Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/28/24
Area Forecast Discussion
National Weather Service Amarillo TX
707 PM CDT Wed Mar 27 2024
...New AVIATION...
.SHORT TERM...
(This evening through Thursday night)
Issued at 127 PM CDT Wed Mar 27 2024
A band of rain showers in the west-central Texas Panhandle is making
its way southeast toward the south-central Texas Panhandle, and
current thinking is that it will continue moving through the day.
Some showers have developed back into northeastern New Mexico and
southeastern Colorado, moving southeast. RAP Mesoanalysis as of
18z suggests there is around 100-200 J/kg of MLCAPE which is
beginning to flirt with the potential for a thunderstorm, and
gusty winds would be possible. Further destabilization is possible
over the through around 4-6 PM, and if sufficient destabilization
can occur, very cold temperatures aloft (500mb temperatures
between -25C to -30C) may also support the development of small
hail. This group of rain will continue moving southeast down the
western half of the combined Panhandles through the afternoon with
a continued chance for a thunderstorm.
Southerly winds bring in low-level moisture tonight, and there is
a low-end chance for fog to develop on the caprock later tonight.
Winds turn southwesterly and become sustained at 15-25 mph which
is effective at pushing out moisture and bringing in dry air.
Elevated fire weather conditions are possible for the western and
central Texas Panhandle. Temperatures warm into the 70s across the
area due to prominent mixing, downsloping winds, and warmer 850mb
temperatures. Winds remain around 10-20 mph tomorrow night as the
steep surface pressure gradient remains in place.
Vanden Bosch
&&
.LONG TERM...
(Friday through next Tuesday)
Issued at 127 PM CDT Wed Mar 27 2024
An upper-level trough will dip down off the coast of California on
Friday, and west-southwesterly winds spread from the base of the
trough to the Rockies. An embedded shortwave trough in that flow is
favored to reach the Rockies on Friday which creates a leeside
Rockie low. 15-25 mph sustained winds are favored for the west-
central Panhandles with 20-25 mph sustained winds for the western
Texas Panhandle. Elevated fire weather conditions are possible for
the western Texas Panhandle. Temperatures warm into the 70s for much
of the northern combined Panhandles, and upper-70s to mid-80s for
the southern Texas Panhandle.
The upper-level trough amplifies Saturday which amplifies the ridge
over the southern/central Plains. 15-20 mph sustained southwesterly
winds are currently favored for the far western combined Panhandles
with low relative humidity values. Elevated fire weather conditions
are possible for the western Texas Panhandle. Breezy winds continue
overnight, and poor relative humidity recovery is expected.
Additionally, with the introduction of a 30-50 kt LLJ, wind gusts up
to 30 mph is favored with some guidance suggesting periodic gusts up
to 40 mph is possible.
Sunday... the upper-level trough begins to move east and a more
robust wind field moves toward the Panhandles. This results in a
stronger surface low that develops in eastern Colorado or western
Kansas. With a steeper surface pressure gradient, 15-25 mph
sustained southwesterly winds are favored across the area, but
sustained winds around 25-35 mph are favored in the northwestern
combined Panhandles. Mid to upper-level clouds are forecast to
spread across much of the Panhandles, perhaps with exception to the
northwestern combined Panhandles. This should keep the potential for
single digit relative humidity values and higher-end gusts at bay
for much of the area. However, wind gusts up to 45 mph are still
possible in the northwestern combined Panhandles. As such, solidly
elevated fire weather conditions are favored for the western half of
the combined Panhandles, and low-end critical fire weather
conditions are possible in the northwest combined Panhandles.
Models begin to significantly diverge with respect to what happens
as the trough ejects east of the Rockies. Depending on how it
ejects, Monday may see sustained southwesterly winds around 15-25
mph but relative humidity may be too high to support elevated fire
weather concerns due to prominent cloud cover. A cold front moves
in later on Monday, but the trend has been to bring it in
quicker. Currently forecasting the cold front to move in to the
northern part of the CWA in the mid-afternoon hours. Breezy
northerly winds with partly to mostly cloudy skies can be expected
behind the front Monday night and perhaps into Tuesday. There is
a slight chance for precipitation behind the front and into
Tuesday. If the airmass turns out to be cooler than currently
anticipated, and as suggested by some guidance, a rain/snow mix or
snow may be possible.
Vanden Bosch
&&
.AVIATION...
(00Z TAFS)
Issued at 617 PM CDT Wed Mar 27 2024
VFR conditions are prevailing at area TAF sites. Showers have been
moving through the KDHT area and will continue to be in the
vicinity for another hour or two. Otherwise, VFR conditions are
expected through the Panhandles overnight into tomorrow. Winds
will be out of the south around 8-10kts, shifting out of the
south-southwest tomorrow morning through the afternoon. Speeds
should increase during the morning with sustained winds around
15-20kts, gusting to 25-30kts during the afternoon.
Culin
&&
.FIRE WEATHER...
Issued at 127 PM CDT Wed Mar 27 2024
Elevated fire weather is possible from Thursday through Monday due
to low RH and breezy southwesterly winds. There is question
regarding how receptive fuels will be given recent snowfall,
especially in the northwestern combined Panhandles where up to 3
inches of snow recently fell. However, poor nighttime RH recovery is
expected Friday night for the southwestern Texas Panhandle, and
again Saturday night for the western half of the combined
Panhandles. Given that, and with windier conditions expected Sunday
and low RH values expected to develop again, low-end critical fire
weather conditions are possible on Sunday for the northwestern
combined Panhandles and perhaps the west-central Texas Panhandle.
Breezy winds may continue into Monday, but RH values are currently
favored to stay around 15-20%. A cold front comes in from the north
Monday afternoon with a quick change to northerly winds.
Vanden Bosch
&&
.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX 31 72 45 80 / 10 0 0 0
Beaver OK 29 72 45 80 / 0 0 0 0
Boise City OK 28 67 36 74 / 0 0 0 0
Borger TX 33 75 48 84 / 0 0 0 0
Boys Ranch TX 30 74 42 81 / 10 0 0 0
Canyon TX 30 72 45 80 / 0 0 0 0
Clarendon TX 31 72 46 82 / 0 0 0 0
Dalhart TX 25 70 36 78 / 0 0 0 0
Guymon OK 28 71 40 79 / 10 0 0 0
Hereford TX 30 73 43 81 / 0 0 0 0
Lipscomb TX 30 71 47 82 / 0 0 0 0
Pampa TX 32 72 48 82 / 0 0 0 0
Shamrock TX 30 70 45 80 / 0 0 0 0
Wellington TX 30 70 44 79 / 0 0 0 0
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...None.
OK...None.
&&
$$
SHORT TERM...52
LONG TERM....52
AVIATION...28
Area Forecast Discussion
National Weather Service Boston/Norton MA
958 PM EDT Wed Mar 27 2024
.SYNOPSIS...
A frontal wave will bring more widespread rain to the region from
tonight through Thursday, and possibly lingering into early
Friday. This additional rainfall may lead to renewed flooding
concerns. Rain coming to an end Friday may finish as a quick
burst of light snow. Sunny, but windy, Friday afternoon and
Saturday, with a chance for a few showers Saturday night into
Sunday morning. Mix of clouds and sun on Sunday and Monday with
near to above normal temperatures.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
10 PM update...
Bands of showers moving across SNE this evening. Modest mid
level lapse rates of 6-6.5C/KM enhancing updrafts and yielding
moderate rain at times. Although, not sufficient for any
lightning, at least not yet. Otherwise, previous forecast
remains on track. Hence, no changes with this update. Earlier
discussion below.
Previous Update...
Clouds had dissipated across quite a bit of central
southern New England, but more clouds are waiting just off to
the west. Steep inversion remained in place, along with the
humidity below it. Thus, clouds should be quick to return past
sunset and temperatures drop. Widespread rainfall still expected
to overspread southern New England between 10 PM and 2 AM.
Could be a little earlier along and west of the CT River.
Thinking rainfall tonight will be on the lighter side, generally
one half inch or less.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Key Messages...
* Widespread rain likely
* Axis of heaviest rain remains uncertain
Latest guidance suite still has some issues with the axis of the
heaviest rainfall Thursday into Thursday day. Now looking like
there may be two axes of heavier rainfall. One would be over the
ocean towards the outer Cape and east of Nantucket, so not much
of a concern. The other looks to be right where we would not
want it, eastern CT, northwest RI, and portions of eastern MA.
Since this area already had several inches of rain for this past
weekend, will be issuing a Flood Watch for portions of southern
New England.
Right now, thinking that 1-2 inch rainfall amounts would be most
likely. However, ensembles do suggest a 30-50% probability for
more than 2 inches of rainfall across RI and portions of
southeast MA. Should that amount of rainfall occur, it is
possible that more significant river flooding would result.
Will need to closely monitor this potential over the next 24-36
hours.
Not much wind for this rain event. So the focus is all on the
rainfall and potential flooding.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Highlights
* Rain comes to an end Friday morning and may briefly transition
to snow as low pressure departs into the Gulf of Maine
* Blustery conditions Friday into Saturday will lead to sunnier
conditions to start the weekend
* Unsettled conditions mid week next week garner our next
significant precip chance
Friday and Saturday...
Inverted trough/low pressure gradually swings to our
east/northeast Friday allowing precipitation to come to an end
by around lunchtime. It`s possible that there is a brief period
of snow wrapping around cyclonic flow as 850mb temps drop to as
cold as -6 behind the departing low. Given warm antecedent
conditions and a very saturated ground, thinking that some of
the Hi-Resolution solutions, like the HRRR and NAM12 are much to
aggressive with their 10:1 snow accumulation forecasts of
3-6"+, and even with their positive snow depth change estimates
of up to 2-3" of snow across parts of eastern MA, but would not
be shocked to see a few 10ths of an inch of snow accumulate
across the high terrain before precip ends around mid day.
Blustery conditions will develop late Friday and will maintain
overnight Saturday through mid day as pressure gradient remains
quite tight on the back side of the low. Additionally, a 925mb
jet of 40-50kt will mix to the surface, yielding gusts in the
30-35kt range, with gusts to 40kt possible across the highest
terrain of the Berkshires. Will note the NBM guidance was quite
high compared to other models, which has been the case in
estimating wind gusts as of late, so, blended in the NBM1 10th
percentile guidance to keep gusts below wind advisory criteria.
It`s not out of the question that we see the strongest axis of
the LLJ shifts a bit west would allow more widespread 40kt gust
to develop, thus, not completely ruling out the potential need
for a wind advisory for the period.
The column dries pretty rapidly thanks to brisk NW flow,
yielding sunny skies the second half of Friday through the first
half of the weekend; a welcome sight for southern New
Englanders after a mostly cloudy week. May see some spotty rain
showers overnight Saturday as a weak shortwave tracks across
northern New England.
Sunday and Monday...
Winds subside to around 20kt by Sunday as gradient slackens and
more zonal mid level flow develops. Should see a mix of clouds
and sun on Sunday and Monday as PWATs surge to near a half an
inch, with moisture concentrated between the top of the boundary
layer and 700mb. Mid level ridging building from the west lat
Sunday into Monday will bring above normal temps back to
southern New England, with temps approaching the mid 50s by
Monday afternoon!
Mid Next Week...
Unsettled weather returns mid next week as low pressure digs
from southern Ontario before emerging off the southern New
England coast sometime between late Tuesday and Thursday. At
this time, there remains significant uncertainty in the timing
of this system, but we would be remiss to not at least mention
the possibility of some mixed precipitation, especially across
the high terrain, as cold air infiltrates the region on
north/northeast flow.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High- greater than 60 percent.
Tonight...high confidence.
MVFR/VFR at 00z, lowering to IFR/MVFR as showers overspread the
region tonight. LIFR possible across the hilly terrain of CT and
MA. Light SSE winds.
Thursday and Thursday night...high confidence.
Widespread IFR/LIFR in rain, heavy at times possibly across
eastern CT into RI and eastern MA. Light/variable wind becoming
NNE.
KBOS TAF...High confidence in trends, some uncertainty in exact
timing of details. MVFR quickly degrading to IFR/LIFR this
evening. Rain should hold off until ~04Z tonight as stratiform
rain impacts the terminal through much of the period. Very light
winds take on a slight NNE direction tomorrow morning, with
winds generally less than 5kt much of the day.
KBDL TAF...High confidence in trends, some uncertainty in exact
timing of details. Rain will persist through at least 00Z
tomorrow, but may be scattered in nature through sunrise before
becoming more stratiform. Very light to calm winds much of the
day given how slow this cold front is moving.
Outlook /Friday through Monday/...
Friday: Mainly VFR, with local MVFR possible. Windy with gusts
up to 30 kt. Chance RA.
Friday Night through Saturday: VFR. Windy with gusts up to
35 kt.
Saturday Night: VFR. Windy with local gusts up to 30 kt. Slight
chance RA.
Sunday through Sunday Night: VFR. Breezy.
Monday: VFR. Slight chance RA.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
* NNE winds finally shift to the SSE Wed afternoon
* Heavy rain possible late tonight into Thursday Night
Weak high pressure remains over the waters into tomorrow. Showers
become widespread, limiting vsby. Low pressure intensifies at it
moves offshore Thursday into Thursday night. Rain, heavy at
times, limits vsby.
Outlook /Friday through Monday/...
Friday: Strong winds with gusts up to 30 kt. Rough seas up to
10 ft. Chance of rain.
Friday Night: Strong winds with gusts up to 35 kt. Rough seas
up to 10 ft. Slight chance of rain.
Saturday: Strong winds with gusts up to 35 kt. Areas of rough
seas.
Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Seas up to 5 ft. Slight chance of rain.
Sunday through Sunday Night: Winds less than 25 kt. Areas of
seas approaching 5 ft.
Monday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Flood Watch from 2 AM EDT Thursday through late Thursday night
for CTZ004.
MA...Flood Watch from 2 AM EDT Thursday through late Thursday night
for MAZ004>007-012>024-026.
RI...Flood Watch from 2 AM EDT Thursday through late Thursday night
for RIZ001>007.
MARINE...Small Craft Advisory until 8 AM EDT Friday for ANZ250.
Small Craft Advisory until 8 AM EDT Thursday for ANZ251.
Small Craft Advisory until 8 PM EDT Thursday for ANZ254>256.
&&
$$
SYNOPSIS...Belk/KS
NEAR TERM...Belk/Nocera/KS
SHORT TERM...Belk
LONG TERM...RM
AVIATION...Belk/KS
MARINE...Belk/KS
Area Forecast Discussion
National Weather Service Duluth MN
631 PM CDT Wed Mar 27 2024
.KEY MESSAGES...
- Snow showers taper off tonight as high pressure moves into the
region.
- Next chance for precipitation is on deck for Friday into
Saturday as a clipper crosses the region. Some mixed
precipitation is possible along with marginal snowfall
amounts.
- Quiet conditions with a few low chances for precipitation will
be seen to end the weekend and into into the new week with
temperatures trending warmer.
&&
.DISCUSSION...
Issued at 452 PM CDT Wed Mar 27 2024
Low pressure was located just west of James Bay this afternoon
with high pressure stretching from the Canadian Plains into the
Lower Mississippi Valley. A cold front stretched from the low
near James Bay into western Quebec into the Appalachians.
Various inverted troughs were analyzed around the area of low
pressure into the Upper Midwest and into northwestern Ontario
and Manitoba. Within this cyclonic flow regime across the
Northland, snow showers were observed across much of the region.
A few snow squalls moved along the US2 corridor around midday
across northwest Wisconsin and led to some minor impacts as they
moved through. A few snow squalls will remain possible over the
next few hours mainly in areas east of US53. Latest RAP analysis
further focuses this area along the US2 corridor across
northwest Wisconsin where about 50-100 J/kg of CAPE and low
level lapse rates of 7-8C/km coincide. Much of this activity
should taper off this evening and tonight as the low lifts
further to the northeast and high pressure builds in from the
west. Any additional accumulations tonight will be around an
inch or less with slightly higher amounts across the Bayfield
Peninsula.
Thursday looks dry across the region with high pressure in
control at the surface. However, cyclonic flow aloft will
persist and a streamer of vorticity looks to pass through
during the day. This may lead to some light flurries, mainly
across the Arrowhead, but dry air near the surface may prevent
anything from reaching the ground. Temperatures will be warmer,
but still about 4 to 8 degrees below normal.
A clipper system is then progged to move across the Upper
Midwest for Friday into Saturday. Despite being about 48 hours
from the start of any potential precipitation, models still
offer differing solutions. The ECMWF is the quickest spreading
precipitation across much of northern Minnesota by Friday
afternoon. The GFS and NAM are a touch slower and hold chances
off until the late afternoon and evening Friday. QPF for this
system looks to be around 0.15" or less with some rain/snow mix
possible at times, especially across our southern zones. There
is also a chance (about 20%) for some freezing rain in spots
across northwest Wisconsin. The southern portions of Price
County currently have the highest chance of any freezing rain
with up to a tenth of an inch of accumulation possible. However,
given the timing differences between the models, this is still
very much subject to change. As for snowfall amounts, most areas
will see around an inch of accumulation or less with possible
some slightly higher amounts across the Arrowhead before the
system exits the region by Saturday afternoon.
For the remainder of the weekend and into early next week, high
pressure looks to dominate across the region. Models continue to
show a system in the area for Sunday into Monday, but the 12z
suite of models have shifted this well to our south will dry
conditions prevailing through the period. A cold front does move
through during the time period as a low passes well to our north
that may squeeze out some QPF however. Any weekend travel plans
look ok at this point, but should the system to the south trend
back northward, some minor issues will be possible. Warming
temperatures are then expected heading into the new week with
readings near to perhaps slightly above normal by midweek.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 631 PM CDT Wed Mar 27 2024
Scattered snow showers this afternoon are moving across portions of
the Arrowhead, Twin Ports, and into NW WI. These snow showers bring
quick bursts of snow that will briefly reduce visibility. This
activity will taper off over the next several hours as we lose
diurnal heating. MVFR ceilings are largely expected to linger
through the overnight period with improvements beginning in the
southwest tomorrow morning. VFR conditions are expected to overtake
the majority of the region tomorrow but there is a 60s% chance of
clouds lingering over the Arrowhead and impacting HIB/INL.
&&
.MARINE...
Issued at 452 PM CDT Wed Mar 27 2024
Westerly to west-southwesterly winds will persist tonight at 10
to 20 knots with gusts to 25 to 30 knots. Snow showers will
remain possible this evening and may reduce visibilities to 1
mile or less at times in some of the stronger showers. Winds
will remain around 10 to 20 knots with gusts to 25 to 30 knots
for Thursday out of the west then turn northwesterly late in the
day and begin to diminish. Small Craft Advisories remain in
effect into Thursday evening for these winds. Winds Thursday
night into Friday will be around 5 to 15 knots will slowly
become easterly as a clipper approaches the region. Winds then
ramp up Friday afternoon to 15 to 20 knots with gusts to around
25 knots which, along with waves of 3 to 5 feet, will create
conditions hazardous to small craft for a period Friday
afternoon into Saturday for a period, mainly in the western arm
of the lake.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Winter Weather Advisory until 7 PM CDT this evening for MNZ010-
011-018-019.
Winter Weather Advisory until 10 PM CDT this evening for
MNZ012.
WI...None.
MARINE...Small Craft Advisory until 7 PM CDT Thursday for LSZ121-
140>148-150.
&&
$$
DISCUSSION...BJH
AVIATION...Britt
MARINE...BJH
Area Forecast Discussion
National Weather Service North Platte NE
548 PM CDT Wed Mar 27 2024
.KEY MESSAGES...
- Two upper level disturbances are expected to affect wrn/ncntl
Nebraska this weekend and Monday.
- Rain chances continue Saturday night and Sunday. Rain changing
to wet snow is likely Sunday night and Monday. Travel impacts
are possible Sunday night and Monday morning.
&&
.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 347 PM CDT Wed Mar 27 2024
Until the loss of daytime heating occurs this evening, northwest
flow aloft may support sprinkles or light showers. The HRRR and
radar show this activity forming off the Black Hills, Pine Ridge and
the Cheyenne divide.
Parts of ncntl Nebraska get patchy fog tonight. This forecast is
supported by the short term model blend and a developing warm front
across the region which should provide a focus for moisture pooling.
It appears this will be a marginal event. Light south winds and
increasing moisture aloft will likely limit the radiational cooling
necessary for dense fog.
Forecast interests revolve around a warm front and milder
temperatures Thursday. The RAP and HRRR models are leading the model
pack with highs in the 60s along and west of highway 83 but it`s
worth noting the warmest air will still be across ern Colo/ern WY at
21z Thursday. Thus, the prospect of highs reaching 70 are low at
this point. There is also high cloudiness moving in late in the
afternoon. Winds aloft, northwest today, will flatten and become
west with increasing moisture above 500mb, according to the RAP
model.
The warm air aloft, aka a thermal ridge, will move through wrn and
ncntl Nebraska Thursday night with a weak Pacific to follow Friday
morning.
Low temperatures tonight and Thursday night lean on the short term
model blend plus bias correction for lows in the 20s tonight and 30s
Thursday night. Continuous warm air advection is the reason for
using the warmer model blend versus the cooler guidance blend which
works the better during radiational cooling events.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 347 PM CDT Wed Mar 27 2024
In the wake of the Pacific cold front Friday, sfc low pressure
will form on the central high Plains and remain in place
Saturday and Sunday. This low will kick out east through KS
Monday with a shot of Canadian high pressure building in behind
it. Cold air will remain in place Tuesday with milder air
returning Wednesday.
Near or below average temperatures are in place Friday through
Tuesday and this is consistent with low pressure drawing cooler air
through the nrn Plains, which are mostly snow covered.
There is little change in the extended precipitation forecast. Rain-
snow chances continue Saturday, Sunday and Monday. The upper low off
the coast of the Pacific Northwest will drift very slowly south and
eject energy through the Rockies and into the cntl/nrn Plains in two
pieces. The first, Saturday night and Sunday would most likely be
rain associated with warm air advection. The second, Sunday night
into Monday would be rain or wet snow.
The setup, a stalled cold front across srn Nebraska or nrn KS should
pool moisture north of the front and the upper level dynamics would
support forcing or lift. Moisture for both systems appears
sufficient, even abundant for the second system with PWAT above 0.50
inches in the GFS. The WPC QPF forecast has responded by increasing
amounts to 0.25 to 1 inch of liquid. This is certainly consistent
with the ECM ensemble; less so with the drier GFS ensemble which is
south of the ECM ens. WPC favors the wetter ECM ens for this
forecast which places the best amounts across nrn Nebraska.
&&
.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 544 PM CDT Wed Mar 27 2024
VFR conditions will prevail over the next 24 hours. Mid level
clouds will continue to diminish this evening, with scattered
high clouds possible through the overnight. Winds will remain
light, generally less than 5 kts through the overnight. Winds
across the northern Sandhills into north central Nebraska will
turn more southerly and be around 5 to 10 kts by Thursday
afternoon. Across western and southwest Nebraska winds will be
south to southwesterly around 5 to 10 kts by Thursday
afternoon.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Gomez
Area Forecast Discussion
National Weather Service Marquette MI
701 PM EDT Wed Mar 27 2024
.KEY MESSAGES...
- Westerly lake effect snow continues tonight through Thursday
evening, mainly across the Copper Country.
- Moderate to heavy lake effect snow and blowing snow is expected,
mainly across the Copper Country through tonight.
- Heaviest snow amounts expected through tonight from Twin Lakes to
Painesdale.
- Next chance of widespread precipitation occurs Friday night
and Saturday, followed by a system worth monitoring for
Monday/Tuesday next week.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 311 PM EDT Wed Mar 27 2024
Latest water vapor imagery and RAP analysis show broad troughing
over the Great Lakes, with an embedded closed low circulation moving
towards western Lake Superior. Chilly WSW flow with 850mb
temperatures around -13 to -16C is keeping in lake effect snow
showers across the WSW wind snow belts across the western UP.
Occasionally heavier banding is apparent on satellite at times off
the Bayfield peninsula, directed into the Keweenaw. Meanwhile, with
the approaching midlevel low, widespread lower level stratocumulus
remains across most of the UP, with widely scattered flurries and
light snow showers.
With better mixing this afternoon courtesy of CAA and diurnal
instability, inversion heights are increasing in model soundings to
around 7kft with much of the mixed layer occurring in the DGZ. Still,
soundings are not overwhelmingly moist and there is an inverted-v
type signature below the cloud layer, which may be helping to cut
down on snowfall rates...at least, apart from where we are seeing
heavier banding. Thus, for the rest of the afternoon, across most of
the area may be fairly light, well below an inch. In the snow belts
of the western UP, a general 1-3in is more favored among guidance,
but higher embedded totals are possible where we are seeing heavier
banding into the area.
Soundings moisten up into the evening as the midlevel low heads into
the area. Crosshair signature is also noted in the model soundings
with the best model omega/lift intersecting the DGZ, maximizing snow
growth. As a result, expect LES accumulation to really take off as
we head closer to 00Z. HREF guidance shows a widespread quarter to
half inch/hr snowfall rates across the western UP, with higher
embedded rates up to 1in/hr from northern Houghton through southern
Keweenaw counties. This should bring in several more inches of
snowfall overnight, but this starts to taper off into the early
hours of Thursday as the low moves north of Lake Superior, inversion
heights begin to lower, and soundings start to dry out. Though the
heaviest snow totals will be in the western snow belts in the western
UP, but some light snow accumulations (generally a trace) are
possible across much of the UP at least through the first half of
the night with the low moving through. Expect another 4-8 inches of
snow overnight from the Porcupines northward through the Keweenaw,
with the highest amounts from Twin Lakes to Painesdale. This would
lead to event totals near a foot in the warning area from this
afternoon through early Thursday.
Meanwhile, increased mixing from the colder air is leading to
blustery west winds this afternoon, with gusts as high as 30-40 mph
at times across portions of the Keweenaw, exacerbating occasional
whiteout conditions in blowing snow. Elsewhere, gusts are staying in
the 20-30mph range. Wind gusts fall back into the night, with most
of the area gusting up to 20mph and higher gusts around 20-30 mph
more common in the Keweenaw.
With blowing snow and a potential for several more inches of snow
across the western UP, our winter headlines remain in place through
Thursday morning.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Issued at 249 PM EDT Wed Mar 27 2024
Medium range guidance continues to handle the overall theme in the
extended forecast period well, presenting a consistent picture of
the main features in play going into the weekend. Starting off on
Thursday, the mid-upper level low that`s been responsible for the
snow and rain these past few days will continue its northeastward
exit toward James Bay while increasing anticyclonic flow and ridging
builds across the Plains. At the surface, high pressure will press
into western Wisconsin through the day, helping to pull in dry air
and subsidence that will result in diminishing lake effect snow
activity for the west wind snow belts. While the trend will be
decreasing activity, another inch or two of snow should be expected
in the Copper County, with the highest amounts being along the Spine
of the Keweenaw. Elsewhere, mostly dry conditions are expected.
Daytime highs should climb into the 30s, maybe near 40F for the
southern portions of Menominee County. The dry conditions will
persist overnight and Friday. Overnight lows should be mostly in the
teens interior west and low to mid 20s elsewhere. Daytime highs
Friday should top out in the 40s except mid to upper 30s near Lake
Superior and in the Keweenaw.
During the day on Friday, the mid-level ridge axis will shift
through the region as a surface low organizes in the Central Plains
and a northern stream shortwave presses through the Northern Tier
along the international border. As these features move into the
Upper Great Lakes, precip will move into the forecast area. Timing
among the various guidance packages suggest increasing precip
chances Friday evening that should persist through Saturday as the
surface low lifts through southern Lake Michigan and southern Lower
Michigan and the attendant inverted trough moves through Upper
Michigan. Precip type appears to be a mix of rain, snow, and maybe,
freezing rain, at least early on. As the event progresses through,
warm nose feature around 2-3k feet should break down as weak cold
air advection sets up. This should help any precip transition over
to rain or snow. Precip should come to an end Saturday evening,
followed by a dry Sunday thanks to another surface high moving
through the region.
Attention then shifts to a the potential interaction of a trough
exiting the Rockies and shortwaves dropping out of Canada. Model
trends with this system appear to be moving south and there is a
general trend toward potential phasing with a shortwave late Monday
and Tuesday. GEFS and EC ensemble systems continue to suggest weak
clustering of their membership and both their ensemble means move
the surface low near southern Lake Michigan and into southern Lower
Michigan. The same ensemble systems suggests the greater probability
of moderate QPF being near the ensemble means. This suggests a
significant precipitation event/snow event is becoming less likely,
but certainly continues to warrant monitoring in the coming days.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 701 PM EDT Wed Mar 27 2024
As lake-effect snow continues over the Keweenaw tonight into
Thursday, expect the scattered snow showers to slowly diminish and
end across the rest of the TAF sites tonight. While KSAW could see a
few snow showers here and there, no vis or cig restrictions are
expected throughout the entirety of the TAF period. Meanwhile, KIWD
looks to initially hang out in MVFR as the low-level clouds and the
occasional snow shower make there way over the TAF site. However,
as moisture from the low pressure lifts away from our area late
tonight, expect the conditions to improve over KIWD, eventually
becoming VFR by around dawn Thursday morning. With lake-effect snow
remaining across KCMX tonight into Thursday, I`m thinking it will
stay in solid IFR conditions this evening; the heavier snow bands
will more than likely (70%+ chance) drop vis down to around airport
mins from time to time this evening. Late tonight into Thursday, as
the lower levels dry out and ridging begins building into the area,
I`m thinking the conditions will gradually improve across KCMX; the
terminal could improve to VFR as early as Thursday afternoon.
Otherwise, expect the blustery westerly winds to continue across the
TAF sites tonight into Thursday.
&&
.MARINE...
Issued at 249 PM EDT Wed Mar 27 2024
Strong, mostly westerly and southwesterly winds will persist this
afternoon and evening as a surface low slowly pulls away into Hudson
Bay, leaving behind continued lake-induced instability and modest
pressure gradient forces thanks to high pressure building in across
the Plains. Expecting today`s low end gales to lighten through the
night as these forces begin balancing, but given the persistent
colder airmass aloft, near 30kt gusts should be expected at least
through Thursday. The colder airmass and wind will also make
freezing spray accumulation possible, although the trend to weaker
winds should reduce the risk through late tonight into Thursday. No
changes were made to the current gale warnings. Winds lighten to
around 20kts or less Thursday night, then remain light going into
the weekend.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Weather Advisory until 8 AM EDT Thursday for MIZ001-002.
Winter Storm Warning until 8 AM EDT Thursday for MIZ003.
Lake Superior...
Gale Warning until 11 PM EDT /10 PM CDT/ this evening for
LSZ162-241>244-263-264-266.
Small Craft Advisory until 8 AM EDT /7 AM CDT/ Thursday for
LSZ240-249.
Small Craft Advisory from 11 PM EDT /10 PM CDT/ this evening
to 8 PM EDT /7 PM CDT/ Thursday for LSZ241>244.
Small Craft Advisory until 2 AM EDT Friday for LSZ250-251.
Lake Michigan...
Small Craft Advisory until 2 AM EDT Thursday for LMZ221-248-
250.
&&
$$
SHORT TERM...LC
LONG TERM...JTP
AVIATION...TAP
MARINE...JTP
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
815 PM EDT Wed Mar 27 2024
...New UPDATE, AVIATION...
.UPDATE...
Issued at 749 PM EDT Wed Mar 27 2024
Early evening KTBW radar imagery is showing largely stratiform
rain remaining from the robust afternoon convection, with light
rain and occasional showers expected to continue shifting onshore
through the next few hours. HRRR and other high resolution models
are continuing the indicate a temporary clearing out of the rain
by around midnight tonight, then another band of showers expected
closer to daybreak along the frontal boundary.
With the breezy northwest winds on Thursday, there will be a high
risk of rip currents at area beaches, so a rip current statement
has been issued from Thursday morning through Friday morning.
Otherwise the forecast looks on track, and only minor adjustments
to early evening rain chances were made for the evening update.
&&
.AVIATION...
(00Z TAFS)
Issued at 749 PM EDT Wed Mar 27 2024
While the strongest convection has already died down, some light
showers will continue to move across or near area terminals
through around 03z, with MVFR and variable winds expected. More
widespread MVFR and isolated IFR ceilings will develop around
08-10z, then spread south with another round of showers before
conditions improve from north to south around 12-16z. Breezy
northwest winds will hold through the rest of the day under
clearing skies.
&&
.MARINE...
Issued at 249 PM EDT Wed Mar 27 2024
An area of low pressure is expected to bring periods of showers and
storms to the Gulf waters through Thursday. Erratic and gusty winds
are anticipated near thunderstorms, so mariners should remain
cautious during this time. Then, winds and seas will increase to
Small Craft Advisory levels behind the front on Thursday, before
diminishing again Friday through the weekend. Pleasant boating
conditions are expected for the rest of the period.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 69 76 57 77 / 60 50 0 0
FMY 72 81 57 80 / 40 40 0 0
GIF 69 79 54 78 / 50 50 0 0
SRQ 69 79 58 80 / 50 50 0 0
BKV 64 76 49 78 / 60 50 0 0
SPG 69 74 61 76 / 60 50 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk from Thursday morning through Friday
morning for Coastal Charlotte-Coastal Hillsborough-Coastal
Lee-Coastal Manatee-Coastal Sarasota-Pinellas.
Gulf waters...Small Craft Advisory from 8 AM Thursday to 8 AM EDT Friday for
Charlotte Harbor and Pine Island Sound-Coastal waters from
Bonita Beach to Englewood FL out 20 NM-Coastal waters from
Englewood to Tarpon Springs FL out 20 NM-Tampa Bay waters-
Waters from Bonita Beach to Englewood FL out 20 to 60 NM-
Waters from Englewood to Tarpon Springs FL out 20 to 60 NM.
&&
$$
UPDATE/AVIATION...Fleming
PREVIOUS MARINE...ADavis