Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/08/22
Area Forecast Discussion
National Weather Service Boston/Norton MA
1020 PM EDT Thu Apr 7 2022
Low pressure moves up the eastern seaboard tonight, with rain
heavy at times overnight along with a few thunderstorms
possible. Behind the departing low, Friday should feature mainly
dry and mild weather. Trending cooler over the weekend,
especially Sunday. Scattered showers are expected Sat morning,
followed by a drying in the afternoon. Drier, cooler and breezy
Sunday, but can`t rule out a few brief afternoon showers,
certainly not a washout. Next week will feature a warming trend
but also a few episodes of showers are possible from time to
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
1015 PM Update:
Tweaked PoPs, Wx and QPF a bit, focusing most of the heavier
rains through 06z from Worcester to Block Island westward, then
preferentially east of this same area into the Boston-Providence
corridor after 07z.
As of this writing, currently intermittent light showers were
evident across most of SNE. That will be changing in a more
substantial way as heavy rains and embedded thunderstorms now
from the lower Hudson Valley down to just offshore of the DE
coastline translate ENE to NE through the after-midnight
period. This is associated with a frontal boundary and weak
surface low near the Chesapeake Bay region with elevated PWAT
values along and ahead of this feature, in a regime of strong
moisture convergence. That cloud tops continue to cool with
active lightning seen in GLM products asssociated with this area
of precip certainly indicates convective processes continue
despite the unfavorable time of day, and this is leading to
efficient rain rates with a few LSRs from PHI/OKX in the
northeast NJ area indicating some flooding. Think the HRRR has
the best handle on timing of these heavier showers with embedded
thunder into SNE, generally between 04-07z (midnight to 3 am)
across interior MA/CT, and around 06-10z (2-6 am) into RI and
much of eastern MA. Hydrologic response should be limited to
rises on streams and creeks and urban/poor drainage type
flooding, a part of which could intersect with the Friday
morning commute across eastern MA and RI.
It`s been a fairly breezy night as well with ESE winds around 25
to 35 mph. SE low level jet increases tonight and overnight to
around 65 kt, and while speeds could increase about 5-10 mph in
gusts, stable low-levels should keep us from gusts rising to
level where wind headlines would need to be considered.
Temps and dewpoints should continue to slowly rise overnight,
with temps by daybreak in the upper 40s to lower 50s and
dewpoints at similar levels.
Deep moisture continues to stream northward over eastern NY and
southern New England this afternoon ahead of a digging trough over
the entire eastern half of the U.S. This is evident on visible
satellite where we see thick cloudcover over the northeast with more
convective elements over PA into MD. The more robust and dynamic
weather eventually makes its way into southern New England tonight
bringing with it periods of heavy rain along with some lightning.
Beneath said 500 mb trough the parent surface low spinning over the
Great Lakes will strengthen a secondary low along the cold frontal
boundary this evening which will move over southern New England
tonight and into Maine by Friday night. Along with PWATs near 1.25"
we`ll also have strong dynamics from a 50-60 kt low level jet
centered over the Cape and islands which will help to squeeze a lot
of moisture out of the atmosphere between now and 8 am Friday.
Rainfall amounts will range from a quarter inch to an inch, locally
higher, with the heaviest amounts over the high terrain of western
MA and CT where east to southeast orographic flow will assist. These
amounts don`t concern us with regard to any widespread flooding as
they`re well below flash flood criteria. Also fortunate is the
timing which brings the heavy rain in late tonight and pushes it out
before the Friday morning commute. The southeasterly onshore flow
will also help to cap things, with a stout inversion in the low
levels keeping winds, while gusty, below advisory criteria. As the
low moves overhead it will bring the warm sector into our area which
means a few things; one, that we`ll have a non-diurnal temperature
swing tonight with temperatures surging up into the low 50s for many
toward sunrise Friday. This also introduces some elevated
instability into the forecast overnight, with CAPE values of several
hundred J/kg focused first over CT then shifting into RI and
southeast MA. Fortunately with the strong inversion in place this
will all be elevated in nature.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
Things will be significantly drier on Friday behind the cold front;
PWATs below 0.50" with surface dewpoints dropping from the 50s back
into the 30s or 40s. We`ll see significant clearing after 8 am with
perhaps some diurnal clouds in the afternoon, especially for areas
farther north where moisture lingers at 850 mb. Winds back out of
the southwest for a very mild day, in the mid 60s!
Friday night the broad trough overhead sends another shortwave
through the flow overhead kicking off another round of light showers
as a weak surface low passes overhead. Guidance has slowed a bit so
the best chance of these showers looks to be toward the latter half
of the night or early Saturday. Low temperatures bottom out in the
40s, save for the high terrain which may not make it out of the
.LONG TERM /SATURDAY THROUGH THURSDAY/...
* Scattered showers Sat morning, then dry for the afternoon
* A few afternoon showers possible Sunday & cooler, but not a washout
* A warming trend next week, but a few chances for showers too
Lots of short waves rotating through high amplitude mid/upper level
trough over the eastern Great Lakes and OH valley this weekend. One
of these impulses moves across SNE Sat morning, with ample forcing
for ascent and mid level moisture to yield scattered showers Sat
morning, especially across the interior. As previous forecaster
noted, cold air aloft may provide enough instability for a few
thunderstorms across the interior Sat morning. Fast flow aloft, so
behind the departing wave, a drying trend for Sat afternoon along
with increasing sunshine. Drier Sunday, but -30C cold pool at 500 mb
along with cyclonic flow will result in increasing diurnal clouds
from late morning into the afternoon, along with isolated shower
threat. By no means a washout, with most of Sunday being dry. High
amplitude trough finally moves offshore by Monday, with dry weather
and plenty of sunshine. Next chance of rain, sometime Monday
night/early Tue with mid level warm front and airmass change to
milder weather and not as dry, with dew pts rising from the 20s
Monday to the 40s Tuesday. Then some uncertainty Wed/Thu, with
potential for backdoor front Wed, possibly returning northward as
warm front Thu. Just unable to resolve these smaller scale details
at days 6-7.
Still mild Saturday with core of the cool air remaining west of New
England. Highs Saturday should climb into the upper 50s and lower
60s. Normal high for this time of year is low to mid 50s. A bit
breezy Sat afternoon with WSW winds 15-25 mph, but mild temps and
increasing afternoon sunshine will yield pleasant weather by
early/mid April standards. Cooler and breezy Sunday as core of cold
air aloft (-30C at 500 mb) is centered over SNE. Although,
seasonably cool with highs in the 50s. Morning sunshine gives way to
lots of afternoon clouds, given cold air aloft and cyclonic flow.
Core of cold air aloft finally moves offshore, thus setting the
stage for a nice day Monday, with highs in the upper 50s and lower
60s. Breezy and cool in the morning, but high pressure advecting
into SNE, winds should diminish Mon afternoon. Change in airmass
Tuesday with east coast ridge. Thus trend toward warmer
temperatures, but lots of uncertainty regarding the strength of
northern stream energy climbing over this ridge and possibly
delivering a backdoor front and a cooler airmass around Wed. This
front may lift back north Thu, with a return to warmer weather, but
again difficult to nail down these details at days 6-7. While it
fits climatology, overnight temps the next 7 days likely remain
above freezing across most of the region.
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
00Z TAF Update: broken line of heavy showers and embedded
thunderstorms expected to move across CT/RI/MA between 06z-09z
from southwest to northeast, exiting Cape Cod around 11z Fri.
Earlier discussion below.
Today: Moderate confidence.
Generally SCT-OVC VFR and MVFR today, lowering to IFR from
southwest to northeast late afternoon. Should be generally dry
with a better chance for showers BDL- BAF after 00z.
E/ESE winds will be 10-15 kt, with gusts 20-25 kt.
Tonight: Moderate confidence.
Generally MVFR/IFR with improvement behind the cold front.
Ahead of the front a line of showers and thunderstorms will
bring periods of heavy rain between 03 and 10Z. Confidence in
the occurrence and timing of thunder is moderate. Heavy rain may
reduce visibility to IFR for a time.
SE low level jet of 45 to 55 kt will cause SE gusts to increase
to 25-30 kt from the SE.
Friday: High confidence.
VFR. Mostly dry weather after 14Z. Winds become SW 5-10 kt,
gusts 18-20 kt across Cape Cod and Islands.
Friday night: High confidence.
Mainly VFR with local MVFR possible in scattered rain showers
after 08Z. Light S winds.
KBOS TAF...Moderate confidence in TAF.
KBDL TAF...Moderate confidence in TAF.
Outlook /Saturday through Tuesday/...
Saturday: Mainly VFR, with areas MVFR possible. Breezy. Chance
Saturday Night: VFR. Breezy.
Sunday: Mainly VFR, with local MVFR possible. Breezy. Slight
Sunday Night through Monday: VFR. Breezy.
Monday Night: Mainly VFR, with local MVFR possible.
Tuesday: Mainly VFR, with local MVFR possible. Breezy. Slight
Forecaster Confidence Levels.
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
A southeast low level jet of 65 kt kicks up this evening
bringing SE gusts to 35 kt tonight, with up to 40 kt across the
eastern waters. Seas will increase overnight to as much as 15
ft near the northeast MA coast with 7-10 ft seas across the
southern waters. We will see potential for thunderstorms on the
waters during the overnight hours, with visibility briefly
reduced to as low as one mile at times.
Gale warnings will need to be converted to SCAs into Friday with
winds becoming SW and decreasing through Friday night.
Outlook /Saturday through Tuesday/...
Saturday: Winds less than 25 kt. Seas up to 5 ft. Slight chance
of rain showers.
Saturday Night: Winds less than 25 kt. Local rough seas.
Sunday: Winds less than 25 kt. Seas up to 5 ft.
Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas.
Monday: Winds less than 25 kt. Local rough seas.
Monday Night: Winds less than 25 kt. Seas locally approaching
Tuesday: Winds less than 25 kt. Slight chance of rain showers.
MARINE...Gale Warning until 8 AM EDT Friday for ANZ230>232-251-255.
Gale Warning until 4 AM EDT Friday for ANZ233>237-256.
Gale Warning until noon EDT Friday for ANZ250-254.
Area Forecast Discussion
National Weather Service Burlington VT
1029 PM EDT Thu Apr 7 2022
Occasional rain with embedded heavier downpours will continue
across the North Country tonight, along with gusty southeast
downslope winds along the Western Slopes. A few gusts in the 50 to
55 mph range are expected this evening, which may cause isolated
power outages. Drier weather returns for Friday, with temperatures
warming back into the mid 40s to lower 50s, before better chances
for showers redevelop again on Saturday with cooler temperatures.
.NEAR TERM /THROUGH FRIDAY NIGHT/...
As of 1028 PM EDT Thursday...Overnight forecast continues to
work out well with several sites along the western slopes now
gusting to 50 mph as precipitation has briefly waned as the
850mb jet aloft materialized. Adjusted PoPs and wind gusts for
the next few hours to match trends, otherwise the forecast
remains on track.
Previous Discussion...Fcst concerns tonight wl be gusty
southeast downslope winds and timing of rain with embedded
heavier downpours. Big picture shows deep and closed 5h/7h
circulation over the western Great Lakes, while potent 5h vort
is aiding weak 1001mb low pres over SE VA this aftn. This energy
which has produced some lightning acrs south-central PA wl
interact with developing robust southeast llvl jet to produce a
period of moderate rainfall acrs the cwa tonight. Based on nose
of se jet, pws near 1.0, and nose of 120 knot jet at 25h, expect
eastern dacks and se upslope regions of the southern-central
Greens wl receive the highest qpf with amounts 1.0 to 1.50,
while downslope regions of the western slopes and NEK get 0.50
to 0.75 by Friday morning. Based on rainfall and trrn influence
on qpf fields, Ausable River Basin wl need to be watched,
otherwise just in bank rises anticipated on rivers/streams acrs
The magnitude of southeast downslope winds along the western slopes
this evening is tricky based on anticipated precip fields and
impacts of llvl mixing. Overall RAP/NAM/GFS and RGEM in all good
agreement showing progged 850mb se jet of 60 to 70 knots developing
over southern VT around 00z and lifting northward and thru our cwa
by 06z. However, the depth of mixing associated with moist adiabatic
mixing profiles in occasional rain makes it challenging. Crnt
thinking a brief lull in rainfall is anticipated btwn 22z-04z from
south to north and this combined with bottom of mixed layer winds of
40 to 55 knots, wl support localized gusts in the 45 to 55 mph range
along the western slopes in Rutland and eastern Addison Counties.
Sounding analysis at Rutland shows inversion height near 3500 ft,
with mixed layer winds of near 50 knots at 22 to 00z this evening,
supporting the advisory. If slightly more dry air develops with
better mixing, wind gusts to 55 to 65 mph will be possible, but
feel the probability of this occurring is low given radar
coverage attm. Wl brief evening shift on this potential, as HRRR
and RAP show stronger wind potential. Otherwise, for the
central western slopes, jet is slightly higher up and top of the
mixed layer is slightly less, so general idea of gusts to 40 to
50 mph acrs eastern Chittenden and parts of Lamoille Counties
Finally, lets not forget about the white stuff, which wl only occur
near summit level and have no impacts acrs our cwa. Soundings show
profiles becoming near isotherm around 0C this evening from 3000
feet and higher, especially eastern dacks, where se upslope flow
enhances the cooling process. This thermal profile wl produce a
period of wet snow when the heaviest precip occurs for the eastern
dacks with a quick inch or two possible above 3000 feet by 12z
Friday. Over VT thermal profiles show warm nose above 5000 feet of 3
to 4C air with llvl se jet, while pocket of air remains near 0C from
2500 to 4000 feet, supporting some mixed precip for the eastern
slopes of the Greens. Only a minor glaze of ice accumulation possible
on elevated sfcs above 2500 feet or so possible overnight. Temps
range from near freezing summits to lower 40s warmer valleys.
Friday, soundings show developing dry layer btwn 850-500mb
which is supported by well defined drying on water vapor moving
overhead. This wl decrease the areal coverage of precip by 15z,
with just some scattered aftn showers. Best potential wl be
southwest upslope regions of the High Peaks and portions of the
northern/central Green Mtns. Temps with a few breaks in the
overcast should warm into the mid 40s to lower 50s.
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 341 PM EDT Thursday...Showery weather will continue through the
weekend as the North Country remains under the influence of the
upper trough. Another embedded impulse will pass through the flow
aloft on Saturday, producing a surface low across New England. As
the upper trough axis draws closer, temperatures aloft will cool
causing lapse rates to steepen and marginal instability to develop.
Meanwhile, a cold front will trek across the region. Together this
will result in the development of scattered to numerous rain
showers, with the possibility of isolated thunderstorms across
south-central Vermont during the afternoon. Some locations may even
see a bit of graupel. Westerly flow will become established in the
wake of the boundary and cooling aloft will result in a mix of
rain/snow showers for locations above 1500 ft elevation by Saturday
night. However, the areal coverage of showers will decrease late
Saturday into Sunday as a weak nose of high pressure sneaks into the
area. High temperatures on Saturday will be in the mid 40s to low
50s with overnight lows in the low to mid 30s.
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 341 PM EDT Thursday...Dreary, cool weather continues for Sunday
as the main trough axis finally moves through the Northeast. As it
does so, we will see yet another cold front traverse the North
Country. This will initiate renewed chances for scattered rain and
mountain snow showers, especially along the northern slopes of the
Adirondacks and northern Green Mountains as flow becomes
northwesterly. Northwest winds will increase up to 10-15 mph with
gusts up to 25 mph. High temperatures will only be in the low to mid
40s making for an overall yucky day weather wise. Given the cooler
surface temperatures on Sunday, there exists very little chance of
thunder, though again a bit of graupel cannot be ruled out.
Dry weather is then expected for Monday as high pressure settles
across the region. Temperatures will start out chilly with morning
lows in the mid 20s to mid 30s, though daytime highs will reach into
the 50s aided by filtered sunshine. A gradual warming trend is
expected thereafter under a regime of westerly/southwesterly return
flow. High temperatures during mid-week will be in the 60s with
overnight lows in the 40s. Chances for periodic rain showers and an
occasional thunderstorm exist as moisture rolls around the top of
the upper ridge, especially Tuesday into Wednesday. However, timing
differences remain among global model guidance. By the end of the
week, there exists increasing chances for widespread precipitation
as a full-amplitude trough approaches the East.
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Through 00Z Saturday...Mix of VFR/MVFR across the region
currently will deteriorate to IFR/MVFR mainly after 06Z with the
main contributer being ceilings. In widespread rain through
around 12Z, visibility will mainly be VFR/MVFR with brief
periods of IFR possible. Thereafter conditions will gradually
improve, though remaining at least MVFR through 18Z and
trending VFR by 22Z. For all sites except KRUT and KMPV winds
will generally be less than 10kts though briefly gusty at KBTV
this evening. Otherwise, southeast winds will continue to ramp
up substantially at KRUT where gusts in excess of 40kt will be
possible through the early overnight period. At KMPV gusts ramp
up as well, but should only peak in the 20-30kt range through
midnight. LLWS and turbulence aloft associated with 40-60kts at
mountain top levels is additionally likely through 12Z Friday.
Equipment note: AMD NOT SKED continues for MPV TAF owing to a
communications issue, with a tech expected on-sote Monday 04/11.
MSS lost observations at 17Z on 4/7, so AMD NOT SKED there as
well for the time being.
Friday Night: VFR. Chance SHRA.
Saturday: Mainly MVFR, with areas VFR possible. Numerous SHRA.
Saturday Night: Mainly VFR, with areas MVFR possible. Scattered
SHRA, Chance SHSN.
Sunday: Mainly MVFR, with areas VFR possible. Chance SHRA.
Sunday Night: Mainly VFR, with areas MVFR possible. Slight chance
Monday: Mainly VFR, with areas MVFR possible. NO SIG WX.
Monday Night: VFR. Slight chance SHRA.
Tuesday: Mainly MVFR, with areas VFR possible. Slight chance
Rainfall has ranged from 0.25 to 0.50 across northern NY today
with isolated higher amounts near 0.75, while VT has seen
amounts <0.25. Additional widespread rainfall is anticipated
overnight with another 0.50 to 1.0 expected, producing 24 hour
storm totals of 0.5 to 1.75 inches, with localized higher
amounts up to 2 inches possible. This rainfall will cause sharp
rises on area rivers and streams, with the Ausable River
expected to approach action stage by Friday.
VT...Wind Advisory until 6 AM EDT Friday for VTZ006-011-017>019.
Area Forecast Discussion
National Weather Service Indianapolis IN
1129 PM EDT Thu Apr 7 2022
...Updated Aviation Discussion...
Issued at 958 PM EDT Thu Apr 7 2022
Surface Analysis this evening shows deep low pressure in place over
eastern WI. The low was spreading its influence with cyclonic flow
across the Great Lakes...Upper midwest and the Ohio valley. GOES16
shows a classic pinwheel cloud formation across the region...with
another spoke over Central IL...poised to push across Central
Indiana overnight. With the loss of heating...diurnal showers have
ended and some of the lower level stratocu has also dissipated. Cold
air advection was continuing...as 850mb temps of -6 to -8 were being
pushed toward Central Indiana.
Overnight the cyclonic flow is expected to remain across the region
as the cut-off low makes little progress eastward. The previously
mentioned trough within the flow is expected to push across Central
Indiana late overnight...thus have ramped up pops late overnight as
this forcing feature passes. Any precip amounts should remain light.
Given the expected increasing clouds and possible precip trended
toward nearly steady state temps as temperatures upstream were quite
similar to current conditions.
.Short Term...(This evening through Friday night)
Issued at 241 PM EDT Thu Apr 7 2022
...Gusty winds today with scattered showers...
...Chance of snow Friday into Saturday...
A deep trough and associated stacked low pressure system currently
resides over the region. The slow-moving trough is expected to keep
temperatures below average for the next several days. Cold air
advection aloft will continue through the period, with 850 mb temps
bottoming out around -10 C by 12z Saturday. A mix or even a
changeover to snow is possible by Friday night and Saturday.
Today into Tonight
Today started out clear to partly cloudy across much of the area,
but clouded over as daytime heating quickly steepened lapse rates.
The unstable air has had two main effects so far: scattered showers
and gusty winds. Momentum aloft has been easily transported downward
leading to frequent wind gusts of 25 to 35 kts. Gusty conditions
should continue until sunset, only diminishing once some stability
returns. As the core of the stacked low gets closer, winds aloft
should decrease a bit. So not currently expecting as windy of a day
for Friday. Rain showers have also developed and are fairly
widespread across the state. These should continue into tonight,
though the aforementioned loss of instability will lead to a decrease
in coverage. However, shower chances will not completely diminish,
and we`ve kept slight to chance PoPs across portions of the CWA.
Some snowflakes could mix in tonight as well, since cold air
continues to filter in aloft.
Friday into Saturday
Similar situation for Friday, with a cold unstable air mass
overhead. Scattered rain / snow showers and occasional wind gusts to
20 kts will be possible at times. Day time heating should once again
steepen lapse rates Friday afternoon leading to a convective precip
regime. An isolated rumble of thunder is possible within the more
robust showers that develop. Conditions should be warm enough to
allow predominately rain during the day time hours, though some snow
may mix in at times. However, after sunset, temperature profiles
quickly cool and a changeover to snow is shown in the hi-res models.
Concurrently, a vort max rotating around the main area of low
pressure will work its way into Indiana from the northwest. An
enhanced area of precipitation is shown by various models in
response to weak forcing associated with this feature. At the
moment, timing appears to be early Saturday morning, towards the end
of the short term period. A quick coating of snow on grassy surfaces
is certainly possible, especially in the northern counties and if
precip occurs before sunrise.
.Long Term...(Saturday through Thursday)
Issued at 241 PM EDT Thu Apr 7 2022
* Quite chilly Saturday, warming trend begins Sunday afternoon
* Temps at or above normal much of next week
* Episodic showers and storms possible early next week
* Strong/severe storm potential mid next week
A significant weather pattern change will occur from this weekend
into next week. The deep, winter-like trough aloft across the OH
Valley and Great Lakes will finally begin to lift ENE on Saturday.
However, residual morning light snow or snow grains may still occur
as model soundings advertise a saturated air column at or below
freezing. A coating of snow from overnight Friday night should
remain mainly on grassy areas and elevated surfaces Saturday
morning, as road temps generally remain above freezing. Any leftover
precip will end during the day as the trough pull outs, although
clouds should remain (maybe some late day clearing west) which will
make for another chilly early spring day, with high temps only in
the 40s. The morning coating of snow will melt during the day.
* Saturday night...
Surface high pressure will build into the OH Valley Saturday night
in the wake of the departing system. As a result, skies will clear
and surface temps will fall as effective radiational cooling
commences. Expect low temps Sunday morning to reach around 30, will
some areas (especially valleys/sheltered locations) in the upper
20s. Coupled with weak surface winds, a widespread frost should
occur with a light freeze in areas. With sufficient vegetation
growth already across our southern counties of central IN, headlines
for frost and/or freeze may be needed in later forecasts across
about the southern two rows of counties, i.e., along/south of
Sullivan to Bloomington to Columbus to Greensburg. Farther north in
central IN, vegetation may not yet be enough for headlines, but
frost/freeze awareness is still needed. We will evaluate later data
as we approach Saturday night.
As a high pressure ridge aloft builds into the OH Valley, the
surface high will quickly move off to our east, allowing a return S
to SW low-level flow to commence with an influx of milder air. At
the same time, the warm advection also means some isentropic lift
and some clouds in the afternoon, which could limit diurnal warming
a bit after a cold start, but still enough sunshine to warm
afternoon highs to 55-60 northeast and 60-65 southwest parts of
* Sunday night through Tuesday...
As a broad but deep trough aloft forms across the western CONUS
early next week, S to SW flow aloft will result downstream across
the nation`s midsection into OH Valley, with embedded pockets of
shortwave energy ejecting out of the trough. This will provide
periodic enhancement to northward moisture transport from the Gulf
of Mexico to produce episodic convection across the central U.S.
into parts of the OH Valley. As expected, some model differences
occur which is not unusual in a transitory weather pattern with
broad, fast SW flow aloft and embedded shortwaves. Thus, forecasting
the timing and location of the greatest chances for precip,
coverage, and intensity across our area at this time is somewhat
tenuous, but expect both periods of rain and dry weather.
With at least modest isentropic lift across the OH Valley Sunday
night into early Monday, scattered showers may occur during this
time period, although again there are some differences in forecast
solutions. Model soundings do show some steepening of lapse rates
aloft above a stable boundary layer, so a few elevated convective
cells may occur as well, if showers materialize.
Right now, solutions range from dry weather Monday night and early
Tuesday with a frontal passage, to good rain chances along a
stalling front. For now, given SW flow aloft, would not expect the
front to make it too far south, and model blended forecasts show at
least scattered showers during this time frame over central IN,
which appears prudent for now. Additional scattered showers and
elevated storms could occur later Tuesday as well, but any chance
for organized severe storms during this forecast period should
mainly remain S and W of central IN. Expect high temps Monday and
Tuesday in the upper 60s and lower 70s.
* Wednesday and Thursday...
The middle part of next week is a long way off, but could be
interesting. Guidance suggests a consensus signal for increasing
convective potential and even a severe weather threat. Models
generally show the western trough lifting to the NE into the central
and northern Plains. As this occurs, it would create a strengthening
low-level jet downstream in response to divergence aloft. Models
hint at better instability as well along and ahead of the system`s
associated cold front. Storms are possible over the OH Valley for at
least part of Wednesday, with the best chance at strong to severe
storms either late Wednesday or Thursday associated with a linear
forced line of convection (QLCS) across the mid MS Valley and into
the OH Valley. Uncertainly still exists, but awareness of this
potential situation is important.
.Aviation...(06Z TAF Issuance)
Issued at 1129 PM EDT Thu Apr 7 2022
- Scattered rain showers return overnight, no vsby restrictions
- VFR CIGS expected to deteriorate to MVFR and possibly IFR
DISCUSSION: Brief break in light rain showers is expected over the
next 1-3 hours before the next weak trough pivoting around the low
begins to push across Indiana.
Forecast soundings overnight continue to show steep lapse rates with
good saturation in place amid the cyclonic flow. Thus an isolated
shower during the overnight hours cannot be ruled out. HRRR shows
shower development late tonight and toward daybreak in the wake of
the previously mentioned trough that is expected to pass. Thus have
trended toward a return of MVFR Cigs overnight along with a VCSH
mention for possible rain showers. IFR cigs will be possible.
Once again on Friday afternoon...steep lapse rates remain in place
with saturation and attainable convective temperatures...providing a
good signal for another afternoon of instability showers...with a
possible mix of graupel...rain and/or snow. have used a tempo group
during peak heating hours to account for best chances for precip.
Area Forecast Discussion
National Weather Service Marquette MI
1145 PM EDT Thu Apr 7 2022
.SHORT TERM...(This evening through Friday)
Issued at 449 PM EDT THU APR 7 2022
Water vapor imagery and RAP analysis show a large mid-level low
centered over WI. At the sfc, associated low pres was located in ne
WI. With the sfc thru mid-level low just s of the area, pcpn
movement across Upper MI today is following the cyclonic flow around
it, lifting n toward eastern Upper MI, then moving e to w across the
central then curving to a nne to ssw direction across western Upper
MI. Pcpn has been rain across central Upper MI and rain/snow across
the w. High terrain of western Gogebic/Ontonagon counties has been
all snow today. Although there has been steady -sn there, temps
around 32F and Apr solar insolation, limited as it is thru the cloud
deck, has resulted in roads/parking lots being mostly just wet per
webcams. The snowfall rates have just not been great enough to
overcome that. So, snow accumulation is occurring mainly on the
ground and trees. Low-level winds have had just enough of an
easterly component so far to minimize upsloping in western Upper MI.
Across the stateline, particularly toward Ashland, steady, heavier
snow has fallen thru the day.
Fcst thru Fri will revolve around pcpn details, coverage/type, as
center of aforementioned broad mid-level low drifts to northern Lake
Huron. As it moves e, low-level cyclonic flow will back to a
northerly direction tonight/Fri and air mass will cool further. The
cooling will lead to pcpn changing over to all snow from w to e
tonight, then daytime heating on Fri may result in a little -ra
mixing back in across the s central and e. While the cooling air
mass with 850mb temps dropping to -8 to -10C later tonight/Fri will
add a modest lake component to the pcpn, upsloping will be the prime
driver of steadier/heavier pcpn. All of the cams have a very
distinct signal of max pcpn aligned right on the high terrain just
inland from the lake across the w and toward the n central where
northerly wind upsloping is maximized. That looks right on track
with what would be expected for this type of event. So, the greatest
snow amounts will be very localized to the high terrain areas
favored by upsloping. Those areas roughly include Ironwood to the
Porcupine Mountains to Bergland, around Twin Lakes, around Calumet,
from Phoenix to Delaware and from just inland of L`anse to Herman
and e across the high terrain of northern Marquette County to the
north of M-28. In general, from this evening to early Fri aftn,
expect 4-8 inches of wet/dense snow accumulation in the
aforementioned areas with perhaps as much as isolated 10 inches.
Snow accumulations will rapidly fall off away from those areas.
Winter wx advys have been posted from Gogebic County thru the
Keweenaw then east to Marquette County, but in reality, advy
criteria snowfall will be limited in coverage across those
counties. Advy currently only runs thru early Fri aftn with
expectation of limited daytime heating working to limit aftn snow
accumulation on roadways.
Lows tonight will fall to 24 to 30F, coolest w. Highs on Fri will
only top out around 30F w to the mid 30s s central and e.
.LONG TERM...(Friday night through Thursday)
Issued at 406 PM EDT THU APR 7 2022
The slow-moving, vertically stacked low keeps cool and damp weather
going into Saturday. A warming and drying trend is expected late
Saturday into early next week with precip chances increasing again
toward the middle of next week.
Starting with Friday night, orographic snow showers will be ongoing
within nearly saturated north-northwest flow. Shower coverage and
intensity wanes by sunrise on Saturday with most precip focused
across the east half to two thirds. The east should stay mostly
cloudy if not overcast all day whereas the west may become mostly
sunny by the afternoon. Tried to warm daytime temps across the west
by 1-2F and vice versa across the east. Sunday looks mostly sunny
with good mixing beneath ridging at the surface and aloft. I nudged
temps warmer with widespread upper 40s to lower 50s look like a good
bet. The fly in the ointment is an afternoon lake breeze looks
fairly likely so pinning down the diurnal temperature curve will be
The ridge axis shifts east on Monday as a deep upper level trough
digs into the western CONUS. The western trough/eastern ridge
pattern appears to stick around for most of next week resulting in a
prolonged period of SW flow aloft and above normal temperatures.
Precipitation chances are less clear, but a shortwave trough lifting
northeast across MN on Monday may allow for some precip, mainly
across the west. This system pushes a cold front to our eastern
zones by Tuesday morning where it may stall until a much stronger
mid-week system lifts northeast across the Plains. Ensemble means
show a fairly deep surface low over KS on Wednesday morning that
lifts northeast into the Upper Great Lakes by Thursday night. Most
available guidance indicates rain will be the dominant p-type, but
that is subject to change depending on the exact low track.
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1143 PM EDT THU APR 7 2022
Poor flying conditions expected for the duration of this TAF
period as well as a low pressure system continues to rotate over
the Great Lakes. Generally LIFR conditions with some fluctuation
at times to IFR can be expected. Meanwhile, winds will generally
be northerly with some gusts up to 22 to 24 kts at KIWD/KSAW. But,
KCMX will experience stronger wind gusts up to 28 to 30 kts for a
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 406 PM EDT THU APR 7 2022
NNE gales around 35 kts continue over the western two thirds of Lake
Superior this evening then back northerly as a low pressure system
digs southward towards Lower MI. This low then lifts northeast into
Canada on Friday with winds backing to the NNW and becoming 20 to 30
kts across the lake. NNW winds of 20 to 30 kts are expected to
persist throughout Friday night, falling below 20 knots across the
western lake. NW winds of 20 to 25 kts continue over the eastern
lake on Saturday. Light winds of 20 kts or less are expected by
Saturday night as surface ridging moves over the lake. The light
winds of around 20 kts or less are expected to remain over Lake
Superior until Sunday night. Southeast winds of 20 to 25 knots
develop over the north-central lake Sunday night and gradually
diminish by Monday evening. Winds stay below 20 knots Monday night
through next Wednesday.
Winter Weather Advisory until 2 PM EDT /1 PM CDT/ Friday for
Gale Warning until 1 AM EDT /midnight CDT/ Friday for LSZ162.
Gale Warning until noon EDT Friday for LSZ264.
Gale Warning until 11 AM EDT Friday for LSZ263.
AREA FORECAST DISCUSSION
National Weather Service Raleigh NC
840 PM EDT Thu Apr 7 2022
A cold front will push east and off the North Carolina coast
tonight. This will be followed by a second cold front passage
through North Carolina Friday night through early Saturday. A cool
ridge of high pressure will build over the East Coast late Saturday
through Sunday, then a warm front will lift northward through the
area Monday, bringing a return to warmer weather.
.NEAR TERM /THROUGH TONIGHT/...
As of 840 PM Thursday...
The surface low and trailing cold front have pushed into far eastern
sections and are on pace to exit the forecast area in the next hour
or so, in tandem with the departing high PW. A trough (actually an
outflow) extending from the surface low WSW across the southern CWA
will continue to drop southward as cooler/drier and more stable air
builds in slowly from the NW and W. But the risk of showers will
persist through tonight, mainly across the N half, as the large
upper low over the Great Lakes eases eastward, resulting in
prominent height falls over the Mid Atlantic through Carolinas along
with a shot of DPVA as sheared vorticity swings NNE through the
region, atop a weak surface frontal zone that will cross our area
overnight. While mostly showers are expected, RAP forecast soundings
depict fairly steep lapse rates and moistening up through 600 mb,
including the mixed phase region, such that lightning is possible,
particularly as the dynamic forcing for ascent couples with 100-200
J/kg of SBCAPE. But no additional strong storms are expected, as the
00z GSO sounding as well as RAP forecast soundings depict a strong
warm/stable layer through the 500-400 mb depth. Otherwise, expect
partly to mostly cloudy skies overnight as that moisture in the
upper reaches of the deep mixed layer persists overnight with large
scale lift. Expect lows in the 40s to around 50. -GIH
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 200 PM Thursday...
The deep trough(2 to 3 S.D. before normal) currently centered over
the Midwest/Great Lakes region will progress slowly eastward through
the Eastern US through Saturday night. Coincident with several
prominent spokes of shortwave energy diving SEwd through the mid-
Atlantic region, through the base of the trough, central NC will see
periodic flare-ups of enhance cloud bands along with isolated shower
and/or sprinkles across the area late Friday afternoon/evening and
Deep afternoon mixing to 8-10kft both days will support breezy
conditions in the 20 to 30 mph Friday, 15 to 25 mph Saturday.
After daytime highs in the 60s on Friday, expect unseasonably cool
daytime highs 55 to 60, which is 10 to 15 degrees below normal.
Behind a series of weak surface troughs/cold fronts traversing the
region cool high pressure will begin to move east into the area
Saturday night, at which time skies are also expected to finally
clear out. Low-level thicknesses Sunday morning are expected to
lower into the 1295-1300 meters, which would be supportive of min
temps in the lower to mid 30s across portions of the western and
central Piedmont and northern coastal plain counties. A Frost
Advisory will likely be needed.
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 210 PM Thursday...
Temperatures will quickly moderate early next week as the
anomalously deep upper trough departs and upper-level ridging moves
atop the region through the mid week period. Well above normal highs
in the upper 70s to lower/mid 80s will return by Tuesday and will
temps will remain well above normal until a cold frontal passage
Well removed from a strong/deep closed low and upper trough centered
over the central/northern US Plains, rain chances will remain low
with some scattered showers possible mainly across the far western
zones late Wednesday and Thursday from glancing shots of weak upper
level impulses moving through the region.
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 710 PM Thursday...
There is high confidence that VFR conditions will start the TAF
period. Some lingering showers/storms are still near RWI, but should
quickly move out of this TAF site shortly before 01Z. Elsewhere, VFR
conditions are expected through the 24-hour TAF period. Given that
RWI has seen rainfall from storms today, as well as lingering low-
level moisture, introduced a period of MVFR VIS prior to daybreak
Fri for potential fog development. Gusty southwest winds between 25
and 30 kts will be present Fri afternoon and early evening at all
terminals with a deep upper-trough over the region. The trough may
produce some scattered showers/sprinkles at GSO/INT.
Outlook: Gusty west winds are again possible Sat under some possible
VFR showers/sprinkles. Otherwise, VFR conditions will prevail Sat
Area Forecast Discussion
National Weather Service Shreveport LA
948 PM CDT Thu Apr 7 2022
After due consideration of several contributing factors, the
existing minimum temperatures forecast for daybreak Friday morning
continue to look reasonable enough to carry with this update.
While temperatures have indeed dropped noticeably after sunset
this evening and skies areawide are quite clear, sustained
northwest winds in excess of 5 kts areawide through the night look
to facilitate mixing sufficient to prevent unrestrained
radiational cooling. The 01Z HRRR and RAP13 solutions suggested
minimum temperatures equal to our existing minT grids, even a
degree or two warmer at some sites. Thus, have elected to keep low
temperatures for the Four State Region in the low to mid 40s,
with a few upper 30s possible in southwest Arkansas, and locally
warmer values in urban areas. Ingested the temperature and
dewpoint observations from the last several hours and interpolated
through the aforementioned lows at 12Z Friday.
.PREV DISCUSSION... /issued 626 PM CDT Thu Apr 7 2022/
For the 08/00Z TAFs, VFR vis/cigs will prevail throughout the
course of this TAF period. The only complicating factor will be
gusty northwest winds, with sustained speeds of 10 to 15 kts
calming somewhat overnight to 4 to 8 kts with gusts of 10 to 15
kts still possible before becoming still gustier tomorrow, with
speeds of 15 to 20 kts and gusts of 20 to 25 kts likely.
PREV DISCUSSION... /issued 300 PM CDT Thu Apr 7 2022/
SHORT TERM.../Tonight through Friday Night/
Todays AFD could darn near just be a copy/paste from yesterday, as
there really is no change in the pattern anticipated over the next
36 hours. Aloft, the region will remain under under a strong NW
flow, which will continue the very try trend across the area.
Winds will likely remain on the gusty side into tomorrow as well
under a tight pressure gradient. However, they appear to look
slightly weaker than today, and wind headlines may not be needed
tomorrow. That decision will likely come with the overnight
shift. Temperatures tonight and tomorrow night will very much be
on the cooler side. Lows tonight should range in the low to mid-
40s, with lows tomorrow dropping into the mid-30s and low-40s.
Given additional time in the cold regime, afternoon highs tomorrow
look to be slightly cooler than today, with highs getting into the
low to upper-60s area-wide.
LONG TERM.../Saturday through Thursday/
Our streak of dry and pleasant weekends with active weather holding
off until the workweek will remain intact during this long-term
period. Sfc high pressure will dominate this weekend and together
with an advancing upper level ridge, temperatures will moderate as
southerly flow returns by late Saturday. This will result in a rapid
warming trend through early next week as afternoon highs jump back
into the 80s areawide from Sunday through Wednesday.
However, this warming trend will come at a price as it often does
this time of year as we enter the peak severe weather season of mid
April. During the day on Monday, strong warm and moist air advection
will precede a shortwave disturbance while a cold front remains well
to the west over the Texas panhandle region. As the shortwave pivots
into the eastern half Texas late Monday, a strong capping inversion
across our region will begin to erode as we cool aloft with rapid
development of thunderstorms expected as early as late afternoon in
our westernmost zones and farther east as we progress through the
evening and overnight hours. Sfc-based CAPE values could be pushing
2000-2500 J/kg during this late Monday into Monday evening timeframe
so this certainly justifies the convective outlook in SPC`s Days 4-6
with similar values expected again on Tuesday and Wednesday as we
remain very warm and unstable ahead of a cold front finally expected
to arrive Wednesday night into Thursday with increasing bulk shear
during this timeframe ahead of the cold front. All modes of severe
weather will possible from early to mid week, in addition to the
threat of heavy rainfall and flooding as we will remain mired in SW
flow aloft for much of the period next week.
As the cold front clears the region later on Thursday, we should
finally see a reprieve from the wet and unsettled weather to end the
period. Temperatures will also return closer to seasonal averages as
well with highs in the mid 70s to lower 80s on Thursday afternoon as
a more zonal pattern sets up through the end of the workweek on
.PRELIMINARY POINT TEMPS/POPS...
SHV 47 67 41 79 / 0 0 0 0
MLU 45 65 40 75 / 0 0 0 0
DEQ 40 64 34 75 / 0 0 0 0
TXK 44 64 39 76 / 0 0 0 0
ELD 42 63 37 74 / 0 0 0 0
TYR 44 68 41 80 / 0 0 0 0
GGG 44 67 39 79 / 0 0 0 0
LFK 44 70 41 82 / 0 0 0 0