Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/10/22

Area Forecast Discussion

National Weather Service Denver/Boulder CO

 836 PM MDT Sat Apr 9 2022

.UPDATE...
Issued at 830 PM MDT Sat Apr 9 2022

Currently, there are some showers inedited over mountains and
upstream of the CWA to the west currently. Observations are
showing the incoming cold front into Weld County and just through
Greeley 5 minutes ago. There are also a few showers producing
virga over the far northeast corner. The latest high resolution
models are still showing some minor showers overnight, especially
over the mountains. Will make a few adjustments to pops, with a
bit less for the plains overnight. Will make sure the timing of
this evening`s front is accurate. Will also adjust temperatures
overnight and Sunday; just a little.

&&

.SHORT TERM...(This evening through Sunday)
Issued at 215 PM MDT Sat Apr 9 2022

A storm system will move across northern Colorado this evening
with snow showers expected to increase in the mountains. Latest
RAP shows a brief window of moderate QG ascent from 00z-06Z this
evening of 20-30 mb/hr. Storm totals in the 1 to 5 inch range
expected, highest north of the I-70 corridor.  Some instability
with this feature as well with a 90 kt jet max. Will add isold
thunderstorms as well primarily over the northern mountains and
the plains along the northern border. A cold front associated with
this system will push into Denver in the 8-10 pm range with
northeasterly post frontal winds. The best chance of precipitation
will remain north and northwest of Denver, but 20-30 percent pops
seem okay for now as a few of the models are showing a little
qpf. On Sunday, it will be around 20 degrees cooler. Gusty bora
winds will develop with good mid level lapse rates and decent
downward mid level subsidence expected. Not enough wind for a high
wind warning, but strong winds will elevate the fire weather
conditions in spite of the cooler temperatures. Reference the fire
weather discussion below for details.

.LONG TERM...(Sunday night through Saturday)
Issued at 148 PM MDT Sat Apr 9 2022

Broad zonal flow aloft will be in place Monday ahead of an
approaching strong storm system. Mid-level southwesterly flow will
help warm temperatures back into the 60s across most of the lower
elevations during the day. Gusty winds will be likely across the
Palmer Divide and far eastern plains where elevated or perhaps
critical fire weather conditions will be possible yet again. Lee
troughing will keep winds light across the foothills and urban
corridor but warm/dry conditions are still forecast there.

We should start to see some mountain rain and snow showers late
Monday night into Tuesday as a broad, deep upper trough moves
across the intermountain west. Guidance continues to slowly trend
towards a largely unfavorable storm track for Colorado, with the
initial upper level low weakening across the northwestern Rockies
before reforming somewhere in the Northern Plains. With
southwesterly flow likely to continue Tuesday, we should see highs
in the 60s to 70s over the plains with unsettled weather
continuing across the mountains. Even in the high country,
moisture isn`t particularly impressive and the current QPF
forecast isn`t particularly robust.

Cold air should push in Tuesday night into Wednesday as a strong
cold front works across the plains. There may be a brief window of
opportunity east of the divide to see some rain or snow late
Tuesday night/early Wednesday AM with a short period of upslope
flow combined with at least a little surface moisture. The non-GFS
blend is bullish on QPF over the Foothills, but would like to see
a lot more consistency before making any major deviations from
blended guidance.

Uncertainty increases through the rest of the week as longer-
range guidance struggles with the evolution of the longwave
trough. There is fairly good ensemble support for cool weather to
continue into next weekend, but any specifics are too uncertain to
discuss in detail. We`ll likely need to wait a couple days... at
least until the models figure out the first wave... until we have
a clearer picture.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 830 PM MDT Sat Apr 9 2022

The current cold front looks to be moving southward across the CWA
a bit quicker than was earlier advertised. Will make appropriate
adjustments.  Will go with a brief period of ceilings in the
BKN030-040 range from 08Z- 12Z. Will also leave in VCSH in that
time frame. Will bring in Sunday`s expected strong northwesterly
winds in by 16Z.

&&

.FIRE WEATHER...
Issued at 830 PM MDT Sat Apr 9 2022

Critical fire weather conditions have subsided early this evening
so the Red Flag Warning has expired.

Dry and windy conditions are expected across the urban corridor
and northeast plains on Sunday, in spite of the cooler
temperatures. Therefore the Fire Weather Watch has been upgraded
to a Red Flag warning and also included Fire Weather Zones 246 and
247.

Elevated or near-critical fire weather conditions will be possible
on Monday and Tuesday ahead of a strong storm system. Minimum
humidity both days is expected to fall in the 15-20% range across
the Palmer Divide and into the far eastern/northeastern plains.
Winds are expected to be lighter across the Foothills and urban
corridor limiting fire danger. We may eventually need additional
headlines... especially along and southeast of I-76... but
confidence is too low at this time.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM to 7 PM MDT Sunday for COZ238>251.

&&

$$

UPDATE..........Koop
SHORT TERM......Coop
LONG TERM.......Hiris
AVIATION........Koop
FIRE WEATHER....Koop/Coop/Hiris



Area Forecast Discussion

National Weather Service Lincoln IL

 938 PM CDT Sat Apr 9 2022

.SYNOPSIS...
Issued at 156 PM CDT Sat Apr 9 2022

After another chilly night in which frost and freeze temperatures
will remain a concern, the pattern breaks in a major way. By
tomorrow, temperatures will surge into the 70s with near daily
chances for showers and thunderstorms between Sunday and
Wednesday. Some of these storms will be severe, so be sure to
check the forecast each day for updates.

&&

.UPDATE...
Issued at 930 PM CDT Sat Apr 9 2022

The weather the rest of the night will be on the quiet side, as
central Illinois will be between systems. The gusty afternoon
winds have diminished, and skies are relatively clear of clouds
under a narrow corridor of high pressure. Diurnal cooling will be
maximized in our eastern counties, where winds will remain light
through morning. That will allow low temps to drop to freezing or
slightly below. The Freeze Warning counties still look good, and
no adjustments will be needed with that headline.

Areas west of I-55 will see increasing southerly winds later
tonight. That will cause late night temps to steady out or even
slowly rise before sun-up, keeping low temps in our western
counties above freezing in the mid to upper 30s.

Deep mixing will occur early Sunday morning, responding to a
tightening surface pressure gradient. Wind gusts by mid-morning
will climb toward 30 mph, with up to 40 mph southerly gusts by
mid-day.

&&

.SHORT TERM...(Tonight through Monday)
ISSUED AT 156 PM CDT Sat Apr 9 2022

The few targets of opportunity over the short term include (1)
low temperatures tonight and how they impact frost/freeze
headlines, (2) gusty winds on Sunday, and (3) PoPs for late
Sunday evening.

Frost/Freeze:
Glancing through the latest suite of 12z hi-res guidance suggests
that locations east of a Lacon-to-Olney line have the best chance
of temperatures falling below 33 degrees tonight. Given the
immaturity and non-uniformity of early-season vegetation across
central and southern Illinois, it`s challenging to architect
Frost/Freeze headlines. Nevertheless, we`ve collaborated a Freeze
Warning for a good handful of our SE counties. Be sure to check the
latest Vegetation Freeze Susceptibility Guidance
(mrcc.purdue.edu/VIP/frz_maps/guidance_map.html) to better
understand how we decide which counties to include in headlines.

Our decision to upgrade to a warning comes down to the effects
of diurnal cooling, and is supported by the latest hi-res guidance.
As skies clear and winds go light overnight across portions of
central and east central Illinois, temperatures will crash near
their dew point. Both the 12z HRRR and latest NBM v4.1 suggest
temperatures will fall near or below 33 degrees across the eastern
third of our cwa late tonight, while the 12z HREF offers a
slightly milder solution. Regardless, we anticipate widespread
frost to develop across our eastern third into Sunday morning
before an uptick in wind speed.

Gusty Winds:
The surface pressure gradient will begin to tighten Sunday morning
ahead of a robust 500-mb trough and its attendant surface low.
Both hi-res and multi-model guidance reveal occasional gusts
between 30-40 mph, mainly north of the I-70 corridor. Some of the
highest gusts of the day may occur late in the morning east of the
Illinois River Valley where strong warm-air advection and
steepening lapse rates support deeper mixing.

PoPs Sunday Night:
Showers and storms are trending later into Sunday evening, and
look likely to extend into mid-morning Monday before the LLJ
recedes and convection wanes. Any strong/severe storms will likely
focus along the front, which appears to sag south of the I-72
corridor by the time the LLJ and mid-level shortwave impulse helps
initiate convection in our area. Model soundings continue to
exhibit a strong capping inversion during this timeframe, so
storms will mainly remain elevated; but elongated hodographs may
support a few instances of large hail across portions of central
and south central Illinois late Sunday night into Monday morning.

.LONG TERM...(Tuesday through Saturday)
ISSUED AT 156 PM CDT Sat Apr 9 2022

A stalled out surface front will begin to lift back northward
across the region by Tuesday in response to a deepening surface
cyclone over the Plains. This will position central Illinois
within a broad warm sector with low 60s dewpoints amid
strengthening low- and mid-level flow. Despite an increasingly
juicy boundary layer and backed surface winds in the vicinity of
the warm front, thermal profiles appear too capped for storms to
initiate by Tuesday afternoon. The better triggers arrive Tuesday
evening as a potent shortwave trough lifts across the Mid-
Mississippi Valley. This along with a strengthening/veering LLJ
will serve as the catalysts for a late- evening convective
episode. CAPE/Shear profiles do support severe weather in the
vicinity of that warm front, which will likely be somewhere
between the I-72 and I-80 corridors Tuesday night. At this time,
the focus looks to be west of the Illinois River Valley, where
lapse rates will be steepest.

The multi-model consensus continues to favor Wednesday evening as
the most active day of the period as the upper-level low pivots
across the Missouri Valley and eventually drives a surface cold
front across the region. Notable spread remains among global
models with respect to timing and amplitude of this upper-level
low, with the NBM favoring a EPS/CMCE solution over the GEFS.
Regardless of FROPA timing, thermodynamics and kinematics are
looking favorable for a classic severe weather outbreak with all
modes of severe weather possible. We`ll continue to drill down on
the details over the next couple of forecast cycles as global and
ensemble guidance resolves the pattern a little better.

Cooler, drier, and otherwise windy conditions will evolve over the
region on Thursday in the wake of frontal passage. Temperatures
will fall into the 50s/60s with overnight lows in the 30s/40s.
Winds will begin to relax a bit by Friday as the powerhouse storm
system makes its departure, but yet another frontal system
threatens to bring additional unsettled weather Friday night into
Saturday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 710 PM CDT Sat Apr 9 2022

The cumulus field from earlier this afternoon has shifted east and
dissipated as a drier air mass continues to overspread the area from
the west. VFR conditions are expected to prevail through the
entirety of this TAF period.

Surface winds will start out W-NW 5-10KT this evening, then
become light southerly after 06z/1am. Southerly winds will then
steadily increase Sunday morning with peak gusts exceeding 30 kts
by late morning or afternoon.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Freeze Warning until 8 AM CDT Sunday for ILZ054>057-061>063-
066>068-071>073.

&&

$$

UPDATE...Shimon
SYNOPSIS...MJA
SHORT TERM...MJA
LONG TERM...MJA
AVIATION...Shimon



Area Forecast Discussion

National Weather Service North Platte NE

 656 PM CDT Sat Apr 9 2022

.SHORT TERM...(This evening through Sunday night)
Issued at 402 PM CDT Sat Apr 9 2022

For tonight, an upper level trough will approach the area. Surface
low pressure will move east from western into central KS. A
deformation zone with frontogenetical forcing will exist across
the panhandle and northwest Sandhills. The NAM and GFS in good
agreement with placement across the northwest tonight. The HRRR
and RAP13 also agree on location, with slower timing for arrival
mainly after 06Z. The surface low in KS will drawn in some colder
air with a good surge of north winds 20 to 30 mph, mainly across
southwest and central NE. Temperature profiles will be able to
support some snow from the panhandle up through the northwest
sandhills with around an inch of accumulation near the Pine Ridge
and lesser amounts further south and east. Lows will range from
the around 30 northwest Sandhills to the mid and upper 30s
southeast.

On Sunday, snow showers remain possible during the morning across
the northwest Sandhills. The upper trough axis will move across
north central NE, with a continued chance for showers in the
afternoon and evening. Highs will only reach 45 far northwest,
with the far southeast reach to around 60. A surge of dry air will
move across the southeast panhandle into west central and
southwest NE and combine with a gusty northwest wind up to 35 mph.
This will bring critical fire weather conditions to fir zones
south of Interstate 80.

.LONG TERM...(Monday through Saturday)
Issued at 402 PM CDT Sat Apr 9 2022

The main forecast concern in the long term will be the potential
for strong winds Tuesday through Thursday.

A deep upper trough will dig across the Pacific Northwest Monday
and the Northern Plains and Central Plain Tuesday through
Wednesday night. The ECMWF has maintained its further north track,
yet is still further south than the GFS. There will remain
chances for rain showers, and snow showers during the night and
early morning. POPs however have been reduced from the previous
forecast as the main system should track from WY across the
Dakotas and MN. Strong northwest winds will be a concern.
Increased winds to the NBM 90th percentile from Tuesday afternoon
through Thursday. Models have been showing a consistent support
for strong winds. With the system expected to track further north,
the winds do not looks as strong as they did from a few days
ago. Still, think northwest winds could range 25 to 35 mph with
gusts to 45 mph during this timeframe. Highs Tuesday may reach the
70s to around 80 as the cold front moves in, then mainly in the
40s Wednesday through Saturday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 656 PM CDT Sat Apr 9 2022

Light precipitation will move into northern Nebraska tonight
impacting KVTN. Dry air across the south will keep precipitation
limited to the north. Gusty northwest winds will continue overnight
and through Sunday with northwest wind gusts up to 25 to 30 knots.

&&

.FIRE WEATHER...
Issued at 402 PM CDT Sat Apr 9 2022

Critical fire weather conditions will continue across portions
of western and north central Nebraska through Tuesday.

On Sunday, a Red Flag Warning is in effect for zones 210 and
219 in southwest Nebraska. Northwest winds 20 to 25 mph with
gusts to 35 mph will combine with afternoon humidity as low as
14 percent.

On Monday, Fire weather conditions appear elevated on Monday
with minimum RH in the upper teens to low 20s and southerly
winds gusting up to 25 mph.

On Tuesday, a storm system will approach the region. A cold
front will move into western Nebraska with warm temperatures
ahead of the front in the 70s to around 80. At this time,
elevated fire conditions are possible across southwest and central
Nebraska.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon CDT /11 AM MDT/ to 8 PM CDT /7 PM
MDT/ Sunday for NEZ210-219.

Red Flag Warning until 8 PM CDT this evening for NEZ208-209-219.

&&

$$

SHORT TERM...Roberg
LONG TERM...Roberg
AVIATION...Kulik
FIRE WEATHER...Roberg



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