop. Overnight lows will drop into the 50s.
.LONG TERM...(Monday through Saturday)
Issued at 313 AM CDT SUN MAY 17 2015
For Monday through Tuesday, a surface ridge of high pressure is
expected to build south through the forecast area. With this being
a modified Canadian airmass, temps are forecast to be below
normal. Shortwave ridging and a lack of an obvious shortwave is
expected to lead to dry weather prevailing.
By Tuesday evening, models show a return flow setting up over the
surface ridge with good moisture advection developing over the
area. Weak perturbations are also expected to move over the area
as a closed low lifts through the central Rockies. With there
being good agreement and consistency among the models, there
there will be another round of widespread showers. Models remain
relatively cool with the column so there is little instability for
intense convection. With this in mind, have continued to focus on
showers being the predominant weather and trended POPs higher for
Tuesday night. Have kept some likely POPs across eastern KS
Wednesday morning, but expect the overall trend Wednesday to be
one of precip ending as the mid level perturbations weaken and low
level moisture advection diminishes. Wednesday may end up being
the coolest of the week due to precip initially and cloud cover
limiting insolation. Have highs in the mid 50s to near 60 because
Wednesday night and Thursday appear to be a time without precip as
shortwave ridging redevelops over the central plains. Continued
surface ridging at the surface is expected to limit any warming
trend. Highs are progged to be in the mid 60s on Thursday. For
Friday and Saturday, the ECMWF and GFS show the next mid level low
moving into the southwest and eventually lifting through the
central plains. While there are some timing and strength
differences between the two solutions, this fits in with the
current pattern of energy coming out of the southwest every couple
days, so have maintained POPs through the period. The better
chances should be Friday night and Saturday when the southwest
flow aloft sets up for energy to propagate overhead. Temps should
modify gradually but the forecast doesn`t get carried away as the
GFS/MEX would suggest thinking cloud cover and precip chances
could hinder the warm up.
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1233 PM CDT SUN MAY 17 2015
Skies continue to clear leaving VFR conditions for the entire
period. Gusty SW winds will die down by 00Z and then shift from the
N around 10Z tomorrow. Winds will pick back up again tomorrow after