Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/10/23
Area Forecast Discussion
National Weather Service Grand Rapids MI
1031 PM EST Thu Feb 9 2023
LATEST UPDATE...
Update/Marine
.UPDATE...
Issued at 1031 PM EST Thu Feb 9 2023
Low pressure is centered over Georgian Bay of Northeast Lake Huron
at 03z. A trough extends from the low to the southwest to near
Saginaw Bay, Lansing and Battle Creek. The trough will continue to
the east tonight and northwest winds will take over in its wake.
Colder air will gradually flow in, but the cold air does lag a
distance back to the west. Temperatures in the 30s extend all the
way back to northwest Wisconsin.
Some precipitation, mostly in the form of rain it appears, will
work through the forecast area in the next 3 to 6 hours. This
precipitation is associated with the back edge of the upper wave
that is pivoting to the east through the state. Any precipitation
from here on out will be on the lighter side, generally a tenth of
an inch or less. As we cool a bit in the next few hours, its not
out of the realm of possibilities to see some light accumulations
of snow. This would be most likely across Central Lower Michigan
and would be on the order of a dusting to a half inch.
Regarding the wind, the Wind Advisory was allowed to expire given
gusts being below criteria this evening.
&&
.DISCUSSION...(This evening through next Thursday)
Issued at 312 PM EST Thu Feb 9 2023
Forecast concerns continue to deal with the wind this evening and
snow potential on the back side of the departing low, which is
approaching Holland.
...Windy with some snow and rain tonight...
Sfc obs indicate winds are gusting from 40-46kts across east central
IL. The 17z HRRR seems to have the best handle on this and will be
followed through the rest of the afternoon/early evening. It shows
the core of the strongest winds...35-43kts moving northeast across
north central IN and into far south central MI...east of a Sturgis
to Marshall line, which is in line with our earlier thinking that
this wind event would be focused on our southeast CWA. We`re going to leave
the Wind Advisory as is. The Wind Advisory for all but Ottawa,
Allegan, Van Buren counties expires at 7 pm which looks pretty
perfect given Bufkit wind profiles. The aforementioned three
counties expire at 11 PM, mainly for wind that develops on the back
side of the low and moves over the lake.
Regional radar shows two main areas of precipitation. The pcpn on
the southern side just ahead of the cold front is all rain and that
will move into the cwa this afternoon. The more extensive pcpn is
mostly snow on the north side of the comma and is fueled more by
deformation. The northwest cwa will be on the southern side of the
deformation pcpn.
Colder air will advect into the cwa behind the departing low. Still
looks like there could be some accumulating snow over the far
northwest cwa. Model accums vary between 1-3 inches northwest of a
Hart to Clare line with the GFS heaviest and the HRRR on the lighter
side. South of there, there may be some light slushy accums...less
than an inch...during the overnight hours.
The brief shot of colder air tonight may lead to a brief period of
lake effect snow showers late tonight/Friday morning. H8 temps fall
to around -12c by 15z, but by then, the boundary layer is drying out
and any snow that develops will quickly end.
...Sunny weekend...
High pressure builds into the region Saturday/Sunday and we`ll see
sunny skies. Most of the ECMWF ensemble members show clear skies
over the weekend and we`ll remain dry through most of Tuesday.
...Rain midweek...
The next system arrives Tuesday night/Wednesday in the form of an
inverted trough. Highs in the mid to upper 40s will ensure that the
pcpn is all rain. More rain is possible late in the week too. Both
the ECMWF and GFS show a southern stream wave phasing with a
northern stream trough to produce pcpn Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 715 PM EST Thu Feb 9 2023
Low pressure has moved northeast through Southwest Lower Michigan
this evening and is situated over Lake Huron. A cold front is
sweeping into western portions of the state at 00z with South
Haven and Holland having switched to a westerly wind direction in
the last hour or so. The cold front will sweep rapidly to the east
the next few hours bringing a period of low ceilings (LIFR to
IFR). Otherwise, we are looking at a mix of IFR and MVFR this
evening as the front works east through the region.
The general trend should be one of improvement as the LIFR should
go east of the area by around 06z. A trend from IFR to MVFR should
then occur between 06z and 12z. Finally, on Friday during the day
MVFR ceilings will gradually lift with a trend to VFR Friday
evening.
Precipitation will be a bit off and on tonight, with the back edge
of the current rain/snow moving northeast of the TAF sites by 02z.
Another batch of precipitation will work through the TAF sites
between 05z and 09z. The current precipitation is mainly rain, but
the second batch coming overnight will be rain/snow or snow.
Winds will be gusty through the night as the pressure gradient
across the area is fairly strong. 15-25 knot winds will be common
from the west and northwest.
&&
.MARINE...
Issued at 1031 PM EST Thu Feb 9 2023
The Gale Warning has expired and we have issued a Small Craft
Advisory into Friday evening. We may see a few more hours of gale
force gusts down towards South Haven, but overall the wind trend
will be down and the threat of gales are in the process of ending.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until 10 PM EST Friday for LMZ844>849.
&&
$$
UPDATE...Duke
DISCUSSION...04
AVIATION...Duke
MARINE...Duke
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
529 PM CST Thu Feb 9 2023
.DISCUSSION...(This evening through Thursday)
Issued at 257 PM CST Thu Feb 9 2023
KEY MESSAGES:
- Breezy and colder through Friday night with clearing skies.
- Above normal temperatures to resume this weekend into next week.
- Active weather pattern possible for the middle of next week
bringing numerous chances of rain and/or snow. There is low
confidence in the timing and track of these systems.
THIS AFTERNOON THROUGH TOMORROW NIGHT
Surface analysis this afternoon shows a dry secondary cold front
sweeping eastward across northern/western MN, and should be across
all of MN and most of WI by early this evening. Meanwhile, extensive
high pressure over the western CONUS has been slowly spilling over
the Rockies. Low stratus over much of central-southern MN into
western WI has greatly diminished this afternoon as the front
arrives, leaving mainly mid-to-upper level cloud cover in place for
this evening into the early morning hours. In addition, the tightened
pressure gradient behind the departing front and incoming high
pressure will make for breezy conditions through the rest of the
afternoon-evening hours and most of the overnight. Winds will
gradually diminish during the pre-dawn hours into Friday morning and
remain generally 10mph throughout the day Friday, but will pick up
again Friday night as a warm front pushes across the Upper Midwest.
Though no precipitation is associated with this warm front (much like
today`s cold front), there will be a small uptick in cloud cover. As
for temperatures, the aforementioned cold front will bring a brief
shot of colder air to the Upper Midwest, forcing highs in the 30s
today back into the 20s on Friday. In between, lows tonight will
plummet back into the single digits. Combined with the strong winds,
this will make for wind chills tonight through Friday morning to drop
as far as between 0 and 10 below zero. However, as mentioned, this
cold air surge will be short-lived since the warm front arriving
Friday night into Saturday morning will make for lows only dropping
into the teens to near 20 degrees Friday night followed by a return
to highs into the 30s area-wide (and potentially near 40) for
Saturday.
SATURDAY THROUGH TUESDAY
Not much change in the long-term forecast since the last update.
Thermal ridging is expected to enter the region Saturday which will
allow temperatures to rebound back into above normal values for this
time of year. The weather pattern for this period continues to be
tranquil as a split flow pattern will keep a weak polar jet to our
north and subtropical jet to our south. Skies through most of the
forecast period will be a mix of clouds and sun, with dry conditions.
On Tuesday, the subtropical ridge to our south amplifies into the
Ohio River Valley which will allow greater WAA to advect into our
region and could see a few 40s for highs.
WEDNESDAY THROUGH FRIDAY
The second half of the week continues to produce quite a mixed signal
regarding a developing system to enter the Central U.S. by next
Wednesday. Guidance still signaling a large spread amongst its
members regarding if we see considerable precip here in our region or
not. Today`s run of the NBM has introduced likely PoPs in
Southeastern MN and Southern WI as compared to yesterday at this
time. However, it is possible that the NBM could be taking more of an
aggressive approach whereas both the GEFS and EPS still have enough
disconnect between their members to where high-confidence exists just
yet. Thus, used blended guidance with a slight reduction of PoPs to
coincide with current confidence levels. Once the cold front passes,
our high temperatures reduce to below normal values for this time of
year in the low-20s and lows in the single digits.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 520 PM CST Thu Feb 9 2023
This is pretty much a wind forecast this period as high pressure
moves in for Friday and skies clear out. The one thing to watch
that`s currently not covered in the TAFs is the potential for fog
near the Dakotas border late tonight into Friday morning. There are
several models, including the HRRR that show fog and/or stratus
moving into AXN Friday morning. Confidence in this happening is not
high enough to include it in the AXN TAF at this time, but it is
something we`ll have to watch tonight.
KMSP...High confidence in the TAF with no additional concerns.
/OUTLOOK FOR KMSP/
Sat...VFR. Wind SW 10-15 kts.
Sun...VFR. Chance IFR cigs/vis. Wind lgt & vrb.
Mon...VFR. Wind SW 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...JPC/RMD
AVIATION...MPG
Area Forecast Discussion
National Weather Service Norman OK
933 PM CST Thu Feb 9 2023
...New UPDATE...
.UPDATE...
Issued at 933 PM CST Thu Feb 9 2023
The low-level air is still dry enough that much of the
precipitation observed on radar is evaporating before reaching
the ground. Enhanced reflectivity over Childress TX was enough to
let precip reach the ground and measure 0.01 inches, but
measurable rainfall has only fallen there and West Texas mesonet
sites near Turkey and Quitaque - also both 0.01 inches. Low-level
humidity will increase as temperatures slowly decrease diurnally
so we still may see some precipitation survive to the surface
overnight, but trends in both radar and model data are not quite
as optimistic about widespread measurable precipitation. Have
lowered POPs in general with this update and reoriented them based
on current trends. Temperatures are also not falling very fast
thanks to the cloud cover, and so have trended hourly forecast
temperatures toward the HRRR for this evening, which will also
likely delay any potential phase change.
&&
.SHORT TERM...
(This evening through Friday)
Issued at 347 PM CST Thu Feb 9 2023
Through Daybreak Friday: Another round of wintry precipitation,
perhaps mixed with rain, is possible from late this evening
through early Friday. A high-amplitude upper wave is quickly
shifting towards the southern CONUS this afternoon, with the
upper low centered across eastern New Mexico. An associated cold
front continues to advance across western into southwestern
Oklahoma this afternoon. Momentum transport of 30-35 knot low-level
(925-850 mb) flow will continue to promote breezy conditions,
especially across the western half of Oklahoma, through the
overnight period.
The mid-level low is expected to pivot eastward across western/north
Texas through the overnight period. As frontogenetical forcing
increases in the 850-700 mb layer on the periphery of this
feature, combined with broad/weak synoptic-scale ascent, chances
for precipitation (some wintry) are expected to increase.
The all-important question is what will the dominate hydrometeors
(and impact) be during the period? Precipitation is expected to
spread into western-north Texas/far western Oklahoma by ~01-03
UTC this evening. A sufficiently deep near-surface warm layer
looks likely at precipitation onset such that a rain-snow mix is
expected early in the evening. As the core of the upper wave
passes overhead, 500 mb temperatures of -25 to -30C, combined with
cooling wet-bulb temperatures, suggest a transition towards
all/mostly snow would be favored.
This scenario presents a complex forecast regarding expected
impacts. At its most simplistic, the degree of nocturnal cooling
and precipitation rates/potential for mesoscale banding plays a
significant role in determining sensible outcomes by Friday
morning. With temperatures warming into the upper-40s to mid-50s
across all areas this afternoon, combined with increasing cloud
cover overnight, temperatures overnight may end up hugging the
freeze point in areas along and south of the I-44 corridor.
However, with wet-bulb temperatures dipping into the mid to
upper-20s, especially along and northwest of the I-44 corridor,
light accumulations of wintry precipitation/snow may be noted
(especially on elevated and grassy surfaces) by daybreak Friday.
The threat for light accumulations is especially possible in any
mesoscale bands (heavier rates) that develop during the overnight
period. At present, this seems most likely from southwest into
east-central Oklahoma.
Bottom line, is a repeat of surface impacts observed yesterday
(Wednesday) evening possible tonight? Yes, and most possible along
and northwest of the I-44 corridor where overnight temperatures are
expected to dip below freezing. However, expected lesser
magnitudes/coverage of mesoscale banding and a drier atmospheric
column increase uncertainty in the overall spatial extent of
impact, especially across southern/southeastern Oklahoma.
Friday: Scattered areas of light wintry precipitation may linger
across far eastern zones through the early afternoon. As the mid-
level low advances sluggishly eastward across the ArkLaTex,
continued forcing for ascent may allow areas of light
precipitation/snow to linger across the far eastern forecast area.
There currently exists some uncertainty in the evolution/track of
the mid-level low, and how quickly is dives southward towards the
Lower Mississippi Valley on Friday. Should this feature progress
more slowly than advertised in mid-morning guidance, areas of
precipitation may linger longer in areas further west (towards
I-35 corridor) than currently captured at this update.
Temperatures will remain seasonable during the afternoon, with low
to mid-40s expected across the region.
Ungar
&&
.LONG TERM...
(Friday night through next Wednesday)
Issued at 347 PM CST Thu Feb 9 2023
This Weekend: This period looks to contain pleasant weather with
low-to-nil surface impact. The upper pattern across the Southern
Plains will be characterized by ridging aloft, with cutoff
systems placed along both eastern and western coasts. A gradual
warming trend is expected, with afternoon high temperatures in the
upper-50s to low-60s expected. With breezy southerly winds
redeveloping across the area, combined with rather dry surface
conditions, at least small areas of elevated fire weather concern
look to develop across northwest Oklahoma. A dry front looks to
pass through the area late Sunday/early Monday.
Early Next Weekend: Impact from a more potent (closed) upper wave
continues to be advertised, with increasing chances for rain
across all areas by late Monday through early Tuesday. For now,
the main weather message may become areas of heavy rainfall
(depending on evolution of the main wave). The pattern looks to
remain active into the midweek, with another chance for
precipitation (and perhaps some fire weather concern) across the
forecast area.
Ungar
&&
.AVIATION...
(00Z TAFS)
Issued at 614 PM CST Thu Feb 9 2023
Gusty northwesterly winds will continue this evening. MVFR
ceilings are expected to develop later tonight behind the cold
front. There is also chance for some rain and snow, but the
probability is too low to include for a given terminal. Ceilings
should improve tomorrow morning with VFR conditions returning area
wide.
Mahale
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 29 43 22 51 / 40 20 0 0
Hobart OK 27 46 22 53 / 40 0 0 0
Wichita Falls TX 32 47 24 53 / 20 10 0 0
Gage OK 22 45 19 57 / 20 0 0 0
Ponca City OK 26 44 20 50 / 30 10 0 0
Durant OK 36 44 27 53 / 20 20 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
SHORT TERM...34
LONG TERM....34
AVIATION...26
Area Forecast Discussion
National Weather Service Sacramento CA
156 PM PST Thu Feb 9 2023
.SYNOPSIS...
Dry weather today into early Friday with patchy Valley fog in the
morning. Light precipitation late Friday into Saturday, mainly in
the mountains. Breezy north to east winds develop late Saturday
night into early Monday. Another weak system Monday night into
Tuesday will bring additional light precipitation and breezy
northerly winds.
&&
.Discussion...
Latest GOES-West visible satellite imagery shows widespread
sunshine being observed across interior northern California early
this afternoon. Upper level ridging will remain over the region
today, allowing for dry weather, mostly sunny skies and light
winds to prevail. Daytime high temperatures are trending near to
slightly above normal for much of the area today, with most of the
Valley and foothills expected to see highs in the 60s. Temperatures
are currently trending 2 to 6 degrees warmer than 24 hours ago as
of 130 PM PST this afternoon.
Patchy to locally dense fog will be possible again Friday morning,
as the HREF advertises probabilities of 30 to 70 percent chance for
a half mile visibility or less generally from Oroville southward.
The HRRR is also suggesting patchy areas of fog tomorrow morning.
Motorists should watch for sudden reductions in visibility with
patchy fog. A quick-hitting weather system will approach the West
Coast on Friday, although at this point minor impacts are
expected. There is not much moisture associated with this system,
and generally light precipitation is forecast late Friday into
Saturday, along with slightly cooler temperatures and increasing
cloud cover. Snow amounts have trended upward slightly since
previous forecast, but much of the snowfall will be in the
overnight hours into early Saturday. Snow levels start out around
5,000 feet to 6,000 feet Friday evening and lower down to around
4,000 feet early Saturday. Slick roads and travel delays will be
possible in the mountains.
Breezy north to east winds will develop behind the passage of this
system late Saturday into Sunday. The Extreme Forecast Index (EFI)
continues to highlight anomalous wind speeds and wind gusts for
portions of the Valley and mountains during this timeframe. The
strongest wind gusts will be in the northern and western
Sacramento Valley with gusts around 30 to 40 mph, and over the
Sierra Nevada with gusts up to around 50 mph. Winds are expected
to be strongest during the early morning hours on Sunday.
&&
.EXTENDED DISCUSSION (Monday THROUGH Thursday)...
Ensemble guidance is in agreement for an additional weak weather
system to drop down early next week, bringing renewed chances for
light precipitation and breezy winds. The National Blend of Models
(NBM) probabilistic data indicates a 30 to 50 percent probability
of observing an inch of snow or greater, and a 20 to 40 percent
probability of observing 2 inches of snow or greater up at the
higher elevations in the mountains late Monday into Tuesday. This
system will also bring along another round of breezy northerly
winds to interior northern California next week.
&&
.AVIATION...
Areas of MVFR/IFR conditions due to fog could return to the
Valley for locations near and south of Sacramento 10z-18z Friday.
Otherwise, VFR conditions expected next 24 hours with winds less
than 10 kts.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$