Area Forecast Discussion
Issued by NWS Goodland, KS
FXUS63 KGLD 200435
Area Forecast Discussion
National Weather Service Goodland KS
1035 PM MDT TUE JUL 19 2016
.SHORT TERM...(This afternoon through Wednesday)
Issued at 147 PM MDT Tue Jul 19 2016
Early afternoon WV imagery and RAP upper level analysis show large
scale ridge centered over the plains dominating the pattern across
the US. Moist monsoonal plume is wrapping around the western extent
of ridge into the Rockies. At the surface; low pressure is in place
across eastern Colorado with a trough axis extending from northeast
Colorado and across northern Kansas. Southwest flow is in place
across much of our cwa.
This afternoon-Wednesday: Mean storm track remains well west of our
CWA with focus mainly in the central Rockies. A few weak shortwaves
may try rotating towards the northwest part of our CWA. West and
northwest parts of our CWA (near surface trough) also have better
chance to see any thunderstorm activity due to weaker CAP and better
instability. Further south and east in our CWA guidance shows a
stronger CAP and eventually a significant decrease in CAPE as
profiles warm and dry out during the afternoon periods. Strongest
precip signal in guidance matches with these trends (northwest). A
slightly stronger shortwave and shift in trough axis Wednesday (as
indicated by some models) may support a few thunderstorms moving a
little further east-southeast Wednesday afternoon (far northwest
Regarding temperatures/heat indices: Air mass aloft is only
expected to become warmer and consensus shows highs 2-4F warmer
than today. A major question on heat indices is Tds (which may mix
lower in our west). As Tds decrease below 60 heat indices actually
decrease from ambient temperature. Td recovery during the
nighttime periods we will see overnight heat indices in the 68-76
range (minimum) which is quite mild for our CWA. There may be a
few counties along western periphery of current heat advisory that
remain below "exact" advisory criteria, but it is close enough and
considering the very warm nighttime heat indices and several days
in a row of the hot temperatures the decision was made to upgrade
watch to heat advisory. Consecutive day requirement is not
expected to be met for issuance of heat warning at this time, so
advisory was favored.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 213 PM MDT Tue Jul 19 2016
Overall, not much has changed in the long term. Hot temperatures
are still the main story in the midterm while precipitation
chances persist throughout the extended.
Wednesday night through Friday, high pressure dominates the pattern.
Above normal temperatures are anticipated with highs from the upper
90s to the low 100s on both Thursday and Friday, with Thursday being
the hotter day for most locations. With dewpoint temperatures in the
lower 60s, heat indices will be around 105 generally east of a line
from Russell Springs, Kansas to Benkelman, Nebraska. This has
warranted a heat headline for these locations. As mentioned in the
short term discussion, the watch has been upgraded to a heat
advisory (beginning Wednesday afternoon) and extended to cover
through Friday afternoon. Expect somewhat dry conditions for the
majority of the area, with only slight chances for convection each
afternoon/evening as monsoonal moisture filters into the region
along the western side of the ridge and disturbances pass through
the upper flow.
Friday night and the weekend, the ridge across the CONUS breaks down
as a trough tracks from the Pacific Northwest and across the
northern Plains, sending a cold front south. Will see more seasonal
temperatures over the weekend. With a boundary nearby, expect
thunderstorm chances through the weekend.
Early next week, guidance differs on how the pattern develops.
Consensus seems to be that the high pressure retreats to the west,
bringing more of a west/northwest flow to the region. Some
perturbations round the northern side of the high, traveling from
the Rockies to the High Plains. This setup generates an opportunity
for additional precipitation as the trough impacting the region
during the weekend continues to push towards New England.
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1030 PM MDT Tue Jul 19 2016
For KGLD and KMCK, vfr conditions expected through the period.
Only a few mid and high clouds expected through the period. Winds
begin the period from the south to southeast occasionally gusting
near 20kts. This continues overnight with a slight veering to the
southwest around 10kts or so after 14z. Both terminals will see
wind shear in the 07z-12z timeframe.
KS...Heat Advisory from noon Wednesday to 7 PM CDT Friday for
NE...Heat Advisory from 11 AM MDT /noon CDT/ Wednesday to 6 PM MDT /7
PM CDT/ Friday for NEZ079>081.