Area Forecast Discussion
Issued by NWS Goodland, KS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KGLD 161108

Area Forecast Discussion
National Weather Service Goodland KS
508 AM MDT Mon Apr 16 2018

.SHORT TERM...(Today through Wednesday night)
Issued at 330 AM MDT Mon Apr 16 2018

Upper ridge axis will be over the region today, resulting in
mostly sunny skies and warming temperatures. Highs will range from
the upper 50s in the McCook area to the middle 70s in Kit Carson,
Colorado. There will be an area of elevated fire weather
conditions south of a line from Flagler to Leoti, where relative
humidity may get as low as 15 percent and southeast winds will be
15 to 25 mph.

Upper trough will move out of the Rockies on Tuesday and across
the local area Tuesday afternoon and Tuesday night. Wind and fire
weather will be the main impacts. Southwesterly winds will
increase through the afternoon in northeast Colorado then turn
northwest Tuesday evening behind a strong cold front as it moves
into northwest Kansas and southwest Nebraska. May see a few gusts
approaching high wind criteria, but wind speeds have come down
slightly from previous model runs. Could not get a collaborated
watch, and combined with low confidence will not issue any wind
highlight at this time. For areas south of Interstate 70, the
strong winds coupled with relative humidity less than 10 percent
will result in extreme fire weather conditions.

As the trough moves through Tuesday night there will be a few
widely scattered showers north of the Interstate, which may help
to mix down some stronger winds, but otherwise produce little in
the way of measurable rainfall.

Wednesday will be cooler with shortwave ridging behind the
departing trough. May see elevated fire weather conditions in
southwest half once again, but winds will be lightest where
humidity is lowest.

.LONG TERM...(Thursday through Sunday)
Issued at 351 AM MDT Mon Apr 16 2018

Main concern is the storm system to affect the area at the end of
the week as active pattern continues. Satellite showing a highly
amplified pattern from the Pacific into eastern North America.

Models in remarkable agreement through 12z Friday, taking incoming
closed low to near the Four Corners by this time. After that, the
models begin to diverge with ensemble spread also increasing. Even
though the models are different during the day on Friday, models are
still not too bad. However that changes Friday night. At 12z
Saturday, the 00z Canadian and Ecmwf were much further south and a
little slower, over east central New Mexico than the Gfs which was
over southeast Colorado.

Gefs mean and most individual members were more supportive a further
south solution. However, they were faster than the Canadian and
Ecmwf, and about the same or faster than the operational Gfs. Wpc
discussion/manual progs show/indicate a compromise with going toward
the slower solution, but had the low center in the middle of the two

The same trend continues on Sunday with the deterministic and
ensembles with the Ecmwf and Canadian further southwest than the
Gfs. Trends from previous run were the Gfs and Canadian being
further south and the latest Ecmwf being slightly further north.

At this time, the differences appear to not affect the chance of
precipitation with all the output indicating very high chances from
Thursday night into Saturday evening. Where the differences show up
is on the precipitation timing and especially amounts. So confidence
is high in measurable precipitation. So as a result made little to
no changes on qpf, pops, and temperatures from what the builder gave
me. The main change made was to increase the winds a little Thursday
into Friday night as a result of the surface ridge pushing off to
the east and the large height falls from the incoming system.

What is impressive and concerning is not only the qpf amounts given
to me by the Forecast Builder but also the 5 to 7 day totals, 1.50
to 2 inches over most of the area, depicted by WPC. This is also
reflected in the impressive precipitable water values forecast
during this time. Surface wind/pressure forecasts from Thursday into
Saturday night shows that our area has a good connection to Gulf
moisture. PW values get into the 0.75 to almost 1 inch range.
Comparing this to SPC sounding climatology that is above the 90
percentile. This is from near 2 to around 2.5 standard deviations
above normal.

At this time, it looks like most of the phase will be in the form of
rain with only locations along and especially to the west of the
Colorado border getting snow. So based on the above data believe the
threat of moderate to heavy rainfall is real. Right now there does
not look like a lot of thunderstorm activity, mainly in first 12 to
18 hours. This will have to be watched closely.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 507 AM MDT Mon Apr 16 2018

VFR expected at both KGLD and KMCK through the TAF period. Upper
ridge will be over the area resulting in mostly clear skies and
light winds.


KS...Red Flag Warning from noon MDT /1 PM CDT/ to 8 PM MDT /9 PM CDT/
     Tuesday for KSZ013-027-028-041-042.

CO...Red Flag Warning from noon to 8 PM MDT Tuesday for COZ253-254.



AVIATION...ERRYK is the U.S. government's official web portal to all federal, state and local government web resources and services.