Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/27/25
Area Forecast Discussion
National Weather Service Bismarck ND
957 PM CST Sun Jan 26 2025
.KEY MESSAGES...
- Seasonably mild and windy tonight through Tuesday.
- Not as windy through the rest of the week, with above normal
temperatures continuing, especially southwest and south
central.
- No greater than a 10 percent chance of precipitation through
Friday.
- Likely transition to a colder and more active pattern this
weekend into early next week.
&&
.UPDATE...
Issued at 952 PM CST Sun Jan 26 2025
No big changes to the forecast tonight. Embedded wave withing
north/northwest flow aloft will bring an increase in mid to
upper level cloud cover for several hours tonight into early
Monday morning. Decent gradient forcing will persist, so expect
breezy westerly winds through the night. e
UPDATE
Issued at 547 PM CST Sun Jan 26 2025
Changes with this forecast issuance were minor. Updated sky
cover based on latest satellite imagery and trends, with an
area of mid to upper level clouds moving south into the Northern
Plains from south central Canada. Cloud bases will overall be
greater than 10kFT AGL, so precipitation chances are very low if
not zero. Other forecast elements remain on track.
&&
.DISCUSSION...
Issued at 210 PM CST Sun Jan 26 2025
Synoptic features that are exerting the greatest influence on
Northern Plains weather this afternoon include broad surface high
pressure centered over the Central Plains and a northerly
anticyclonic flow aloft. Warming of the low levels is being driven
by Chinook flow off the Canadian Rockies, and a surface low
approaching Hudson Bay is tightening the surface pressure gradient.
The rest of the afternoon will remain mostly sunny and breezy, with
temperatures topping out in the 20s where there is appreciable snow
cover, and lower to mid 30s where there is not.
Flow aloft will turn northwesterly tonight as rising heights along
with a strong deep-layer gradient will allow a 50-60 kt westerly low-
level jet to translate through the region from north to south. This
will keep windy conditions and mild temperatures through the
overnight. Forecast lows around 20 could occur during the late
evening, with slowly rising temperatures expected as winds pick up
later tonight. Most areas will see surface winds around 15-25 mph
overnight, but higher terrain areas could see isolated gusts as high
as 45 mph. Deterministic guidance also shows a weak mid level
shortwave embedded in the northwest flow moving south from southern
Manitoba through eastern North Dakota tonight. A few runs of the RAP
and a couple other CAMs have hinted at light precipitation
associated with this wave, with isentropic ascent also assisting in
lift. However, RAP soundings from runs that included this
precipitation showed 10-15 kft ceilings and a lack of consistency in
column saturation above the could base. It therefore seems highly
unlikely that any precipitation will reach the ground, which is what
the majority of guidance is projecting. Even if precipitation does
reach the surface, only trace amounts at most can be expected.
However, the most likely precipitation type would be freezing rain
(really more like "freezing sprinkles") given forecast temperatures
aloft above freezing. The probability of even just minor impacts
though is near zero.
The main story for Monday through Thursday will be seasonably mild
temperatures as upper level ridging over the Pacific Northwest
pushes up against deep troughing over eastern Canada. NBM
temperature spread through Thursday is low and keeps all of western
and central North Dakota above average. Areas south and west of the
Missouri River, as well as south of Interstate 94 east of the river,
are favored to see highs mostly in the 40s. This is especially true
where there is little to no snow cover, and could easily see a
couple days with highs above 50 at such locations. For Monday and
Tuesday, the high temperature forecast was raised to at least the
75th percentile where observed/analyzed snow depth is less than 2
inches. Areas farther to the north are still likely to see 30s for
highs Monday and Tuesday, but could fall back to just below freezing
for Wednesday and Thursday as a couple of vort streaks clipping the
Red River Valley push back on the western ridge. It will remain
windy Monday through Tuesday, with lower confidence in surface wind
intensity thereafter (but more likely to be not as windy). There are
no mentionable chances for precipitation through the upcoming work
week.
Ensemble spread in all fields grows rapidly on Friday, especially in
high temperatures with the middle 50th percentile spread in the NBM
around 20 degrees Fahrenheit. The warmer solution would keep the
milder trend going, while the colder solution would return
temperatures to near normal south and below normal north. Ensemble
cluster analysis is nearly evenly split on the cold vs. warm outcomes
for Friday. There is a wide variety of outcomes in ensemble guidance
for the weekend into early next week, but all solutions point toward
a cooling trend and a return of chances for snow. 6-hour NBM
probabilities for measurable snow only max out at around 30 percent
Saturday through Monday, but these values are similar to global
ensemble probabilities for at least one inch of snow over any given
24-hour period during that timeframe.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 952 PM CST Sun Jan 26 2025
VFR conditions and westerly winds around 15-20 kts with gusts
to 25-30 kts are expected through the 06Z forecast period. Low
level wind shear will impact all terminals this evening through
early Monday morning, with 45-55 kt west-northwest winds around
1,000 ft above the surface.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...NH
DISCUSSION...Hollan
AVIATION...NH
Area Forecast Discussion
National Weather Service State College PA
1055 PM EST Sun Jan 26 2025
.SYNOPSIS...
Numerous shortwaves will rotate through the base of an upper
level trough over the Northeast CONUS the next several days. The
most potent shortwaves and associated cold fronts will arrive early
Tuesday and late Wednesday. The upper trough will likely lift
out by the end of next week, as a weakening southern stream
shortwave approaches from the Mississippi Valley.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
A mix of mid and high clouds will stream east across the region
overnight. Evening temps were mainly in the mid to upper 20s
across the north and west where the clouds were more prevalent
and a light WSW breeze was blowing. Mainly clear skies and a
decoupled blyr with near calm air over the Lower Susq Valley and
points just to the west have allowed temps to dip into the upper
teens to low 20s.
Late night clearing acrs the NW Mtns and cloud advection into
the SE part of the CWA should narrow gap in the temps. Overnight
low temps will be in the upper teens to low 20s areawide and
highly dependent on differences in cloud cover and wind speed.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH TUESDAY/...
The next shortwave in the train will move down across the Great
Lakes and into PA later Monday night. The wind along and just
behind the the front associated with the upper trough will reach
70KT down to around 2500ft. The mixing during the fropa and
withing a few hours of it could mix these winds to the sfc,
mainly on the highest ground. The Laurel Highlands should see
the highest gusts, and probably on the Allegheny Front (Cresson, more
so than Laurel Mtn) perhaps due to a helper from the downslope
flow. We`re confident that some 40+KT gusts will occur, and have
issued a wind advy for the 4 SW counties for midnight (Monday
night) thru noon on Tuesday.
The strong/sharp cold advection along the front will make some
snow showers with the moisture it can gather from the Great
Lakes. But, the moisture will be a bit more limited with Lake
Erie continuing to freezing over. The lift along the front could
make a few stronger SHSN, but (severe) squalls won`t be likely,
mainly due to the time of day and relative lack of CAPE (vs
perhaps what will happen Wed).
Temps looks similar Mon to Sunday, but maybe 2-3F cooler in the
SE. Monday night, the temps may stay steady until the front
arrives. Maxes Tues range from the L20s in Potter Co to m30s in
the Lower Susq which are 3-7F below normal maxes.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Clipper low tracks east southeastward from the U.P. of Michigan
across upstate NY into New England Tuesday night through
Wednesday evening. A period of WAA snow is likely along the
northern tier of CPA/NY border region in the 00-12Z timeframe.
GFS/NAM CIPS model guidance continues to indicate a risk of
snow squalls (via SNSQ parameter) with the trailing cold frontal
passage Wednesday PM along with widespread 30-40 mph wind
gusts. Higher confidence in llvl CAA/NWly flow driving lake
effect/upslope snow showers over the northern and western mtns
into Wednesday night with light/minor accumulation probable in
the Warren/McKean County snowbelts and ridgetops and summits in
the Laurel Highlands. We were keen to ramp POPs well above base
NBM which is has a systematic low/dry bias in these light QPF
LES regimes. Sfc ridge building into the area on Thursday will
shut off the snow showers and provide fair/dry wx conditions for
the second to last day of January.
A very brief visit by milder Southern Stream air and moisture to
close out January, then the Northern Stream and predominant WNW
flow aloft resumes through the 1st week of February.
Confidence is increasing for a mixed precip event to close out
January and begin February. A southern stream shortwave and
occluded low pressure system moving eastward across the southern
Plains will send moisture/precip into the shallow cold air at
the southern edge of a modified arctic airmass.
Details with respect to the exact timing on fast moving and
relatively weak northern stream short waves and the exact
location of the low-mid level zero C wetbulb line, make the
forecast for precise ptypes very difficult this far out.
Without a robust area of high pressure/cold dome to the
northeast, we continue to favor more rain/ice vs. snow as
strong WAA could bring precip into the area faster than the
models project. We liked the higher POPs via NBM in the 60-70%
range although there remains uncertainty in the timing/ptype
details. Mixed precip could transition back to snow on the
backside of the low as it exits the Mid Atlantic coast.
Temperatures will generally be near to above the historical
average for the end of January/early February. Thursday 1/30
looks like the coldest day with max temp departures 3-6F below
climo in most locations.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
VFR conditions will continue for all airfields outside of BFD
through 00Z Tuesday with very high (90-100%) confidence. The
main concern at all airfields outside of BFD will be gusty winds
after 18Z Tuesday, with gusts upwards of 20-25kts. LLWS at this
time is possible (~20-30%); however, given marginal confidence
and impact at this time, have decided to leave mentions out of
the 00Z TAF package. If LLWS is to occur, highest confidence at
JST/AOO, with lower confidence further north/east.
At BFD, there is moderate (~50-60%) confidence in MVFR
ceilings, based on a combination of RAP/GLAMP guidance, coupled
with 12Z HREF probabilities. Have decided to trend closer to
GLAMP given recent guidance is in fair agreement, with onset
closer to ~04Z Monday. The window of restrictions continues to
look fairly narrow, with the bulk of guidance outlining
improvement towards VFR close to ~08Z Monday. Given recent RAP
cross- sections, trended closer to ~07Z Monday with moderate
(~60-70%) confidence on timing. Alternative solutions entail a
slightly longer period of MVFR conditions; however, this remains
a lower confidence (~20-30%) solution.
Outlook...
Tue...Gusty northwest winds. Occnl IFR in SHSN N/W, MVFR S/E.
Tue PM-Wed...Light snow possible nrn mtns. Snow squalls
possible W Mtns. WSW wind gusts in excess of 35 KTS possible.
Thu...Lake effect SHSN early. Otherwise VFR.
Fri...Increasing chances of SHSN with restrictions possible.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from midnight Monday night to noon EST Tuesday
for PAZ024-025-033-034.
&&
$$
SYNOPSIS...Lambert/Dangelo
NEAR TERM...Lambert/Dangelo
SHORT TERM...Lambert/Dangelo
LONG TERM...Lambert/Steinbugl
AVIATION...NPB
Forecast Discussion at weather.gov/mqt.
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...Wind Advisory from 4 AM to 4 PM CST Monday for MNZ020-021.
WI...None.
MARINE...Gale Warning until 4 PM CST Monday for LSZ140>143.
Gale Warning until 10 AM CST Monday for LSZ144-145-148.
Gale Warning until noon CST Monday for LSZ146-147-150.
&&
$$
DISCUSSION...Unruh
AVIATION...JDS
MARINE...JDS
Area Forecast Discussion
National Weather Service Hastings NE
520 PM CST Sun Jan 26 2025
...Aviation Update...
.KEY MESSAGES...
- Dry conditions and above normal temperatures through midweek.
- Near-critical fire weather conditions are expected across most
of south central Nebraska on Monday afternoon.
- Upper level storm system will approach the region late in the
week and bring our next chance for moisture. Cold air is
lacking, so appears rain will be the primary precip type.
- Ensembles bring temperatures cooler and closer to normal for
the first full week of February.
&&
.DISCUSSION...
Issued at 355 PM CST Sun Jan 26 2025
Clouds have been a bit peskier today than expected 24 hours ago,
esp. for the Tri-Cities, W and S. Overall, though, still a
decent late Jan day with relatively light winds and temps in the
mid 30s. Dry and quiet conditions will persist overnight.
Fire weather is the primary concern on Monday. Overall, it`s a
pretty typical cold season setup for both temps and winds to
overachieve a bit...1) sunny skies 2) deep westerly flow through
the lowest 3km 3) very dry air following a 1035mb sfc high
pressure and 4) bare ground. As such, have trended both temps
and winds up, and dew points down...and if data such as the 15Z
RAP/18Z HRRR are any indication, there may need to be more
adjustments in later forecast updates. These updates now bring
most of south central Nebraska into solid near-critical
criteria, with some areas esp. N/W of the Tri-Cities possibly
even exceeding Red Flag Warning criteria for at least an hr or
two right around midday. Coordination yielded a consensus to
continue messaging the fire weather concerns, but without a
watch as the overall duration of fire conditions could be
limited. The strongest winds look to be a bit earlier in the day
before the boundary layer has really mixed out to its fullest
potential high temp and low dew point. The cold start to the
day (widespread teens) will also take some work to overcome.
Nonetheless, recent dry conditions are a concern and sometimes
these first 1-2 warm days coming out of a cold spell can catch
people off guard. We`ll continue to address the concerns in the
HWO and in SM and reassess with more short term data tonight.
Current forecast highs are in the low to mid 50s, but it
wouldn`t shock me if one or two spots hit 60F even on Mon.
Tuesday is a few degrees warmer across the board than Monday,
and again, wouldn`t be surprised to see some spots W/SW of the
Tri-Cities hit 60F. Despite the warmer temps, fire concerns
aren`t quite as high (though still "elevated"), owing to
slightly higher RHs (mid 20s-low 30s) and lighter winds. Dry and
mild conditions persist through Wed with another day with
widespread highs in the 50s.
A storm system will begin to eject out of the Desert SW mid to
late week and begin to bring us at least slight chances for
moisture as early as Thu AM. I still think the majority of the
daytime hrs will be dry, though, as these types of systems
(closed upper lows) tend to move slower than modeled 4-5 days
out. Given the persistent mild temps early to mid week, this
system isn`t going to have any cold air to work with, at least
initially. So expect any of the warm air advection moisture
early on in the system (Thu-Thu night) to remain liquid. Even
the tail end of the system on Fri has trended warmer with most
models keeping any snow accums limited to higher elevations of
the High Plains where upslope flow and dynamic cooling with the
negatively tilted trough will be co-located. 12Z EPS gives on
10-30% chance for at least 1" of snow, which is trended lower
than the 20-40% chance 24 hrs ago. Also, with the primary upper
low forecast to track closer to I-35 corridor, some W/N zones
may struggle to receive any appreciable moisture at all. In
fact, 12Z EPS keeps probs for >0.1" of moisture only a 50/50
proposition for areas NW of the Tri-Cities. In contrast, our KS
zones have a 30-40% for exceeding 0.5".
The system should pull out of the region Fri night, leaving dry
and mild conditions for most of next weekend. Ensembles are
still pointing towards a cooldown (at least back closer to
normal) for the first full week of February.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 510 PM CST Sun Jan 26 2025
For KGRI/KEAR Airports:
High confidence VFR conditions through the period with mid level
clouds expected to clear out over the next few hours and clear
skies expected for the remainder of the period. Light SW winds
will continue overnight...increasing after 27/15Z...with some
gusts to near 30 KTS possible during the afternoon hours Monday.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
DISCUSSION...Thies
AVIATION...Rossi
Area Forecast Discussion
National Weather Service Northern Indiana
611 PM EST Sun Jan 26 2025
.KEY MESSAGES...
- Temperatures near to above normal through the period.
- Windy late Mon morning into the afternoon with some gusts 40
to 45 mph mainly along/north of US-6.
- Small chances for light snow Monday evening and Wednesday
with better chances for precipitation by the weekend.
&&
.DISCUSSION...
Issued at 309 PM EST Sun Jan 26 2025
Weak CAA persists across the area along with mid and high clouds,
keeping temperatures in the 20s to near 30. This appears to be the
last "cold" day for the next 7 as a slow pattern shift commences
through the upcoming week.
The upper level NW flow will remain intact into Thursday with a
series of disturbances every couple days. While low levels will
begin to warm, each of these systems will likely mess with thermal
fields until later in the week when upper level ridging takes hold.
This will result on some possible temp gradients in the coming days,
but still an upward trend to above normal for many areas.
The first trough will bring a few concerns for the area Mon/Mon
night with the greatest in the form of increasing winds as 40 to 45
kt winds at 925 mb (below the inversion) and somewhat higher
at/above the inversion height attempt to mix down ahead of and along
a cold front. BUFKIT soundings show higher confidence in winds gusts
of 30 to 40 mph late morning into the afternoon, but as is typically
the case with WAA patterns, are more limited with advisory level
gusts. HREF probs fairly high for 40 mph gusts but drop fast moving
up from there with the greatest potential north of US-6. HRRR
similar in gust potential. Mid clouds will be moving in that could
limit mixing despite the dry layer below the inversion. After
collaboration, have opted to increase wind gusts, but hold shy of
criteria and for the time being defer any wind headline to the
overnight forecast on what will likely be a marginal (3 to 4 hour
period) situation. The second, lesser concern is some signals of at
least a touch of light snow Monday evening. Models indicate
moistening of the column down to at least 850 mb but differ on lower
levels, resulting in low confidence on snowflakes reaching the
ground and possibly accumulating. Have increased pops somewhat and
expanded further south for the evening hours, but keeping in slgt
chc to chc range for now.
Yet another system arrives late Tue night into Wed with a low
potential for some light snow. Signals not as impressive (even
though they weren`t that impressive earlier) for measurable precip,
but maintained low pops.
Focus then shifts to the impacts of a deepening upper low that will
eject from the four corners region into the Great Lakes.
Timing/strength differences remain with some models still showing a
sooner arrival to some light precip Thur night into early Fri before
stronger lift arrives Fri night into Sat. Strong warm nose of +5 to
possibly as high as +10 C will settle in, with sfc temps key in
precip type (rain or freezing rain). Coverage of freezing rain has
diminished and been limited to far NE areas and only during the
overnight hours Thu night and Fri night. A non diurnal temp trend
may occur Fri night which eliminates the threat, but for now just
running with it.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 606 PM EST Sun Jan 26 2025
High confidence in VFR conditions through the TAF period thanks
to high pressure centered over the Central Plains. However,
increasing pressure gradient after sunrise Monday as a low races
across Ontario. Mainly clear skies will promote adequate mixing
of a 35 to 45 knot jet located 2k-4k FT AGL. This low-level jet
strengthens toward 50 knots at the tail end of the TAF period
presenting a non-zero risk of LLWS. Wind gusts in excess of 25
knots linger into early Monday night before subsiding.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Gale Warning from 10 AM to 11 PM EST Monday for LMZ043-046.
&&
$$
DISCUSSION...Fisher
AVIATION...Brown
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
531 PM CST Sun Jan 26 2025
.KEY MESSAGES...
- Strong winds are expected Monday through Wednesday, gusting to
45+ mph Monday (especially near/north of I-88) and over 30
mph Tuesday and Wednesday.
- Unseasonably mild temperatures are expected Monday, Tuesday,
and Thursday; mild weather possible Friday and next weekend as
well, but confidence lower in that time period.
- Next chance of precipitation isn`t until Friday at the
earliest; dry weather is expected until then.
&&
.DISCUSSION...
Issued at 249 PM CST Sun Jan 26 2025
Through Monday Night:
Our main forecast concern continues to be the strong west-
southwest winds on Monday, along with a focus on the mild
temperatures (and how warm high temps get). We issued a Wind
Advisory earlier this afternoon, for areas roughly near and north
of I-88, in effect 9am-6pm CST Monday.
The lack of snow cover and influence of slightly stronger late
January sun helped temperatures recover to right around normal
this afternoon. While ~1030 mb high pressure centered over
eastern Kansas retains enough influence this evening amidst
clear skies, temperatures will quickly dip into the teens
outside of Chicago. This surface high and powerful low pressure
taking shape near Hudson Bay will be the main players in
tomorrow`s strong winds. The surface low will deepen to around
970 mb early Monday near James Bay, while the surface high
settles into the southern Plains. An induced strong westerly low
level jet of 40+ kt with its base down to about 950 mb will
develop overnight. This plus a tightening pressure gradient will
result in gradually increasing southwest winds. The winds and
onset of warm advection will result in temperatures becoming
steady and then slowly rising through sunrise.
A key component of tomorrow`s temperature and wind forecast is the
lack of snow cover across the area, vs. operational model guidance
still holding onto at least patchy light snow cover in its snow
depth initialization, and then not melting this phantom snow cover.
The only guidance with a good handle on this is the RAP/HRRR, and
not coincidentally, they are featuring the strongest winds. While
skies remain mostly sunny in the morning through midday, temperatures
should be off to the races, considering how temps behaved on
Saturday and Friday 1/17. This will help quickly increase mixing
heights and enable tapping into the base of the strong low-level
winds. With 45-50 kt speeds reaching down to about 925-900 mb,
particularly north of I-80, we`re expecting a quick ramp up in
winds once to late morning.
Even for model guidance that is in all likelihood cool-biased,
forecast soundings suggest top of the mixed layer winds into the
40-45 kt range. The extended RAP and HRRR runs today didn`t get
quite as warm as previous runs last night due to thickening mid-
level overcast from a mid-level impulse moving in from the
northwest. This is the main wildcard for how temps get, but even
if low-mid 40s are observed (our range is 41-47F), the RAP/HRRR
soundings suggesting solid support for mixing down advisory (45+
mph) gusts near/north of I-88 increased confidence in hoisting a
Wind Advisory with this afternoon`s forecast package.
The 12z HREF had 60-80% probabilities of gusts >45 mph for the
advisory counties/zones. In addition, with the tight pressure
gradient, it will be windy area wide. Expanding to >40 mph wind
gust probabilities, the 12z HREF had 60-100% probs from south to
north. If temps and as a result winds overperform a bit vs.
forecast, there may be a need to expand the Wind Advisory a bit
farther south (ie. down to I-80 corridor counties/zones), and
will let subsequent shifts assess this.
Skies will become mostly cloudy in the afternoon and early
evening, and there is even some guidance that suggests high-based
sprinkles will be possible for the northeast 1/3 or so of the CWA.
Added in some silent PoPs for this, but no explicit sprinkles
mention. If nothing else, we`ll see temps cool down some once the
clouds spread in. Winds will also ease towards sunset, though it
will remain blustery until the late evening. In coordination with
WFO MKX, went with a 6pm end time for the advisory for now.
A weak cold front will approach the area Monday night, and this
front will likely wash out and/or fail to make it through the
CWA by early Tuesday. Diminished winds and clearing skies in the
frontal trough will enable lows to dip down into the mid to upper
20s (locally lower 20s), solidly above normal for the date.
Castro
Tuesday through Sunday:
A strong an active northwesterly upper-level flow pattern will
persist this week, and drive a couple of additional clipper
systems southeastward across the Upper Great Lakes into New
England through Thursday. Across our region, each of these
clipper systems are expected to produce warm sectors that
feature unseasonably mild and gusty southwest winds, followed by
modest and breezy cold frontal passages.
The first of these clippers is slated to induce strong warm
advection on breezy southwest winds across our area on Tuesday.
Local climatology suggests surface high temperatures should have
no problem topping out well into 40s Tuesday afternoon given
the lack of snow cover and 925 mb temperatures progged to be
around +2C. Given the tendency for the NBM to be too cool in
these warm and breezy warm sectors, I have continued the trend
of steering the forecast temperatures towards the NBM 90th
percentile. Expect southwest wind gusts of 30-35 mph to
accompany these warm temperatures during the day in advance of
an approach cold front. This cold front is expected to drop
across our area, with only a glancing blow of the colder post
frontal airmass, Tuesday night. Breezy northwest winds and a bit
colder conditions are thus expected in its wake for Wednesday,
with highs generally in the upper 30s to low 40s.
The second clipper system will follow quickly on the heals of
Tuesday`s, likely tracking to our northeast during the day
Thursday. Similar to Tuesday, gusty southwest winds (gusts 30-35
mph) are likely to develop during the day Thursday, with very warm
temperatures looking to once again be in order. Temperatures on
Thursday actually even look to be warmer than those on Tuesday,
with readings possibly climbing into the low to mid 50s, which
would be near record territory for the 30th (current record highs
for the 30th are 55 at Chicago, 52 at Rockford).
Friday into the first part of the weekend forecast confidence
remains low. Medium range guidance continues to suggest that
the cut off low over the southwestern U.S. will get booted
eastward across the country as northern stream long wave trough
begins digging into the western U.S. However, a lot of
uncertainty regarding the track, intensity, and even some
uncertainty with timing, as this upper low ejects out into a
confluent flow over the Midwest and likely is in a weakening
phase as it approaches the area. Nevertheless, it appears much
of the area will be headed towards a period of inclement weather
with better precipitation chances Friday into Saturday.
KJB
&&
.AVIATION /00Z TAFS THROUGH 06Z MONDAY/...
Issued at 531 PM CST Sun Jan 26 2025
Aviation Forecast Concerns for the 00Z TAFs:
- Strong west-southwest winds Monday, with gusts near/around 40
kts likely by afternoon.
Deep surface low pressure is forecast to move across northern
Ontario and James Bay Late tonight into Monday. Though this is
well north of the local area, the resulting tightening of the
surface pressure gradient is expected to produce a period of
strong/gusty west-southwest winds across the terminals on
Monday. Winds will begin to ramp up slowly early Monday morning,
becoming gusty near 30 kts after sunrise. Winds will continue
to increase through early afternoon as mixing deepens and a
50-60 kt low level jet develops overhead, supportive of
sustained winds in excess of 20 kts and gusts near 40 kts. The
low level jet then shifts east of the area by Monday evening,
which along with a fairly quick easing of the pressure gradient
should result in winds diminishing fairly quickly during the
evening hours.
VFR conditions are expected through the period, with only
patchy high clouds expected through late Monday morning.
Various forecast guidance differs with how quickly a lowering
mid-level VFR deck develops Monday afternoon, with some guidance
as early as midday and others late afternoon/toward sunset.
While not impactful from a flight category perspective (VFR),
the thickness of this cloud cover may play a role in strength of
gusts are during the afternoon with a thicker overcast likely
muting peak gust speeds. Current TAF favors the slower
evolution of this potential cloud cover.
Ratzer
&&
.MARINE...
Issued at 249 PM CST Sun Jan 26 2025
Impressively deep low pressure will track north of the Great
Lakes into Monday. Meanwhile, expansive surface high pressure
will settle into the south central US, resulting in a tight
pressure gradient and strong west-southwest winds. Despite a
mild air mass moving over the cold lake waters, a dry air mass
on land should help mix the strong winds at least a couple miles
out into the nearshore waters. With continued forecast sounding
support for 40+ kt gusts, confidence was high enough to upgrade
the Gale Watch to a Gale Warning for the entire nearshore from
Winthrop Harbor to Michigan City. The Gale Warning is in effect
from 9 AM to 9 PM Monday.
KJB/Castro
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Wind Advisory from 9 AM to 6 PM CST Monday for ILZ003-ILZ004-
ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-ILZ012-ILZ013-ILZ103-
ILZ104.
IN...None.
LM...Small Craft Advisory from 9 PM this evening to 9 AM CST Monday
for the IL and IN nearshore waters.
Gale Warning from 9 AM to 9 PM CST Monday for the IL and IN
nearshore waters.
&&
$$
Visit us at weather.gov/chicago
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
548 PM CST Sun Jan 26 2025
.KEY MESSAGES...
- Above normal temperatures for the week ahead with multiple
daily highs in the 40s.
- No significant precipitation chances, but chances for
flurries.
&&
.DISCUSSION...
Issued at 128 PM CST Sun Jan 26 2025
After a cool start this morning ample sun and neutral to
slightly warm air advection aloft temperatures have been
climbing quickly today. Temperatures have warmed the fastest
over snow free areas and especially along the Buffalo Ridge
where above freezing highs have already occurred. This warming
will continue into tomorrow and Tuesday, with the warmest early
week temperatures expected on Tuesday. Monday will however also
see some more moisture advecting in which will increase our
cloud cover and limit heating somewhat. This saturation could be
deep enough for some flurries or maybe even light snow late
morning into afternoon. Current high resolution guidance shows
the deepest moist layers in western Wisconsin. So PoPs have been
increased in this area. Without a good source of forcing though
little to no accumulation is expected. Basically it would be
like the snow we got on Saturday. For wind today and tomorrow
will be diurnally gusty with our warming temperatures helping to
mix down higher winds.
Warm air advection peaks on Tuesday with 850 mb temperatures of
zero to six degrees Celsius. The highest temperatures will be in
southwest Minnesota with colder to the north and east. This is
because of a clipper moving across the Great Lakes region. The
track of this clipper will be to our north with only a few
counties in central Minnesota and western Wisconsin with a
10-25% chance of seeing some snow. Outside of the snow another
impact of this clipper will be cloud cover, as the clouds will
extend farther south than the snow. This will help limit how
warm temperatures will get on Tuesday. High temperatures for
Tuesday have been increased, especially in southwest Minnesota
as this is where the overlap between the warmest temperatures
aloft and lowest sky cover are. Mid to Upper 40s are likely with
a chance to break 50. With favorable mixing and an increased
pressure gradient supplied by the clipper this will be another
gusty day. Cold air advection on the backside of this clipper
will allow for the gusty winds to continue into Tuesday night.
Behind the clipper Wednesday will be cooler, but still well
above normal. This slight cool down won`t last long either with
more warm air advecting in for Thursday and Friday. Thursday
will be competing with Tuesday as the warmest day of the week. On
a precipitation front, we will be in a fairly quiet northwesterly
flow pattern with few chances for precipitation. However, this
pattern does start to break down near the end of the week. This
has some ensemble members giving us increased chances for a
system to move in this weekend. Still a minority of members with
most global ensembles keeping the main system to our south.
Even if we get missed again this does look like a more active
pattern to start February as more and more ensemble members
start to show QPF. With the inherent uncertainty in models a
week or more out confidence remains low.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 548 PM CST Sun Jan 26 2025
No major changes were introduced for the 00z TAF period. VFR
with west/southwesterly winds between 10-15 kts tonight. Main
aviation concern will be a 4-6 hour period of low-level wind
shear forecast to develop over the terminals after ~09z.
Surface winds will turn more westerly by midday, which will
bring an end to the threat of LLWS. Kept ongoing PROB30s for the
potential of VFR -SHSN at STC, MSP, RNH, EAU mid to late
morning. Forecast guidance illustrates that the best chance for
MVFR vis associated with the snow showers will be at RNH/EAU,
though confidence was too low to include in the TAF. RAP
guidance suggests PROB30 windows may be need to pushed back an
hour or two, but have opted to push that to forthcoming TAF
issuances.
KMSP...Westerly LLWS around 50 knots expected to develop after
10z and persist through 15/16z. VFR snow showers possible mid-to
late morning, but dry air throughout the profile should limit
further impacts. WNW gusts will approach 30 knots.
/OUTLOOK FOR KMSP/
TUE...VFR. Wind W 10-15G25 kts.
WED...VFR. Wind NW 10-15G20 kts.
THU...VFR. Wind SW 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...NDC
AVIATION...Strus
Area Forecast Discussion
National Weather Service Marquette MI
659 PM EST Sun Jan 26 2025
.KEY MESSAGES...
- Strong southwest to westerly winds tonight will continue
Monday across Upper Michigan. Strongest winds, up to 55 mph
are possible in the Keweenaw by Monday morning. 45 mph winds
will be possible near Lake Superior, especially in Marquette
County.
- Southwest gales to 40 knots this afternoon in western Lake
Superior increase this evening and continue Monday as they
become westerly and then northwesterly. Winds to 45 knots will
be possible across a majority of the lake tonight and Monday.
Storm force winds to 55 kts possible north-central this
tonight.
- Passing Clipper systems will bring in rounds of mainly light
lake effect/enhanced snow through the extended period, but
widespread significant snowfall is not expected this week.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 136 PM EST Sun Jan 26 2025
Weak surface trough with mid-upper level ridging over the region has
supported some light snow showers here and there, but overall, a
mostly dry day with temperatures in the teens so far has been
observed across Upper Michigan. Lake effect snow downwind of Lake
Superior into Alger/Schoolcraft/Luce this morning has ended as
southwest winds have shifted the showers offshore toward Ontario.
Convergent flow in the Keweenaw also produced shower activity mainly
north of Houghton this morning and early afternoon. Additionally,
light snow/flurries have been noted moving through central Upper
Michigan late this morning and early afternoon. Otherwise,
transient patches of clouds and provided a mix of clouds and
sunshine to the forecast area today so far.
A cutoff upper level low is currently analyzed spinning along the
California Coast with stout ridging across the eastern Pacific
moving up western Canada and Alaska. Broad troughing downstream
stretches from the Canadian Rockies eastward through the rest of
Canada while mid-upper level ridging stretches across the southern
states. A weak shortwave is noted across Minnesota, southwestward
toward Wyoming. At the surface, a 1032mb high centered near Kansas
City is observed per RAP analysis while a sub 995mb low moves
eastward into western Huron Bay. As we progress through tonight,
Upper Michigan will be caught between these two surface features
while the low to the north explosively deepens to near 970mb by 12z
Monday. Warm air advection under southwesterly 850mb flow will begin
after the weak shortwave moves through the region late this
afternoon, then as the low to the north deepens, tightening pressure
gradient characterized by 4-10mb per 6 hour pressure falls will
support strong winds developing across the region. In the Keweenaw,
winds will gradually shift westerly and increase to 40-45 mph this
evening and overnight. By morning, 50-55 mph winds will be possible.
HREF wind probabilities suggests 50+ percent chance of 50 mph winds
by 5am EST. Potential for these strong winds to begin is a little
earlier then the previous forecast, so opted to move up the start
time of the inherited Wind Advisory in the Keweenaw Peninsula to
start at 0z. Model soundings elsewhere are mixed on overnight mixing
given the warm air building in aloft, but areas prone to downsloping
winds under southwest flow could see gusts near 35 mph. This
increases to near 45 mph by late morning, especially near the Lake
Superior lakeshore areas of Marquette.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
Issued at 307 PM EST Sun Jan 26 2025
The extended period will remain active as split flow develops with a
closed midlevel low moving from Southern California to the Four
Corners, and midlevel troughing over the Great Lakes. This will
leave us sensitive to passing clipper systems throughout the work
week. Temps mainly remain above normal through the period with highs
in the mid 20s to mid 30s, except upper teens to 20s on Wednesday
behind a passing clipper system. Lows will be in the teens to 20s,
some single digits are possible in the interior Monday night through
Thursday night. These temp/precip patterns are captured well by the
CPC 6-10 day outlooks.
A strong and deepening low around western Hudson Bay today tracks
through far northern Ontario tonight into Monday, sending a strong
cold front south over the region late in the day Monday. Blustery SW
winds persist into the morning with the tight pressure gradient in
place, veering westerly into the early afternoon and then
northwesterly into the evening as the cold front drops through. Wind
gusts up to 30mph will be common across the UP, higher to around
40mph closer to Superior. However, stronger gusts up to 40-50mph are
expected across the Keweenaw and for a brief period during the
morning nearer Lake Superior in Marquette county as SW downsloping
flow is favorable for stronger wind gusts. A Wind Advisory remains
in effect for the Keweenaw late tonight through Monday morning, and
has been issued for Marquette county for Monday morning. NW winds
may reach advisory criteria nearer to Superior in Alger and Luce
counties Monday afternoon and evening, but confidence is not high
enough for a headline just yet (around 20-40% chance for advisory-
level gusts per HREF guidance).
Meanwhile, a quick burst of snow accompanies the surging cold front
is possible late Monday afternoon into the evening, with some lake
enhancement in the west to NW wind belts particularly across the
eastern UP. Widespread accumulations up to 0.5" to 2" with a brief
period of visibilities dropping down to around 1/2 mi or less are
the main impacts anticipated. Lower visibility will be a particular
concern near Lake Superior, where gusty winds may lead to blowing
and drifting snow. This may necessitate a headline down the line,
but will hold off for now until confidence increases. Trailing light
north-northwest lake enhanced/effect snow is then expected Monday
night.
A shortwave/clipper low dives southeast over the Upper Great Lakes
from the Canadian Prairie Tuesday into tuesday night, with latest
deterministic guidance bringing the surface low right over Lake
Superior/Upper Michigan Tuesday afternoon and evening. This should
bring widespread light snowfall totals around 1-3in Tuesday, with
light trailing LES in the NW snow belts at least through Wednesday
evening. Winds remain elevated Tuesday into Wednesday, though gusts
will not come in as high as earlier in the work week. Mainly dry
weather is expected Thursday into Friday as winds back to the W/SW
with a drier airmass in place, but with some onshore wind component
as guidance continues to show weak waves rippling through Ontario
during this period, will not totally rule out some sporadic LES to
wrap up the work week. Confidence is low (20% chance after Wednesday
night).
Our flow finally begins to evolve into next weekend as the midlevel
low finally moves northeastward through the Plains. This should be
somewhere over the Midwest or Great Lakes by late Saturday or early
Sunday. A further north track would result in a warmer airmass and
better support for rain over snow, while a more southerly track
would give us a better chance at seeing snow - or nothing at all, if
the system dodges us too far to the south. With little run-to-run or
mode suite-to-model suite consistency, will simply deal with this
now by leaning NBM and keeping an eye out to see how things change
in the coming days.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 658 PM EST Sun Jan 26 2025
Tight pres gradient will develop across the area tonight btwn high
pres over the Southern Plains and a deep low pres tracking ese to
southern Hudson Bay. With stability near the sfc, LLWS is expected
at IWD/SAW into Mon morning as gustiness will be somewhat limited.
Sustained sw sfc winds will be generally in the 15-20kt range while
45-55kt flow is overhead at 2kft agl. Both terminals will be VFR
tonight. At CMX, expect westerly winds gusting to 35-45kt to
increase to gusts of 45-50kt late tonight/Mon morning. Flow in the
lowest 2kft is likely to be very turbulent, but did maintain a
mention of LLWS Mon morning when winds at 2kft agl peak at 55-60kt.
The gusty winds will create blsn at CMX, resulting in frequent MVFR
vis, but some IFR is not totally out of the question. A period of
MVFR cigs is possible in the 04-08z time period. A cold front will
drop s across the area during Mon aftn, bringing MVFR cigs to all
terminals along with a period of -shsn, especially at CMX/SAW. Winds
at CMX will diminish with gusts falling to 35-40kt. IWD/SAW will see
gusts to around 30-35kt.
&&
.MARINE...
Issued at 307 PM EST Sun Jan 26 2025
Southwest winds of 20 to 30 knots continue across the eastern half of
the lake, but are already increasing to gales to 35-40kts across
western Lake Superior to north of the Keweenaw this afternoon. Gales
further increase to 45 knots over the west half of the lake by this
evening and by around midnight tonight over the east. These winds
continue to strengthen overnight into Monday as a strong low level
jet drops south across the lake; storm force winds to 55 kts are
expected over the north-central portion of the lake (particularly,
north of the Keweenaw) late tonight through Monday morning. A Gale
Warning remains in effect for the west half of the lake, continuing
through 7 PM Monday. In the east, the Gale Warning begins at 7 PM
this evening and continues through 1 AM Tuesday. A Storm Warning is
in effect for the north central lake starting at 1AM EST Monday;
this warning may need to be expanded further eastward into central
Lake Superior in future updates as the probability of gusts
exceeding 47 kts is around 50% in those zones. Monday morning,
expect the winds to veer to the northwest, weakening a little to
gales of 35-45 kts across the lake (highest over the eastern lake).
Expect north- northwest winds to weaken Monday night behind the
sharp cold front, reaching 20 kts or less Tuesday morning. Some 20-
30 kt winds may return Tuesday afternoon into Wednesday with a
clipper system moving over the lake, with around a 20% chance for
gale-force gusts to 35 knots. Behind this clipper system, expect
winds of 15-25 kts across the lake through the rest of the work week.
The cold front dropping through Monday afternoon and evening brings
freezing spray back to the lake with some heavy freezing spray
possible over the east half of the lake Monday night. Otherwise,
wave heights build up to 10-20 ft over the north half of the lake by
Monday morning. Waves lower to 5-15 ft and shift toward the southern
shores (higher east half) by Monday evening as winds become more
northerly. Waves gradually fall below 6 ft across the lake late
Monday night/Tuesday morning.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Lakeshore Flood Advisory until 7 PM EST Monday for MIZ001-003.
Wind Advisory until 1 PM EST Monday for MIZ001-003.
Wind Advisory from 7 AM to 1 PM EST Monday for MIZ005.
Lakeshore Flood Advisory from 4 PM Monday to 1 AM EST Tuesday
for MIZ006.
Lakeshore Flood Advisory from 1 PM Monday to 1 AM EST Tuesday
for MIZ007.
Lake Superior...
Gale Warning until 1 AM EST Tuesday for LSZ245>251-265>267.
Gale Warning until 7 PM EST /6 PM CST/ Monday for LSZ162-
240>242-263.
Gale Warning until 1 AM EST Monday for LSZ243-244-264.
Storm Warning from 1 AM Monday to 1 AM EST Tuesday for LSZ243-
244-264.
Lake Michigan...
Gale Warning until 1 AM EST Tuesday for LMZ248-250.
&&
$$
SHORT TERM...JTP
LONG TERM...LC
AVIATION...Rolfson
MARINE...LC
Area Forecast Discussion
National Weather Service Morristown TN
806 PM EST Sun Jan 26 2025
...New UPDATE...
.UPDATE...
Issued at 754 PM EST Sun Jan 26 2025
No changes to the forecast for tonight during the evening update.
Rain will develop and move into the region from the southwest over
the next couple of hours. Some showers are already developing near
our office in Morristown. A changeover to light snow is still
expected late tonight/early morning in the East TN mountains, SW
VA, NE TN and the Upper Cumberland Plateau. A SPS is out in those
locations for the possibilty of light snow accumulations.
Elsewhere, it will be warm enough for an all rain event.
&&
.SHORT TERM...
(This evening through Monday)
Issued at 305 PM EST Sun Jan 26 2025
Key Messages:
1. Precipitation chances return tonight into the first part of
Monday. Southern areas will see rain, but a rain/snow mix is more
likely north of I-40. Some light snow accumulations are possible
from the Northern Cumberland Plateau and eastward along the TN/KY
line into northeast TN and southwest VA. Confidence in snow
accumulations across these areas is low to moderate. Light snow
accumulations are expected across the higher elevations of the east
TN, southwest NC, and southwest VA mountains.
Discussion:
Moisture increases tonight as a southern shortwave moves across to
our south. The trends continues to favor slightly higher snowfall
amounts across our east TN, southwest, VA, and southwest NC
mountains. This is also true for the northern Cumberland Plateau and
points eastward along the TN/KY line and into northeast TN and
southwest VA.
Confidence in light accumulating snowfall across the mountains is
moderate to high, where temperatures will be coldest. Most
elevations above 4,000 feet should see 1 to 2 inches. An isolated 3"
amount is probable across locations such as Newfound Gap and Mt.
LeConte.
Confidence in light accumulating snowfall from the northern plateau
and eastward into northeast TN and southwest VA is only low to
moderate. Temperatures at the current hour, across the lower
elevations, are in the upper 40s to low 50s. Though snow is likely to
fall, it`s difficult to say how much will actually accumulate.
Having said that, Hi-Res models such as the HREF and HRRR continue
to show a narrow stripe of 0.5 to 1" of snow accumulation across
these areas during the early morning hours. This narrow band of
accumulation looks to coincide with an area of vorticity enhancement
at 500mb. An isolated 2" amount can not be ruled out in this
enhancement zone. The HREF max/min ensemble spreads support these
snowfall values while also highlighting the uncertainty. The min has
zero inches while the max shows 1 to 2 inches.
Most areas dry out by late Monday morning as precip shifts eastward.
However, upslope flow snow showers could persist into the afternoon
hours across the east TN mountains. Sunshine west of I-40 by lunch
time but clouds likely linger east of I-40 through most of the day,
especially across the mountains.
&&
.LONG TERM...
(Monday night through next Sunday)
Issued at 305 PM EST Sun Jan 26 2025
Key Messages:
1. Normal to just above normal temperatures through next week.
2. Very low probability (10-15%) of light rain across southern
valley locations Wednesday, otherwise, mostly dry conditions persist
Tue through Thu. Breezy winds area-wide Wednesday.
3. Widespread rain chances return Friday into the weekend, though
with high uncertainty on timing. Gusty winds in the mountains and
adjacent foothills will be possible with this system.
Discussion:
Southwesterly flow at the surface will promote the start of a
warming trend Tuesday, with H5 height rises reinforcing near to
slightly above normal temperatures through at least the remainder of
the work week. Guidance continues trending towards a mostly dry
solution as a moisture starved front makes passage Wednesday. The
greatest probability(a measly 10-15%) for a light rain will be along
the TN/GA border. Southwesterly surface winds will be breezy
Wednesday, especially during peak afternoon mixing when stronger H85
flow is transported to surface levels. Probabilities of 24-hour max
wind gusts greater than 25mph ranges from 50-90% across the forecast
area.
Widespread precipitation chances make a return Friday into Saturday
as a vertically stacked system ejects over central CONUS and towards
the Great Lakes region. Typical when dealing with the ejection of a
cut-off low this far in advance, there are still many uncertainties,
especially in regards to timing. Models are in decent agreement with
a southwesterly to southerly H85 LLJ that could bring gusty winds to
the mountains and adjacent foothills but the track & strength of the
surface low will play a key role in the expected winds as well. Rain
chances gradually diminish to end the weekend as the system departs
north and east.
&&
.AVIATION...
(00Z TAFS)
Issued at 616 PM EST Sun Jan 26 2025
Conditions will begin to deteriorate this evening as rain moves
in from the southwest. IFR conditions are expected late tonight
and through most of the morning. VFR conditions will return by
early afternoon. A changeover to snow or rain/snow mix is expected
near TRI but little to no accumulation is expected.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 38 50 29 55 / 90 20 0 0
Knoxville McGhee Tyson Airport, TN 36 46 28 51 / 80 40 0 0
Oak Ridge, TN 34 47 27 51 / 80 20 0 0
Tri Cities Airport, TN 32 42 26 45 / 70 40 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...
LONG TERM....KRS
AVIATION...McD
Area Forecast Discussion
National Weather Service Omaha/Valley NE
952 PM CST Sun Jan 26 2025
.KEY MESSAGES...
- Temperatures in the 30s today, with temperatures rising into
the 50s Monday, Tuesday and Thursday. Warming temperatures
will allow for ice break up and ice jamming on area rivers. If
an ice jam develops, rivers may rise quickly and minor
flooding may occur.
- Elevated fire weather risk on Monday due to warm temperatures,
low relative humidities and gusty west to southwest winds
- Next chance for precipitation arrives late Thursday into
Saturday. A wintry mix of precipitation is possible Thursday
night into early Friday, with rain transitioning to snow
Friday into Saturday. Snow accumulations of trace up to 2
inches may be possible. Differences remain in the storm track
and timing, which could limit snow potential.
&&
.DISCUSSION...
Issued at 305 PM CST Sun Jan 26 2025
Pretty quiet across the region early this afternoon with surface
high pressure dominating and temperatures as of 3 PM mostly in
the lower to mid 30s. Looking at the larger scale pattern, main
feature of note was a cutoff low spinning over CA which will
approach us later in the week and bring some precip chances.
Otherwise, roughly the eastern two thirds of the country
remained under zonal flow with various pockets of precipitation
across the southeast and northeast.
Heading into Monday, the surface high will push south while the
pressure gradient tightens over the forecast area and leads to
strengthening westerly to southwesterly flow. Combined with
downsloping, this will allow temperatures to climb into upper 40s to
mid 50s. In addition, decent mixing should allow us to tap into some
25 to 35 kt winds aloft, depending on the guidance you look at
(26.15Z RAP is probably most aggressive), and should also allow RH
values to drop into the upper teens to mid 20s across a good chunk
of the area. As such, fire weather will be a concern. There was some
conversation about issuing a Fire Weather Watch, but current
forecast indicates only spotty areas reaching criteria for about an
hour or two (mainly northeast NE). In addition, 26.12Z HREF guidance
suggests only a 20-30% chance of reaching criteria near the
NE/SD border. However, if other guidance starts to trend toward
the aforementioned 26.15Z RAP, we may end up needing a Red Flag
Warning. Regardless of headline, definitely a day to practice
fire safety and avoid burning.
The warm weather will stick around through the week with daily highs
in the 40s and 50s. Tuesday and Thursday look to be the warmest days
when a few locations could make a run at 60 degrees. A cold front
will slide through Tuesday evening and bring a return to northwest
winds on Wednesday, but temperatures will still top out in the mid
40s to lower 50s. Given the warm weather, we could see some
increased ice movement on area rivers which increases the potential
for ice jams. That said, temperatures at night still look to get
below freezing which should at least somewhat limit ice movement.
By Thursday night/Friday, that cutoff low currently over CA should
be somewhere in the TX/OK panhandle vicinity. The associated precip
shield on the north side will be approaching the NE/KS border at
this time, but there`s still a lot of spread in various guidance on
exact timing track. The EPS and GEPS ensembles are generally a
little faster and a little farther south with the track, with some
members even keeping us completely dry. In contrast the GEFS mean is
farther north, but even several of its members miss us completely.
As of now, we`re looking at about a 30 to 50% chance south of an
east-west line through Omaha, with chances quickly tapering off to
the north. As far as precip type, the warm air in place would
favor mostly rain, but some wintry precip could mix in at times
depending on exact timing (night time precip would mean a wintry
mix). So bottom line, we`re highly confident that there will be
a low pressure system that brings precip to the central to
south- central US toward the end of the week. However,
confidence is low that we see any wintry impacts from it, with
some potential we get missed completely. For what it`s worth the
Probabilistic Winter Storm Severity Index suggests only a 5-10%
chance of minor impacts south of Interstate 80.
Additional precip chances may clip us Saturday night/Sunday
(20% chance) as a shortwave trough and surface low slide by to
our north. However, forecast confidence is even lower in this
timeframe, as it will depend at least somewhat on how the
previous system pans out.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 950 PM CST Sun Jan 26 2025
Winds continue to be mostly out of the west-southwest with a few
spots in southwest Iowa being southerly and very weak. Clouds
will continue to be hard to come by with VFR conditions expected
to win out for the next 24 hours. Winds pick up late in the
morning and gust to as strong as 23-38 kts during the afternoon
hours before dropping off by 00-01z tomorrow evening.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...CA
AVIATION...Petersen
Area Forecast Discussion
National Weather Service Blacksburg VA
950 PM EST Sun Jan 26 2025
.SYNOPSIS...
A low pressure system crossing the Southern Appalachians late
tonight will spread light precipitation into the mountains
through Monday morning. Gusty winds and above normal
temperatures are expected Monday night through Wednesday until
high pressure builds into the region. The next chance for
widespread precipitation will arrive at the end of the week.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 800 PM EST Sunday...
Cloud cover has increased across the southern half of the CWA as
low pressure to the south moves closer. Still no reports of
snowfall at the moment and radar suggests it may still be a few
more hours until precipitation makes it to the area. Snow still
expected to be mainly confined to the western mountains from NW
NC northward into SE WV. Very light accumulations expected.
As of 105 PM EST Sunday...
Key messages:
- Chance of light snow tonight southwest VA into western NC
Upper level flow remains zonal tonight with subtle ripples of short
wave energy tracking from west to east. A wave in the southern
stream crosses the southeast United States late tonight and Monday
morning. Far southwest Virginia and the southern Blue Ridge will be
on the northern side of any synoptic scale lift with this feature.
The low level jet weakens briefly this afternoon but will still have
the potential for wind gusts up to 25 kts in the mountains tonight
and Monday.
A more defined short wave reaches the area from the northwest on
Monday morning lowering heights and turning the 500 MB flow to the
northwest. Some small scale differences in the short range
models, but northern edge of the deeper moisture and locations
goes from around Richlands to Farmville at 12Z/7AM Monday then
drop back into North Carolina by Monday afternoon. Clouds exit
to the east behind this wave. Air mass will moisten from the top
down. Since clouds will not be clearing in southern Virginia
and northern North Carolina until later in the day, will be
trending toward cooler side of guidance for highs on Monday.
Because of such a deep layer with a westerly component to the winds,
precipitation will be confined to the mountains. HRRR has very
light precipitation reaching Bluefield around 00Z/7PM but the better
coverage and steadier snow is not expected to arrive until around
midnight. The probability of getting 0.1 inch of snow is 25 percent
as far north and east as Bluefield and Boone, but the probability of
getting one inch of snow is less than 5 percent.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 130 PM EST Sunday...
Key Messages:
1) Gusty winds will be possible through the entire period,
especially west of the Blue Ridge.
2) Warmer temperatures continue, with above average highs Tuesday.
3) Upslope rain/snow showers will be possible in WV Wednesday night.
The synoptic setup for the midweek will see a large high pressure
system centered over the Gulf Coast, while a very strong low
pressure system in eastern Canada and associated deep upper-level
trough will cause the pressure gradient to tighten across the Mid-
Atlantic. Westerly winds will increase to 15-25 mph west of the
Blue Ridge and gusts of 30-40+ mph possible. The piedmont will
see lighter but still elevated winds with gusts of 15-25 mph.
Winds may briefly relax Tuesday night as the low moves away, but
an Alberta Clipper system moves across the Great Lakes Region
and into the Northeast late Wednesday. This will once again
tighten the pressure gradient, and keep strong winds across the
entire area. Winds could potentially be even stronger with this
setup, depending on the track and intensity of the low.
Precipitation is expected to be minimal through the period due to a
lack of moisture in the area. Despite a cold front moving in late
Wednesday with the clipper system, most locations will remain dry,
with the exception of our WV counties Wednesday night as northwest
flow behind the front will allow light rain/snow showers to develop.
This does not last long, as more dry air from the west associated
with high pressure quickly moves in. Rain totals would be only a few
hundredths at best, with any snow accumulation reserved for Western
Greenbrier County.
Temperatures will remain near to above normal with highs generally
in the 40s/50s. Wednesday will possibly see parts of the piedmont
reach into the low 60s due to southwesterly flow. Low temperatures
remain consistent, with 20s/30s expected each night.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 130 PM EST Sunday...
Key Messages:
1) Next chance of precipitation arrives late Friday into Saturday.
2) Near to above average temperatures continue through the period.
High pressure will remain in place across the area for Thursday and
part of Friday before pushing offshore into the western Atlantic.
The next system develops across the Great Plains and moves into our
area Friday with a warm front bringing light rainfall across the
region. This will be a better organized system with adequate
moisture available as it moves in, which will provide a good chance
of precipitation area-wide, particularly on Saturday. Due to
temperatures that will remain above average, precipitation type
is expected to be all rain, aside from some initial snow mixing
in north of I-64 west of Lexington. Rain will linger into
Sunday morning as the system moves through before tapering off
midday.
Near average to above average temperatures will continue through the
period, with highs generally in the 40s/50s each day. Lows will be
in the 20s/30s late week but rise into the upper 30s to around 40
for the weekend.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
As of 800 PM EST Sunday...
High clouds increasing, but all terminals still VFR. Some sub-
VFR across the mountains by Monday morning.
Some small scale differences in the short range models, but
northern edge of the deeper moisture and locations goes from
around Richlands to Farmville at 12Z/7AM Monday then drops back
into North Carolina by Monday afternoon. Have ceilings lowering
to MVFR at KBLF around 05Z/midnight, but not at KLWB and KBCB
until around 10Z/5AM. Clouds exit to the east behind this wave
after the 18Z end of the TAF forecast period.
Because of such a deep layer with a westerly component
to the winds, precipitation will be confined to the mountains.
Light precipitation reaching Bluefield is not expected to
arrive until around midnight or shortly thereafter.
Conditions should improve to VFR again for all terminals by late
in the current valid TAF period.
OUTLOOK THROUGH THURSDAY...
Monday night through Wednesday: Any remaining MVFR clouds in
the mountains will dissipate by Monday evening. Winds will be
come gusty. Wind gusts up to 35kts will be possible at the
highest elevations, with low level wind shear possible at KLWB,
KBLF, KROA and KBCB Monday night into early Tuesday.
Thursday and Friday: Widespread light rain is expected. There is
a low probability for snow at KLWB.
&&
.EQUIPMENT...
As of 115 PM EST Sunday...
Server and software corruption has interrupted the ability to
update the forecast on the NWS Blacksburg phone system.
Technicians will address this issue on Monday. Until then check
weather.gov/rnk for the latest forecast.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/BMG
SHORT TERM...JCB
LONG TERM...JCB
AVIATION...AMS/BMG
EQUIPMENT...AMS
Area Forecast Discussion
National Weather Service San Diego CA
145 PM PST Sun Jan 26 2025
.SYNOPSIS...
A weather system will continue to bring cool and showery weather
through the early part of the week. This includes rain and a
chance of thunderstorms for the coast and western valleys, along
with modest accumulating snowfall above 5,000 feet. Drier and
continued cooler weather will continue through the rest of the
work week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (Through Tuesday)...
A 1016mb area of low pressure nearing Point Conception is
providing a chilly day out there with scattered showers across the
region. Some areas have received over half to near one inch of
rainfall so far with mountain areas above 5,000 feet expected to
receive an additional 2-6 inches, locally over 8 inches. Snow
levels will drop further this evening into Monday morning, mainly
near 3,500 feet in northern areas, 4,000 ft in San Diego County.
Hi-res models HRRR/WRF in fairly good agreement of showers
increasing in coverage this evening through Monday morning. The
chance for thunderstorms remains for areas mainly west of the
mountains. Lightning strikes have been observed closer to the low
in LA and points west. RAP analysis shows some areas with over 200
J/kg MUCAPE values, indicating enough instability for storms to
form across the region. Thunderstorms look most likely to occur
overnight, with chances lessening in the morning on Monday. Any
storms that do form may produce locally heavy rainfall and small
hail, along with localized flooding, particularly near burn
areas.
The center of the low will push inland by Monday morning, bringing
in drier air behind it. This will decrease chance for rainfall
toward the coast and western valleys, but orographic lift will
continue to maintain a better chance of light rain/snow in
foothills and mountains. As the low pushes into Arizona, leftover
clouds from northerly flow aloft may produce some light showers by
Tuesday, looking to see the best chance across San Diego County.
Sunshine will come back in closer to the LA Basin and high desert,
but clouds may linger for areas further south and east. Cool
weather will continue today and Monday, with highs near 10 degrees
below average. Some places who see the sun Tuesday will warm a bit
more, but still near 5 degrees below average. Tuesday morning will
be the coolest morning of this event after the low departs, where
western valleys will cool to the 30s, locally below freezing. This
will lead to patchy frost for areas that are wind sheltered.
&&
.LONG TERM (Wednesday through Next Weekend)...
Models are in good agreement on progressing the area of low
pressure mentioned above further to the east by Wednesday, where
shower activity will diminish as we welcome more sunshine. The
system may elongate, keeping heights lower over the area, so not
much warming looks to take place. An area of high pressure to our
southwest will begin to strengthen by Thursday into Friday.
Heights rise some, so subtle warming will occur. Most areas west
of the mountains into the high desert will make it into the 60s
with lower 70s across the Coachella Valley. A majority of model
guidance further strengthens the high pressure system into the
weekend, moving closer to Southern California. NBM guidance was
used to portray a further warming trend with some areas west of
the mountains possibly getting into the low 70s and 50s in the
mountains.
A deep area of low pressure will be forming off the coast to our
northwest by the latter half of the week, which will bring a high
chance for rainfall across far Northern California into the
Pacific Northwest. This trough may become strong enough to dip
farther south closer to our region by early next week, but
confidence on the placement of this system and if it will bring us
any more wet weather as we enter the month of February is low at
this time.
&&
.AVIATION...
262100Z...SHRA, mostly light, will continue on and off through
Monday afternoon for everywhere but the deserts where things will be
more isolated. SHSN in the mountains, especially higher elevations
generally above 4000ft. Cloud bases will be variable, 2000-6000ft
MSL with widespread mountain obscurations. Heaviest SHRA/SHSN will
occur tonight and Monday morning with local VIS 2-4SM at lower
elevations below the clouds and 0-2SM in the mountains. Conditions
will improve for much of the region after Monday morning, although
low VIS due to clouds pushing up against the mountains will likely
continue through Monday afternoon.
NWS San Diego is aware of limited communications of observations
from KTRM since January 8th. We are working with the FAA to address
this issue.
&&
.MARINE...
Low pressure aloft will bring occasional showers through Tuesday,
with an isolated thunderstorm possible this afternoon through
Monday. Thunderstorms will be accompanied by lightning and could
contain locally gusty and erratic winds. Weak to occasional moderate
onshore flow will prevail most of this week. A Marine Weather
Statement is in effect and contains more details.
&&
.BEACHES...
There is a 15% chance of a thunderstorm at any beach location
through Monday. Cloud-to-ground lightning strikes and brief gusty
winds could accompany any thunderstorm that develops.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Storm Warning until 4 PM PST Monday for Riverside County
Mountains-San Bernardino County Mountains.
Winter Weather Advisory until 4 PM PST Monday for San Diego
County Mountains.
Winter Weather Advisory from 10 PM this evening to 10 AM PST
Monday for Apple and Lucerne Valleys.
PZ...None.
&&
$$
PUBLIC...APR
AVIATION/MARINE...99