Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/07/20
Area Forecast Discussion
National Weather Service Dodge City KS
704 PM CST Fri Mar 6 2020
...Evening Updated to issue Fire Watch east and south of Dodge
City...
.UPDATE...
Issued at 702 PM CST Fri Mar 6 2020
NAM, GFS, and HRRR BUFR soundings were all in decent agreement
late today with a low level jet of around 50 knots developing
overnight. These strong winds will mix down to the surface by late
Saturday morning and then continue through late day. Sustained
winds during the afternoon are expected to range from 25 to near
35 mph with gusts of 45 mph being possible at time. In addition
to these strong winds the afternoon dew points may also end up
being lower than previously thought given the depth of the mixed
layer and forecast moisture profiles in this mixed layer. Have
therefore lowered the surface dew points during the day on
Saturday and as a result am noticing that the afternoon relative
humidity values are now expected to range from the teens to around
20 percent. These strong winds and lower humidity values will
contribute to ongoing drying fuels. The potential exists for fires
to escape control more easily and containment is difficult.
Conditions in some locations will come very close to Red Flag
conditions, mainly east of a Liberal to Dodge City to near Hays
line. As a result will be issuing a Fire Weather Watch for
locations east of a Liberal to Dodge City to near Hays line.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 223 PM CST Fri Mar 6 2020
A broad ridge of high pressure in the mid-upper troposphere
overspread much of the western and central CONUS today. Meanwhile, a
deep trough encompassed the eastern CONUS with a significant storm
developing off the Mid-Atlantic Coast. A surface ridge of high
pressure was centered from Iowa south into Texas. A new leeside
trough was developing fairly quickly as the upper level flow pattern
was starting to increase and become increasingly southwesterly
component across the Central and Northern Rockies. The main sensible
weather element of interest through this period will be the strong
winds. A strong south-southwest wind was already underway along and
west of the U283 corridor with a number of observations showing 25
to 30 mph sustained wind, especially across far southwest Kansas.
As the leeside trough continues to develop and increase its
influence on the pressure gradient, the strong south-southwest winds
will continue to expand its areal extent. Tonight`s winds will be in
the 15 to 25 mph range pretty much everywhere across western Kansas
without any break. These strong winds through the night will keep
temperatures up in the 40s. Saturday will be the windiest days
coming up, with all areas expected to experience 25 to 35 mph
sustained winds. Some gusts in the 40 to 45 mph range will also
occur, especially in the afternoon. We updated the temperature
forecast for Saturday adding more (warmer) HRRR weight over the NBM
starting point.
.LONG TERM...(Saturday night through Friday)
Issued at 223 PM CST Fri Mar 6 2020
A fast-moving southern stream storm will be pushing northeast out of
New Mexico and across Kansas late Sunday/early Monday. Low level
moisture will increase quite a bit over what have been seeing
lately, as dewpoints increase to the mid to upper 40s. These
dewpoints will be enough to result in just enough MUCAPE to support
inclusion of thunder in the Wx grids (Slight Chance). Overall, the
forecast has not changed much with respect to POP and QPF, although
some of the latest runs of the GFS and ECMWF support a little more
precipitation now, perhaps up to one-quarter inch in some areas
along/east of U283. The cold air advection behind the Sunday Night
storm system will be brief and largely inconsequential. The highs
Monday will be 5 to 10 degrees cooler across the whole region. The
Another storm will be digging down south off the California coast,
which will cut off from the northern branch. This is starting to
look like a more impressive system for the southern and central
Great Plains with perhaps widespread substantial rainfall toward the
end of next week. So much can and will change with respect to this
storm around March 12-14, including how much cold air may be
involved north of the front (wherever it may be positioned once the
California low comes out).
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 514 PM CST Fri Mar 6 2020
Gusty south southwest winds at around 20 knots at 23z Friday will
decrease some after sunset as the boundary layer winds decouples
this evening. Breezy conditions however can still be expected
overnight with a south wind at 15 to 20 knots. HRRR, NAM and even
the GFS BUFR soundings indicating wind speeds in the 1500 to 2000
ft AGL will increase to 45 to around 50 knots by 06z Saturday and
then continue through early Saturday morning. As a result have
included a low level wind shear group at GCK, DDC, HYS, and LBL
overnight. These winds in the 1500 to 2000 ft AGL level will then
mix down to the surface by 15z Saturday which will result in gusty
south southwest winds increasing to around 25 knots. Only High
level clouds (greater than 15000ft AGL) can be expected over the
next 24 hours.
&&
.FIRE WEATHER...
Issued at 223 PM CST Fri Mar 6 2020
Elevated to Near-critical fire weather conditions were occurring
across southwest and west central Kansas west of U283 where
sustained winds were in the 20 to 30 mph range. There is just enough
moisture with dewpoints in the upper 20s to lower 30s to prevent the
relative humidity from reaching the critical 15-percent. There will
likely be a few hours later in the afternoon/early evening when the
RH will be around 20 percent or so. Regardless, very aggressive fire
behavior can be expected along and west of U283. Saturday will be
windier everywhere with sustained winds of 25 to 35 mph. Again, the
afternoon relative humidity is not expected to fall much below 25-
percent as dewpoint temperatures are expected to remain mostly in
the lower 30s. Given how strong the winds will be, Near-critical
fire weather behavior can be expected on Saturday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 42 71 45 70 / 0 0 0 10
GCK 42 71 44 73 / 0 0 0 10
EHA 42 73 45 72 / 0 0 0 10
LBL 40 71 43 70 / 0 0 0 10
HYS 42 73 45 72 / 0 0 0 0
P28 37 70 42 67 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch Saturday afternoon for KSZ046-065-066-078>081-
086>090.
&&
$$
UPDATE...Burgert
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Burgert
FIRE WEATHER...Umscheid
Area Forecast Discussion
National Weather Service North Platte NE
604 PM CST Fri Mar 6 2020
.SHORT TERM...(This evening through Saturday night)
Issued at 301 PM CST Fri Mar 6 2020
The guidance blend plus bias correction was the basis for the
temperature forecast tonight through Saturday night. The models
continue to show h850mb temperatures rising to around 15C and
h700mb of 0C to 5C. This should support highs in the upper 60s to
upper 70s throughout wrn and ncntl Nebraska Saturday. Nearly full
sun is expected but some patches of cirrus will move through at
times. These high clouds are associated with an upper low
affecting the swrn U.S. and are not expected to affect the heating
cycle across Nebraska.
The guidance blend plus bias correction keeps overnight lows in the
upper 20s and 30s tonight with 30s and 40s Saturday night. The RAP
and NAM models shows a 40kt low level jet developing both nights and
this should disrupt the radiational cooling process. The thermal
ridge moves overhead Saturday night and this will contribute to the
lows which will be close to record warm in some areas.
.LONG TERM...(Sunday through Friday)
Issued at 301 PM CST Fri Mar 6 2020
The models have collectively slowed the progress of the cold
front approaching nrn Nebraska Sunday afternoon. Several models
hold the front north of Nebraska until 21z. The temperature
forecast Sunday has warmed a few degrees and now features highs
mostly in the upper 60s to mid 70s. The models show high clouds
during the day and this will have a modest affect the heating
cycle.
Rain chances continue Sunday night and Monday and the models are
showing signs of modest amplification of a wave moving off the the
Colorado Rockies. The models are tracking the disturbance east
northeast through Nebraska and this would favor wrn and ncntl
Nebraska for the best rain chances vs earlier model runs which
favored KS.
The rain forecast Tuesday and Thursday now indicates chances of
showers and the GFS ensemble is perking up on rainfall amounts with
each of these disturbances.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 604 PM CST Fri Mar 6 2020
The main aviation concern heading into the next day will be the
gusty winds across the eastern Panhandle and northern Nebraska. KVTN
will continue to experience gusty winds up to 25 knots through early
evening. Gusty winds return on Saturday afternoon at KVTN with gusts
again up to 25 knots. VFR conditions are expected at KLBF through
Saturday afternoon.
&&
.FIRE WEATHER...
Issued at 301 PM CST Fri Mar 6 2020
A blend of the guidance suggests temperatures in the upper 70s
and wind speeds of 15 to 25 mph across northwest Nebraska Saturday
afternoon. The dew point and humidity forecast using the HRRR,
RAP and short term model blend produces humidity values near or
below 15 percent. All of this, assuming the forecast is not too
aggressive, warrants a Red Flag Warning across parts of western
Nebraska Saturday.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 7 PM MST Saturday for NEZ204.
Red Flag Warning from noon to 8 PM CST Saturday for NEZ206-208.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Kulik
FIRE WEATHER...CDC
Area Forecast Discussion
National Weather Service Pocatello ID
242 PM MST Fri Mar 6 2020
.SHORT TERM...Today through Sunday night...Current satellite
imagery shows our area in southerly flow with the high pressure
ridge axis well east of our area. There is an approaching Pacific
trough that is currently coming on shore off the Washington and
Oregon coasts. Models continue to show this system move over our
area tomorrow afternoon into early Sunday morning.
Still expecting much warmer than normal temperatures this
afternoon through Saturday afternoon.The NOHRSC modeled snow melt
has 0.50 to 1.00 inch (with localized amounts in our southeast
areas up to around 1.5 inches) of snow melt today through
Saturday with the warm temperatures ahead of this system as well
as rain on snow for mainly the Upper Snake Plain between
Blackfoot and Idaho Falls extending south and east across the
Southeastern Highlands, especially the Franklin/Oneida region.
Models are indicating around 0.05 to 0.25 inch of rain to fall on
the snow areas mentioned above. This snow melt/rain on snow will
likely cause minor ponding of water. Idaho Falls and Malad are the
two bigger cities in these areas that will likely see some
ponding of water.
The cold front that is currently off the Washington and Oregon
coasts moves through Saturday into Sunday morning from west to
east bringing valley rain and mountain snow. Expect snow levels
around 5500 feet rising to 6500 to 7000 feet. Snow amounts look
to be around 4 to 8 inches for the northern Central mountains
above 7000 to 7500 feet where a winter weather advisory remains in
place above 7500 feet. Galena Pass will be the main travel way
that will have impacts. Look for 2 to 5 inches for the Eastern
Highlands above 6000 to 6500 feet and the Southeastern Highlands
above 6500 to 7000 feet. Winds will be breezy, especially for
our Southeast areas on Saturday afternoon into the evening. Sunday
morning the snow lingers along our eastern areas with
colder/drier air moving into the Central mountains. By late Sunday
models are showing precipitation to redevelop mainly for our
southeast area with snow levels around 5000 to 5500 feet which
could add additional rain on snow below these levels. Wyatt
.LONG TERM...MONDAY THROUGH NEXT FRIDAY...
In the wake of our weekend shortwave trough/storm system, the parent
high pressure center is forecast to track east across Canada, with
an attendant second, more pronounced shortwave trough loading up
along the Pacific coast. Models continue to show decent agreement on
the approaching lift generating another round of precip starting
late Mon AM, focused across the srn/ern highlands and Bear Lake
(although light showers will be possible anywhere). Meanwhile, a
fairly intense low pressure center will be approaching the CA coast,
and strong SW flow may pick up additional moisture from this low and
feed it NE ahead of the shortwave trough. There remain some slight
timing differences between the GFS/ECMWF/Canadian on when the trough
axis/associated cool front will cross SE Idaho, but the general
window is between about sunrise and sunset Tues, with precip ending.
More seasonal temps for this time of year will again support a mix
of rain/snow depending on elevation, with snow levels running about
5,000 to 6,000 feet during the day and close to valley floors at
night. We used a WPC/NBM blend for QPF, which still doesn`t look
terribly concerning for snowfall, generally a dusting to an inch
below about 6,000 feet and 1 to 5 inches above with a pretty decent
terrain-based gradient, again mostly across the srn/ern highlands.
This forecast is running near or slightly above the NBM 50th
percentile, which increases our confidence that overall impacts are
looking limited from this system. (Even the NBM 90th percentile is
only painting some advisory-level snowfall in this zone.) GFS/EC
ensembles are running hot for the Teton Valley, suggesting 4 inches
or more of snow, but this seems potentially overdone, especially if
temps are warm enough for any rain to mix in Mon (it will be
borderline). Overall, plan on some potentially slick travel
south/east of the Snake Plain Mon afternoon into Tues, especially
over mntn passes, with little to no impact elsewhere. Winds do not
appear to be a concern at this time. From Wed onward, the main story
will be the closed low shifting east into the 4-corners region. At
this time, all models keep this storm south of our forecast area
with little to no impact for ID, but we will continue to monitor
trends for any shifts in the track. Temps mid-late week are forecast
to run near to slightly above normal, generally topping out in the
40s to low 50s. Model agreement breaks down by next weekend, but in
general it appears another low pressure system or trough may drop
into the northern Rockies with another round of precip. - KSmith
&&
.AVIATION...High pressure remains firmly in control of our weather today across
the region with VFR cigs/vsbys, but wind has been the big story. NAM
time-height plots and NAM/NAMNest/RAP BUFKIT soundings all show a
strong SW flow reaching 20-30 knots as you ascend toward 2,000 feet
(weaker in the Central Mntns), with PIREPs even suggesting 10+ knots
of gain in just the lowest 500 feet. At KPIH, strong southerly
downsloping (well overperforming MOS guidance but captured by the
HRRR) has mixed the stronger winds down to the surface and reduced
shear (and increased runway crosswinds), but with a rather weak
northerly wind field at KIDA and no expectation of SW winds reaching
the terminal or much of a diurnal increase, we are likely close to
or meeting LLWS criteria, and we have amended to add this to the TAF
throughout the day. Winds just off the surface may strengthen even
further tonight, possibly reaching 30-40 knots by 1,500 to 2,000
feet, just in time for sfc winds to decouple. Thus, we carry LLWS at
KPIH, KIDA, and KDIJ throughout the night into Sat. The magnitude of
the shear looks a little weaker at KBYI, so we left LLWS out of
their TAF for now as our confidence is lower, but we will need to
continue to reevaluate this in future TAFs. LLWS concerns will
likely remain right through the end of the 18z TAF period or just
beyond. The HRRR supports the strong S 22G32kt downslope and
crosswind concern continuing through 02z this eve at KPIH before
rapidly decreasing, and this matches well with when their winds have
tended to drop off previous evenings. Our weekend storm will arrive
from NW to SE over the course of the day Sat, and we have KSUN
dropping to MVFR cigs by 17z with RASN. Onset of the greatest
impacts is just beyond the TAF period for the rest of the major
terminals, but in general, expect a trend toward MVFR cigs and
increasing precip over the course of Sat afternoon/Sat night, with
possibly IFR vsbys at KDIJ during periods of snowfall. - KSmith
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 5 AM to 11 PM MST Saturday for
IDZ072>074.
&&
$$
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Saturday)
Issued at 350 PM CST Fri Mar 6 2020
South to southwest winds increase for tomorrow with temperatures
still running about 15 degrees above normal.
A meridional surface high pressure cell axis shifted east of the
forecast area this afternoon, with south to southeasterly winds
slowly increasing on its backside. By 3pm, winds at Concordia had
already risen to 15 to 20 kts with the increasing pressure
gradient upstream. This area of pressure falls shifts eastward
tonight, with winds at higher elevations staying mixed just mixed
enough to keep speeds from dropping overnight. Despite a small
degree of lower-level theta-e advection taking place overnight on
this return flow, strong daytime mixing should quickly result in
dewpoints falling into the mid-20s and high temperatures pushing
the 70 degree mark.
South to southwest surface winds rapidly strengthen at the onset
of daytime mixing, with gusts over 35 kts possible at times. At
this point, did not go with a wind advisory for Saturday, but
conditions will be very close and will need reassessing tonight.
The only fly in the ointment to the forecast is a a band of high
clouds trailing the H500-300 ridge axis, which may temper mixing
slightly. The 18Z HRRR, however, still shows very deep mixing akin
to today and given the recent verification success of the HRRR in
this pattern, did trend dewpoints towards this solution. Extreme
fire weather conditions are likely on Saturday--please see the
fire weather section for more information.
.LONG TERM...(Saturday night through Friday)
Issued at 350 PM CST Fri Mar 6 2020
A more active weather pattern sets in for next week with multiple
chances of precipitation through the rest of the forecast period.
The broad upper level ridge shifts east of the forecast area by
Saturday evening ahead of a longwave trough digging into the
western CONUS. Southwesterly flow becomes established Sunday
morning behind the aforementioned shortwave embedded near the
crest of the longwave ridge. Lower tropospheric theta-e advection
increases Saturday night into Sunday on an H850 40-50 kt jet,
setting the stage for a warm day on Sunday, though dewpoints will
be 20 degrees higher than Saturday. Lee cyclogenesis results in a
low pulling off the Front Range Sunday evening with broad
isentropic upglide ahead of the system possibly resulting in rain
for Sunday night.
As the low shifts eastward, it will drag a weak surface cold
front through during the morning on Monday. NAM/GFS forecast
sounding lapse rates are rather shallow for thunder potential, but
did still keep some mention of thunder in the forecast at times
with the passage of this system. There is some uncertainty with
the timing of the wave based on the various medium range
solutions, but there should be a period of drier weather on
Tuesday before a northern stream wave drops southward midweek. No
real appreciable airmass changes are forecast for the week,
resulting in highs in the upper 50s/60s and lows in the 40s.
Both the 12Z EC and GFS do depict a much more potent system for
late in the week, but confidence in its track, evolution, and
impacts are low at the present time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 536 PM CST Fri Mar 6 2020
VFR conditions will continue with only some areas of thin cirrus
throughout the forecast. The only minor changes were to winds and
wind shear with notable wind conditions developing by 08Z and
persisting well beyond this forecast.
&&
.FIRE WEATHER...
Issued at 350 PM CST Fri Mar 6 2020
South to southwest winds increase Saturday morning to between 20
and 30 mph with gusts to 40 mph by midday. Transport winds will
push 35 to 40 mph and mixing heights rise to over 4 kft, promoting
excellent ventilation rates. Daytime humidity values are forecast
to fall to around 20 percent, though there is slight degree of
uncertainty in these values due to an increase in high cloud cover
during the day that may temper daytime mixing. There is also a
chance that humidity values fall even lower if temperatures are
warmer or dewpoints lower than forecast as a few model solutions
are depicting. A very high to extreme fire danger will be present
during the afternoon hours. A fire weather watch has been issued
for Saturday afternoon for these conditions.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch Saturday afternoon for KSZ008>012-020>024-026-
034>040-054>056-058-059.
&&
$$
SHORT TERM...Skow
LONG TERM...Skow
AVIATION...65
FIRE WEATHER...Skow