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Area Forecast Discussion (AFD)

Issued by Topeka, KS (TOP)

FXUS63 KTOP 150422

Area Forecast Discussion
National Weather Service Topeka KS
1122 PM CDT Sun Jul 14 2019


.SHORT TERM...(This evening through Monday)
Issued at 302 PM CDT Sun Jul 14 2019

This afternoon a broad mid-level ridge remained stretched across 
much of the CONUS, with Tropical Storm Barry progressing northward 
across Louisiana and Arkansas.  Visible satellite imagery showed 
some low/mid clouds in association with Barry extending as far north 
as into northeast and east central KS.  However, there were enough 
breaks in this cloud cover to still support decent afternoon heating 
today with highs reaching into the low 90s.  With models showing 
temperatures at or near the convective temperature across far east 
central KS, cannot rule out the potential for a few isolated showers 
and storms to pop-up through late this afternoon.  However, with 
limited available moisture and lift present, confidence remains low 
for this isolated development so have only some slight-chance PoPs.  

For tonight, some short-range models show the potential for enough 
low-level moisture to be present to support some very shallow fog 
development briefly Monday morning around sunrise near river valleys 
and in low-lying spots.  Due to low confidence, haven't mentioned 
fog in the forecast, but it will be something to monitor this 
evening/overnight.  Otherwise, the continued northward progression 
of the surface/mid-level lows associated with Barry will support 
increasing coverage of low clouds across much of northeast and east 
central KS Monday morning into the afternoon hours.  There is still 
some model uncertainty with how long this cloud cover will linger 
through the afternoon hours, which is resulting in a model spread of 
nearly 10F degrees still for high temperatures across that area. 
Have continued to trend a couple of degrees cooler across eastern KS 
to account for this cloud cover with highs ranging from the mid 80s 
to low 90s from east to west across the CWA, respectively. Much like 
today, temperatures may be near the convective temperature tomorrow 
to possibly support a few isolated showers/storms, however with very 
little forcing present, confidence is quite low so only have some 
slight chance PoPs mentioned for far east central KS.  

.LONG TERM...(Monday night through Sunday)
Issued at 302 PM CDT Sun Jul 14 2019

By Tuesday, the remnants of Barry will start tracking further to the 
northeast, which will allow the mid-level ridge to build back in 
across the central U.S.  There is the potential for the ridge axis 
to become more zonal by mid-week as a weak mid-level shortwave 
trough tracks eastward across the Northern Plains. This passing 
shortwave to the north may deepen enough to cause some embedded 
disturbances within the mid-level flow to skim near the KS/NE border 
to produce some scattered precipitation chances.  However, 
confidence in any precipitation chances mid/late week are low due to 
varying model solutions with how far north the ridge axis will be 
able to build and, thus, where any embedded disturbances will track. 
At this time, have some slight chance PoPs near the KS/NE border 
Wednesday night, but otherwise have a dry forecast through the end 
of the work week.  The mid-level ridge looks to steepen through the 
latter half of the week and possibly even into next weekend as a mid-
level trough moves into the Pacific Northwest.  As a result, this 
pattern will support continued reinforcement of the heat and 
humidity with steady warm, moist-air advection into the area.  The 
GFS seems to be trending a few degrees cooler with high temperatures 
by late week but it seems to be more of an outlier so have continued 
to trend toward the warmer model guidance. With 850mb temperatures 
surging into the 25C to 30C range by late week, it should support 
high temperatures rising into the mid/upper 90s to low 100s starting 
Wednesday persisting through at least the end of the work week. 
These temperatures combined with dewpoints in the mid/upper 60s to 
low 70s will support heat index readings soaring into the 103 to 109 
degree range through the end of the week and possibly even into 
Saturday. As a result, continue to anticipate the need for heat 
headlines for the latter half of the week.   

Model solutions start to diverge by next weekend as some keep the 
steep mid-level ridge in place while other models try to break down 
the ridge some with embedded waves within the ridge axis possibly 
tracking near the CWA.  Confidence at this time is low for any 
precipitation chances, but it will be something to monitor in the 
upcoming days as it could certainly have an impact on whether or not 
the excessive heat persists into next weekend.  


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1122 PM CDT Sun Jul 14 2019

Models show a low potential for some ground fog overnight. With
forecast soundings showing the boundary layer moisture to be
relatively shallow with some wind at the top of the layer, think
any fog would be isolated and brief. Otherwise VFR conditions
should prevail with a CU field redeveloping over east central KS
by the late morning. No obvious forcing or lift would suggest any
convection would be isolated and this is supported by the latest
CAMs solutions. 




SHORT TERM...Hennecke
LONG TERM...Hennecke