Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/21/22
Area Forecast Discussion
National Weather Service Gray ME
1042 PM EST Sun Nov 20 2022
.SYNOPSIS...
Scattered snow showers will diminish south of the mountains
early this evening while remaining numerous across the
mountains through tonight. Another area of low pressure will
pass north of the area late Monday and Monday night, bringing
more gusty winds and another round of snow showers toward the
mountains, some of which could again be heavy. After a
relatively quiet mid-week period, a storm system is likely to
impact our area late in the week... although its impacts remain
quite uncertain at this time.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
0340z Update...
After a second burst of strong winds this evening, winds should
begin to diminish somewhat again shortly. Temperatures may fall
into the single numbers by morning across the north and teens in
the south. The cloud cover and snow shower activity will also
continue to diminish across the north as we move through the
night per latest HRRR solution as well as satellite and radar
trends.
0025Z Update... Latest update was to increase pops for
southernmost New Hampshire near the Massachusetts border to
account for a large and long lake effect snowband coming in off
Lake Ontario this evening.
Update...
Webcams and latest radar imagery continues to show snow showers
in the mountains and foothills, occasionally making a run for
the coastal plain from time to time. Latest HRRR has this
precipitation this evening over the mountains before gradually
diminishing during the overnight hours. Have made minor
adjustments to pops for the near term portion of the forecast as
well as temperatures and surface dew points. Winds will
continue to gradually back off from their afternoon intensity
during the overnight period.
Prev Disc...
Isolated to scattered snow showers will continue south of the
mountains through the rest of this afternoon but will continue
to diminish in coverage as we lose diurnal instability. However,
toward the mountains, snow showers will remain numerous into at
least this evening with the ongoing upslope flow following the
passage of the upper trough axis. With how poorly guidance has
performed so far, I will leave in at least a scattered mention
of SHSN through most of the overnight hours across the mountains
before gradually tapering off PoPs toward daybreak as high
pressure builds in. There continues to be the possibility of a
few heavy snow showers or squalls with all of this activity,
which could bring brief but very rapid reductions in visibility
and gusty winds to 40 mph.
Even outside of snow showers, gusty winds of 25 to 35 mph will
continue well into this evening, possibly exceeding 40 mph on
occasion, bu will slowly diminish through the overnight hours.
Flow aloft will transition to northwest as the upper trough
continue to move east, and the strong cold air advection will
carry in some of the coldest air of the season so far. Have not
gone quite as cold as some guidance on low temps since we should
stay pretty well mixed through the night. That said, widespread
lows in the teens are expected with some embedded single
digits, especially farther north. However, wind chills will be
in the single digits, perhaps even a few degrees below zero.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
The upper low will continue to scoot across the Canadian Maritimes
allowing a ridge of high pressure to build over New England to start
off Monday. We`ll start off mostly sunny with the ridge overhead,
but the ridge will quickly shift east through the morning and
afternoon as another shortwave trough and cold front approach,
eventually crossing through the area during the evening and
overnight hours. Ahead of this wave, clouds will increase through
the day as well as winds aloft, and winds are expected to again
become gusty in the afternoon and evening hours. While not looking
quite as strong as today, gusts to 25 to 35 mph look reasonable
based on forecast soundings, possibly a couple reaching 40 mph
at times.
Increasing lift and moisture with the approaching trough will get
another round of mountain snow showers going by late afternoon or
early evening, and once the front and trough axis cross, upsloping
snow showers are expected to increase in coverage and continue
through the overnight hours. Not unlike today, steep lapse rates
and sufficient moisture in the low-levels along with some
instability could result in some heavier snow showers and
possibly a snow squall or two toward the mountains and
foothills. It`ll be another chilly night with lows in the teens
to lower 20s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
The overall upper air pattern is expected to amplify a bit
later this week into the weekend, although a potentially
impactful late- week system is still proving quite difficult to
pin down with a significant spread in model solutions. Thus
while moderate to high confidence in the forecast exists through
the middle of the week... that quickly drops off late in the
week with solutions ranging from yet-another-clipper to a big
coastal storm with a wallop of warm, moist air... and anything
in between. Of note, the GFS/GEFS continue to be wildly
different from the ECMWF/EPS and CMC/GEPS
Starting Tuesday... flow aloft flattens out somewhat in the
upper levels, which allows high pressure centered over the Mid-
Atlantic to spread northward into our area. A modest
southwesterly return flow develops as a result, with a warmer
day under mostly sunny skies in the 30s to mid-40s... except
perhaps lagging back in the 20s in the western Maine Mountains
where the return flow doesn`t quite reach. The PGF between low
pressure over eastern Canada and high pressure to our south
doesn`t relax enough to go all-in on strong radiational cooling
for Tuesday night, especially toward the north amid modest
pressure falls... so have stuck with the multi-model blend for
the most part, except to blend in slightly cooler temps in the
sheltered valleys... bringing lows into the teens and 20s, near
30 at the immediate coast. A broad upper level trough centered
over northern Quebec / Newfoundland swings an axis across
Wednesday with little fanfare for New England, other than snow
shower potential in the higher terrain near the international
border but also spreading down through the Whites and Blues
through the day as a cold front sinks south and allows for some
low/mid- level moisture convergence.
Confidence in the overall pattern drops off precipitously
Thursday through the end of the forecast with large disparities
in the major model suites. Of note... there is considerable
difference in the handling of a longwave trough as it exits the
Rockies Thursday into Friday. Euro and Canadian suites have held
this long wave together... painting an amplified pattern across
the eastern CONUS through the end of the week and weekend with
a big coastal developing. Meanwhile the American has cut off low
pressure in the southern Plains or southern Rockies with a far
less amplified, clipper-type low pushing across in recent runs...
although the latest 12Z deterministic GFS has trended slightly
toward keeping the trough together with a more amplified
pattern. Though, even the more amplified cluster of solutions
have their own gamut of potential scenarios with differences in
trough orientation as it reaches the coast, which has big
implications for what sort of mid-level jet and associated
temperatures/forcing we`ll have to work with.
All this to say... while precipitation is likely Friday and
Saturday, the details beyond that remain quite uncertain besides a
higher likelihood of frozen precipitation in the mountains, as
usual. Thursday, while very much reliant on how strongly upper level
ridging builds in and reinforces Canadian high pressure at the
surface (stronger in a more amplified solution)... is not expected
to be impactful, except when considering the antecedent airmass and
strength of the CAD should a coastal low come to fruition. Otherwise
it will likely be cooler than Wednesday with a greater northerly
component to flow.
Some signals we`ll be looking for in the coming days, assuming a
more amplified pattern comes together like cluster analysis and a
majority of members suggest: configuration and orientation of the
upper-level trough and associated jets, which will drive about every
other ingredient and dictate the track of the storm; amplitude and
orientation of the mid-level circulation and jet, which would rely
heavily on the upper-level dynamics and drive mesoscale
precipitation processes along with ptype; and strength of
antecedent CAD through the low- and mid-levels, which would also
inform ptype (stronger CAD = more frozen precip) and determine
if this storm takes on classic Nor`easter characteristics.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
Short Term...Can`t rule out a brief snow shower at AUG/PWM/RKD
through this 21-22Z or so, but most of the snow showers will remain
farther north toward the mountains and HIE. Some of these could
produce brief but very rapid IFR visibilities. Elsewhere, VFR
conditions are expected through tonight with brisk W/WNW winds
continuing into this evening before slowly diminish through
tonight. High pressure will bring VFR to all sites on Monday,
but another low pressure will move through late Monday into
Monday night bringing more gusty winds as well as snow showers
toward HIE.
Long Term...VFR prevails Tuesday through Thursday with a non-
zero threat of on- and-off MVFR for KHIE with SHSN. Confidence
is quite low for the end of the week, however a storm system
crossing New England is expected to bring a period of flight
restrictions Friday and Saturday, perhaps into Sunday in some
locations. Some solutions suggest strong winds, significant
reductions in visibility, and lowered ceilings.
&&
.MARINE...
Short Term...Solid Gale conditions will continue through
tonight before a brief lull on Monday. Another low pressure
passing north of the waters and the passage of a cold front will
bring another period of Gale conditions from Monday evening
through early Tuesday.
Long Term...High pressure builds into the waters from the
south through the mid-week period which will allow conditions to
improve over the waters... with winds and seas falling below SCA
thresholds by the end of the day Tuesday. A significant coastal
storm may develop late in the week with a period of active seas
at any rate as we head into the weekend. Stronger solutions
produce at least Gale force winds... however confidence is quite
low at this time.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Gale Warning until 7 AM EST Monday for ANZ150>152-154.
Gale Warning until 1 AM EST Monday for ANZ153.
&&
$$
NEAR/SHORT TERM...Cannon
LONG TERM...Casey
Area Forecast Discussion
National Weather Service Midland/Odessa TX
631 PM CST Sun Nov 20 2022
...New AVIATION...
.SHORT TERM...
(This afternoon through Monday night)
Issued at 225 PM CST Sun Nov 20 2022
Main concern overnight is whether or not FG/FZFG will form. Clouds
will modulate the development of FG/FZFG and indications are that
clouds will clear from w to e in the afternoon/early evening to
early morning, respectively. HRRR VSBY forecast is aggressive with
other data, like NAM12, favoring the Pecos River Valley. It make
some sense that areas which received measurable precip this morning,
like the srn PB, will also have greater potential of FG/FZFG.
Consensus is that lows will below freezing most all areas, so FG
that develops early will transition to FZFG, except parts of srn PB.
Winds will be light and some locally dense FG is certainly possible
and have opted to include in Pecos River Eddy Co and srn PB.
Otherwise temps will slowly warm up into M50s-U50s Mon PM with an
abundance of sunshine. Another cold morning Tue with FG/FZFG a
possibility, generally across srn areas.
&&
.LONG TERM...
(Tuesday through Saturday)
Issued at 225 PM CST Sun Nov 20 2022
The extended portion of this forecast will consist of a slight
warming trend with cool, dry weather expected. Zonal flow aloft
and continued southerly sfc winds on Tuesday and Wednesday will
bring high temperatures back into the low 60s for most locations.
However, our streak of days with below normal temperature in
Midland should continue through at least Friday as a dry cold
front is progged to arrive on Thanksgiving Day. This front will
not be arctic in origin and will only serve to knock temperatures
down by a few degrees on Thursday and Friday. The cold front will
also bring much drier air into the region, resulting in dew points
falling into the 20s and 30s making for some crisp weather. By
next weekend, temperatures will rebound well above normal as
westerly downsloping winds increase across the forecast area,
promoting highs in the upper 60s to low 70s. All long range models
are now showing a dry forecast through next weekend, so kept
grids dry through the extended.
-Salerno
&&
.AVIATION...
(00Z TAFS)
Issued at 538 PM CST Sun Nov 20 2022
All TAF sites but FST are now VFR and FST should become VFR by
06Z. Models show considerable uncertainty as to whether or not
MVFR or IFR conditions will redevelop later tonight. Several
different models show HOB dropping to low MVFR or IFR with more
uncertainty for the other TAF sites so have introduced IFR CIGs
for now only at HOB. A south to southwest wind direction does not
favor very low VIS so this is a lesser concern right now.
Hennig
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 30 58 33 62 / 0 0 0 0
Carlsbad 26 57 29 60 / 0 0 0 0
Dryden 35 54 37 56 / 0 0 0 0
Fort Stockton 31 58 33 64 / 0 0 0 0
Guadalupe Pass 30 52 34 56 / 0 0 0 0
Hobbs 25 57 30 60 / 0 0 0 0
Marfa 23 57 26 62 / 0 0 0 0
Midland Intl Airport 28 57 32 60 / 0 0 0 0
Odessa 29 57 32 60 / 0 0 0 0
Wink 26 57 29 61 / 0 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
TX...None.
NM...None.
&&
$$
SHORT TERM...49
LONG TERM....24
AVIATION...10