Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 01/14/22
Area Forecast Discussion
National Weather Service Buffalo NY
954 PM EST Thu Jan 13 2022
.SYNOPSIS...
Colder air will start to ooze to the south across our forecast area
tonight in the wake of a wavy frontal passage. The change of
airmasses will be accompanied by some light snow as well with minor
accumulations. The much colder airmass will support nuisance lake
snows over the western counties on Friday. Dangerously low wind
chill values can then be expected Friday night and early Saturday...
particularly across the North country. A major winter storm could
then impact the majority of the region Sunday night and Monday with
widespread significant snowfall possible.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
A wavy frontal boundary will make its way to the south through our
region tonight. This will lead to way for an increasingly cold
airmass, one that will help to generate some snow with minor
accumulations tonight. The first round of mixed rain/snow showers
has already moved mostly ENE through interior sections of WNY, with
plenty of saturated air and patchy fog in its wake.
The airmass then will support fairly widespread nuisance lake snows
on Friday (wrn counties only). Snowfall amounts will be under an
inch in most areas tonight with one to two inch amounts expected on
Friday. The higher amounts will be across the counties lining the
south shore of Lake Ontario. It will be notably colder on Friday
with temps generally falling through the course of the day. readings
during the afternoon will range from the single digits across the
North country to the teens elsewhere.
Friday night will feature bitter cold wind chill values. While the
western NY will experience wind chills of 10 to 15 BELOW...sites
east of Lk Ontario will have to deal with values of -25 to -40. The
latter will result in the wind chill watch being upgraded to a
warning. Wind chill advisories for Friday night will be issued for
the remainder of the forecast area in a later package.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
...Dangerous Wind Chills continue through Saturday Morning...
...WIDESPREAD Heavy Snowfall Possible Sunday Night and Monday...
A frigid N/NNE flow will keep dangerously cold wind chills going
across the area through the first half of Saturday with the Wind
Chill Warnings running through 1 PM Saturday east of Lake
Ontario. Wind chill values will then remain a bit below zero
south of Lake Ontario and well below zero east of Lake Ontario
through Sunday morning. This same cold N/NNE wind crossing the
relatively warmer lake waters will allow a light spray of lake
effect snow showers to continue as well with nuisance
accumulations possible from the Niagara Frontier to the Finger
Lakes through the day Saturday. High pressure will then build
across the area Saturday night before sliding off the New
England coast by late Sunday with its ridge axis still
extending back across New York State and New England providing
dry weather for the second half of the weekend. Otherwise,
daytime highs in the single digits to low teens and single
digits below zero North Country Saturday will warm significantly
for Sunday as highs top out in the teens North Country with 20s
elsewhere. Saturday night will be another very cold one with
negative teens below zero across the North Country to within
plus or minus a few degrees of zero elsewhere.
Our attention then turns to a potential significant synoptic system.
The 12Z GFS/Canadian/ECMWF continue to be in very good agreement
overall with the longwave pattern evolution and synoptic scale
details. The deterministic runs continue to show a low track further
west than climatology, however the 12Z GFS/ECMWF have trended a
LITTLE further east, which is to be expected this far out.
Nonetheless, things remain on track for a possible significant event
across our region.
East coast systems typically track along the coast and close to the
coastal front, but in this case the strong synoptic scale dynamics
may overcome that trend and force the low track farther west and
well inland across the Mid Atlantic and PA. One big reason for this
can be blamed on a large surface high that will precede the
storm...with the high moving off the New England coast and blocking
a more typical storm track up the coast. Nor`easters usually run up
the coast ahead of the Canadian high...but the timing is such that
the surface high may force the storm system inland and up the
coastal plain. Storms of this nature have a history of generating
widespread snow throughout all of western and north central New
York.
The upper level energy that will force this system is currently over
the Pacific Northwest. This will allow it to be better sampled by
the radiosonde network and aircraft soundings from this point
forward, which should continue to promote converging model solutions
and increasing forecast confidence over the next day or two.
Increased the PoPs to categorical for later Sunday night through
Monday given the continued overall run to run agreement within the
model suites. If the models continue to support this solution,
confidence will continue to increase for a widespread, impactful
snow event late Sunday night through Monday. Following this system,
expect some wrap around snow showers and at least some limited lake
effect east/southeast of the lakes Monday night.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
Though on a smaller scale, this period features additional chances
for snow each day behind the departing large scale winter storm.
Tuesday lake effect snow will continue to the south and southeast of
the Lakes. Snow will likely be found heaviest near Lake Ontario
where a secondary trough will be dropping across the Lake, enhance
low level convergence and moisture.
Wednesday a fast moving alberta clipper will pass across our region,
leaving several inches of snow in its wake. Ahead of this feature
temperatures will rise to around freezing Wednesday before another
arctic airmass drops across our region to close out the week.
Thursday will be colder with highs in the lower 20s, with chances
for lake effect snow south of Lake Ontario on a light northerly
flow. With the arctic airmass featuring little ambient moisture,
any lake effect snow will be fluffy and light.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
IFR/LIFR conditions are expected throughout the night as a wavy
frontal boundary near Lake Ontario settles to the south. Low cigs
may be accompanied by some light rain/snow/fog with IFR to MVFR
vsbys.
On Friday...IFR conditions across the region will improve to
MVFR...with VFR weather est of Lake Ontario at KART and KGTB.
Outlook...
Saturday...Mainly VFR, but likely MVFR conditions in light lake
snows immediately south of Lake Ontario (ie. KROC and poss KIAG).
Sunday...VFR.
Monday...IFR conditions likely for most of the region with
widespread snow. Potential MAJOR impacts to airport operations.
Tuesday...Mainly VFR...but MVFR in lake snows at KROC and KJHW.
&&
.MARINE...
Gentle northerly breezes on the lakes this evening will freshen
overnight and Friday. This will lead to small craft advisory
conditions...initially for the Lake Ontario nearshore waters west of
Mexico Bay (incl LOWER IAG Rvr)...then possibly for Lake Erie. Have
issued SCA`s for the former.
SCA conditions will then persist through at lest Friday evening.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Wind Chill Warning from 6 PM Friday to 1 PM EST Saturday for
NYZ006>008.
MARINE...Small Craft Advisory from 4 AM Friday to 1 AM EST Saturday for
LOZ030.
Small Craft Advisory from 4 AM Friday to 10 AM EST
Saturday for LOZ043-044.
Small Craft Advisory from 4 AM Friday to 4 AM EST Saturday
for LOZ042.
&&
$$
SYNOPSIS...RSH
NEAR TERM...RSH/Zaff
SHORT TERM...Hitchcock/JM/RSH
LONG TERM...Thomas
AVIATION...RSH/Zaff
MARINE...RSH
Area Forecast Discussion
National Weather Service Phoenix AZ
449 PM MST Thu Jan 13 2022
.UPDATE...Updated Aviation Discussion.
&&
.SYNOPSIS...
Overall dry conditions, periods of clouds, and above normal
temperatures will persist through at least early next week. A weak
upper level disturbance passing by the region on Friday will bring
thicker clouds followed by breezy conditions later Friday into
Saturday. The weather pattern will essentially be stalled through
early next week providing little day to day change in temperatures
and highs mostly in the lower 70s across the lower deserts.
&&
.DISCUSSION...
Satellite and objective analysis this afternoon shows a ridge axis
over the Gulf of California and up through Arizona. Deep southerly
flow is seen on the west side of this ridge with high clouds
continuing to stream north into the Southwest. The ridge has also
led to another degree or two of tropospheric warming from
yesterday, as indicated by aircraft soundings, and surface
temperatures so far today have been warming slightly quicker than
yesterday. Still anticipating highs today to top out in the low-
70s.
The most identifiable feature on water vapor this afternoon,
across the western CONUS, is the low that has rounded the north
side of the eastern Pacific rex block and has now pushed inland
into the PacNW. Satellite shows this low is currently
transitioning to an open shortwave and has already taken on a
positive tilt. This shortwave is expected to quickly dig
southeast through the Great Basin and Four Corners area, clipping
through Arizona, through Friday. With this trajectory, the overall
sensible impact to the local area will be minimal. While 500 mb
heights will lower, surface temperatures are not expected to lower
much, if at all. NBM forecast still has highs near the 70 degree
mark for the lower deserts through this weekend.
The one impact worth mentioning is a strong north to northeast
gradient wind Friday night into Saturday as strong high pressure
develops in the Great Basin following the shortwave. This should
lead to breezy conditions in Arizona on Saturday. Forecast
soundings show the strongest winds, upwards of 40-45 mph, will be
mostly in the 850-700 mb layer and during the overnight hours.
This will likely limit the strongest surface gusts to the higher
terrain/ridges north and east of Phoenix. The ECMWF EFI is showing
the potential for a seasonably anomalous wind event in central
Arizona and HREF is indicating lower desert surface gusts up to
20-30 mph will be common Saturday, especially in the morning,
while ridges and mountain tops could see gusts up to 45-55 mph.
Breezy north winds are also expected in SoCal beginning Friday
afternoon. So, caution should be taken if planning to recreate
outdoors Saturday, especially in mountainous areas of south-
central Arizona Saturday morning.
As far as precipitation chances over the next several days, there
is not much to speak of. NBM probabilities of measurable
precipitation anywhere in the CWA through early next week is under
10%. EPS and GEFS do show the best push of moisture into the
region over the next 7 days will actually be tonight through
Friday, with IVT peaking briefly around 250 kg/ms. Ensembles show
great consensus on this, but also still keep higher moisture
content to the south and maintain a very dry layer subcloud layer,
below 700 mb, through this period. Increased cloudiness and lower
clouds, along with virga radar echoes, are expected. Maybe some
rogue rain drops, but again the chance of measurable rain is very
low (under 5%). The mid-levels dry out following the passage of
the trough from the northwest later Friday.
.PREVIOUS DISCUSSION...
The rest of the weekend into early next week should see the cut-
off low weakening further as it most likely drifts from just off
the southern CA coast through our region some time early next
week. Model ensembles continue to trend drier with this most
likely scenario with the NBM now showing less than 10% PoPs
through the first half of next week. Likely the only impact with
this weak system passing through our region will be another round
of clouds. NBM forecast temperatures for the first half of next
week change very little with highs generally ranging from the
upper 60s to lower 70s, or a few degrees above seasonal normals.
&&
.AVIATION...Updated 2345Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT; and
Southeast California/Southwest Arizona including KIPL and KBLH:
An upper low centered off the northern Baja peninsula will spread
increasing cloudiness over the region today and tonight. Mid-level
CIGs will lower to 10-15 kft late tonight from west to east.
Periods of virga and sprinkles are also likely from late tonight
through Fri afternoon. Clouds decrease Fri afternoon over the
Phoenix area but linger over SE CA. Surface winds will remain
light (AOB 7kts) and favor diurnal patterns through the daytime
Friday. Otherwise gusty N winds are expected to develop at KBLH by
mid Fri afternoon with gust of 20-25 kts likely.
&&
.FIRE WEATHER...
Saturday through Wednesday:
Dry weather with warmer than normal temperatures are expected
through the first half of next week. A couple weak upper level
disturbances are likely to bring periods of clouds and maybe some
isolated very light showers, but chances for wetting rains are
generally less than 5%. Minimum afternoon humidity levels will
mostly fall into a 15-25% range following fair to good overnight
recovery around 30-55%. Winds will start off breezy on Saturday, but
are expected to be fairly light through the rest of the period.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Benedict
PREVIOUS DISCUSSION...Kuhlman
AVIATION...Sawtelle/AJ
FIRE WEATHER...Kuhlman