Weather Prediction Center

National Oceanic and Atmospheric Administration

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
258 PM EST Sat Jan 28 2023

Valid 00Z Sun Jan 29 2023 - 00Z Tue Jan 31 2023

...Heavy snow over parts of the Great Lakes...

...There is a Slight Risk of excessive rainfall over parts of the Central
Gulf Coast into the Southeast...

...Pockets of rain/freezing rain over parts of the Southern Plains to the
Great Lakes...

...Temperatures will be 15 to 35 degrees below average over parts of the
Northern/Central Rockies and High Plains...

A wave of low pressure over the Middle Mississippi Valley will move
northeastward to off Northern New England Coast by Monday evening. North
of the low, snow will develop over parts of the Middle Mississippi Valley
on Saturday evening. Moderate to heavy snow will develop over parts of the
Great Lakes overnight Saturday. On Sunday, light to moderate snow will
develop over parts of Northern New England and northern New York State.
Light snow will continue over the Great Lakes, especially downwind from
the lakes, on Sunday, too.

In addition, moisture from the Gulf of Mexico will stream northward over
the Western Gulf Coast/Lower Mississippi Valley into the Ohio Valley. The
moisture will produce rain and embedded thunderstorms over parts of the
Western Gulf Coast and Lower Mississippi Valley from Saturday evening into
early Sunday. Rain will develop over parts of the Middle Mississippi
Valley that will expand into the Ohio Valley overnight Saturday into
Sunday. The rain will then expand into parts of the Northeast and
Mid-Atlantic on Sunday afternoon.

Along the rain/snow line, pockets of light rain/freezing rain will develop
from the Middle Mississippi Valley into the Great Lakes from Saturday
evening into Sunday evening. On Monday, light snow will continue over
parts of the Northeast into the Central Appalachians. The snow will result
in reduced visibility and the snow/ice will produce hazardous driving
conditions.

Meanwhile, cold high pressure over the Northern Plains will move southward
to the Central Plains by Monday. The cold air will bring temperatures 15
to 35 degrees below average over parts of the Northern/Central Rockies and
High Plains. As the cold air moves southward, the pockets of rain/Freezing
rain will extend from parts of the Southern Plains into the Ohio Valley
from Sunday evening into Monday.

Furthermore, the moisture will aid in producing showers and thunderstorms
with heavy rain over parts of the Western/Central Gulf Coast and part of
the Southeast on Sunday. Therefore, the WPC has issued a Slight Risk of
excessive rainfall with these thunderstorms over the region from Sunday
into Monday morning. The associated heavy rain will create mainly
localized areas of flash flooding, with urban areas, roads, and small
streams the most vulnerable.

Additionally, some of the thunderstorms will be strong to severe.
Therefore, the SPC has issued a Marginal Risk of severe thunderstorms over
parts of the Western/Central Gulf Coast and part of the Southeast from
Sunday into Monday morning. The hazards associated with these
thunderstorms are frequent lightning, severe thunderstorm wind gusts,
hail, and a few tornadoes. The threat of excessive rainfall and severe
thunderstorms ends on Monday.

Moreover, an upper-level low will develop over Northern California on
Sunday and move southward to Southern California and Northwestern Mexico
by Monday evening. A front associated with the energy will also move
southward from the Pacific Northwest to the Southwest by Monday evening.
The system will produce coastal rain and higher-elevation snow over the
Pacific Northwest on Saturday evening into Sunday morning. The coastal
rain and higher-elevation snow will move into California on Sunday.
Furthermore, snow will develop over parts of the Northern Intermountain
Region and Northern Rockies from Saturday evening into Sunday morning. On
Sunday, the snow will move into the Great Basin and Central Rockies and
parts of the Southwest on Monday. The snow will result in reduced
visibility and hazardous driving conditions.


Ziegenfelder

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

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
154 PM EST Sat Jan 28 2023

Valid 12Z Tue Jan 31 2023 - 12Z Sat Feb 04 2023

...Notable precipitation likely next week including heavy rain in
the south-central to southeastern U.S. with freezing rain/snow on
the northern side...

...Dangerously cold temperatures and wind chills are forecast
across the Northern Plains and Upper Midwest at times through next
week...


...Overview...

It remains the case that periods of troughing are likely through
much of the northern U.S. next week extending from a persistent
Hudson Bay closed low, leading to colder than average temperatures
for much of the northern tier. The cold temperatures and wind
chills could be most hazardous for the north-central U.S. during
the first half of the week, with significant cold extending into
the Northeast for the latter half of next week. Meanwhile a
ridge/upper high over Cuba during much of next week should keep
the Southeast warmer than normal. Between these upper-level
features and temperature regimes, expect active weather as a
southern stream upper trough/low ejects from the Southwest Tuesday
(with some rain and higher elevation snow there) and tracks across
the central/southern tier of the CONUS. This combined with a
couple wavy fronts along with periods of Gulf inflow will support
a couple of significant precipitation events with possibly heavy
rain to the south/southeast and wintry weather in the colder air.
Later in the week, the West Coast may see increasing precipitation
chances with the approach of an eastern Pacific upper trough.


...Guidance/Predictability Assessment...

The WPC medium range product suite is primarily derived from a
composite blend of reasonably well clustered guidance from the 00
UTC GFS/ECMWF/UKMET/Canadian valid Tue-Thu in a pattern with above
normal predictability. The 06 UTC GFS became less aligned with the
progression of embedded systems, especially by later next week,
but 12 UTC guidance has trended back more in line with the
composite solution that also has decent ensemble and National
Blend of Models support. Despite overall flow similarities, some
minority insertion of GEFS/ECMWF ensemble mean guidance into the
WPC blend seemed reasonable by Friday/next Saturday to mitigate
growing shortwave differences. This solution maintains decent
overall WPC product continuity.


...Weather/Hazard Highlights...

The upper trough/low atop the Southwest on Tuesday could produce
some rain and higher elevation snow there lingering from the short
range period. Then this feature and the overall trough and other
shortwaves will provide support for frontal boundaries with waves
of low pressure through the south-central to southeastern U.S.,
which combined with Gulf moisture streaming in could lead to
multiple rounds of precipitation. On the southern side locally
heavy rain is expected, which could cause localized flooding
especially at times when there is sufficient instability for
higher rain rates. At this time a Slight Risk is in place in WPC's
experimental Excessive Rainfall Outlook for day 5/Wednesday given
good upper-level support, namely excellent difluence/divergence in
the right entrance region of the jet, and somewhat wet antecedent
conditions. The latest rendition has been shifted slightly
westward from WPC overnight continuity in line with guidance
trends. QPF in this region has increased in both the NBM and even
slightly more from WPC given better 00 UTC model agreement and
slightly slower trend. Then on the northern side of the
precipitation chances, there is potential for snow across parts of
the southern half of the Plains and Mississippi Valley into the
Ohio/Tennessee Valleys and the Mid-Atlantic at times, but low
confidence continues in the specifics. This is also a pattern that
could support freezing rain with ice accumulations with the cold
air in place at the surface and potential for warm moist air to
flow overtop it. The placement of heaviest rain, freezing rain,
and snow all remain in question as small-scale details like
surface frontal positions and late week shortwave specifics remain
uncertain. Elsewhere, periods of lake effect snow are possible to
the lee of the northern/eastern Great Lakes. Some light
precipitation is possible in the Northwest on Tuesday, but more
limited to western Washington by Wednesday. The West Coast could
see increasing precipitation chances by the latter half of the
week but with uncertainty over the southward extent and amounts.
Currently the best potential for at least some rain/mountain snow
is over the Pacific Northwest with moisture possibly extending as
far south as northern California.

Very cold conditions over the north-central U.S. during the short
range period will continue into next week, in the wake of a strong
cold front producing a surge of arctic air. Highs in the single
digits and even at or below zero are possible in the Dakotas into
Minnesota while bitterly cold lows combined with wind will produce
dangerous wind chills. Much below normal temperatures should
extend across much of the central U.S. through midweek especially,
as well as across much of the Interior West with temperatures
15-25F below normal through Tuesday with gradual moderation
thereafter. Meanwhile the far Southeast and Florida Peninsula
should see the most consistent above average temperatures, with
highs 10-15F above average and plus 10-20F anomalies for lows. A
few record highs are possible Tuesday-Wednesday. While the
western/central U.S. moderates later in the week, the East will
trend somewhat colder with New England possibly seeing highs
10-20F below normal by next Friday.

Tate/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, experimental excessive rainfall
outlook, winter weather outlook probabilities and heat indices are
at:

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

Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
259 AM EST Sat Jan 28 2023

Valid 00Z Sun Jan 29 2023 - 00Z Sun Feb 05 2023

A rather wet weekend and early next week are in store for much of
Hawaii. A surface trough currently causing heavy rainfall and
flooding across Maui will remain across the islands and gradually
drift west over the next couple days, helping to focus moisture
and showers. Model guidance such as the HREF indicates that the
main axis of showers could drift atop Molokai and perhaps as far
west as Oahu Saturday into Sunday, and the Honolulu Forecast
Office has a Flash Flood Watch in place from Oahu to Maui for the
potential of continued training showers. Meanwhile aloft, a closed
low is in place centered around 40N, and its trough is expected to
lengthen, with upper-level energy drifting southward over the
state and closing off a subtropical upper low by around 12Z Monday
perhaps centered just to the southwest of Hawaii. This will draw
in deep tropical moisture as well as provide instability with a
removed inversion given the lowering heights aloft, for even more
support for widespread rain and thunderstorms. Moisture levels
will be quite high with precipitable water values showing to be
over the 90th or 95th percentiles. Recent ECMWF runs hit the Big
Island particularly hard with heavy precipitation around Monday,
while GFS runs show the heaviest totals offshore, but the
potential is certainly there for heavy amounts across much of the
state. More instances of flooding are certainly possible. Kauai
may see a wetter trend by Sunday and especially Monday, but
regardless will start out on the backside of the upper trough/low
and could see continued breezy north-northeasterly winds through
early next week. Models generally indicate that the closed upper
low should drift a bit west away from the state around
Tuesday-Wednesday but be slow to erode. This would allow for some
above average moisture to be present even through midweek and
beyond, but likely to a lesser extent. Meanwhile more typical
trade winds are forecast to set up at the surface, so a wet trade
wind pattern looks to be in store through the latter part of next
week.

Tate

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
1058 AM EST Sat Jan 28 2023

Day 1
Valid 12Z Sat Jan 28 2023 - 12Z Sun Jan 29 2023

The probability of rainfall exceeding flash flood guidance is less
than 5 percent. Per collaboration with WFOs HGX, LCH, and SHV,
have opted to remove the Marginal Risk that was in place across
the Upper TX Coast-Eastern TX into western and northern LA.
Guidance trends, including the 12Z CAMs, have really backed off on
the timing of the more organized convection (and setup more
favorable for training) along/hear the Gulf Coast, i.e. mainly
after 12Z. 12Z HREF exceedance probabilities have followed suit as
well, with probs of >1"/hr rates no higher than 30-35% through 12Z
Sun (where current 01 hr FFG is >2"/hr).

Hurley


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

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
219 PM EST Sat Jan 28 2023

Day 2
Valid 12Z Sun Jan 29 2023 - 12Z Mon Jan 30 2023

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE SOUTHEAST AND CENTRAL GULF COAST...

2000 UTC Update -- Very few notable changes with the latest
forecast update, based on the latest (12Z) guidance QPF trends
(deterministic and probabilistic). A slowly strengthening upper
level jet streak will put much of the Slight Risk area in the
right entrance region of the jet streak. Small disturbances riding
along the jet may locally trigger convection across the Slight
Risk area as they race northeastward with the jet. Much of the
dynamics for this rainfall event will be in the lower levels of
the atmosphere as broad southerly flow covering the whole of the
Gulf peaks in intensity as far as the LLJ is concerned over
southern LA midday Sunday. The LLJ will reintensify as the
convection moves east across the FL Panhandle and southern GA
Sunday night, including values as strong as 60 kt over the FL
Panhandle, far SE AL and far SW GA. Thus, expect convection to be
quite efficient at producing heavy rainfall as it moves eastward
Sunday and Sunday night. To be sure, the greatest threat within
the Slight Risk area will be across western areas from TX through
MS, with slightly lower threats for flash flooding further east.
Peak storm total rainfall may exceed 3 inches in portions of
southern LA through southern MS-AL-GA, within a more favorable
thermodynamic environment with PWs close to 1.75" along with
better deep-layer instability (MUCAPEs 500-1000 J/kg). The 12Z
HREF in fact indicates clusters of 40-60+ percent probs of
>3"/24hrs within the Slight Risk, with the highest probs (60-80%)
just north of the Upper TX Coast through much of southwest LA.
There continues to be good model consensus however that the axis
of heaviest rain will remain north of New Orleans.

While main-stem rivers and soil moisture across all of SC remain
high, with a few of the main-stems in flood stage, the flashier
creeks and smaller tributaries are quite dry, and are likely to
handle the 1 to 2 inches of rain expected during the overnight
hours Sunday night in this area. Model guidance is in excellent
agreement on the swath of heaviest rain falling in the new Slight
Risk area. Additional trimming of the Slight Risk was done on the
western end with good agreement that metro Houston may largely
miss out on the heaviest rain, and also that the heaviest rain
will miss the Mississippi River Delta to the north. Confidence
wasn't quite there to remove Houston from the Slight given some
variability, but extreme southeastern LA was downgraded to a
Marginal with this update.

Hurley/Wegman

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

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
221 PM EST Sat Jan 28 2023

Day 3
Valid 12Z Mon Jan 30 2023 - 12Z Tue Jan 31 2023

The probability of rainfall exceeding flash flood guidance is less
than 5 percent.

Hurley

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

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
124 PM EST Sat Jan 28 2023

Valid 00Z Sun Jan 29 2023 - 00Z Wed Feb 01 2023

...The West...
Days 1-3...

Expansive mid-level trough will persist across much of the CONUS
this weekend before amplifying across the West Monday and Tuesday.
This amplification will be in response to an impressive 500mb low
digging southward along the CA coast Sunday night into Monday,
with height anomalies approaching -3 standard deviations at 500mb
according to the NAEFS ensemble tables Monday morning. At the same
time, a northern stream shortwave with less amplitude will be
spinning across the Northern Plains and into the Great Lakes,
resulting in a positively tilted longwave trough from the Great
lakes into the Southwest by the start of D3 /Monday night./ This
evolution will dislodge a surface cold front, pushing it southward
across nearly the entirety of the Intermountain West this period,
ending up south of the Four Corners by Tuesday evening. Waves of
low pressure along this front will help enhance lift already
expected to be significant thanks to the height falls, favorable
position of the strengthening subtropical jet streak, and
post-frontal upslope flow. Additionally, moisture will slowly
begin to increase across the region as SW flow around the
sharpening trough advects Pacific moisture eastward, especially
into the Four Corners, although PW anomalies are progged to remain
just below normal to near normal for early February.

The overlap over forcing and moisture will result in periods of
moderate to heavy snow, generally along and ahead of the southward
advancing cold front. Snow levels ahead of the front will
generally be 2000-3000 ft, and while some snow is likely behind
the boundary as snow levels crash rapidly to the surface,
additional accumulation at that point appears to be minimal, with
most accumulations occurring in the terrain and ahead of the
boundary. Still, overall transient features and modest moisture
should limit snowfall overall. For D1, the heaviest snow is likely
across the northern Sierra, northern Wasatch, and into the CO
Rockies, near the Park Range, where WPC probabilities for more
than 6 inches are 50-80%, and locally 12 inches is possible near
the Park Range. For D2, the axis of heavy snow shifts south with
WPC probabilities for more than 6 inches above 30% reaching the
San Bernadinos/San Gabriels, and extending into the southern
Wasatch, and continuing a second day across much of the CO
Rockies. By D3, the focus shifts to the Mogollon Rim where WPC
probabilities for more than 6 inches are 20-40%. Although much
lighter, as snow levels crash behind the front, some snowfall
accumulations are possible into the lower terrain and
valleys/passes, including Tejon, Cajon, and Tehachapi passes where
up to 1 inch of snow is possible.


...Upper Midwest, Great Lakes, and Northeast...
Days 1-3...

A shortwave moving across the Central Plains today will begin to
shear out an accelerate to the northeast tonight through Sunday as
it becomes entrenched in increasingly confluent flow north of a
bulging ridge over the Southeast. The associated surface low
beneath this impulse will begin to weaken as it shifts northeast
along the low-level baroclinic zone, which will also be pushing
northward downstream as WAA surges into the Mid-Atlantic and
Northeast on Sunday. Although ascent through upper ventilation in
the LFQ of an expanding jet streak will remain favorable, overall
forcing will begin to wane Sunday, with the low-level fgen driving
the heaviest snowfall also expected to collapse. The low tracking
northeast will allow the warm nose to surge as far north as lower
Michigan, Upstate NY, and Central New England, resulting in a band
of moderate to heavy snow from near Milwaukee, WI, through the St.
Lawrence Valley and Northern Adirondacks on D1, extending into
Northern Maine on D2. Modest forcing and near climo SLR should
allow for some snow rates nearing 1"/hr at times as everything
advects eastward, which should accumulate to several inches along
this max stripe of snow. WPC probabilities along the fgen band are
40-80% for more than 4 inches, with locally more than 6 inches
likely, especially in the L.P. of MI and the NW corner of ME.

A secondary elongated shortwave will move through the broad
eastern CONUS trough Monday night into Tuesday, leading to further
lowering of heights and increasing CAA on W/NW flow in its wake.
The column becomes quite cold behind this next impulse, which will
lead to steep lapse rates across the Great Lakes, albeit with
modest inversion heights. This suggests at least periods of heavy
LES in the favored W/NW snow belts, but rates may be tempered a
bit due to the cold column resulting in just modest SLRs for LES.
WPC probabilities for LES exceeding 4 inches are around 20% for
the Keweenaw Peninsula and near Whitefish Point, and 30-40% for
the Tug Hill Plateau.


...North Texas through the Mid-South...
Day 3...

A closed mid-level low moving into the Southwest from the Pacific
on Tuesday will yield downstream height falls into the Four
Corners and Southern Plains, but a downstream ridge over the
Southeast will expand through this evolution, leading to
impressively confluent mid-level flow into the MS VLY and Southern
Plains. There is quite a bit of disagreement among the
deterministic models as to how this will evolve on Tuesday, but
there appears to be an increasing threat for an overrunning
mixed-precipitation event from central TX through the Ozarks and
into the TV VLY D3 and even beyond this forecast period. While the
strong cold front is likely to surge southward, and moisture will
begin to arc northward on SW flow out of the Pacific and Gulf of
Mexico, there is uncertainty into how far the moisture will stream
to get into a region favorable for freezing rain due to
sub-freezing wet bulb surface temps with above freezing mid-level
temps along the warm nose. The GFS suggests precip will struggle
to surge far enough north for significant ice accretion, while the
EC/CMC and their ensembles are much more aggressive. Examination
of the DESI clusters indicates more support for the CMC/EC camp
than the GFS, and will lean more in that direction. With broad
overrunning likely and ascent enhanced through the strengthening
RRQ of a subtropical jet streak, periods of moderate freezing rain
appear likely which could result in around 0.25" of ice. The
highest risk for 0.1-0.25" of ice right now according to WPC
probabilities extends in a stripe from near Abilene, TX, through
Kiowa, OK, and towards Memphis TN where 0.1" probabilities are
20-50%, with some pockets of 10-20% probabilities for 0.25". There
is potential for higher amounts as reflected by WSE plumes, and
while current pWSSI probabilities for moderate impacts are only
20-30%, expect these will start to climb as the event gets closer
and model consensus, hopefully, starts to merge.


Weiss

Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
154 PM EST Sat Jan 28 2023

Valid 12Z Tue Jan 31 2023 - 12Z Sat Feb 04 2023

...Notable precipitation likely next week including heavy rain in
the south-central to southeastern U.S. with freezing rain/snow on
the northern side...

...Dangerously cold temperatures and wind chills are forecast
across the Northern Plains and Upper Midwest at times through next
week...


...Overview...

It remains the case that periods of troughing are likely through
much of the northern U.S. next week extending from a persistent
Hudson Bay closed low, leading to colder than average temperatures
for much of the northern tier. The cold temperatures and wind
chills could be most hazardous for the north-central U.S. during
the first half of the week, with significant cold extending into
the Northeast for the latter half of next week. Meanwhile a
ridge/upper high over Cuba during much of next week should keep
the Southeast warmer than normal. Between these upper-level
features and temperature regimes, expect active weather as a
southern stream upper trough/low ejects from the Southwest Tuesday
(with some rain and higher elevation snow there) and tracks across
the central/southern tier of the CONUS. This combined with a
couple wavy fronts along with periods of Gulf inflow will support
a couple of significant precipitation events with possibly heavy
rain to the south/southeast and wintry weather in the colder air.
Later in the week, the West Coast may see increasing precipitation
chances with the approach of an eastern Pacific upper trough.


...Guidance/Predictability Assessment...

The WPC medium range product suite is primarily derived from a
composite blend of reasonably well clustered guidance from the 00
UTC GFS/ECMWF/UKMET/Canadian valid Tue-Thu in a pattern with above
normal predictability. The 06 UTC GFS became less aligned with the
progression of embedded systems, especially by later next week,
but 12 UTC guidance has trended back more in line with the
composite solution that also has decent ensemble and National
Blend of Models support. Despite overall flow similarities, some
minority insertion of GEFS/ECMWF ensemble mean guidance into the
WPC blend seemed reasonable by Friday/next Saturday to mitigate
growing shortwave differences. This solution maintains decent
overall WPC product continuity.


...Weather/Hazard Highlights...

The upper trough/low atop the Southwest on Tuesday could produce
some rain and higher elevation snow there lingering from the short
range period. Then this feature and the overall trough and other
shortwaves will provide support for frontal boundaries with waves
of low pressure through the south-central to southeastern U.S.,
which combined with Gulf moisture streaming in could lead to
multiple rounds of precipitation. On the southern side locally
heavy rain is expected, which could cause localized flooding
especially at times when there is sufficient instability for
higher rain rates. At this time a Slight Risk is in place in WPC's
experimental Excessive Rainfall Outlook for day 5/Wednesday given
good upper-level support, namely excellent difluence/divergence in
the right entrance region of the jet, and somewhat wet antecedent
conditions. The latest rendition has been shifted slightly
westward from WPC overnight continuity in line with guidance
trends. QPF in this region has increased in both the NBM and even
slightly more from WPC given better 00 UTC model agreement and
slightly slower trend. Then on the northern side of the
precipitation chances, there is potential for snow across parts of
the southern half of the Plains and Mississippi Valley into the
Ohio/Tennessee Valleys and the Mid-Atlantic at times, but low
confidence continues in the specifics. This is also a pattern that
could support freezing rain with ice accumulations with the cold
air in place at the surface and potential for warm moist air to
flow overtop it. The placement of heaviest rain, freezing rain,
and snow all remain in question as small-scale details like
surface frontal positions and late week shortwave specifics remain
uncertain. Elsewhere, periods of lake effect snow are possible to
the lee of the northern/eastern Great Lakes. Some light
precipitation is possible in the Northwest on Tuesday, but more
limited to western Washington by Wednesday. The West Coast could
see increasing precipitation chances by the latter half of the
week but with uncertainty over the southward extent and amounts.
Currently the best potential for at least some rain/mountain snow
is over the Pacific Northwest with moisture possibly extending as
far south as northern California.

Very cold conditions over the north-central U.S. during the short
range period will continue into next week, in the wake of a strong
cold front producing a surge of arctic air. Highs in the single
digits and even at or below zero are possible in the Dakotas into
Minnesota while bitterly cold lows combined with wind will produce
dangerous wind chills. Much below normal temperatures should
extend across much of the central U.S. through midweek especially,
as well as across much of the Interior West with temperatures
15-25F below normal through Tuesday with gradual moderation
thereafter. Meanwhile the far Southeast and Florida Peninsula
should see the most consistent above average temperatures, with
highs 10-15F above average and plus 10-20F anomalies for lows. A
few record highs are possible Tuesday-Wednesday. While the
western/central U.S. moderates later in the week, the East will
trend somewhat colder with New England possibly seeing highs
10-20F below normal by next Friday.

Tate/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, experimental excessive rainfall
outlook, winter weather outlook probabilities and heat indices are
at:

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