Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/03/21
AREA FORECAST DISCUSSION
National Weather Service Albany NY
936 PM EST Tue Mar 2 2021
Short wave, mid level warm front and mid level jet were all
approaching from the west. 00Z sounding depicts notable warm
advection underway centered around H700. In fact, a batch of
stratocumulus developed across the heart of the CWA and banked
up the western slopes of the Greens and Berks with the backedge
approaching the Hudson River as of 930 PM. The aforementioned
wave, front and jet will continue to advect moisture and lift
for some light snow/snow showers to develop across the Dacks
soon. This will attempt to spread into the Lake George-Saratoga
Region including southern Greens of VT overnight. Temperatures
are expected to steady off as well with cloud coverage on the
increase. So overall update was to sky coverage, PoP/Wx grids
per recent and forecast trends within the HRRR and 00Z NAM3km,
and refresh of hourly temps/dewpts/winds.
Cold and breezy conditions are expected to persist across the region
through the afternoon, with winds diminishing overnight. Some light
snow is possible for the southern Adirondacks tonight into tomorrow
morning. A retrograding upper-level low will keep us under the
influence of troughing and cyclonic flow aloft through the weekend.
As this feature moves off to our east, temperatures may moderate
towards the beginning of next week.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Temperatures are currently in the teens and 20s across the region
this afternoon mostly clear conditions seen on GOES 16 satellite.
Winds are still gusty, with gusts between 25-35 mph common across
the region with some locally higher gusts in the higher terrain
especially in the Berkshires.
Mixing to near 850 mb as seen on BUFKIT soundings supports continued
mixing down of gusty winds through the rest of the afternoon, but
expecting a general decreasing trend in wind gusts through the
afternoon into the evening as the pressure gradient relaxes and we
lose daytime solar heating. Winds may become light and temperatures
are expected to drop this evening as a weakening 850 mb ridge axis
Current water vapor imagery shows a shortwave located to the north
of the Great Lakes moving towards our region. Clouds are expected to
increase in advance of this upper-level impulse this evening into
tonight with a few snow showers possible, mainly in the southern
Adirondacks. A few inches of snow is possible for the upslope areas
of the Adirondacks, but not expecting advisory criteria to be
reached due to the lack of moisture and relatively weak forcing for
ascent with this shortwave.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Light snow or snow showers are expected in the Adirondacks to begin
the day Wednesday, but elsewhere across the region should remain
dry. Temperatures are expected to warm into the 30s and 40s across
the region Wednesday as partial clearing, especially for the Mid
Hudson Valley is expected behind the upper-level impulse.
As this shortwave departs, flow aloft is expected to become more
cyclonic Wednesday night through Thursday night as an upper-level
low in southeastern Canada retrogrades towards our region. This will
be accompanied by another shot of cold air late Wednesday night. Low
temperatures Wednesday night are expected to be in the 10s to 20s,
with highs Thursday only in the 20s to upper 30s for the Mid Hudson
valley. Thursday night we will be in the heart of the cold air, with
850 mb temperatures between -10 to -15 expected. Accordingly, low
temperatures are expected to drop into the single digits across the
Adirondacks Thursday night. Breezy conditions are still expected
through this period due to our region being located between high
pressure over the Great Lakes and low pressure in southeastern
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Broad mid to upper level cyclonic flow will be established over the
Northeast U.S. and eastern Canada late in the week and through the
weekend. Mid to upper ridging will build into the region from the
central U.S. early next week. Overall, a quiescent weather pattern
can be expected with an uptrend in temperatures during this long-
term forecast period.
We start off the extended forecast period Friday with the mean axis
of an upper level trough to our east over eastern Quebec into
Labrador Canada. This setup will allow for a northwest flow aloft
regime to be in place. A series of weak mid to upper level
perturbations will pivot around the aforementioned upper trough
Friday and Saturday. These shortwaves will affect areas primarily
west of the Hudson Valley (i.e. SW Adirondacks, western Mohawk
Valley, Schoharie, and the eastern Catskills). Because there will be
limited availability of low-level moisture, expect just low chance
PoPs for some snow showers at best for these areas Friday and
Saturday. Temperatures will be cold running below normal during this
The mid to upper trough finally moves further east away from the
region Sunday into early next week. Ridging will build in from the
central U.S. with a broad and strong 1032 hpa surface high pressure
area building into the region. Subsidence from these weather
features will result in a continuation of dry and tranquil
conditions Sunday through Tuesday.
As far as temperatures, we`ll see a moderation in temperatures
during this time period from colder than normal levels to warmer
than normal levels. Highs in the upper 20s to lower 30s Friday will
transition to highs in the upper 40s to lower 50s by Tuesday. Low
temperatures will start off from the mid teens to lower 20s Friday
night/Saturday morning to the mid 30s Tuesday night/Wednesday
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Generally, expected mainly VFR conditions tonight with an
increase probability for MVFR ceilings toward sunrise Wednesday,
especially north of KPOU.
As upstream system approaches from the eastern Great Lakes,
clouds will be on the increase. There will also be some snow
with best chance into KGFL later this evening where we will
retain VCSH at this time. These clouds will slowly thicken and
lower tonight which will persist into most of Wednesday. MVFR
ceilings for KPSF and KGFL with remaining VFR for KALB-KPOU.
West-northwest winds 10-20kts this evening will subside less
than 10 kts overnight. Magnitudes increase once again daylight
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: Low Operational Impact. Breezy. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: Low Operational Impact. Breezy. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
No hydro issues are anticipated through the rest of the week.
Dry weather is expected for today with temperatures remaining
below freezing. A northern stream disturbance will bring some
light snow showers to the Adirondacks for tonight into
Wednesday, otherwise, the rest of the day will remain dry
through the mid-week period. No major storm systems are expected
through the rest of the week and any additional light precip
that does occur would be in the form of snow showers.
Temperatures should be close to normal for Wednesday, but mainly
below normal for the rest of the week. Some snowmelt may occur
during the daytime for valley areas as temperatures reach above
freezing, but any melt will slow down or stop at night as
temperatures fall back below freezing across the entire area.
Due to the limited and diurnal nature of the melting, no
flooding is expected, as any snowmelt looks to be rather slow
and river flows won`t be increasing too rapidly at this time.
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
Area Forecast Discussion
National Weather Service Gaylord MI
1033 PM EST Tue Mar 2 2021
Issued at 1033 PM EST Tue Mar 2 2021
Evening composite analysis reveals a mid level short-wave moving
through southern Ontario with attending elongated low pressure
across northern Lake Superior and sharp cold front that stretches
back across northern Minnesota. Most of northern Michigan sits
within the warm sector along the southern side of the low with an
axis of warm air stretching from the northern Plains eastward into
Brief period of warm advection forcing aimed across eastern Upper
Michigan and tip of the mitt did bring a batch of thicker mid/high
cloud cover and a few hours of radar returns sliding through that
region...although no ob sites actually reported any precip. That
activity is just about done with a shrinking band of mid/high
cloud cover all that`s left.
To the north, some cloud cover is sneaking into eastern upper
Michigan at the moment. But otherwise, skies are fairly clear
elsewhere across the CWA with gusty winds continuing (PLN and MCD
just reported gusts >35 knots).
Rest of tonight: Winds and cloud issues are the main concerns.
Strongest winds are right now through around 06Z with overall
pressure gradient/stronger winds aloft gradually relaxing through
the overnight hours. Not enough gustiness to warrant any land
based wind headline. But, I may have to extend out the gale
warning a bit longer for the northern part of Lake Michigan.
Meanwhile, earlier model guidance was bullish in developing a
corridor of lower cloud cover from Wisconsin across Lower Michigan
this evening and overnight. So far that has not happened and
recent HRRR guidance is much less on board with that idea until
after FROPA on Wednesday. Granted, we could yet some some
moisture flux off Lake Michigan into northern Lower Michigan and
subsequent development of some lower cloud cover. But I have
backed off on cloud cover to some extent...trending more toward
the partly cloudy side of things.
Issued at 354 PM EST Tue Mar 2 2021
High Impact Weather Potential: Minimal.
Pattern Synopsis/Forecast: 999mb surface low sits over northwest
Ontario at mid afternoon...propagating east-southeast toward a
5mb/3h pressure fall center east of Lake Superior. A warm front
extends south from the low into western Wisconsin/western
Illinois...with another surface trough over northwest Minnesota/
southeast South Dakota (lying within a low level thermal
ridge)...and a cold front that trails back to the west across
southern Manitoba. Water vapor imagery shows a lead short wave
trough pushing southeast to the west of Lake Superior with some
thicker but mostly mid/high cloud out ahead of it. There have been
some radar returns throughout the day across eastern Upper but
haven`t seen anything reach the ground yet though there is some
blowing snow across eastern Upper with winds gusting over 40kts at
ANJ in the past hour.
Surface low will make a beeline past Lake Superior this evening and
is expected to be in southwest Quebec Wednesday morning. Will get
into the "warm sector" of this clipper tonight...trailing cold front
will likely slip across the Upper Peninsula Wednesday morning.
Primary Forecast Concerns: Pretty minimal...dealing mostly with
cloud issues and temperatures. Initially gusty winds will be at
their peak during the late afternoon hours before diminishing across
land areas with loss of diurnal heating. But winds should stay
gusty over the lakes into the early part of the evening. Thicker
cloud cover this evening will be across eastern Upper and the tip of
the mitt...and maybe some flurries across eastern Upper during the
evening. Clouds with this system should strip out pretty quickly
per satellite imagery...problem for the overnight is a pretty good
signal for lower clouds to develop ahead of the approaching cold
front. Not totally sure how extensive this will be especially
across northern Lower as boundary layer has really dried out this
afternoon with dew points in the 10-15F range...though we will be
advecting in higher dew points from the southwest this evening. Will
allow for some additional cloud cover later tonight especially
across the interior higher terrain (will adjust sky cover forecast
to allow for a later onset of cloud cover). Clouds over eastern
Upper may be augmented by increasing instabilty over Lake Superior
in northwest flow/cold advection behind the cold front Wednesday
.SHORT TERM...(Wednesday through Friday)
Issued at 354 PM EST Tue Mar 2 2021
High Impact Weather Potential: Minimal...
Pattern Synopsis/Forecast: Starting off the short term now on
Wednesday morning...we see a weak shortwave moving through the
otherwise relatively zonal northern stream of the flow...with
strong troughing on either end of the North American continent. A
similar pattern is noted in the southern stream, with a cutoff low
moving onshore into southern California...and a pronounced
shortwave moving off the southeastern coast of the US. As the flow
progresses...northern stream troughing digging off the west coast
of the US will continue to convince southern stream low to move
eastward into the Desert Southwest...at the same time as ridging
across the Northern Rockies becomes amplified. Downstream
troughing across eastern Canada begins to retrograde going into
Thursday...though as ridging builds into the Plains and the
southern stream low moves through the flow to our south...looks as
if we may see stronger influence of the upstream ridge than the
downstream trough...at least through Friday.
Primary Forecast Concerns: minor precipitation chances Wednesday
into Thursday...perhaps again Friday?? ...Temperature forecast
through the end of the period...
With weak 500mb shortwave moving into the region and accompanying
surface cold front dropping down from the north early Wednesday
morning...there is a very remote possibility something may try to
pop up. HOWEVER...the trough is quite weak, and mid-levels are
pretty dry. This should serve to minimize precipitation potential
for the day Wednesday...though couldn`t entirely rule out something
popping up along the front, I suppose. Only very minor QPF has been
added to the forecast...particularly for Wednesday morning across
the typical northwest flow belt of northern Lower...where better
convergence will be located with that front moving through. Could
see some LES return late Wednesday into Thursday along Lake Huron as
850 temperatures approach -10 or so along some kind of convergence
axis (probably a backdoor cold front scraping our east side ahead of
a weak shortwave in the upper-levels)...though the core of the
coldest air attm looks to stay to our east...and synoptic moisture
assistance is pretty low.
Another shortwave swings down through the flow Friday as that pesky
trough sits downstream of us. There is some uncertainty in how much
synoptic moisture will be available to this one...though would not
be surprised if the lake started to respond as 850 Ts fall again
across the Great Lakes...though this may occur more towards Friday
night. Something to keep an eye on in the coming days, anyway.
Either way...it remains to be seen just how quiet the end of this
week will actually end up being.
Additionally...with all these backdoor cold fronts leading to
primarily dry northerly flow, and high pressure just to our west
through most of the period...will want to keep an eye out for low
temperatures at times, as any clearing and light winds under a cold
airmass aloft could signal potential for below-normal low
temperatures (which by the end of the week will be in the teens,
even for Pellston).
.LONG TERM...(Friday night through Tuesday)
Issued at 354 PM EST Tue Mar 2 2021
As mentioned above in the short term...weak lobe of energy dropping
through the region with a backdoor cold front late Friday could be
enough to kick off some precipitation chances Friday night...
especially as colder 850 Ts move in. This may be supported by more
synoptic-level moisture as that downstream trough draws in
Atlantic moisture...but there are some questions surrounding how
that all evolves. Timing is also somewhat uncertain regarding the
passage of this and other weak shortwaves moving through the flow
this weekend...so things may not be entirely quiet...but until
things become clearer...will keep things dry for now. Either
way...looks like ridging tries to press eastward late in the
weekend, thus bringing us another shot at warmth going into the
start of next week...though there is some discrepancy in timing of
a shortwave moving through the flow that could mess things up a
bit. Watching for a shift to a troughing- west, ridging-east
pattern for early next week...that could signal a switch to above-
normal temperatures...though it would come with a price: active
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 759 PM EST Tue Mar 2 2021
Surface low pressure continues to move E/SE through Ontario...just
north of Lake Superior, with a sharp cold front extending back
into the Upper Midwest. Surface low will weaken and advance into
New England overnight with the cold front sagging down into
northern Lower Michigan through Wednesday. Some model guidance
hints at development of a corridor of lower cloud cover spreading
into northern Lower Michigan later this evening and overnight
ahead of the boundary, although there is no sign of that
occurring for the moment. Other model guidance (HRRR) keeps cloud
cover to a minimum until after the cold front passage on
Tough call for aviation forecasts. Have kept the going theme of
developing lower MVFR cloud cover overnight and persisting through
the day Wednesday. However, we may not see much in the way of
lower cloud overnight. May have to revamp 06Z TAFS accordingly.
Issued at 354 PM EST Tue Mar 2 2021
Gale force winds will continue on Lake Michigan into early this
evening...but expecting winds to drop off rather quickly toward
midnight and after. Small craft conditions on Lake Huron should
subside as well Wednesday morning...though waves may still be a
bit choppy in the vicinity of Presque Isle Light.
LH...SMALL CRAFT ADVISORY until 5 AM EST Wednesday for LHZ345>349.
LM...SMALL CRAFT ADVISORY until 5 AM EST Wednesday for LMZ323-341-342-
GALE WARNING until 11 PM EST this evening for LMZ323-341-342-
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
621 PM EST Tue Mar 2 2021
Southwest winds will continue to gust into this evening as the
pressure gradient remains tight with low pressure passing north of
the of the Great Lakes. With a decrease in boundary layer mixing
with sunset, these gusts should decrease gradually and subside by
midnight into the overnight. A trailing cold front will settle into
the area on Wednesday as this low continue into Quebec. Some mid
level cloudiness will initially be possible in advance of this front
some MVFR stratus not out of the question within the northwest flow
in its wake Wednesday afternoon.
.DTW THRESHOLD PROBABILITIES...
* Low in ceilings at or below 5000 feet Wednesday afternoon.
Issued at 408 PM EST Tue Mar 2 2021
Split stream upper level flow is in place across North America with
a progressive northern stream driving the sensible weather for
Southeast Michigan. Southeast Michigan this afternoon is sandwiched
between modified polar high pressure off of the Carolina coast with
low amplitude shortwave/Clipper north of Lake Superior. The net
result is a dry southwest flow over Southeast Michigan with
temperatures this afternoon rising into the middle to upper 30s.
The main feature(s) of interest will be a series of 2 weak cold
fronts that will coast southward away from the aforementioned
northern Great Lakes shortwave. These cold front will push through
Lower Michigan within the next 28 hours. Latest consensus of model
data has the first one as a wind shift slipping through the area
between 12-14Z. Models differ on the amount of moisture available at
the top of mixed layer in the wake of the windshift. NAM is more
moist, which not surprisingly limits mixing heights. The HRRR is some
>3500 ft deeper with mixed layer and supports much warmer daytime
temperatures. The second cold front is expected to push off of Lake
Huron during the late afternoon under pseudo lake breeze dynamics
across the eastern cwa. This secondary feature is expected to push
inland at the Tip of the Thumb/Lake Huron shoreline areas after 21Z
with the cold aggregate air mass oozing through the remainder of the
forecast area between 3-10Z. Preference is to side with dry/higher
mixing depths with -4C/5000ft agl yielding temperatures pushing 50
degrees across the southern Forecast area. Saginaw Bay shadow is
expected to impact the Thumb but temperatures should reach to around
40 degrees before winds switch to north northeast and cool off after
Deeper column cold air advection and hydrostatics will cause
meridional surface high pressure ridge to nose straight southward
across Lower Michigan Thursday. Temperatures are expected to be
considerably cooler with polar trajectories, highs in the 30s
areawide. Subtle increase in anticyclonic flow from Lake Superior
through Lower Michigan combined with significant AVA dipole digging
through Wisconsin will cause retrograding to surface high pressure
late Thursday through Saturday. Amplification of strong lower height
anomaly over far northeastern NOAM/Greenland will bring strong
blocking scenario to carry through the duration of the weekend.
Proximity of governing features suggests that warm air advection will
be limited through Saturday. The uncertainty is whether or not
southwest flow can develop Sunday and cause massive uptick in air
Low pressure tracks from central Ontario this afternoon to the
eastern Great Lakes by Wednesday morning. The gradient produced by
this inbound system is ramping up southwest gusts across the region
with the peak in intensity expected over central Lake Huron late
this afternoon and evening. A Gale Warning remains in effect until
10pm as well as Small Craft Advisories. Winds weaken tonight and
veer to the west. The exiting system then pushes a backdoor cold
front through the region on Wednesday with wind becoming northwest
around 15 to 20 kt through the day. A secondary front drops through
Thursday morning and shifts winds to the north/NNE. This succession
of fronts drives the wave field southward to the southern Lake Huron
basin and another round of Small Craft Advisories will likely be
needed for the nearshore zones beginning Wednesday. NW to N flow is
then favored through the late week with the likelihood for
additional headlines remaining low.
Lake Huron...Gale Warning until 10 PM EST this evening for LHZ362-363-462.
Small Craft Advisory until 10 PM EST this evening for LHZ421-441.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
You can obtain your latest National Weather Service forecasts online
Area Forecast Discussion
National Weather Service Reno NV
214 PM PST Tue Mar 2 2021
Slightly above average high temperatures will rise to well above
average for Thursday and Friday. It will be dry except for light
snow showers Wednesday afternoon and evening in Mono County. Winds
increase late week followed by cooler temperatures and chances for
rain and snow for the weekend and into early next week.
Extensive high clouds continue to wash over eastern CA and western
NV this afternoon well ahead of low pressure centered well off
the southern CA coast. The clouds in combination with less flow
aloft (to encourage mixing/warming) has brought slight cooling for
many areas along and south of Hwy 50, although mountain slopes
and ridges as well as areas north of Hwy 50 are showing a bit of
warming over yesterday. In any case, temperatures are rather
seasonable with 40s for Sierra valleys and 50s for lower valleys.
The aforementioned low will track inland over far southern CA-NV
tomorrow afternoon and tomorrow night. Much of the model/ensemble
guidance remains consistent in generating snow showers near the
Sierra Crest over Mono County, possibly extending into southern
Alpine County, Wednesday afternoon-early evening. Blended probabilities
for measurable snow in the high eastern Sierra remain medium at
40-60% with a ~25% chance for up to a couple inches. For Hwy 395,
probabilities for measurable snow remain low at less than 25%. In
addition, given the notable increase in daytime road heating
(which would make any snow melt quickly on roads) this time of
year, very light snowfall rates, and the fact that trans Sierra
passes remain closed, little or no impact is expected for travel
in Mono County Wednesday...especially along and east of Highway
395. The only caveat along Hwy 395 is well after dark Wednesday
when any roads that remain wet could see slick patches as temperatures
fall below freezing.
A ridge axis rebuilds over eastern CA and Nevada Thursday. A
moderate south to southwest flow returns to the Sierra with some
breezes mixing into the valleys Thursday afternoon with some warming
into the lower 60s. -Snyder
.LONG TERM...Friday onward...
* Friday promises to be another mild day with daytime temps about a
month ahead of normal. With gusty south/southwest winds and if
clouds hold off long enough, we could see max temps get into the
90th percentile of NBM guidance ranges. That would yield upper 60s
RNO, mid 70s NFL, and mid/upper 50s for mountain communities from
Tahoe to Mammoth Lakes.
* Saturday`s storm is still on track with a quick-moving negative
tilt wave coming off the eastern Pacific. No major changes here
with ongoing forecast. Good bet for mountain snow accumulations
and travel impacts but the speed of the storm will limit amounts
to a few inches at pass elevations with an inch or two for
mountain communities. Pretty shadowed setup so I am
anticipating just light rain showers for W Nevada coupled with
breezy SW winds.
* Next week is really starting to look more interesting with broad
cold upper trough settling in over the region. Latest NBM and
ensemble guidance brings periods of snow to both mountains and
valleys with colder than normal temps. Best odds look to be
Monday evening through Thursday. Could rack up decent snow
accumulations in the Sierra but water content won`t be overly
impressive with minimal IVT signals. Non-trivial odds in NBM of
seeing at least a few inches of snow in the W Nevada cities as
well but that may be driven more by diurnal instability and
remain scattered. Looks like next week will feel more like that
"winter in March" that we all know and love.
* Upper low swinging through SoCal will send mid and high clouds our
way through tomorrow. Most areas won`t see any significant weather
and winds will generally be light.
* The one exception is over the E Sierra, near MMH, where NAM and
HRRR high resolution guidance is showing decent instability
Wednesday afternoon. This should result in scattered snow and
pellet showers from Bridgeport southward. Most of the activity
will be along the crest with mountain obscuration; however,
we`re looking at about a 40% chance of seeing MVFR-IFR snow
showers at MMH between 22z/Wed and 4z/Thurs. Accumulation
potential appears minimal with NBM guidance indicating about a
10-20% chance of up to 1" if a heavier shower occurs over the
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