Weather Prediction Center

National Oceanic and Atmospheric Administration

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
412 PM EDT Tue Oct 14 2025

Valid 00Z Wed Oct 15 2025 - 00Z Fri Oct 17 2025

...A Marginal Risk of Excessive Rainfall remains for New Mexico for
Wednesday ...

...Winter weather and mountain snowfall are likely in the northern
Rockies...

... Isolated severe weather across the Southern Rockies and Central High
Plains for Wednesday and Thursday...

An impressive closed upper-level low has moved into Southern California
today and has prompted several flash flooding and severe weather local
storm reports. Additionally, the Sierra Nevada has begun to see snowfall
accumulations and will continue to see Winter Storm impacts into tomorrow
morning as snowfall amounts are forecast to reach around a foot with
locally higher amounts possible. This "bowling ball of energy" will
continue to traverse the Mountain West on Wednesday and then start to
enter the Plains by late week. Meanwhile, the central part of the country
will be segmented by a stationary front across the Plains and Midwest that
will lift as a warm front in the middle of the week and bring milder
conditions across the area. The Northeast should see weather improve
starting today and especially by tomorrow as a "backdoor" cold front
pushes through the area and cool high pressure settles into the region.

The active Southwest will continue into tomorrow as a surface low pressure
and trailing cold front traverse Arizona and New Mexico. Combinations of
large scale ascent ahead of the trough, sufficient surface instability,
and saturated soils (low flash flood guidance) will support a Marginal
Risk for Excessive Rainfall and isolated flash flooding across the San
Juan and Santo de Cristo Mountains. For Thursday, there has been another
Marginal Risk for Excessive Rainfall added to eastern Montana and western
North Dakota as moisture and instability creep northwards in association
with the western trough and a developing surface low in the northern
Plains.

There will be enough instability and shear for organized thunderstorms
across New Mexico for Wednesday and across the Central/High Plains
Wednesday and Thursday. The Storm Prediction Center has central New Mexico
to southern Colorado in a Marginal Risk (level 1/5). Hail will be the
biggest threat in thunderstorms that do develop as bulk shear will be
fairly high, but an isolated strong wind gust or two will also be
possible. Eastern Wyoming into western Kansas and South Dakota will also
see isolated thunderstorms capable of producing hail. A similar weather
pattern will be in place on Thursday across the Central Plains with the
possibility of isolated supercells containing hail.

Back to the start of the cool season, the Mountain West will see snow in
the higher elevations for Wednesday and Thursday in the higher elevations.
A Winter Weather Advisory is in effect for the Teton and Gros Ventre
mountain ranges beginning Wednesday night into Thursday. The current
Advisory calls for 1-4 inches around 7-9k feet and around 6-10 inches in
the higher mountain ranges. This is a reminder to prep vehicles for winter
weather travel as the cool season begins.

The other storyline worth mentioning is the anomalous warmth across the
south and central part of the countries. High temperatures will warm into
the middle 80s for states like Illinois and Missouri. This will be around
20 degrees warmer than typical for Mid-October. The South will continue to
be mostly clear and mild as mid-level ridging continues over the region.
Afternoon temperatures should generally reach the middle to upper 80s with
low temperatures mostly in the 60s for this week.


Wilder


Graphics available at
https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
245 PM EDT Tue Oct 14 2025

Valid 12Z Fri Oct 17 2025 - 12Z Tue Oct 21 2025


...Guidance/Predictability Assessment...

Model guidance remains in relatively good agreement during the
medium range period, handling the evolution of several large scale
trough/ridge features across the CONUS reasonably well despite a
highly amplified 500mb flow pattern. Only minor differences were
noted for Days 3 and 4, so a composite blend of the 00Z EC, 00Z
UKMET, 00Z CMC and 06Z GFS deterministic runs sufficed to begin the
period. However, larger discrepancies started cropping up by Day
5, most notably with the evolution of a potent Pacific trough that
is progged to push inland over British Columbia and the Pacific
Northwest late in the weekend into early next week. While the
EC/GFS/UKMET all had similar solutions depicting the trough digging
deeper along the West Coast, the CMC shows the trough becoming
completely sheared apart as it moves across the Pacific Northwest.
As a result of being much faster and flatter than consensus, the
00Z CMC was removed from the blend starting on Day 5 and was not
considered for the remainder of the forecast. To compensate, more
weighting was placed on the EPS and GEFS ensemble means, which
ultimately made up slightly more than 50% of the blend for Day 6
and 7. The greater weighting of the ensemble means resulted in a
more stable forecast that preserved continuity while reducing some
of the timing and positional differences that are typical for the
latter half of the medium range forecast period.

...Weather/Hazards Highlights...

Lingering upper troughing in Atlantic Canada (tied to the current
coastal storm) still supports continued unsettled and borderline
windy conditions over New England through late week with cooler
than normal temperatures that will slowly moderate with time.

The troughing and associated surface frontal boundary in the West
will promote cool and showery weather (with some snow at higher
elevations) over the northern/central Rockies to start, with
broader light rain in advance of the surface low that is poised to
track from the northern Plains into southern Canada. As the
attendant cold front passes through the Plains, moisture will
increase in advance of it through the Mid-MS Valley where rainfall
could increase by Saturday. The WPC Day 5/Saturday Excessive
Rainfall Outlook (ERO) maintains a Marginal Risk area centered over
the Mid-South given favorable upper support, moisture and
instability. Given the somewhat progressive nature of the upper-
level and surface features, this rainfall will continue to spread
eastward into the Northeast later Sunday into early next week,
particularly near and along the track of a deepening/consolidating
low pressure system (and into the Southeast ahead of the cold
front). Temperatures will be mild ahead of the cold front with
highs well into the 70s/80s Friday from the Corn Belt to the Ozarks
with 90s across South Texas.

By late next weekend into early next week, another deepened system
will enter the Pacific Northwest/West Coast with another round of
valley rain and higher mountain snow that will then dig and spread
across the West and downstream to the Rockies. The Day 5/Saturday
ERO maintains a coastal Washington Marginal Risk area given a
favorable guidance signal.

Miller/Schichtel


Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw

Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
241 AM EDT Tue Oct 14 2025

Valid 00Z Wed 15 Oct 2025 - 00Z Wed 22 Oct 2025


Guidance solutions continue to seem reasonably well clustered,
bolstering overall forecast confidence. Light trades may
significantly increase mid-later week into next weekend as high
pressure settles to the northeast and north of the state.
Meanwhile, an unsettling upper low/trough now digging south toward
the state early may linger in vicinity mid-late week before
shifting slowly westward. Pooling moisture and increasing lift
favor increased chances for some local downpours and a few
thunderstorms in a wet period to monitor, especially for the
western portion of the islands.


Schichtel

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
855 PM EDT Tue Oct 14 2025
Day 1
Valid 01Z Wed Oct 15 2025 - 12Z Wed Oct 15 2025

...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL OVER PORTIONS
OF NEW MEXICO...

A Marginal risk will continue into the overnight hours across
portions of central NM. A general lack of forcing and some low to
mid level capping has kept convection fairly isolated to this
point across the area. High res guidance suggests we could see an
uptick in convective coverage tonight as the nocturnal increase in
southeasterly low level flow increases convergence. Still quite a
bit of CAPE present over south central NM, generally 1500-2500
j/kg, and so if convection is able to develop heavy rainfall rates
are likely. Most cells should be quick enough moving to limit the
duration of heavier rain, although localized flash flooding is
still possible. Farther northeast where we had a Slight risk the
combination of lower instability and quick cell motions should
keep the flash flood risk down, although slightly higher convective
coverage here still warrants a Marginal risk for possible isolated
flash flooding.

The risk areas were removed over CA as the heaviest rainfall has
ended. Still could see some locally higher rates near the mid level
low over central CA, but even these rates are forecast to be on
the decline after 03z.

Chenard

Day 1 threat area: www.wpc.ncep.noaa.gov/qpf/94epoints.txt

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
855 PM EDT Tue Oct 14 2025
Day 2
Valid 12Z Wed Oct 15 2025 - 12Z Thu Oct 16 2025

...THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL OVER PORTIONS
OF THE CENTRAL AND SOUTHERN ROCKIES...

...2030Z Update...

No changes were made to the Marginal Risk area which includes
portions of southern Colorado and northern New Mexico. The axis of
heaviest rainfall associated with the right entrance region of a
120 kt jet and approach of a deep cutoff low remains along the San
Juans and Sangre de Cristo mountains. Deep south/southwesterly flow
is keeping the expected heaviest precipitation on the south and
west facing slopes of those ranges, and has not moved from previous
forecasts. Thus, this supports keeping the highlighted area the
same with few changes.

An expansive precipitation shield will extend from northern Nevada
northeast to the northern Plains. Locally heavy rain and snow may
impact the higher elevations around Yellowstone/the Tetons, but
overall precipitation amounts will be low enough in these areas
that a flash flooding risk is not supported.

Wegman

...Rockies...

The evolution of the longwave pattern across the Western CONUS will
lead to the development of a surface low over the Inter-Mountain
West with a trailing cold front anticipated to move west to east
over the Four Corners into the Continental Divide. The combination
of continued ascent within the RER of a vacating jet streak to the
north and the frontal approach will lead to one last instance of
organized precip within the San Juans down into the Sangre de
Cristos. Considering the nature of the pattern bookending quite an
active stretch within the aforementioned areas, the threat for
flash flooding will lie within the MRGL risk threshold despite the
lack of stronger instability that tends to necessitate a greater
flash flood potential. Antecedent conditions will trend very wet
overall leading to lower FFG's across the terrain of northern NM
into southwestern CO. Totals within guidance are currently running
between 0.5-1" with some locally higher amounts based in the
individual deterministic. The greatest threat for higher totals
lies within the San Juans, an area that has been the benefactor of
significant rainfall totals the past 4 days. This will likely be
the greatest area of focus for the setup, albeit a threat that will
be closer to a 6-8 hr. window as the front approaches. The previous
MRGL risk was generally maintained, but trimmed up the southern
edge as model trends point to limited potential for heavier
rainfall south of the Sangre de Cristos in northern NM.

Kleebauer


Day 2 threat area: www.wpc.ncep.noaa.gov/qpf/98epoints.txt

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
855 PM EDT Tue Oct 14 2025
Day 3
Valid 12Z Thu Oct 16 2025 - 12Z Fri Oct 17 2025

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ALONG MUCH OF THE
MONTANA/NORTH DAKOTA BORDER...

...2030Z Update...

...Northern Plains...

The wraparound/comma-head region of a deepening low that will track
north up the Plains will concentrate its longest duration rainfall
along the Montana-North Dakota border Thursday through Thursday
night. Instability will be minimal, however as with most developing
lows, there will still be some on the dry slot-comma-head interface
that will locally increase rainfall rates across this otherwise
typically dry area. Thus, think there could be some isolated flash
flooding impacts, particularly in any poor-drainage areas across
portions of eastern Montana and western North Dakota. Nonetheless,
expect these instances to be quite isolated, and this a low-end and
low-confidence Marginal Risk.

Wegman

Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
245 PM EDT Tue Oct 14 2025


Lingering upper troughing in Atlantic Canada (tied to the current
coastal storm) still supports continued unsettled and borderline
windy conditions over New England through late week with cooler
than normal temperatures that will slowly moderate with time.

The troughing and associated surface frontal boundary in the West
will promote cool and showery weather (with some snow at higher
elevations) over the northern/central Rockies to start, with
broader light rain in advance of the surface low that is poised to
track from the northern Plains into southern Canada. As the
attendant cold front passes through the Plains, moisture will
increase in advance of it through the Mid-MS Valley where rainfall
could increase by Saturday. The WPC Day 5/Saturday Excessive
Rainfall Outlook (ERO) maintains a Marginal Risk area centered over
the Mid-South given favorable upper support, moisture and
instability. Given the somewhat progressive nature of the upper-
level and surface features, this rainfall will continue to spread
eastward into the Northeast later Sunday into early next week,
particularly near and along the track of a deepening/consolidating
low pressure system (and into the Southeast ahead of the cold
front). Temperatures will be mild ahead of the cold front with
highs well into the 70s/80s Friday from the Corn Belt to the Ozarks
with 90s across South Texas.

By late next weekend into early next week, another deepened system
will enter the Pacific Northwest/West Coast with another round of
valley rain and higher mountain snow that will then dig and spread
across the West and downstream to the Rockies. The Day 5/Saturday
ERO maintains a coastal Washington Marginal Risk area given a
favorable guidance signal.

Miller/Schichtel

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
245 PM EDT Tue Oct 14 2025


Lingering upper troughing in Atlantic Canada (tied to the current
coastal storm) still supports continued unsettled and borderline
windy conditions over New England through late week with cooler
than normal temperatures that will slowly moderate with time.

The troughing and associated surface frontal boundary in the West
will promote cool and showery weather (with some snow at higher
elevations) over the northern/central Rockies to start, with
broader light rain in advance of the surface low that is poised to
track from the northern Plains into southern Canada. As the
attendant cold front passes through the Plains, moisture will
increase in advance of it through the Mid-MS Valley where rainfall
could increase by Saturday. The WPC Day 5/Saturday Excessive
Rainfall Outlook (ERO) maintains a Marginal Risk area centered over
the Mid-South given favorable upper support, moisture and
instability. Given the somewhat progressive nature of the upper-
level and surface features, this rainfall will continue to spread
eastward into the Northeast later Sunday into early next week,
particularly near and along the track of a deepening/consolidating
low pressure system (and into the Southeast ahead of the cold
front). Temperatures will be mild ahead of the cold front with
highs well into the 70s/80s Friday from the Corn Belt to the Ozarks
with 90s across South Texas.

By late next weekend into early next week, another deepened system
will enter the Pacific Northwest/West Coast with another round of
valley rain and higher mountain snow that will then dig and spread
across the West and downstream to the Rockies. The Day 5/Saturday
ERO maintains a coastal Washington Marginal Risk area given a
favorable guidance signal.

Miller/Schichtel

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
302 PM EDT Tue Oct 14 2025

Valid 00Z Wed Oct 15 2025 - 00Z Sat Oct 18 2025

...Sierra through the Northern Rockies...
Days 1-3...

An impressive closed low will reach peak intensity tonight just
west of San Francisco before beginning to advect northeast on
Wednesday. NAEFS height anomalies show 500mb percentiles dropping
to below the 0.5th percentile rank in the CFSR climatology before
slowly filling as the entire longwave trough moves across the Great
Basin and then into the Rockies by Thursday. This trough is then
progged to become an open wave by Friday morning as it exits into
the Northern High Plains.

Despite the slow weakening, impressive deep layer ascent will
expand downstream of this evolution, as height falls, PVA, and a
strengthening jet streak overlap to produce surface cyclogenesis.
This low pressure will likely move steadily northeast across the
Great Basin through Wednesday night before occluding, with
secondary lee-cyclogenesis in CO likely on Thursday.

Accompanying the primary closed low tonight into Wednesday,
impressive moisture advection/IVT will push inland reflected by
moderate probabilities (>60%) for 500 kg/m/s pushing into CA and
NV. With snow levels falling beneath the upper low and behind the
cold front accompanying the surface low, this will result in heavy
snowfall, generally above 5500-6000 ft in the Sierra and into the
terrain of Nevada where WPC probabilities for 8+ inches of snowfall
are as high as 50%, with locally 12" or more possible (30%) in the
Ruby Mountains of Nevada through D1.5. Briefly heavy snowfall
rates exceeding 1"/hr are possible (30-50% chance) in the Sierra
and higher terrain of Nevada D1 thanks to elevated instability and
favorably placed ascent into the DGZ. With SLRs likely to be
modest, this will result in at least some moderate impacts at
elevated mountain passes tonight and Wednesday.

Thereafter, the intensity of the snowfall and the impacts should
decrease in response to weaker overall ascent, but heavy snow is
likely to spread into parts of UT and WY, including the Wasatch,
Uintas, and ranges around Yellowstone NP. Snow levels moderate at
this time to, generally hovering around 7000 ft, but steep lapse
rates beneath the mid-level trough could allow for some lowering to
around 6000 ft during times of heavier snowfall as theta-e lapse
rates fall to 0C/km at times suggesting convective snow shower
potential, especially during periods of pronounced upslope into
terrain features. WPC probabilities for 8+ inches on D2 are
moderate to high in the Tetons, Wind Rivers, and highest terrain
surrounding Yellowstone NP, but pass level snow should remain below
6 inches. On D3, snow wanes quickly as the system ejects to the
east, leaving just minimal additional accumulation across the
higher terrain of NW WY.

The probability of significant freezing rain across CONUS is less
than 10 percent.


Weiss

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
245 PM EDT Tue Oct 14 2025

Valid 12Z Fri Oct 17 2025 - 12Z Tue Oct 21 2025


...Guidance/Predictability Assessment...

Model guidance remains in relatively good agreement during the
medium range period, handling the evolution of several large scale
trough/ridge features across the CONUS reasonably well despite a
highly amplified 500mb flow pattern. Only minor differences were
noted for Days 3 and 4, so a composite blend of the 00Z EC, 00Z
UKMET, 00Z CMC and 06Z GFS deterministic runs sufficed to begin the
period. However, larger discrepancies started cropping up by Day
5, most notably with the evolution of a potent Pacific trough that
is progged to push inland over British Columbia and the Pacific
Northwest late in the weekend into early next week. While the
EC/GFS/UKMET all had similar solutions depicting the trough digging
deeper along the West Coast, the CMC shows the trough becoming
completely sheared apart as it moves across the Pacific Northwest.
As a result of being much faster and flatter than consensus, the
00Z CMC was removed from the blend starting on Day 5 and was not
considered for the remainder of the forecast. To compensate, more
weighting was placed on the EPS and GEFS ensemble means, which
ultimately made up slightly more than 50% of the blend for Day 6
and 7. The greater weighting of the ensemble means resulted in a
more stable forecast that preserved continuity while reducing some
of the timing and positional differences that are typical for the
latter half of the medium range forecast period.

...Weather/Hazards Highlights...

Lingering upper troughing in Atlantic Canada (tied to the current
coastal storm) still supports continued unsettled and borderline
windy conditions over New England through late week with cooler
than normal temperatures that will slowly moderate with time.

The troughing and associated surface frontal boundary in the West
will promote cool and showery weather (with some snow at higher
elevations) over the northern/central Rockies to start, with
broader light rain in advance of the surface low that is poised to
track from the northern Plains into southern Canada. As the
attendant cold front passes through the Plains, moisture will
increase in advance of it through the Mid-MS Valley where rainfall
could increase by Saturday. The WPC Day 5/Saturday Excessive
Rainfall Outlook (ERO) maintains a Marginal Risk area centered over
the Mid-South given favorable upper support, moisture and
instability. Given the somewhat progressive nature of the upper-
level and surface features, this rainfall will continue to spread
eastward into the Northeast later Sunday into early next week,
particularly near and along the track of a deepening/consolidating
low pressure system (and into the Southeast ahead of the cold
front). Temperatures will be mild ahead of the cold front with
highs well into the 70s/80s Friday from the Corn Belt to the Ozarks
with 90s across South Texas.

By late next weekend into early next week, another deepened system
will enter the Pacific Northwest/West Coast with another round of
valley rain and higher mountain snow that will then dig and spread
across the West and downstream to the Rockies. The Day 5/Saturday
ERO maintains a coastal Washington Marginal Risk area given a
favorable guidance signal.

Miller/Schichtel


Additional 3-7 Day Hazard information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php

WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation forecast (QPF), excessive rainfall
outlook (ERO), winter weather outlook (WWO) probabilities, heat
indices, and Key Messages can be accessed from:

https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/#page=ero
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml
https://www.wpc.ncep.noaa.gov/#page=ovw