Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/18/22

AREA FORECAST DISCUSSION

National Weather Service Albany NY

 1213 PM EDT Thu Mar 17 2022

.SYNOPSIS...
With a storm passing off the mid-Atlantic coast, expect a cloudy
yet seasonably mild day with some light rain showers mainly for
the Capital Region south and east into the mid-Hudson Valley
and Litchfield Hills. Although dry and mild weather is expected
tomorrow, rainy conditions with cooler temperatures are
expected over the weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

Thicker and lower clouds have spread north through the Capital
District and are now intruding into the Upper Hudson Valley as
a weak disturbance continues to hug the coast and push northward
from the mid-Atlantic towards New England. An area of 700-500hPa
FGEN and sufficient moisture has result in a rather narrow band
of showers that have moved north of the eastern Catskills/mid-
Hudson Valley/NW CT and are now advancing into the Capital
District and the Berkshires with NYS mesonet sites showing up
to a tenth of an inch of rain from this showers. Of the high
res guidance, the HRRR and the RGEM seems to be handling these
showers the best and suggests these showers shift into southern
VT and parts of the Upper Hudson Valley through 18-19 UTC before
dissipating. Just some light mist or isolated shower expected
in the wake for the rest of the afternoon but clouds persist.

Further north, the southern Adirondacks and far northern Warren
County will continue to enjoy pleasant weather today as they are
far removed from the coastal low`s influence; therefore,
expecting mostly sunny skies with temperatures warming into the
mid to upper 50s. In fact, northern Herkimer, Hamilton and
Warren County should be the warmest areas today in comparison to
the rest of the Albany CWA which will struggle to be any warmer
than the upper 40s to low 50s.

As

Previous discussion...The clouds and showers will limit warming
today, with highs in the 50s. Warmest temperatures will
probably be in northern areas that will see the most sun and
smallest chance of showers, with highs near 60.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
The system affecting southern and eastern areas will exit this
evening and weak northern stream upper energy will quickly track
north of the U.S./Canadian border through SE Canada, and the
associated weak cold front, more of just a wind shift to the
north, will drop into our region through Friday morning.

Clouds will decrease late tonight and through Friday morning as
weak low level ridging builds in and light north to northwest
winds can be expected Friday. The low level ridging will exit
later Friday afternoon as warm advection begins to strengthen.
Clouds will increase later Friday afternoon ahead of a strong
upper impulse approaching our region. Highs Friday in the 60s
with near 70 mid Hudson Valley and NW CT and 50s to around 60
northern areas, more proximate to the weak front that will lift
north later Friday afternoon.

Warm advection increases Friday night as a low level southerly
winds increase. Low level jet forcing and isentropic lift will
result in rain spreading across our region Friday night,
continuing Saturday morning. The upper energy approaching our
region will be slow to advance and a midlevel dry slot may
track into our region during the day Saturday. A zone of
marginal instability could also track through the eastern
Catskills and mid Hudson Valley but there are also signals that
the low level flow from the south and southeast could keep our
area more stable than areas to the west. Rain should become more
showery once the midlevel dry slot arrives in our region but
still quite a bit of coverage of showers. Highs Saturday in the
50 with around 50 higher terrain.

By Saturday night, one piece of upper energy within the broader
upper troughing will track through, as should the leading edge
of the cold advection. Upper energy lagging behind will support
continued chances for showers and cold advection will be slow
and gradual until the mean upper troughing exits Sunday and
beyond. Cold advection will be slow and gradual enough so that
rain should be just rain showers as temperatures Saturday night
should remain above freezing.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The first half of the long-term period will start off dry and
quiescent before another chance for additional precipitation takes
aim at the forecast area during the second half of the period.

We start off the period on Sunday where things will be drying out as
a storm system continues to depart away to our northeast. High
pressure will build into the area during the day on Sunday.
Subsidence associated with the surface high will result in a period
of dry weather beginning Sunday and persisting through Tuesday.

Global deterministic models and their ensembles continue to signal
the possibility of another potential storm system impacting our
region in the Tuesday night through Friday timeframe. Confidence has
increased some on this possibility as models/ensembles have remained
consistent over the past 24 hours. There still remains some
uncertainty and there is still quite a bit to figure out in the days
ahead as far as the magnitude of this storm system, it`s track,
precipitation type, and ultimately it`s potential impacts to the
area. While thermal profiles suggest a mainly rain/liquid event
along the river valley floor areas, a rain/snow is also possible.
All will depend on how strong the high pressure to our north is in
being able to channel colder air over Canada into the region as the
storm system approaches to the area. The greatest confidence for a
rain/snow mix will be over the higher elevations. For now, at this
timestamp, will keep mainly rain for the valley areas with snow or a
rain/snow mix confined to the higher elevations until we get more
clarity on the exact synoptic setup as we are still several days
away and this storm system is still out over the Pacific Ocean.

As far as temperatures, anomalies overall are progged to average out
normal to slightly warmer than normal levels for the balance of the
period. Daytime high temperatures are generally expected to be in
the upper 40s to mid 50s along the valleys (upper 30s to mid 40s
higher elevations). Overnight lows are generally expected to be in
the 30s and 40s along the river valleys (20s and 30s higher
elevations).

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
Through 12z Friday....As rain showers associated with a low pressure
system approaching from the south nears, the main weather concerns
will be probability of rain showers over some of the TAF sites as
well as cigs/vis trends. Under clear to mostly clear skies, dewpoint
depressions have narrowed overnight over KGFL/KPOU/KPSF. As a
result, there has been some mist/fog development over KPOU/KPSF.
have included TEMPOs for those sites. There still remains the
possibility for mist/fog development over KGFL over the next couple
of hours.

Right now, the greatest chance for rain showers and associated
MVFR/IFR cigs and visibilities are are over KPOU and KPSF. KGFL and
KALB should remain VFR for the most part through the day today and
for that matter the rest of the TAF cycle. Once this low pressure
system moves further away off the coast, VFR conditions should
return to KPOU and KPSF tonight.

Light and variable to calm winds this morning will become southerly
between 5-10 kts today before trending towards calm once again
tonight.

Outlook...

Friday Night: High Operational Impact. Definite RA.
Saturday: High Operational Impact. Definite SHRA...RA.
Saturday Night: High Operational Impact. Likely SHRA.
Sunday: Low Operational Impact. Breezy. Slight Chance of RA.
Sunday Night: Low Operational Impact. Breezy. NO SIG WX.
Monday: Low Operational Impact. Breezy. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.

&&

.FIRE WEATHER...
With a storm passing off the mid-Atlantic coast, clouds will
increase for Thursday and a few light rain showers are possible
for the Capital Region on south and east. Although dry and mild
weather is expected for Friday, rainy conditions with cooler
temperatures are expected over the weekend.

Minimum RH values this afternoon should be 60 percent or
greater with scattered showers, and near 100 percent tonight.
Minimum RH values Friday afternoon should range between 45
percent and 60 percent.

Light south winds at 15 mph or less today will become west to
north tonight. North to northwest winds at less than 15 mph are
expected Friday

&&

.HYDROLOGY...
No hydrologic issues are anticipated through at least the
several days.

Temperatures will continue to be above normal over the next few
days, which will continue to allow for snow melt to occur.
Although there will be a few light rain showers for southern
areas tomorrow, amounts will be very minor. Otherwise, it will
be dry through Friday evening, keeping river levels fairly
steady.

Over the weekend, some rain is expected across the entire area.
Rainfall amounts look to be about a half inch to possibly up to
an inch. Some rises are expected on rivers and streams, but no
flooding is anticipated at this time.

Dry weather will return for early next week, allowing for rivers
and streams to recede.

For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.

&&

$$
SYNOPSIS...NAS/Speciale
NEAR TERM...NAS/Speciale
SHORT TERM...NAS
LONG TERM...Evbuoma
AVIATION...Evbuoma
FIRE WEATHER...NAS
HYDROLOGY...NAS



Area Forecast Discussion

National Weather Service Denver/Boulder CO

 846 AM MDT Thu Mar 17 2022

.UPDATE...
Issued at 841 AM MDT Thu Mar 17 2022

|Upper level trof continues to slowly move across Colorado this
morning with snow continuing from the east slopes and extending
through all of Northeast plains of Colorado. The heaviest snow
is anchored over the Southern Front Range foothills with another
heavier band across the plains from Limon to Akron and points to
the east. Web cameras showing roadways mainly wet/slushy with some
better road snow accumulations in the foothills and further south
over the Palmer Divide. Will let current hilites remain in place
for the morning hours. Main change to forecast was to delay the
decrease/ending of snowfall by 2-4 hours, more into the afternoon
then late morning. Additional snowfall will mainly be accumulating
on grassy surfaces now that we are in daylight. Still with the
heavier snowband could see 1-2 inches per hour snowfall rate over
grass surfaces. Still some lingering showers into early evening
with moisture and some instability around.

&&

.SHORT TERM...(Today and tonight)
Issued at 246 AM MDT Thu Mar 17 2022

This morning, the upper level trough is located along the south
central boundary of CO/NM with mainly weak qg mid/upper level qg
ascent over northern CO expected through the rest of this
morning. Heaviest snow late last evening and early this morning
developed across eastern/southern parts of Denver, with snow
amounts ranging from 3-6 inches from DIA south of Castle Rock.
Convergent boundary was evident at the surface and in the mid
levels (700/500 mb layer). This feature has shifted to the east at
this time. Areas along Interstate 70 east of Denver to Limon may
still experience snowfall rates up to one inch per hour through 6
am. Rain and changed over to snow north and northeast of Denver.
Best accumulating snowfall there should be on grassy surfaces but
minimal on the pavement. Roads were especially hazardous in the
foothills west of Denver this morning. Will continue with the
Winter Storm Warnings already in place. HRRR and radar indicate
redevelopment will occur near the Southern Front Range
Foothills/Palmer Divide areas the rest of the morning, as a
deeper upslope component could still develop. Could see addition
accumulations in the 2-5 inch range in those areas. Less confident
in areas from around Boulder northward. Northerly winds
downsloped off the Cheyenne Ridge overnight, which produced
slightly warmer temperatures near or just above freezing.
Consequently accumulations were minimal from Boulder north of Fort
Collins. Main issues with snowfall the rest of this morning will
be west of Boulder in the foothills and north of Ft Collins along
the CO/WY border. Will allow the winter weather advisories to
expire for zones 35/38 at 6 am. Contemplating extending the
advisories for zones 34 and 37,through 9 am. Will see how things
develop over the next couple of hours on radar and make that
decision closer to 6 am. Conditions still expected to improve from
north to south this afternoon. Still enough moisture/instability
around for a few residual showers through 00z. Clearing and cold
overnight.

.LONG TERM...(Friday through Wednesday)
Issued at 246 AM MDT Thu Mar 17 2022

Northwest flow aloft will prevail Friday with a trough off to the
east of Colorado and a ridge over the western states. This will
usher in warmer air with highs in the upper 40s to mid 50s over
northeast Colorado. The ridge passes over the Central Rockies
Saturday with southwest flow aloft in advance of the next Pacific
storm system for Sunday. This will bring a warming trend for the
weekend. For Sunday, highs should be well into the 60s across
northeast Colorado. A few low 70s not out of the question as well.

This next storm system begins to affect the area Sunday night. A
deep sharp trough moves across the Great Basin and Rockies
Sunday/Sunday night. On Monday, a strong closed low forms
somewhere over the Southern Rockies. Models are still trying to
pin point where this low will form. The 00Z GFS trended farther
south while the 00Z ECMWF shifted the closed low north. This storm
system taps into gulf moisture and should be an impressive
system. Expect severe weather ahead of it across the Southern
Plains. For the Colorado, expect snow to move into the mountains
Sunday night. For Monday and possibly into Tuesday expected
precipitation to begin as rain and then turn to snow as colder air
filters in from the north. Amounts still highly uncertain at this
time as it depends on the where the low forms.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 841 AM MDT Thu Mar 17 2022

Main change this morning was to delay the decreasing/improving
conditions and will keep the ongoing light/moderate snowfall for
the rest of the morning hours. Now that daytime is here,
accumulations on runway surfaces will be less than 1 inch of
wet/slushy stuff. Conditons improving to VFR by later this
afternoon but could see continued ILS conditons at DEN through 06Z
tonight.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until noon MDT today for COZ036-039>041-045.

Winter Weather Advisory until noon MDT today for COZ034-037-046-
047.

&&

$$

UPDATE...Entrekin
SHORT TERM...Cooper
LONG TERM...Meier
AVIATION...Entrekin



Area Forecast Discussion

National Weather Service Charleston SC

 1010 PM EDT Thu Mar 17 2022

.SYNOPSIS...
A cold front will slowly move through over the weekend with
high pressure returning for early next week. Another storm
system will then likely impact the area mid next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A few bands of high cloud cover are moving through the region
currently, although with very little perceived impact to sky
condition. Will stick with a mostly clear forecast for all
areas. Low temps largely in the lower to middle 50s, a little
lower in the far western counties and across much of Berkeley
county.

Meanwhile, NBM and NARRE-TL fog probabilities continue to
suggest the develop of at least patchy fog overnight,
particularly up through the SC counties and especially the tri-
county region. This is supported by HRRR overnight forecast
soundings and some MOS products. I`ve beefed up fog working a
little. I don`t think any fog headline will be needed Friday
morning, but of course the overnight crew will need to keep an
eye on it.

Finally, I have made some timing tweaks to PoPs for Friday and
slowed the arrival of showers into the forecast area. Believe
that most areas east of the I-95 corridor will remain dry
through the day.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
High pressure will start to shift away from the region as a
mid-level trough shifts eastward across the U.S. There will be an
uptick in moisture by Friday afternoon as a weak trough moves into
the area. With an increase in shortwave energy, showers and
thunderstorms will be possible late Friday and into early Saturday.
The area is outlooked in a Marginal Risk from SPC for severe
thunderstorms. Although, the bigger rain event will occur on
Saturday with a cold front. While there could be breaks in showers,
the majority of Saturday looks to be overcast. The best chance for
decent rain will be in the afternoon into the evening. In regards to
severe weather, there will be decent surface-based cape as well as
decent shear. Therefore, we could see a few thunderstorms, some
becoming severe. The area is outlooked in a Slight Risk from SPC.
The main hazards will be damaging winds, isolated tornadoes and
hail. Then on Sunday, high pressure will build back into the area
and sunshine should return. Otherwise, sea fog could push onshore
Friday night into Saturday morning but have left out in mention in
the forecast due to uncertainty. High temperatures on Fri/Sat will
be in the mid 70s to low 80s and on Sunday in the low 70s. Lows will
be in the 60s on Friday night then in upper 40s to mid 50s Saturday
night.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
High pressure will prevail into early next week before another low
pressure system could impact the region mid-week. Decent rain
chances are in the forecast starting Wednesday and lasting into
Thursday. With thunderstorms possible, there will be a chance for
severe weather. Although, timing and impacts will need to be refined
with later forecasts.

High temperatures will be in the 70s to 80s each day. Lows will
start out in the 40s to 50s and eventually be in the 60s.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Mainly VFR through 00z Saturday.

Mainly clear skies will prevail tonight into Friday. Some fog is
possible, particularly across the SC counties including the
CHS/JZI terminals. I have MVFR prevailing vsbys for those
terminals after 07z along with IFR tempos between 09Z and 13Z.

VFR persists through Friday, but there will be increasing mid
and high cloud cover through the afternoon.

Extended Aviation Outlook: Flight restrictions will be possible
Friday through Saturday due to a variety of reasons including fog,
low clouds and showers/thunderstorms. Winds could also be gusty at
times, mainly on Saturday with the cold front. By Sunday, VFR should
return.

&&

.MARINE...
Tonight: No marine concerns tonight with weak pressure gradient
in place. Winds will become more south/southwesterly and average
around 10 knots or less. Seas will settle in the 2-3 foot range.

High pressure will shift away from the area as a cold front
approaches the region. Winds could become gusty at times and could
come close to Small Craft Advisory criteria on Saturday. Although,
at this time have gusts below 25 knots. After Saturday, winds less
than 15 knots are expected with seas 2 to 5 feet.

Sea fog could develop across all waters late Friday night into
Saturday. Although, at this do not have explicit mention in the
forecast due to uncertainty.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$

NEAR TERM...TBA
SHORT TERM...RAD
LONG TERM...RAD
AVIATION...ETM/RAD
MARINE...RAD/TBA



Area Forecast Discussion

National Weather Service Cheyenne WY

 527 AM MDT Thu Mar 17 2022

.SHORT TERM...(Today - Saturday)
Issued at 349 AM MDT Thu Mar 17 2022

Light to moderate snow persists across much of southeast Wyoming &
the western Nebraska Panhandle early this morning, aided by strong
QG ascent & isentropic lift associated w/ the frontal passage. The
main concern has been localized heavy snow bands which have become
established along a weak trough/convergence zone at 700 mb. Strong
frontogenesis in this region, coupled with fairly strong slantwise
instability and favorable saturation/omega through a 800 to 1200 m
deep dendritic layer has supported occasional snowfall rates of 1-
2 inches per hour, finally overcoming warmer pavement temperatures
and yielding snow covered roads in some locations. High-res models
including the HRRR have really struggled w/ the mesoscale features
here and have shown very inconsistent QPF forecasts throughout the
last several runs, but do think a general 2-5 inches of total snow
can be expected for our southeastern zones. The heavier bands will
have potential to produce some 6-8 inch totals, but given that the
snow has only recently started to accumulate on roadways we should
keep overall impacts at a sub-warning level even if we technically
get higher reports on grassy surfaces. Morning webcams from WYDOT/
NEDOT generally suggest more of a nuisance event, but definitely a
good justification for expanding Winter Weather Advisories east w/
the worst conditions expected around the morning commute. Roadways
could be especially slick given the substantial melting overnight,
prior to air temperatures falling below freezing. Have also bumped
PoPs upwards to near 90-100 percent through 15z with snow expected
to quickly taper off in the 15-18z time frame. Overall, conditions
will improve this afternoon with only a few lingering snow showers
expected in the high country. Highs today will most likely be just
a bit below guidance with the fresh snow, but should have a decent
opportunity to rebound this afternoon as precipitation ends. Trend
points to warmer and drier conditions on Friday/Saturday as upper-
level ridging returns and 700 hpa temperatures climb back above 0C
across the CWA, at least for a short time.

.LONG TERM...(Saturday Night - Wednesday)
Issued at 349 AM MDT Thu Mar 17 2022

Sunday...The flow aloft backs quickly to southwest as the next upper
trough moves over the Great Basin states, helping a surface lee
trough to develop over our counties, and producing an even more mild
day with 700 mb temperatures near 0 Celsius, and maximum
temperatures from 45 to 55 degrees west of I-25, with 60s east of
Interstate 25. As low and mid level moisture increases, along with
diffluence aloft, there will be a chance of afternoon rain and snow
west of a Douglas to Laramie line.

Monday...Still quite early, though the GFS forecasts an intense
closed upper low slowly moving across eastern New Mexico, with deep,
moist upslope and strong lift across our counties, producing
widespread snow for most locations, with rain across our far eastern
counties. Of course, this system will indeed bear close monitoring.

Tuesday...If correct, the upper trough moves slowly eastward into
the Central Plains states with slowly decreasing lift over our
counties, leading to a decrease in snow chances during the day.
Continued cold and windy with brisk north winds due to the strong
low and mid level gradients.

Wednesday...As the upper trough moves further eastward, north
northwest flow develops over our counties, producing a dry day with
a slow warming trend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 522 AM MDT Thu Mar 17 2022

Wyoming TAFS...VFR at Rawlins and Laramie, with occasional IFR or
MVFR until 16Z.

MVFR at Cheyenne until 18Z, with occasional IFR until 15Z, then
VFR after 18Z. Wind gusts to 23 knots.

Nebraska TAFS...VFR at Chadron, with occasional MVFR until 15Z.

MVFR at Alliance until 15Z, with occasional IFR, then VFR after
15Z. Wind gusts to 22 knots until 15Z.

MVFR at Scottsbluff and Sidney until 16Z, with occasional IFR,
then VFR after 16Z. Wind gusts to 25 knots at Sidney until 02Z.

&&

.FIRE WEATHER...
Issued at 349 AM MDT Thu Mar 17 2022

No fire weather concerns. Despite a trend toward warmer weather as
we head into the weekend, fire growth potential should remain very
low w/ recent widespread measurable snowfall.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until noon MDT today for WYZ106>108-114-
     116>119.

NE...Winter Weather Advisory until noon MDT today for NEZ019>021-054-
     055.

&&

$$

SHORT TERM...CLH
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...CLH



AREA FORECAST DISCUSSION

National Weather Service Hastings NE

 523 PM CDT Thu Mar 17 2022

.DISCUSSION...(This evening through Thursday)
Issued at 510 PM CDT Thu Mar 17 2022

Main concern is the potential for severe winter weather for
portions of north central Kansas tonight.

Summary...Upgraded portions of the Winter Weather Advisory in
north central KS to a Blizzard Warning for the potential of
whiteout conditions in 1-2"/hr snow rates and strong north wind
gusts of 35-45 MPH. There remains some uncertainty, however, owing
to marginal nature of low level thermal profile (1-2 deg could
mean difference of cold rain and very heavy, wet snow), and exact
location of strongest lift. Impacts should decrease with northern
extent due to slightly warmer surface temperatures and weaker
lift/precipitation rates. Quieter conditions return by Friday
afternoon and continue through the weekend. Temperatures will warm
in time for the weekend with 60s expected on Saturday (amidst
light winds!) and 70s on Sunday. The warmth Sunday will come at
the expense of gusty south winds and fire weather concerns. The
next upper trough is on track to arrive early next week and bring
areas of much needed rain, and possibly some wet snow on the back
side of the system.

Forecast Details...It`s been a busy shift so will go right to the
main issue at hand. Very impressive upper trough noted on WV
imagery this aftn over TX/OK Panhandles. 12Z upper air analysis
indicated the primary H5 jet streak was still upstream of the
trough axis, so no surprise the trough has continued to deepen and
bec incr negatively tilted through out the day. Regional radar and
satellite indicate rapid uptick in ascent overspreading the Plains
this aftn, and it appears tonight`s main band of rain/snow is
beginning to take shape over central/western KS into south central
NE. Most of the radar returns in our area have been sprinkles or
virga today, which is not too surprising given 20-25 sfc T/Td
spreads. However, LXN has recently fallen to 37/35 due to top-down
saturation and wet-bulbing, which is likely a sign of things to
come this eve as lift continues to incr/expand. Most of the models
today seem to be in the same general line of thinking in terms of
timing, location, and storm total QPF...with the greatest
uncertainty being the exact temp profile in lowest 1K ft, or so.
NAM/GFS, and to some extent the EC, are colder and more bullish
with snowfall compared to warmer boundary layer solutions of the
HRRR and RAP. Very important to note, however, that HRRR runs from
earlier today were too slow in bringing snow in the W KS. For
example, the 12Z run kept the snow in CO thru 21Z, whereas in
reality, obs such as GLD, CBK and MCK have already turned over to
snow. This leads me to believe these models are running too warm
in the BL, and that at least their snow output should be taken
with extreme caution.

As mentioned above, this is a very dynamic system. Closed,
negatively tilted H5 low, strong upper diffluence, strong mid
level FGEN and deformation zone, co-located with deep moisture are
all important ingredients for heavy snow...and this system has
them. The proverbial "icing on the cake" or "cherry on top"
appears to be fairly widespread and persistent upright instability
per model cross sections and forecast soundings. Given the
presence of deep moisture and lift, even areas of CSI are likely
to be released. This makes a strong argument for heavy, banded
pcpn, particularly as the trough takes on peak negative tilt
between 00Z and 12Z tonight. This leaves the only ingredient for
heavy snow being sufficiently cold air. There is not a lot of
"background" cold air to work with, but given the above mentioned
factors, seems likely this system will be effective and efficient
at creating its own cold air. This is not particularly uncommon
with dynamic spring systems, and it`s often something models
struggle with. An added bonus for a changeover to snow and
eventual accumulations is the fact that this is occurring
overnight with no help from near-equinox sun angle. All of these
factors combined have led us and surrounding offices/national
centers to be fairly aggressive with advertising potentially
serious impacts in our S tonight. This system isn`t necessarily
about the amounts, but the COMBINATION of heavy snow rates and N
winds 35-45 MPH will create very poor visibility and hazardous
travel conditions...at least during periods of heaviest snow.
Despite marginal low level temp profile, seems probable that snow
rates will overwhelm near to above freezing sfcs, and eventually
allow for snow accums. Obviously grassy and elevated sfcs will see
highest amnts, but even paved sfcs should take on snow/slush
accums overnight within the headlined areas. General expectation
is for 2-5 inches in north central KS, with locally higher amounts
possible, esp. within Blizzard Warning. This will all come down
to how things evolve this eve and exact changeover time...so stay
tuned for updates from eve shift. Most accum snow will end by
dawn, but areas that do see snow will likely have lingering
effects thru the AM, which will impact morning commute/travel.

The rest of Friday will be quieter with lighter winds and
gradually decr cld cover. Most areas will see highs well into the
50s, but areas that see snowfall may remain stuck in the 40s.

Very nice conditions are expected to return this weekend. Sat
looks to be especially nice with plentiful sunshine, light winds,
and highs in the 60s. Definitely a day to get outside and enjoy.
Sun will be warmer, but quite a bit windier. Despite the incr S
flow, moisture return will be slow, so Sun aftn could be fairly
significant fire weather day for at least W portions of CWA given
RHs 20-25 percent, strong winds, and very dry fuels.

Next upper trough arrives for early next week. Spent very little
time in this portion of the forecast, but in general...appears to
be fairly high likelihood for at least widespread lgt pcpn, with
hopefully some pockets of moderate moisture. The primary sfc low
may want to track S/SE of the area again, so could be looking at
another chilly rain to wet snow scenario Mon night into Tue AM.


&&

.AVIATION...(For the 18Z KGRI/KEAR TAFS through 18Z Friday)
Issued at 1235 PM CDT Thu Mar 17 2022

Significant weather: Strong winds through the afternoon.

First 12 hours: VFR. Main concern is strong NE winds gusting
around 30kt through the aftn. Wind gusts should decr towards
20-25kt this eve. Have maintained VCSH at both terminals through
the eve and debated adding a prevailing group from around 21Z to
01Z. However, still not confident enough in coverage and
intensity to warrant a prevailing group, but will keep an eye on
it and amend as necessary. CIGs look to be mostly 4-5K ft, with
perhaps some SCT areas near 3K ft in more persistent shwrs.
Confidence: Wind - High, Otherwise - Medium.

Rest of the Period: VFR. Clds will persist through the remainder
of the period but CIGs will continue to rise. Winds will avg
5-10kt out of the N late overnight into early AM before incr mid
to late AM. Confidence: High.


&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...Winter Weather Advisory from 9 PM this evening to 7 AM CDT
     Friday for KSZ005>007.

     Blizzard Warning from 9 PM this evening to 7 AM CDT Friday for
     KSZ017>019.

&&

$$

DISCUSSION...Thies
AVIATION...Thies



Area Forecast Discussion

National Weather Service Gray ME

 1053 PM EDT Thu Mar 17 2022

.SYNOPSIS...
An area of low pressure moves south of New England this
evening. The pattern turns more unsettled this weekend as a
complex low pressure system slowly crosses New England. Sunday,
drier conditions arrive on a northwest wind for the start of the
next work week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
1051 PM Update...
Showers continue to slowly ease off the coast, however some
light precipitation remains over southern New Hampshire. Have
slowed the exit of this rain this evening, similar to the timing
of the latest HRRR solution.

Fog continues to develop and may be dense again in some areas
during the overnight hours as dew point depressions will
continue to fall to near zero. The timing of this fog
development is in relatively good agreement with the latest HREF
run. Have made minor adjustments to dew points, temperatures
and winds for the near term portion of the forecast.

630 PM Update...
Have updated the pops based on latest observational trends and
near term mesoscale model solutions. Showers will continue to
move east from southern New Hampshire and southwest Maine this
evening. Timing suggests the precipitation will be off the coast
later this evening.

Atmospheric profiles suggest there will be plenty of low level
moisture remaining overnight. Fog along the coast this evening
will spread northwards and thicken with time as suggested by the
latest HREF run. Have made minor adjustments to latest weather
conditions as well as the near term forecasts of temperatures
and winds.

Prev Disc...
Some showers this evening and tonight for southern locations,
fog developing along the coastal plain overnight.

Warmest temps of the day were met across northern NH, where
full sun was the theme for much of the day. These warmer temps
did not arrive further east into ME until stratus thinned toward
the coast. But, some of these locations near the coast have now
been overtaken by a seabreeze front, further limiting temps
there.

Some showers have already made their way into southern NH,
although what hits the ground is far delayed than what radar
observations depict. Despite the low levels being rather
saturated, aloft is dry and much of this is evaporating.
Moisture advection will slowly move in to southern areas and
allow these returns to lay down more accurate -RA sfc obs.

Showers will move towards the coast through the late afternoon
before pivoting over the Gulf of Maine waters with light QPF
along the coastal communities and islands. The aforementioned
seabreeze will also be responsible for pushing in moist sfc air
into the Midcoast. This has already brought some fog back
through Freeport, and expect that trend to continue into the
evening and overnight hours. Best confidence for areas of dense
fog through early Fri morning will be the ME capitol region,
down the coast, and southeastern NH. HREF guidance depicts this
low stratus and fog peeling away quickly come sunrise. Decided
to instead thin the fog through the morning hours. How thick a
stratus deck develops will play a hand in how quickly vis
restricting fog erodes.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
Once fog has dissipated, sky conditions should improve rapidly
across south and central areas. Downslope subsidence should
assist in clearing these clouds, with a very warm day set. Highs
in the upper 60s to around 70 will be possible for much of the
foothills and coastal plain south of Augusta.

North of here, terrain may not be persuasive enough to limit
clouds down field. Thus they may limit temps to the lower 60s.
Other than a beautiful spring day for much of the CWA, a few
higher summit rain/snow showers will be possible amid the weak
LLJ moving over northern Maine.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Overview: A cool and unsettled stretch of weather is expected this
weekend as an area of low pressure crosses near the area. While most
locations will receive just plain rain out of this system, mixed
wintry precipitation is likely across the north and mountains
with some minor accumulations possible. A return to more
tranquil but breezy weather is then expected for early next week
before another system approaches New England towards the middle
and end of the week.

Impacts: Locally slippery travel conditions will be possible across
some northern and mountain areas this weekend due to pockets of
mixed wintry precipitation including light freezing rain/drizzle.

Forecast Details: On Friday night a closed low will be located over
the Midwest within the base of a large trough axis stretching
from the Great Lakes down through the southern states. Heights
will begin falling over our area in response to this approaching
trough and the passing of a cold front from the north. During
this same time period, high pressure will be located over Quebec
before moving towards the Canadian Maritimes by Saturday
morning. This will set the stage for a CAD to develop across the
interior. Thankfully, the location of this high will favor an
onshore flow and therefore a prolonged period of mixed wintry
precipitation is not expected.

Frontal precipitation will begin to overspread NH late Friday night
before moving into western ME towards dawn on Saturday. This first
round of precipitation may briefly begin as snow across the far
north and mountains but this will likely be short lived as 850
mb temperatures are forecast to rapidly increase during the day
on Saturday as the low pressure system tracks northward over
Quebec. In doing so, it`s trailing cold front will spark some
coastal cyclogenesis near the Delmarva before approaching the
Maritimes by Saturday night. Both of these systems will combine
to produce a fairly prolonged stretch of unsettled weather
through much of the weekend.

While there is still uncertainty in regards to which of
these low centers will become the dominant player, there is some
growing confidence that the coastal low will ultimately become more
amplified, which increases the potential for a CAD and hence mixed
wintry precipitation. Higher resolution forecast guidance such as
the NamNest are now beginning to cover this period of the forecast
and there are signs of the colder air lingering across the interior
valleys. Soundings via BUFKIT indicate a distinct warm nose aloft
across mountain valley locations with near freezing surface
temperatures, indicative of potential freezing rain. The latest WPC
winter weather probabilities highlight this potential well with 50%
or greater chances for measurable ice across the far north. As a
result and after collaboration with neighboring offices went ahead
and introduced some mixed precipitation including freezing rain into
the forecast for this package. While I am still not expecting a
prolonged period of freezing rain on Saturday there will likely be
at least some and slippery travel is therefore possible.

Across the higher elevations some snow accumulation is still likely
but these amounts should be limited to a couple of inches. The best
chance for some snow accumulations will actually be on Sunday as the
system begins to pull away and in doing so drags down colder air
from the north. Further to the south, just a raw rain is
expected with total QPF ranging between a 0.50-1.00". Locally
higher amounts are possible though, especially along the coast
due to coastal enhancement as well as across the White
Mountains due to upslope flow. We will need to continue to watch
area rivers as at least some rises are likely along with some
ice movement due to the combination of melting snow and rain.
The threat for ice jam flooding continues to be low but also
nonzero. As the previous shift discussed, winds are not expected
to be a major factor with this system but they will likely
become a little gusty on Sunday and these northwest winds will
likely linger through early next week.

High pressure will begin to build back into the area early next week
from the west, which will allow for a return to drier weather along
with cooler temperatures. Another storm system will then likely
impact the area mid to late next week but any potential impacts are
still highly uncertain at this time.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Short Term...VFR will trend towards MVFR/IFR as -SHRA track
through southern NH and ME (KCON/KEEN/KMHT/KPSM/KPWM). Fog will
also develop late this afternoon and overnight, pushing into the
coastal plain. IFR/LIFR vis will be possible from KPSM
northward towards KAUG, possibly lasting through to around 15z
Fri.

Long Term...Low pressure will track near the area this weekend,
which will result in widespread RA across all terminals late
Friday night through early Sunday morning. IFR/LIFR restrictions
are likely before gradually improving on Sunday as RA becomes
SHRA. Across the mountain terminals restrictions will likely
linger through Sunday due to upslope flow resulting in
SHRA/SHSN. VFR conditions return early next week along with
gusty NW winds.

&&

.MARINE...
Short Term...Conditions below SCA. Showers tonight as low
pressure passes south of the coast. Dense fog will again
develop this evening and overnight. Fog and stratus will thin
through the morning hours Friday.

Long Term...Southeast winds on Saturday afternoon and night
will likely increase to SCA thresholds before decreasing on
Sunday morning as they become northwest. Northwest winds may
again exceed SCA criteria on Monday and Tuesday of next week.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$
SYNOPSIS...
NEAR TERM...Cannon
SHORT TERM...Cannon
LONG TERM...Tubbs
AVIATION...
MARINE...



Updated for 12Z Aviation Forecast Discussion below.



 &&

.PREV DISCUSSION... /issued 350 AM CDT Thu Mar 17 2022/

DISCUSSION...

A calm and mostly clear night across the Mid-South at this hour.
Temperatures are steady in the upper 40s to lower 50s with high
humidity. Pockets of dense fog have developed over the past two
hours, prompting a dense fog advisory. Latest HRRR shows more dense
fog developing over the next two hours to encompass much of north
Mississippi and west Tennessee. The threat of dense fog should
end by 9AM, as it burns off with the morning sun.

Another nice day is on tap for the Mid-South today. Highs will
climb into the low to mid 70s due to weak ridging ahead of an
approaching trough. Models are fairly consistent with an MCS
developing overnight near the ArkLaMiss and lifting northeast
through the Mid-South by Friday morning. This system appears to
be mostly elevated, but could still produce pockets of damaging
winds and small hail as it lifts through.

The main threat will be Friday afternoon and evening as the
surface low and associated cold front move across SEMO. Latest
Hi-res models are consistent with a few surface-based storms
developing over west Tennessee late Friday afternoon into early
evening. Severe ingredients look decent, but not overly
impressive. Nonetheless, MLCAPE values will approach 750 J/kg, 0
to 1km values will be in excess of 250 m2/sec2, and winds will be
backed at the surface. The main threats will include damaging
winds and large hail, with a secondary threat of isolated
tornadoes. The real question is how well will the atmosphere
recover from morning showers and storms. Will bump up the wording
in the HWO to include multiple hazards.

Rain will end late Friday night as the cold front pushes through.
Temperatures will trend cool on Saturday with highs only in the
upper 50s. A pressure ridge will build into the region for Sunday
and Monday. Temperatures will top out in the lower 70s each day
as a result.

The next system will drop down the spine of the Sierra
late Sunday into Monday. The trough is expected to cutoff from the
mean flow and deepen considerably as it crosses the Rockies.
Large areas of diffluence will overspread the Lower Mississippi
Valley and spawn showers and thunderstorms Monday night through
Wednesday morning. Following the ECMWF solution, the upper trough
will spawn a surface low near the Texas Panhandle that will take a
northeast track through Central Missouri. As the trough expands
and slightly retrogrades, the frontal zone will remain in good
proximity to the Mid-South. This may result in several rounds of
heavy rainfall early Tuesday morning through Wednesday morning.
Early QPF totals range from 3 to 5 inches across the area with
isolated higher amounts. Will keep the HWO wording for now.

The severe threat for next week looks to remain closer to the
Gulf Coast, as the trough digs down into north central Mexico.
The long term pattern looks dry and seasonable. Expect highs in
the 60s and lows in the 40s.

AC3

&&

.AVIATION...
12Z TAFs

Expect a fairly quick improvement to VFR this morning, following
sunrise and increasing surface winds. As is often the case with
radiative fog, VLIFR visibilities at Memphis metro terminals
(OLV, AWM, NQA) had made limited inroads to MEM. Out west, broken
cirrus over AR did little to inhibit ground fog formation overnight,
and suspect it will have limited effect on slowing improvement to
VFR post-sunrise.

Outer band -SHRA will swing north from the Arklamiss late overnight
tonight, about the time of the MEM outbound push. Latest short
term convection-allowing models continued to show some TS potential,
but later HRRR runs depicted a downward trend in TS coverage, based
primarily on limited instability. Best TS potential late tonight
appears to be south and west of TUP.

PWB

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Dense Fog Advisory until 10 AM CDT this morning for Clay-
     Craighead-Crittenden-Cross-Greene-Lee AR-Mississippi-
     Phillips-Poinsett-St. Francis.

MO...Dense Fog Advisory until 10 AM CDT this morning for Dunklin-
     Pemiscot.

MS...Dense Fog Advisory until 10 AM CDT this morning for Alcorn-
     Benton MS-Calhoun-Chickasaw-Coahoma-DeSoto-Itawamba-
     Lafayette-Lee MS-Marshall-Monroe-Panola-Pontotoc-Prentiss-
     Quitman-Tallahatchie-Tate-Tippah-Tishomingo-Tunica-Union-
     Yalobusha.

TN...Dense Fog Advisory until 10 AM CDT this morning for Benton TN-
     Carroll-Chester-Crockett-Decatur-Dyer-Fayette-Gibson-
     Hardeman-Hardin-Haywood-Henderson-Henry-Lake-Lauderdale-
     Madison-McNairy-Obion-Shelby-Tipton-Weakley.

&&

$$