Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/08/25
Area Forecast Discussion
National Weather Service Burlington VT
1002 PM EDT Mon Apr 7 2025
.SYNOPSIS...
A low pressure system will approach from the west tonight, and cross
our area late on Tuesday. This system will bring a round of
accumulating snow to the region, with a few inches of snow
possible, especially in the northern mountains. Tuesday will be
the coldest day of the week, then we trend back toward normal
temperatures from mid week onward. More widespread precipitation
arrives by the weekend.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
As of 959 PM EDT Monday...With each passing hour, we are slowly
seeing saturation occur across western New York and inching
eastward. Radar returns continue to look decent but the dry
layer continues to remain entrenched across the North Country.
The latest 00Z HRRR that just came in is showing a similar
picture to what we have been thinking over the past few days
with a sharp line of showers expected overnight into the early
morning hours on Tuesday. The model soundings show less
instability that previous runs which hints we may not see the
higher snowfall rates once thought. A cross section of the FGEN
shows the best forcing is well displaced from the DGZ which will
only act to limit efficient snowfall processes.
Previous Discussion...It ended up being a fairly pleasant
afternoon today, particularly in northern areas where sun has been
more prevalent. The fair weather will be coming to an end tonight
and Tuesday though as a potent upper trough and associated surface
low will bring widespread accumulating snow.
The upper trough is currently digging into the Great Lakes this
afternoon, and it will continue to shift its way eastward overnight
and Tuesday. Meanwhile, the surface low will likewise move eastward,
moving from the Great Lakes into the St Lawrence Valley tonight,
then along the international border during the day Tuesday. As the
system moves eastward, it will drag a strong cold front along in its
wake, with a colder airmass spreading in behind it. Guidance
continues to show a band of strong frontogenesis associated with the
front, and can already see the resultant moderate to heavy
precipitation upstream. This band of precipitation will move
eastward into our area overnight, entering the St Lawrence Valley
around or shortly after midnight, then progressing eastward through
the Adirondacks during the early morning hours. Although
temperatures will be in the mid/upper 30s ahead of the
precipitation, expect the precipitation will be heavy enough for wet
bulb cooling to allow rain to quickly change to snow as the
atmosphere saturates. Note that the HREF ensembles indicate snowfall
rates exceeding 0.5 inch/hr, so roads could quickly become snow
covered. Temperatures will fall below freezing with the frontal
passage as well, so any wet roads/snow melt could freeze, though
temperatures won`t drop much below 30F. Unfortunately, the heavy
band of precipitation looks to arrive in the Champlain Valley
sometime 5-8 am, just in time for the morning commute. As the band
moves into the higher terrain, snowfall rates will approach 1 in/hr,
especially along the western slopes in the northern Greens. Again,
this could make for a tricky commute Tuesday morning. Anyone
traveling in the morning should plan on giving themselves some extra
time to reach their destination.
Once the front moves through and the initial band of moderate/heavy
precipitation exits to the east, we`ll get a brief break in the
action as the dry slot wraps in around the low, which will be riding
along the international border. Winds will abate briefly as the low
moves through, but once it goes by, west/northwest winds will
increase, becoming gusty to around 30 mph. Upslope snow will develop
on these northwest winds, and we`ll once again see localized
snowfall rates approaching 1 in/hr along the western slopes of the
northern Adirondacks and northern Greens. Temperatures may rebound a
bit during the day, but highs will still only be in the upper 20s to
mid 30s, so expect snow to continue to accumulate, especially on
grassy or untreated surfaces. The upslope snow will persist through
the afternoon and evening, then gradually wind down Tuesday night.
Snowfall totals will be highest in the northern mountains,
especially along the favored upslope sides; 3 to 6 inches will be
possible in those locations, with higher amounts above 2500 ft.
Elsewhere, 1 to 3 inches of snow will be common, except an inch or
less in most of the Champlain Valley and the lower CT River Valley.
Tuesday night will be cold as temperatures will dip into the teens
and 20s, with brisk northwest winds gradually abating overnight.
&&
.SHORT TERM /WEDNESDAY NIGHT/...
As of 314 PM EDT Monday...Any lingering showers will taper off
Wednesday morning, with dry conditions expected to prevail
throughout much of the day. Daytime highs will be in the 30s and
low 40s, which is several degrees warmer than Tuesday but still well
below climatological normals for this time of year. A few breaks in
the clouds will be possible throughout the afternoon, with
relatively clear skies expected overnight. These clearing skies will
allow for some cold overnight lows, with locations dropping into the
teens and 20s.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 314 PM EDT Monday...After the brief reprieve in the unsettled
weather, chances of precipitation return Thursday night with an
upper level trough amplifying over the region. There looks to be
enough cold air in place that some high elevation snow showers may
be possible at the onset of precipitation, with most locations
seeing rain. While there is still plenty of uncertainty among, it
looks to be a relatively showery and unsettled few days to end the
week into Saturday, with surface low pressure of the coast pushing
eastward. Despite the showery pattern, the NBM probabilities of
72-hr rainfall amounts are generally 20 to 50 percent across the
region, with the highest probabilities across southern Vermont.
Heading into Sunday and early next week, ridging looks to try and
build in and bring another break in the unsettled weather.
Temperatures will trend closer to seasonal normals, with highs
generally in the 40s and 50s and lows in the 30s and 40s.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Through 00Z Wednesday...VFR conditions are expected to continue
through about 03Z-07Z when ceilings thicken and lower as
previously forecast. There is, however, a good amount of dry air
in the atmosphere this evening and latest models are trending
later with the arrival of MVFR conditions and precipitation
reaching the surface. Precipitation is most likely to arrive by
about 05Z-11Z, though it may be difficult to get visibilities
down below 3 miles and ceilings below 1000 feet above ground
level, especially at first. Best chance for any IFR level
conditions during this initial 05Z-11Z period will be at MPV,
RUT, and MSS. Conditions may improve tomorrow morning, with
many sites returning to VFR conditions by about 12Z-18Z, though
some sites (particularly SLK, MSS) could keep ceilings 3000
feet and below for much of the day. South to southeasterly winds
this evening 5-10 knots turn more westerly tomorrow morning,
gusting up to 15-30 knots by about 08Z-18Z following the
frontal passage.
Outlook...
Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHSN.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. Chance SHRA, Slight chance SHSN.
Thursday Night: Mainly MVFR, with areas VFR possible. Chance
SHRA.
Friday: Mainly MVFR, with local IFR possible. Chance SHRA.
Friday Night: Mainly MVFR, with local VFR possible. Likely SHRA.
Saturday: MVFR. Chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Hastings
NEAR TERM...Clay/Hastings
SHORT TERM...Kremer
LONG TERM...Kremer
AVIATION...Storm
Area Forecast Discussion
National Weather Service State College PA
1013 PM EDT Mon Apr 7 2025
.SYNOPSIS...
* Unseasonably cold start to the week in chilly pattern for the
second week of April
* Increasingly windy tonight into Tuesday with snow showers
downwind of Lake Erie over the Allegheny Mountains
* Brief dry spell later Tuesday into Wednesday with periods of
light rain returning for late week
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Cold front currently extends from KELM SSW to eastern Clearfield
and Cambria Counties SSW to around KMGW. Prefrontal rain
showers and temps from the upper 30s through the 40s are quickly
shown the door with FROPA, as moderate snow showers and temps
dropping through the 30s bring a rude reminder that it`s early
April afterall. Road temps are remaining above freezing behind
the front, despite air temps falling to around freezing at KBFD
this hour with 11/2SM vsbys in snow/blowing snow. Elsewhere,
vsbys as low as 1 to 3SM are being seen in the moisture
challenged environment, which is also losing its unstable
characteristics the closer we get to midnight. Still a large
area of flurries and snow snowers and blowing snow from the
Laurels through the NC mountains as the front passes.
So, the forecast remains essentially unchanged for the
overnight. Gusty snow showers will be the rule behind the front.
Moisture in the wake of the front will become relatively
shallow, but the cold NW flow and descending DGZ will likely
continue lake enhanced/orographic snow showers and flurries
going into early Tuesday morning. Snow accumulation <1 inch is
most likely in the snow belts and ridgetops/summits near and to
the west of US219. Min temps in the 20-30F range will be 5 to 10
degrees below climo.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
Unseasonably cold air works in behind the cold front, with
daytime max temps generally fcst in the 30-40F range. Max
temperature departures will be 15 to 30 degrees below the
historical average and some sites will be within 5F of daily
record lowest hi temps. Tuesday will be the coldest day of the
week and perhaps the coldest day until next Fall. A few snow
showers will linger through midday over the Alleghenies before
subsidence increases and brings snow showers to an end by the
afternoon.
Conditions will turn increasingly windy from Monday night
through Tuesday afternoon with peak gusts 30-40 mph from the
WNW. Gusty winds during the day on Tuesday will make it feel
like winter with max apparent temperatures in the 15-30F range.
Downslope flow will promote decreasing clouds southeast of the
Allegheny Front (east of I-99 and south of I-80) Tuesday
afternoon.
Clearing skies and lighter winds expected Tuesday night with
widespread frost freeze potential. While the growing season does
not officially begin until the weekend for the lower Susquehanna
Valley, we added mention of frost across the entire area to
highlight risk to any early season/cold-sensitive vegetation.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Dry weather is expected on Wednesday as high pressure drifts
eastward over Pennsylvania, though the dry weather will be
short-lived as most guidance shows a shortwave approaching from
the west Wednesday night. Precipitation will overspread the
region from west to east into early Thursday morning as a warm
front lifts north towards the region ahead of the surface low.
While most of the precip will fall as rain, ensemble 850 mb
temps just below freezing could allow for a few wet snowflakes
to mix in across the northern mountains through the morning.
Upper level troughing behind this system will keep rain chances
around into the first half of the weekend, but there is
considerable spread in the ensemble members as to the timing
and placement of individual shortwaves moving through the
trough. The trough will eventually be replaced by upper level
ridging which will bring drier weather back for Sunday.
High temperatures through the extended period will generally
range from the 40s and low 50s over the northern and western
mountains, to the upper 50s and low 60s over the southeast.
Late season frost and freeze concerns will return late in the
period, particularly Sunday night, as high pressure at the
surface and aloft will allow temperatures to fall into the low
to mid 30s under mainly clear skies with light winds.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Late evening update.
Strong cold front moving into the BFD area with gusty winds,
falling temperatures, and snow showers, as of 10 PM.
Timing of the activity looked rather good on the 00Z TAF
package, but made some minor adjustments.
Earlier discussion below.
Current conditions outline VFR across the western terminals
(BFD/JST/AOO) with MFVR prevailing across the eastern half of
the forecast area (UNV/MDT/LNS) as of 00Z observations. Slot of
clearing will continue across the central portions of the area
for the next couple of hours, potentially allowing UNV/IPT to
sneak out a couple of observations of VFR; however, low-level
moisture increasing ahead of the approaching cold front will
allow for gradual filling in of the lower-level decks, typically
below VFR thresholds. Example of this can be observed in recent
IPT observations as prevailing MVFR has trended towards VFR.
Radar returns across NW PA (BFD) are likely not hitting the
ground just yet given low-level dry air (dewpoint depression
~12F at BFD); however, cannot rule out a couple of raindrops
hitting the ground with minimal chances (< 10%) of MVFR
prevailing ahead of the cold frontal passage. Cold front is
stationed across Warren County (PA) and will continue to
progress eastward this evening, bringing about a thin window of
initial SHRA before transitioning towards SHSN. MVFR at this
time seems the most likely scenario at BFD/JST/AOO, beginning at
BFD between 00-01Z Tue, gradually filling in eastward towards
UNV by 03Z Tue. Uncertainty on restrictions remains much higher
at UNV/IPT as low-level moisture at UNV suggests SHSN at the
airfield, likely brining MVFR-to-high end IFR ceilings while
drier lower levels outline in RAP model RH cross-sections
outline lower probabilities (~20-30%) in restrictions at IPT
after 05Z Tue. Snow showers at BFD/JST/AOO/UNV are most likely
to bring IFR conditions to BFD/JST (~40-50%); however,
predictability on timing/magnitude of IFR restrictions remains
low (~20-30%), thus have opted to highlight periods of IFR
visibilities/ceilings to SCT007 and TEMPOs to outline best
possible timing.
Conditions are expected to improve towards daybreak (~12Z)
across the western airfields, with moderate (~50-60%) confidence
in all airfields prevailing VFR by 12Z Tue. Gusty winds in the
wake of the cold front will remain the highest aviation concern
with 25-35 kts at 290-320. High confidence (~80%) on wind gusts
and directions; however, cannot rule out slightly higher gusts
with the cold frontal passage in the 00-05Z timeframe west-to-
east. Winds persist throughout much of the TAF period with
highest chances at dipping below 20 kts after 00Z Wed.
Outlook...
Wed...No sig wx/VFR conditions expected.
Thu...Rain spreads west to east; sub-VFR likely.
Fri-Sat...Periods of rain with sub-VFR likely.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...DeVoir/Steinbugl
NEAR TERM...DeVoir/Steinbugl
SHORT TERM...DeVoir/Steinbugl
LONG TERM...DeVoir/Bauco
AVIATION...Martin/NPB
Area Forecast Discussion
National Weather Service Cheyenne WY
949 PM MDT Mon Apr 7 2025
EVENING UPDATE...No major changes overall to the forecast,
however did make some minor adjustments to the temperatures and
dewpoints this evening to account for observed temperatures
across the region. Seeing some discrepancies in the winds for
Chadron as well, but expecting the winds to pick back up a bit
here within the next hour or two and fall more into line with
the forecast.
.KEY MESSAGES...
- Mild to seasonably warm temperatures this week, along with
elevated to near critical fire weather conditions at times. A
Fire Weather Watch is in effect for the southern Nebraska
panhandle Tuesday afternoon.
- Elevated to high winds possible for the southeast Wyoming wind
prones on Tuesday and Wednesday. Wind gusts over 50 MPH are
likely.
- An isolated shower or thunderstorm is possible in the northern
Nebraska panhandle Tuesday and Wednesday.
&&
.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 238 PM MDT Mon Apr 7 2025
Currently a pleasant, sunny day across the area with mild
temperatures in the 50s and 60s for most locations. A little breezy
out west this afternoon with strong winds expected to spread
eastward through the overnight hours. Flow aloft tonight will
gradually turn more westerly as a shortwave moving along the
Montana/Canada border flattens the upper-level ridge. This will
strengthen 700 mb winds over the course of the night, and lead to a
prolonged period of windy conditions as the strong winds persist.
By Tuesday, winds aloft over the Laramie Range and usual southeast
Wyoming wind prones will reach 40 to 50 kts. Combined with decent
subsidence, some of these winds are likely to reach the surface
during the day Tuesday. Held off on any high wind headlines at this
time as both height and MSLP gradients are really lacking. A surface
low moving across the eastern half of the CWA tomorrow afternoon
will really dampen pressure gradients. In-house guidance is also not
too excited about high winds, showing 20 to 30 percent chances for
most wind prones. In-house guidance gives the highest probabilities
to Bordeaux, with almost a 40 percent chance of high winds. Would
agree that this location has the best chance just based off winds
aloft and subsidence alone. However, the lack of any sort of decent
gradient over the Laramie Range gives little confidence in high
winds here. Despite this, the wind prones will likely still see 50
to 55 MPH wind gusts during the day. Will let another model cycle go
through so later shifts can decide if any wind headlines are needed.
Strong winds across the area will also lead to fire weather concerns
during the afternoon hours. Downsloping winds and a dry surface will
lead to elevated fire weather conditions east of the Laramie Range.
Issued a Fire Weather Watch for Tuesday afternoon for the southern
Nebraska panhandle as fuels are ready and this location has the
strongest chance to see relative humidity drop below 15
percent. Models have been fairly consistent with showing mid-
level cloud cover as the aforementioned shortwave drops down
from the north Tuesday night. Increasing mid-level moisture
throughout the day will increase cloud cover and potentially
limit relative humidity from dropping below critical thresholds.
Hi-Res guidance like the HRRR and RAP are rather aggressive and
suggest downsloping winds will overcome the cloud cover. Due to
this and 40+ MPH winds expected in the panhandle, issued the
Fire Weather Watch. Opted to keep the northern panhandle out of
the Watch for now as there is a slight chance for an isolated
shower or two ahead of the incoming shortwave.
Wednesday will be virtually a repeat of Tuesday, but with slightly
better chances for high winds and fire weather. With the shortwave
diving down into the northern High Plains, the exit region of the
250 mb jet will be located over the CWA. Winds aloft over the South
Laramie Range will reach 50 to 55 kts with even stronger subsidence
than Tuesday. MSLP gradients remain unimpressive, but CAG-CPR 700 mb
height gradients do briefly climb over 50 meters, giving Arlington a
shot at high winds on Wednesday. In-house guidance shows just under
a 40 percent chance for high winds for these areas. Have more
confidence in high winds on Wednesday and for more locations, but
held off in case headlines are needed tomorrow. Strong winds will
again lead to fire weather concerns. Fire weather headlines may
likely be needed again during the afternoon hours with continued
gusts above 40 MPH. Relative humidity remains the limiting
factor, however model soundings show a very dry surface.
Combined with downsloping winds, humidity may be able to drop
below critical thresholds. With the shortwave off to the
northeast, the northern panhandle may still see an isolated
shower or thunderstorm during the day. Elevated CAPE values
could lead to a thunderstorm with gusty winds given the
inverted-V soundings.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 238 PM MDT Mon Apr 7 2025
The main weather story in the long range (Thursday and beyond) will
be a big warmup heading into the weekend. Upper westerly zonal flow
midweek transitions to northwest and eventually southwest as a ridge
builds over the Rockies. The ridge appears to be rather progressive
in only sticking around a couple days before breaking down to the
east, but will be rather anomalous. A closed low then dives into the
Dakotas during the latter half of the weekend while a trough digs
into the central Rockies. That system will bring the next potential,
albeit still rather limited (20-30%) of precip and temperatures
closer to normal.
Thursday through Saturday... The forecast area remains on the
periphery of the ridge on Thursday, but quickly falls under its
influence on Friday. NAEFS ensembles suggest H5-7 heights reach
99%ile of climo on Friday as the axis bisects the forecast area. The
magnitude of the ridge combined with decent southerly low level flow
over the Great Plains and westerly downslope flow along the
mountains will encourage well above normal temps to round out the
week. ECM EFI values indicate near certainty in abnormally warm max
temps (0.8-0.9/1) and potential for near records as SoT values >0.
H7 and H85 temps in the guidance also reflect the pattern as they
increase from -4C to +10C in eastern Wyo and from +7C to +25C in Neb
panhandle, respectively. As of now, official forecast highs range in
the lower/mid 60s Thu to mid/upper 70s Fri to lower/mid 80s Sat for
areas east of I-25. These values line up near the 25%ile of the NBM
envelope but closely resemble the MEX. Depending on cloud cover and
prevalence of downslope flow, current forecast may need bumped up.
Saturday`s highs surpass normal values as much as 25 degrees and
approach daily records, so any increase could very easily set new
records. Aside from the warmth, fire weather concerns are definitely
raised as humidity values drop into critical thresholds (<15%).
Thursday may feature the gustier winds, but relatively higher
humidity, but Saturday will need monitored as winds could increase
with the ridge breakdown.
Sunday and Monday... The next upper trough quickly fills in behind
the ridge as the low passes just to the north of the area. The
dynamics in the mid/upper levels appear rather impressive with an
organized H5 vort max and a streak in the H3 jet intensifying from
100 kts over Wyo to 130+ kts in Neb. The surface component features
a secondary low somewhere near the Black Hills driving the warm
front (passage Sat) and then the strong cold front on Sunday. The
primary low will be more closely associated with the upper low over
the Dakotas. Despite the increased forcing, moisture could be a
limiting factor in the overall setup. Low level vectors steer the
greatest flow and convergence east of the forecast area, and most of
the appreciable precip may stay concentrated along the northern tier
of the CONUS. Some wrap-around activity may work into Wyo and
western Neb as cooler air filters into the region. Thermal profiles
would suggest mountain and perhaps nighttime snow and valley/daytime
rain or mix.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 538 PM MDT Mon Apr 7 2025
VFR conditions expected for the forecast period. Expect
increasing mid to high level clouds this evening as a storm
system grazes the area to the north. Increasing winds aloft may
lead to marginal LLWS and occasional brief gusty surface winds
overnight. Gusty winds will mix down mid to late Tuesday
morning and continue through the afternoon. A few isolated
showers and/or storms will develop Tuesday afternoon, and may
bring gusty/erratic winds and a brief rain shower, most likely
in the northern NE panhandle.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...Fire Weather Watch from Tuesday morning through Tuesday
evening for NEZ436-437.
&&
$$
EVENING UPDATE...CG
SHORT TERM...SF
LONG TERM...DS
AVIATION...MN
Area Forecast Discussion
National Weather Service Glasgow MT
820 PM MDT Mon Apr 7 2025
.DISCUSSION...
KEY MESSAGES:
1) Scattered light rain showers will move into the region from
the west overnight.
2) Gusty west to northwest winds Tuesday and Wednesday afternoon
and evening will impact early season recreation out on Fort Peck
Lake. A Lake Wind Advisory for Fort Peck Lake has been issued for
Tuesday from 10 am to 8 pm.
WEATHER PATTERN OVERVIEW:
Evening update: Short term models this evening are showing higher
wind speeds for Tuesday afternoon. The RAP and HREF Grand Ensemble
are showing west winds 15 to 30 mph over the western half of the
forecast area which is strong enough to issue a Lake Wind Advisory
for Fort Peck Lake. The main update to the forecast will be to
increase wind speeds on Tuesday.
Previous Discussion: Upper ridging will give way to the upper
trough off the Pacific Northwest moving onshore. The next round of
light rain showers looks to occur tonight and Tuesday, with total
QPF amounts remaining under 0.10" for most places.
On Tuesday afternoon, gusty winds and low RH may elevate fire
weather concerns for a time but not for widespread or prolonged
enough exposure to merit issuing headlines at this time.
HREF and NBM show CAPE/Shear profiles supportive of an isolated
thunderstorm or two on Wednesday. The main concern operationally
will be developing west to northwest winds ranging from 15 to 25
mph with gusts to 35 or 40 mph, resulting in the potential for the
First Lake Wind Advisory for the season for Fort Peck Lake.
Upper ridging will resume warm and dry conditions over the region
late week before the next rough arrives for the weekend.
FORECAST CONFIDENCE & DEVIATIONS:
NBM was used for much of the forecast period, but NBM 90 was
blended in for Tuesday afternoon. Confidence is high on gusty
weather conditions for a time that afternoon with more widespread
gusty west winds on Wednesday. Lower confidence exists on showers
tonight and Tuesday as well as thunderstorm potential on Wednesday
given marginal support and isolated coverage.
&&
.AVIATION...
VFR conditions will prevail into tonight though lower ceilings
will move in this evening from the west. Showers are also possible
overnight and Tuesday. SE winds 5 to 15 knots tonight will become
west Tuesday morning and increase to 15 to 25 knots Tuesday
afternoon.
&&
.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory from 10 AM to 8 PM MDT Tuesday for Central
and Southeast Phillips-Central and Southern Valley-Garfield-
McCone-Petroleum.
&&
$$
weather.gov/glasgow
Area Forecast Discussion
National Weather Service Grand Rapids MI
950 PM EDT Mon Apr 7 2025
.KEY MESSAGES...
- Snow and Rain Chances Wednesday into Thursday
- Warming Up into the Weekend
&&
.UPDATE...
Issued at 950 PM EDT Mon Apr 7 2025
00Z Raobs show H8 temps of -16C at APX and -13C at GRB. Lake
effect stratocumulus clouds and flurries have been streaming in
off Lakes Superior and Michigan this evening into northern and
central Lwr MI while srn MI is Ptly Cloudy. That should continue
to remain the case overnight although clouds and flurries may
expand farther south along the Lk MI shoreline in the NNW flow.
Otherwise a cold/blustery night for early April with temps in the
20s.
The River Flood Warning at Maple Rapids has expired. Current
reading is 8.93 and flood stage is 9.0.
Have added some low pops for snow showers east of Hwy 131 on
Tuesday afternoon as 00Z HRRR looks rather ambitious with a
diurnal boost to the cumulus in the back/wrn side of the upper
trough.
&&
.DISCUSSION...
Issued at 347 PM EDT Mon Apr 7 2025
- Snow and Rain Chances Wednesday into Thursday
Our next round of precipitation moves in Wednesday as positive
vorticity, warm air, and moisture advection move in ahead of a low
pressure system moves through the region. The overall track and
strength of the system will impact our temperature profile and
overall precipitation type. Our current forecast using the NBM
gives us more of a rain/snow mix transitioning to rain with little
to no snow accumulations. If colder air is realized we may see
amounts closer to the 75th percentile of around an inch.
Probabilities of an inch or more are currently 30 percent or less
across much of the area except for slightly higher probabilities
of 40 to 50 percent in Clare and Osceola counties. Either way with
mild temperatures in place, would expect accumulations if any on
grassy surfaces. Drier conditions then move in Thursday night and
continue into the weekend.
- Warming Up into the Weekend
High pressure builds over the area for the end of the week.
Ensembles highlight the dry period and warming trend into next
week. Highs Tuesday will be in the 30s, but each day highs will
increase by several degrees with 50s and 60s expected over the
weekend.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 657 PM EDT Mon Apr 7 2025
Little in the way of aviation concerns over the next 24 hours.
Diurnal cumulus will diminish shortly after sunset with a a few
hours break before lake-induced stratocu develop overnight. A SCT
to BKN deck in the 5-7 kft range is expected keeping conditions
VFR. Skies then clear out in the last few hours of the TAF window
as high pressure reaches the area. Current northerly winds of
15-20 knots gusting to 25-30 knots subside to northwesterly at
10-15 knots overnight and stay there through the rest of the TAF
window.
&&
.MARINE...
Issued at 347 PM EDT Mon Apr 7 2025
Gusty northerly winds will continue through late tonight with some
isolated gales for the rest of this afternoon. Waves will be slow
to come down, but are expected to fall below Small Craft Advisory
criteria Tuesday morning. Southerly winds move in for Wednesday
along with chances for mainly rain.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 11 AM EDT Tuesday for LMZ844>849.
&&
$$
UPDATE...Meade
DISCUSSION...RAH
AVIATION...Thomas
MARINE...RAH
Area Forecast Discussion
National Weather Service Gray ME
1031 PM EDT Mon Apr 7 2025
.SYNOPSIS...
A weak area of low pressure passes across northern bringing
rain and snow showers to the south, and a steadier snow to the
north on Tuesday, where several inches of accumulation is
possible. Cooler but drier conditions will then return for the
middle of the week before more unsettled weather returns towards
the weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
1025 PM Update...Forecast remains on track. Based on addition
new guidance this evening will expand the winter weather
advisory to the rest of the western ME mountains and northern
Coos County for a general 3 to 7 inches of snow Tue. Will have
to watch Waldo County also depending on how the low level
temperatures profile looks to shake out.
7 PM Update...No significant changes to the going forecast
right now as trends remain on track. Otherwise, may consider
adding a few zones to the winter weather advisory for tomorrow.
Will continue to look at new data that continues to arrive.
Previously...
After a mostly dry day outside of far southern NH, damp weather
returns tonight into Tuesday. Not a large change in thinking,
but three or four main focal points over the next 36 hours.
For tonight, moisture depth remains variable as winds pivot
onshore this afternoon through the night. This will surely
supply moisture at the surface and low levels, but is it enough
for light precip outside of drizzle or fog? General trend for
the forecast is showery rain/snow in the south this evening,
transitioning to areas of drizzle around midnight and pre-dawn
hours for points east/south of the foothills. Surface temps will
play a role if some of this drizzle falls and clings on
elevated surfaces. This is mainly a concern getting into the
interior and foothills were overnight temps near 30 or the upper
20s. It will be hard to get slick surfaces elsewhere given the
warmer antecedent surfaces.
Moisture profiles do begin to saturate into the mid/upper
levels during the pre-dawn hours. This should result in very
light snow mixed with rain showers that will struggle to
accumulate. A more impactful feature approaches western NH
Tuesday morning.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Compact low pressure will quickly make its way out of the
eastern Great Lakes overnight, with its associated cold front
nearing western NH around 8am. Hires models have been fairly
consistent bringing a line of snow showers through along this
sharp forcing. With it expanding east into the forecast area
through the early afternoon, some parts of the line may approach
snow squall criteria with quick reductions in visibility due to
falling snow and gusty winds. Stronger winds appear more likely
behind the line of showers however, hence the downplay in
intensity.
This feature continues east into low level onshore flow. The
increase in convergence will cause more widespread snow to
develop inland from the coast. Rates increase, but should be
hard to accumulate before mid to late evening. Here, HREF
members have been attempting to develop a deformation zone and
perhaps a banding feature into parts of Somerset County. To
emphasize uncertainty in placement, the HRRR takes a narrow
band through Franklin County, while other guidance is nearly on
the border with Somerset/Piscataquis Counties. Considering the
recent westward trend, increased QPF and some snow ratios into
Somerset to at least account for this. This brings enough snow
to warrant a short Winter Weather Advisory Tuesday afternoon
into evening. Model profiles confirm a robust crosshairs
signature of omega and the snow growth zone that increases
confidence in elevated snow rates mid afternoon. The single zone
Advisory is a good start, and can expand if needed should the
above trend continue. Into April, quick and low QPF events can
be hampered by the antecedent warm surface temps, thus expansion
was also weighed against this.
Touched on early Tues winds above, but gust factor looks to
increase come the late afternoon and evening. NW winds increase,
perhaps up to 30 or 35 mph, mainly across southern and central
NH. This then transitions to the ridges and higher summits of
the mountains overnight.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
No significant changes to the going long term forecast. The main
weather event of the long term period still looks to be the
chance for some occasionally heavy rain over the weekend that
could start as a mix in spots Friday.
Previously...
As for Wed, it should be a mainly sunny day, a little breezy
and cool, with highs mid 30s N to mid 40s S. Wed night should be
mainly clear with calm winds, and some rad cooling can be
expected. Lows range from 15-20 in the mtns to the low to mid
20s in the S, probably making it the coldest night in the
forecast range. Thursday looks mostly OK, as winds shift SSW,
although there will be increasing clouds in the afternoon. Highs
range from the low to mid 40s N to the low 50s S. Thu night
looks mostly dry too, but wind will begin to shift onshore, and
clouds will overspread the area, as well, so mins will mostly be
in the 30s. Despite my chance POPS, Im leaning toward limited
showers on Friday, but, with onshore flow through most of the
day it will be cloudy, and highs will generally be in the 40s,
as the marine lyr settles in.
As mentioned, models have shown some run-to-run consistency for
precip Fri night into Saturday, and this where there are some
likely POPS. Its warm enough, that only it will be rain. The
only exception at times, may be the highest elevations. Even
this, just based on the pattern seems low confidence, and by the
time we get to Sunday confidence is even lower.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Short Term...MVFR/IFR ceilings advance northward this evening.
This will be accompanied by light snow and drizzle at times
through the night. This could cause reduced visibility. Can`t
rule out pockets of freezing drizzle at some interior terminals
from LCI/IZG/LEW. After daybreak Tuesday, line of snow showers
will move through east to west bringing about a WNW wind shift.
Snow increases in intensity across central ME and mountain
terminals through the afternoon and evening. Winds will also
increase up to 30 kts across southern NH terminals Tuesday
afternoon/evening.
Long Term...VFR is expected Wed- Thu at least. Probably sometime
Thu night as the flow shifts onshore, will begin to see IFR or
lower first at the coastal sites, and later further inland,
sometime on Friday. KLEB/KHIE, may not see any restrictions
through Friday as they will be downsloping in the onshore flow.
Friday night and Sat expect restrictions everywhere in rain and
low cigs.
&&
.MARINE...
Short Term...Onshore winds continue this evening with inland low
pressure nearing the waters late Tuesday morning into the
afternoon. This low will bring a sharp cold front over the
waters, bringing a abrupt west wind shift and gusts up to Gale
force through the evening and overnight.
Long Term...SCA conds will likely be continuing into Wed
morning, but should subside during the afternoon. Beyond that,
expecting winds and seas below SCA conditions until Saturday.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory from 8 AM Tuesday to 2 AM EDT
Wednesday for MEZ007-008.
Winter Weather Advisory from 11 AM Tuesday to 2 AM EDT
Wednesday for MEZ009-014.
NH...Winter Weather Advisory from 8 AM Tuesday to 2 AM EDT
Wednesday for NHZ001.
MARINE...Gale Warning from 4 PM Tuesday to 2 AM EDT Wednesday for
ANZ150-152-154.
Small Craft Advisory from 4 PM Tuesday to 2 AM EDT Wednesday
for ANZ151-153.
&&
$$
SYNOPSIS...
NEAR TERM...Cornwell/Ekster
SHORT TERM...Cornwell
LONG TERM...Cempa
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Pittsburgh PA
945 PM EDT Mon Apr 7 2025
.SYNOPSIS...
Changeover to snow behind a strong cold front continues tonight,
with isolated lake enhanced snow showers continuing into
Tuesday morning. Impacts are expected to be limited as
accumulations mainly occur on grassy or elevated surfaces.
Another period of seasonably cool and wet weather is expected
Thursday into next weekend.
&&
.NEAR TERM /THROUGH TUESDAY/...
KEY MESSAGES:
- Mainly snow showers behind the frontal boundary, with some
overnight lake enhancement expected.
- Though accumulations of 1 to 2 inches are possible, impacts
will be low due to warm surfaces and roadways.
- Dry but cool weather expected Tuesday.
-------------------------------------------------------------------
The front is approaching the Laurels, and remains about an hour
or so away from MGW. Main impact has been wind gusts, which have
come in a bit higher than NBM/HREF probabilities suggested. Have
seen a number of sites with peak values in the 35 to 45 MPH
range, with PIT having the highest recorded gust at 46 MPH.
Expect these gusts to slowly subside through the night as mixing
eases.
The HRRR has done a decent job of modeling the temperature drop
with the front, and have made only minor adjustments through the
night. Snow rates are light overall, not surprising given the
lagging of colder air and marginal moisture in the DGZ. Road
accumulation has been hard to find, but some grassy accumulation
is noted on area webcams.
Behind the front, dry advection will temper shower activity
until NW flow aloft better taps Lake Erie moisture to develop a
few lake-enhanced snow bands during the overnight hours. HREF
modeling suggests a quick 1-2" of accumulation can`t be ruled
out if band duration/intensity is maximized (especially north of
I-80), but continued warm surfaces should ensure minimal
impacts (accumulations mainly occurring on grassy or elevated
surfaces). The ridges, once they change over to snow, could
accumulate an inch or so thanks to upsloping overnight.
High pressure to the west and slowly rising heights aloft will
erode showers Tuesday and attempt to dissipate lingering
stratocu. The cold airmass in place should lead to areal
temperature that is around 20 degrees below the daily average.
As the growing season hasn`t official started, no freeze
products will be issued; that said, expect each overnight period
to feature below freezing temperature that may necessitate
protection of outdoor vegetation that is vulnerable to cold
temperature.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
KEY MESSAGES:
- Well below normal lows again Wednesday morning.
- Precipitation returns later Wednesday through Thursday.
-------------------------------------------------------------------
Increasing subsidence and a shallower boundary layer will end
any precipitation on Tuesday. Broad surface high pressure
building in from the west will then maintain dry conditions
through Wednesday should keep the area dry for much of Wednesday
before rain returns ahead of an approaching low later in the
day. The mentioned low center is progged to then pass north of
the region on Thursday. Warm advection in southerly flow will
then moderate temperatures.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
KEY MESSAGES:
- Below-average temperatures expected through Saturday
- Precipitation ends later on Saturday
-------------------------------------------------------------------
Long-range ensemble models remain consistent, showing a cool
pattern through Saturday. A large-scale trough over our region
will likely keep afternoon highs below 60 degrees, with less
than a 25% chance of exceeding that, during this time period.
The highest chance of precipitation will be Thursday afternoon
into Thursday night as a low-pressure system moves through the
Midwest and Ohio River Valley. While rainfall amounts of over a
half inch are currently unlikely (less than 20%) higher
elevations could see closer to that amount due to upslope flow.
There`s a possibility of continued precipitation Friday into
Saturday if this noted trough stalls as indicated by a few long-
range ensemble models.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
The advancing SFC cold front is easily identifiable on radar,
satellite and in SFC OBs. Dry, clear and VFR conditions will
continue until the front reaches each port.
Rain begins quickly along the leading edge of the strongly
forced front as CIGs settle in near 5kft. Rain is expected to
switch quickly to snow (likely within an hour or less). Pockets
of heavier snow are embedded in this line and have already been
noted upstream at HZY and CLE. Any heavier bursts of snow can
drop to MVFR CIGs and IFR or LIFR VIS. All told the hit of
organized snow will be rather brief, perhaps an hour or so (CLE
saw snow for 75 minutes). Winds pick up sharply along the front
and shift to the W and then NW as it passes with increasing
gusts towards 25kts for most ports.
Behind the front, snow showers become more sporadic in northwest
flow most focused in the usual spots (FKL/DUJ). CIGs become a
hodgepodge of borderline MVFR/VFR with probabilities of CIGS
<3kft peaking near 60% for much of the area except for FKL/DUJ
which remain north of 80%.
SFC high pressure begins to slowly filter in by midnight but the
lingering upper trough is expected to make snow showers tough to
suppress through the day Tuesday.
Outlook...
High pressure to the west and gradually rising heights aloft
will end precipitation chances and erode VFR/MVFR stratocu by
Tuesday evening.
The next low pressure system arrive late Wednesday into Thursday
and is likely to initiate another prolonged period of
restrictions and occasional precipitation chances as deep Great
Lake troughing develops.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...Frazier
NEAR TERM...Frazier/CL
SHORT TERM...Hefferan/22/88
LONG TERM...Hefferan/88
AVIATION...AK