Drought in Nebraska, March 29 to 31, 2022

AREA FORECAST DISCUSSION
National Weather Service Hastings NE
1125 PM CDT Mon Mar 28 2022

...Aviation Update...

.UPDATE...
Issued at 949 PM CDT Mon Mar 28 2022

Just some of our latest thoughts regarding the various active
weather elements in play Tues-Wed, based on an early perusal of
00Z and higher-res model data. Want to make it clear though that
no changes of ANY substance have been made to the official
forecast since this afternoon, as day shift had things very much
covered (per excellent main discussion below):

- Fire weather:
Without a doubt, we are still overall more-concerned with fire
weather/potential wildfire ignitions Tues afternoon-evening in our
southern zones than we are with severe storm potential in our
eastern zones (comparatively speaking). Although still not as warm
as our official forecast in most spots, even the 00Z NAM is coming
around to a warmer/drier solution Tues afternoon (especially in
southeast half of our coverage area/CWA). Will defer to upcoming
night shift to decide whether to upgrade the six Fire Weather
Watch counties on the northern/western fringes of the critical
fire weather threat, but the 7 existing Red Flag Warning counties
continue to look solid for not only critical but potentially
dangerous/higher-end fire weather conditions (especially given
strong south-southwest winds in the strongly- mixed/drier air
regime). Furthermore, if any fires remain active near/after
sunset, they will be increasingly-prone to a significant wind
directional shift as strong northerlies dive southward behind the
cold front (and this element has been added to the "Impacts"
bullet of the Warning/Watch products).

- Severe storm potential:
As of this time, roughly the southeast 2/3 of our CWA is still
officially included in the Day 2 Marginal Risk from SPC. Based on
a perusal of some of the latest CAPE/instability progs (including
00Z NAM), it would seem that: 1) we could easily get through at
least 6-7 pm without any storms whatsoever...2) for the majority
of the CWA small hail/gusty sub-severe winds would be the main
threat given limited elevated instability. It continues to look
like any legitimate threat for spotty severe storms (quarter size
hail/60-ish MPH winds) should mainly just clip our far east-
southeast fringes, and as a result we continue highlighting areas
mainly east of a York-Osborne line for the main Tues evening
severe storm threat area in our local Hazardous Weather Outlook
(HWOGID). Will be interesting to see if SPC opts to maintain as
"big" of a Marginal Risk area for our CWA on the overnight Day 1
outlook or perhaps trim some of its western extent?

- Pesky, transient snow/snow showers Wednesday?:
Although we still have a little time to better assess this element
(once we get past Tuesday's fire weather/convection), there are
increasing signs that at least transient areas of snow/snow
showers could roam parts of the CWA Wed-Wed evening. Although
agree with our going forecast that any true snow accumulation in
our CWA looks pretty inconsequential at this time, am a little
concerned that transient visibility reductions could occur given
winds gusting 40+ MPH, so have added this mention to our latest
HWO (which admittedly now contains about "everything but the
kitchen sink" for Tues-Wed).

&&

.DISCUSSION...(This evening through Monday)
Issued at 430 PM CDT Mon Mar 28 2022

Primary forecast challenges are in the next 48 hrs and revolve
around fire, severe t-storm, and strong wind concerns, so that's
where the majority of time was spent on this forecast.

Summary: Strengthening low pressure on Tuesday will bring
increasing south to southwest wind gusts and much warmer air. A
dry line is expected to surge into southern portions of the
forecast area Tuesday afternoon and evening, which could bring
both critical fire weather conditions and a brief shot at strong
thunderstorms. The overall best chances for strong storms will be
near and especially east of Hwy 81, so the overall window of
opportunity for our area is narrow/brief. A strong cold front
will then surge through the area Tuesday night and bring the
potential for northwesterly wind gusts of 35-50 MPH that continue
into the daytime hours Wednesday. Some rain and or snow could mix
in on the backside of the system at various times Wednesday into
Wednesday night, but significant precip amounts are not expected
at this time. Near normal temperatures and off and on chances for
light precip continue through the end of the week and into the
weekend.

Forecast Details:
Breezy southeasterly winds will continue through the evening and
into the overnight, so despite decent sun and temps, it will
continue to feel chilly. Return flow could eventually lead to
enough moisture for stratus deck to develop towards dawn that
would continue into Tue AM. Models vary on the extent/coverage and
depth of moisture, but most have at least some semblance of a
stratus look. Can't rule out some patchy drzl, but overall not too
excited about this potential. Basically just converted the
inherited iso sprinkles/showers we had in the N to drzl.

Most models bring a surge of warmer and drier air from S to N late
Tue AM, and esp Tue aftn. RAP/HRRR, GFS, and EC are all in pretty
good agreement that stratus will quickly mix out towards midday
and temps will spike into the 70s and 80s for all but perhaps the
far N/NE. The NAM/NAMNest appear to be an outlier in that it keeps
the primary warm front/triple point mainly S of the NE/KS state
line. Not surprising to see the HREF and SREF hedge this way, as
well. Tend to side with GFS/EC as moisture return has not been
great thus far today, and NAM tends to overdue stratus situations
in the spring/fall. Seems hard to believe the magnitude of WAA and
mixing into dry mid levels won't be enough to erode stratus. Once
this process begins, it likely won't take long for dangerous fire
wx conditions to develop, at least for areas along and S of the
state line, but perhaps further NE as well. Fire weather concerns
are detailed below.

Strong capping and still sluggish moisture return will likely
preclude any tstm development through much, if not all, of Tue
aftn along and dry line and rapidly-shifting N warm front.
However, arrival of strong upper forcing and resultant cooling mid
level temps could eventually support some iso-scat convection
after about 6pm. Model consensus is that area from around Beloit
to York could be right on the W edge of narrow sfc moisture plume,
with Tds rising to perhaps as high as mid 50s. This is probably
best case scenario, though, as deepening mixing and gradually
veering sfc flow will probably shunt the primary area of concern
off to the E of the CWA. Some elevated CAPE lingers further to the
W ahead of the cold front overnight, but again, moisture
quality/depth is definitely in question. Models are NOT in very
good agreement regarding QPF placement/coverage/intensity Tue
night into Wed, so didn't feel comfortable have such widespread
"likely" PoPs and decided to lower a bit. Some wet snow could mix
in, particularly Wed aftn into overnight. Pcpn generally looks to
be lgt, and with warm ground temps think it's unlikely we'll have
snow accums. Finally, worth mentioning that wind gusts of 40 to
50 MPH will be possible behind the cold front Tue night and into
the daytime hours Wed per EC ensemble and NBM 4.1. This is
mentioned in HWO. The strong CAA and cld cover could mean going
highs Wed are a few deg too warm.

Again, didn't spend a whole lot of time in the extended portions of
this forecast. NW upper flow Wed night will transition to more of a
zonal flow for the end of the week and into the weekend. This will
keep temps generally near seasonable levels in the 50s to low 60s. A
series of progressive shortwaves within the zonal flow will move
through the area during this time...most notably Fri aftn/night and
again on Sun. Neither system will have much moisture to work with,
so precip amnts will remain lgt. Depending on exact timing, each
wave may have just enough cold air for some minor, wet snow.

&&

.AVIATION...(For the 06Z KGRI/KEAR TAFS through 06Z Wednesday)
Issued at 1124 PM CDT Mon Mar 28 2022

General overview (including low-end precip chances):
For sure, the first 8-ish hours are more "straightforward" than
the following 16, as the first 8 (or so) will feature high
confidence VFR and relatively consistent southeast winds, while
the latter two-thirds of the period (most of Tues daytime-evening)
will feature a good chance for at least a few hours of of MVFR
(maybe brief IFR?) ceiling, a change in wind direction from
southeasterly, to southwesterly, to westerly and eventually
modestly-strong north-northwesterly, and last but not least a
chance for spotty shower/thunderstorm activity and perhaps another
round of lower clouds toward the end of the period. Precipitation-
wise, no longer believe drizzle is very possible at all Tues AM.
However, have introduced a generic "vicinity thunderstorm" (VCTS)
for Tues evening (after 00Z) to account for spotty shower/non-
severe thunderstorm activity in the general area (small hail/gusty
winds really the only threats). Read on for more element-
specific details if interested.

Ceiling details:
High confidence VFR through at least the first 8 hours or so, with
only varying degrees of passing high clouds. However, sometime
around 14Z models/guidance continue to suggest fairly rapid
development of a low ceiling. That being said, latest guidance
continues to slightly delay the onset of lower clouds and also are
leaning more toward MVFR and less-so IFR. As a result, have
maintained scattered IFR clouds to hint at lower potential, but
officially have MVFR ceiling focused 14-19Z before mixing
out/lifting northward. While much of the afternoon-early evening
features high confidence in VFR, a return of lower clouds behind a
cold front is likely later Tuesday evening. For now have kept this
as a low-end VFR ceiling but MVFR cannot be ruled out.

Winds:
Pretty straightforward the first half of the period as southeast
breezes will average sustained 10-15KT/gusts 15-20KT. Some modest
low level wind shear is ongoing/will continue through around
sunrise, but have omitted a formal TAF inclusion for now as shear
magnitude looks to top out closer to 25KT than 30+KT.

Tuesday afternoon will feature changeable winds as as a passing
low pressure/frontal system will swing direction around to
southwesterly and eventually westerly by around 00Z. Fortunately,
speeds most of the day do not appear overly-strong (generally
sustained around 15KT/gusting 20-25KT). However, a surge of
stronger north-northwest winds will arrive by/after 03Z with
sustained speeds 20+KT/gusts 30+KT.

&&

.FIRE WEATHER...
Issued at 430 PM CDT Mon Mar 28 2022

Near critical to critical fire weather conditions are likely on
Tuesday for much of the area near and south of Interstate 80. The
most potent combination of strong winds and low humidity looks to
be near and southeast of a line from Stockton, KS to Red Cloud,
NE, as this is where humidity values of 15-20 percent are most
likely to coincide with southwesterly wind gusts of 40-45 MPH. A
Red Flag Warning has been issue for these areas. GFDI values are
in the "extreme" category (50-80), with "catastrophic" values not
far away near Hays and Russell. There's still some uncertainty in
the areal coverage of critical conditions, as some models carry
the strong winds and sub-20 percent humidity further northeast
into areas like Hastings, Geneva, and maybe even York. GFS and
RAP/HRRR are most aggressive with this scenario, whereas the
NAM/NAMNest keep fire wx mainly across KS zones. EC is somewhere
in between. Given the uncertainty, a Fire Weather Watch has been
issued for areas immediately surrounding the Red Flag Warning.
Additional expansion of the Red Flag Warning is certainly possible
with later forecasts, esp. if HRRR/RAP trends continue.

Any fire starts Tuesday afternoon that aren't quickly contained will
be impacted by a significant wind shift to the northwest and increase
in speeds behind a cold front Tuesday evening and overnight. Gusts of
35-50 MPH are possible behind this front through much of the
daytime hours Wednesday with humidity values as low as 30-40
percent south and southwest of the Tri-Cities.

While temperatures will be cooler behind the cold front
Thursday...drier air will return and another day with at least
elevated fire weather concerns is possible. No widespread fire
weather concerns are anticipated to finish out the work week.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...Fire Weather Watch from Tuesday afternoon through Tuesday
     evening for NEZ075>077-084-087.

     Red Flag Warning from 1 PM to 8 PM CDT Tuesday for NEZ085-086.

KS...Fire Weather Watch from Tuesday afternoon through Tuesday
     evening for KSZ005.

     Red Flag Warning from 1 PM to 8 PM CDT Tuesday for KSZ006-007-
     017>019.

&&

UPDATE...Pfannkuch
DISCUSSION...Thies
AVIATION...Pfannkuch
FIRE WEATHER...Thies

Hazardous Weather Outlook...CORRECTED
National Weather Service Hastings NE
905 PM CDT Mon Mar 28 2022

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-
291200-
Phillips-Smith-Jewell-Rooks-Osborne-Mitchell-Valley-Greeley-Nance-
Sherman-Howard-Merrick-Polk-Dawson-Buffalo-Hall-Hamilton-York-
Gosper-Phelps-Kearney-Adams-Clay-Fillmore-Furnas-Harlan-Franklin-
Webster-Nuckolls-Thayer-
905 PM CDT Mon Mar 28 2022

This Hazardous Weather Outlook is for south central Nebraska and
portions of north central Kansas.

.DAY ONE...Overnight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

From Tuesday into Wednesday, there are various weather concerns
within the outlook area...some affecting more of the area than
others.

First, at least near-critical fire weather conditions are likely
within several counties mainly south of Interstate 80 on Tuesday
afternoon and early evening. However, and of greater concern,
critical and perhaps even particularly dangerous fire weather
conditions are expected primarily within Rooks, Osborne, Mitchell,
Smith, Jewell, Webster and Nuckolls counties, which stand the
best chance of observing relative humidity as low as 15 percent
and wind gusts of 35 to 45 MPH. These counties are currently
under a Red Flag Warning, with several nearby counties under a
Fire Weather Watch, where confidence in dangerous conditions is
not quite as high.

In addition, isolated to widely scattered thunderstorms are
possible late Tuesday afternoon into the evening, mainly within
counties near and east of the Highway 281 corridor. While most
storms should be fairly weak, there is a Marginal Risk for a few
severe storms mainly between 6 PM and midnight, and mainly east of
a line from York Nebraska to Osborne Kansas. The primary threats
with any possible severe storms will be quarter size hail and
wind gusts to around 60 MPH.

Overnight Tuesday night into Wednesday, strong north winds will
overtake the entire outlook area behind a cold front, with
sustained speeds 30 to 35 MPH and gusts 40 to 50 MPH likely.
Along with the strong winds, parts of the area could see brief
periods of snow Wednesday into Wednesday evening. Although very
little, if any, snow accumulation is currently anticipated, the
combination of strong winds and falling snow could reduce
visibility at times.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight, but any
reports of possible wildfires, hail, and strong thunderstorms
winds on Tuesday would be appreciated.

&&

More information may be obtained at the following web page:
   https://www.weather.gov/hastings

Thies/Pfannkuch