Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/05/25
Area Forecast Discussion
National Weather Service La Crosse WI
500 PM CST Tue Mar 4 2025
.KEY MESSAGES...
- Heavy rain continues to spread into the area this afternoon.
Rainfall amounts of 0.5 to 1.5 inches are expected by 6AM
Wednesday with the highest amounts south of I-94. Frozen
ground will cause ponding and runoff into rivers, within-bank
rises expected.
- Deteriorating travel overnight in snow. Rain changes to snow
from west to east overnight with up to 1 inch per hour rates
across SE MN and W WI. By 9AM, snow is expected across the
entire forecast area. Storm totals range generally from 2 to 8
inches with locally higher amounts possible.
- Blizzard conditions: overnight winds will increase into the
35 to 55mph range. These strong winds will combine with
falling snow resulting in whiteout conditions, especially for
open/rural/wind prone areas west of the Mississippi River
valley.
&&
.DISCUSSION...
Issued at 305 PM CST Tue Mar 4 2025
Today-This Evening: Heavy Rain
The forecast remains largely on track for a complex weather system
to move into the area. A low pressure system currently sits over the
Central Plains and will move northeastward during the day. At the
same time, the associated upper-level trough strengthens and becomes
more negatively tilted helping to increase low-level frontogenesis.
With this increased lift, CAMs continue to show bands of heavier
rain moving into the area this evening into the early over night.
Moisture transport will also be pretty good this afternoon and
evening as low-level southerly flow occurs over the area. PWATs will
continue to increase this afternoon into this evening, ranging from
0.7 to 0.9 inches across much of the area, with values getting close
to 1.0 inches in northeast Iowa and far southwestern Wisconsin.
Lastly, latest RAP shows an area of 100 to 200 J/kg of MUCAPE that
arrives later this afternoon through the evening indicating a
potential for both a rumble of thunder and increased rainfall rates.
Shifting gears to the amount of rain the forecast will receive, the
00Z EFI gives an idea of how anomalous this rainfall will be.
Currently there are values of .8 to .95 across much of the forecast
area with some .95 to 1.00 values in central Wisconsin. These values
indicate that there is increased confidence that the rainfall
received will be towards the higher end of climatology. Since there
will be a transition to snow, rainfall totals will be a mix of
liquid rain and melted snow. So looking at the amount of rain prior
to snow, the 12Z HREF suggest that there is a 40 to 90% of 0.75
inches for areas south of I-94, with the higher percentages in
southeast Minnesota, northeast Iowa, and southwestern Wisconsin as
well as 40 to 60% chance of at least 1 inch of rain by midnight
across southeast Minnesota, northeast Iowa, and far southwestern
Wisconsin. There is still a little uncertainty on the exact timing
of rain to snow which would impact rainfall totals. This uncertainty
could result in snow occurring slightly earlier or later than
forecasted. Regardless of this uncertainty, rain will be falling on
top of frozen ground. This results in much of the rain either
ponding in low-lying areas or quickly running off into area rivers
and resulting in ice break up.
Tonight-Wednesday: Rain Changing to Snow, Strong Winds
Heading into tonight, the surface low continues to make its trek
northeastward. Moisture advection continues overnight and the warmer
low-level southeasterly air mixes in with the northwesterly cold air
advection. As the low moves just south of the forecast area, the
pressure gradient increases and this can be seen in the
frontogenesis values. A strong 900mb frontogenesis band moves
through the CWA overnight with some pockets of stronger
frontogenesis aloft at the same time. This results in an increase in
snowfall rates and this can be seen in the 12Z HREF showing an axis
of 0.75 to 1 inch per hour rates moving across southeast Minnesota,
far northeastern Iowa, and western Wisconsin. These higher rates
will move out of Iowa and Minnesota closer to sunrise, while the
rates in Wisconsin are expected to stick around through most of the
morning. As mentioned before, the timing of rain changing to snow
will be important in determining how much snow occurs.
With the strengthening pressure gradient, winds will increase
significantly. Probabilities for wind gusts greater than 50 mph west
of the Mississippi River continue to range between 60 and 100%, with
wind gusts greater than 40 mph expected for Wisconsin. Combining the
snow rates with the high wind gusts, blizzard conditions are likely
in southeast Minnesota and portions of northeast Iowa overnight into
Wednesday morning and as a result, a Blizzard Warning continues for
these locations. Even though there is no Blizzard Warning for
Wisconsin, blowing snow will occur at times across the forecast
area. This blowing snow will cause hazardous travel, especially in
northeast Iowa and southeast Minnesota. Winds will decrease
Wednesday evening. With the stronger winds outside of the Blizzard
Warning, we have gone ahead and issued a wind advisory for portions
of far southwestern Wisconsin and portions of northeast Iowa.
Snow ratios right at the transition of rain to snow range from 8:1
to 10:1 and after a couple hours of snow, the snow ratios increase
slightly to 10:1 to 12:1. Combining this with increased snow rates,
snow amounts range from 4 to 8 inches for southeast Minnesota and
and western/north central Wisconsin with 1 to 3 inches for most of
northeast Iowa and far southwestern Wisconsin. Snow amounts
increased the most for areas along I-90 in Wisconsin as a secondary
frontogenesis is expected to setup Wednesday morning. Any snow that
falls will be blown by the strong winds resulting in hazardous
travel for much of the forecast area. Snow gradually leaves the area
Wednesday evening.
Thursday-Tuesday: Seasonable Temperatures, More Snow Chances
After this winter system moves through, the longwave trough
continues to sit over the area through the weekend. This allows for
more seasonable temperatures with highs in the mid 30s to low 40s.
Temperatures could be influenced by the amount of snow cover on the
ground from the midweek storm. In addition, this flow regime
promotes some waves to move through and produce some light snow
showers. On Friday there is a shortwave that moves through the
Central Plains into the Midwest that will produce some snow.
Currently the LREF gives a 30 to 70% chance of measurable snow and a
10 to 30% chance of at least 1 inch of snow for northeast Iowa and
far southwestern Wisconsin on Friday.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 1124 AM CST Tue Mar 4 2025
High impact storm bringing rain, then snow, to the region
tonight/Wed along with very strong winds.
CIGS: LIFR/IFR expected through 12z Wed with a slow increase into
MVFR before scattering out Wed evening.
WX/vsby: widespread rain this evening will transition to snow
overnight - toward 06z for KRST and closer to 11z at KLSE. The
transition could be fairly quick - within an hour. Vsby restrictions
through the night/morning. Snow exits west to east in the afternoon
and looks to shift east of the TAF sites by 00z Thu.
WINDS: ramping up this evening, then very strong/gusty through the
day Wed. North sustained at 20 to 30 kts with gusts of 35 to 45 kts
expected. Some BLSN could result, although the high water content
(heavy, wet) of snow will work against blowing/drifting. Some
uncertainty how signficiant vsby will be impacted sans falling snow.
&&
.HYDROLOGY...
Issued at 225 PM CST Tue Mar 4 2025
Forecast precipitation amounts ranging from roughly 1 to 1.75 inches
are expected to fall initially in the form of rain, before colder
air slowly changes rain to a wet snow from NW to SE. With deep frost
in the soil - 20 to 34 inches across the region - expect most
locations to have poor drainage, with water thus tending to collect
and pond on the surface. As temperatures begin to fall near to below
freezing Tuesday night into Wednesday, this ponding of water on the
surface may freeze, further complicating any localized issues. Due
to this, there is low confidence in how local rivers may react. It
is possible that the rain freezes before reaching the rivers, which
would lower individual river responses. Localized ice jamming on
rivers is also possible as ice break up begins, especially
considering patchy thawing seen via satellite on some rivers. The
general public is encouraged to monitor nearby river responses for
potential ice jamming that may overflow on to roadways or on to
personal property. The general public is strongly encouraged take
appropriate actions to protect their property by ensuring water
drains away from their homes, by ensuring gutters on homes are in
working order, and by clearing any nearby storm drains of
debris.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Storm Warning from 3 AM to 6 PM CST Wednesday for
WIZ034-041>044-053.
Winter Storm Warning from midnight tonight to 6 PM CST
Wednesday for WIZ017-029-032-033.
Wind Advisory from 11 AM to 9 PM CST Wednesday for WIZ054-055-
061.
MN...Blizzard Warning from midnight tonight to 3 PM CST Wednesday
for MNZ079-087-088-094-095.
Blizzard Warning from 9 PM this evening to 3 PM CST Wednesday
for MNZ086.
Winter Storm Warning from 3 AM to 6 PM CST Wednesday for
MNZ096.
IA...Blizzard Warning from midnight tonight to 3 PM CST Wednesday
for IAZ008-009-018-019.
Winter Weather Advisory from 3 AM to 6 PM CST Wednesday for
IAZ010-011.
Wind Advisory from 6 AM to 6 PM CST Wednesday for IAZ010-011-
029-030.
&&
$$
DISCUSSION...Cecava
AVIATION...Rieck
HYDROLOGY...Ferguson
Area Forecast Discussion
National Weather Service Billings MT
703 PM MST Tue Mar 4 2025
.KEY MESSAGES...
- Another round of snow for the mountains and foothills of south-
central Montana and northern Wyoming Thursday into Friday
morning. Snow may impact the Thursday morning and evening
commute.
- The greatest snow totals are expected over the foothills of the
Beartooths (4 to 8 inches possible) and Bighorns (3 to 6 inches
possible). Stay tuned to the forecast for updates.
- Warm, dry, and breezy this weekend.
- Unsettled conditions return next week.
&&
.UPDATE...
Trof has exited to our east and is being replaced by ridging and
anticyclonic flow. There remains some low stratus over the east
but it is eroding. Central parts of our forecast area are mostly
clear. To the west, satellite imagery shows a weak but distinct
shortwave moving through WA/OR and approaching northern ID. There
is some light snow associated with this wave along the ID/MT
border. For the remainder of the night, the Pacific wave should
bring a brief period of light snow to our western mountains
between 06-12z, with 0.5-1.0" of accumulation in orographically
favored areas. The other potential issue is fog. Dew points have
fallen to the lower-mid 20s so the fog risk seems to be low at
this time, and the HRRR is not suggesting much, but with the
period of clearing and light winds there could be localized fog in
the overnight hours into early Wednesday. Over time, the
increasing cloud cover and onset of light west winds will remove
any risk of fog over our west. It appears the best chance of fog
is really east of Billings, and this will need to be monitored.
Forecast is in good shape. Have tweaked pops/wx/snow over the
mountains and adjusted fog coverage to show less along the
foothills. JKL
&&
.DISCUSSION...
Rest of Today through Thursday night...
Tonight will be a quiet night as lows drop into the teens to 20s
over the lower elevations, coldest in eastern Montana. With the
fresh snowmelt today and generally light winds, patchy fog is
possible overnight (low to moderate chance). Increasing clouds
from west to east may limit or inhibit fog development all
together though.
Wednesday will be dry for most as temperatures warm back into the
40s to 50 degrees. Periods of light snow are possible in the
Beartooth-Absaroka Mountains tonight into Wednesday, but
accumulations will be light to negligible. Around Baker, MT, light
rain/snow is also possible Wednesday afternoon/evening as a
shortwave moves over the region. This shortwave will also bring
breezy conditions back across most of the region tomorrow. Expect
15 to 30 mph westerly wind gusts to be common during the day.
Around Big Timber and Harlowton, westerly wind gusts of 30 to 45
mph will be common, strongest around Harlowton. At Harlowton, the
chance of a 50 mph gust is 45 percent.
Another round of snow is then expected move into the mountains
and foothills of south-central Montana and northern Wyoming
Wednesday night into Thursday. At this time, the mostly likely
time for snow is during the day Thursday for these areas. The snow
is then expected to taper off Thursday night into early Friday
morning. Because the majority of the energy with this system will
remain south of our area, snow amounts are generally reliant on
upslope enhancement. Therefore, the snow potential drops quickly
off the foothills to the north and east. As far as potential snow
amounts over the mountains and foothills go, uncertainty still
remains. The latest model guidance has stabilized a bit, but
ensemble meteograms still show a decent amount of spread. At this
time, there is a high chance of at least an inch or two of snow
around Red Lodge and Sheridan. At Billings, the chance is low.
While these amounts will likely change a bit, the current
deterministic forecast is 3 to 6 inches of snow around Sheridan
and 4 to 8 inches of snow around Red Lodge. In the mountains,
generally, 4 to 8 inches of snow are also forecast. Stay tuned to
the forecast for updates into Thursday. Arends
Friday through Tuesday...
Ridging will begin to move in Friday, leading to dry conditions
with a warming trend through the weekend. Over the western
foothills, there is potential for stronger winds. Currently, a
decent pressure gradient favoring gap winds is expected to set up
by Sunday, with 700 mb winds increasing into Monday. There is
still uncertainty between the models on when the pressure gradient
will begin to decreases and if the 700 mb wind direction will be
oriented in a way that favors gap winds, so this will be something
to watch.
A pattern change to unsettled conditions is expected by late
Monday/early Tuesday, although the exact timing and extent of
impacts is still uncertain. What is certain is temperatures
beginning to cool to closer to normal for this time of year and
an increased chance of precipitation.
Highs on Friday will be in the 40s to 50s, increasing to 50s to
60s by Sunday. Then, temperatures begin to decrease again,
falling back to 40s to 50s by Tuesday. Archer
&&
.AVIATION...
Low cigs in the south and east will gradually raise and thin out
this evening. For now, expect MVFR conditions around KBHK, KMLS,
and KSHR. Elsewhere, expect VFR conditions to prevail. Expect
winds to increase Wednesday morning, with gusts in the 10-20s
knots. Matos
&&
.PRELIMINARY POINT TEMP/POPS...
Wed Thu Fri Sat Sun Mon Tue
-----------------------------------------------------------
BIL 025/050 028/037 023/046 029/053 035/059 038/061 036/054
00/B 14/S 20/U 00/B 00/B 00/B 13/R
LVM 027/046 025/031 018/040 023/047 029/051 032/053 031/047
10/B 26/S 30/B 00/N 00/N 00/N 24/O
HDN 020/050 025/037 020/047 027/055 031/061 031/063 031/056
00/B 02/S 20/U 00/B 00/B 00/B 13/R
MLS 018/047 024/037 020/045 028/052 033/060 035/062 032/053
00/B 00/E 00/U 00/B 00/U 00/B 01/B
4BQ 019/047 026/035 022/044 028/051 033/060 031/062 032/055
00/B 01/E 20/U 00/U 00/U 00/B 01/B
BHK 012/042 019/035 017/042 023/048 029/056 030/059 028/049
02/O 00/B 00/U 00/B 00/U 00/B 01/B
SHR 017/047 022/033 015/040 018/049 026/059 028/060 027/053
00/B 29/S 81/B 00/U 00/U 00/B 03/R
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Cleveland OH
946 PM EST Tue Mar 4 2025
.SYNOPSIS...
Deepening low pressure over the Great Plains this evening will
lift into the Great Lakes region tonight. The low will lift a
warm front north across the area overnight tonight before
dragging a cold front east during Wednesday afternoon and
evening. Lingering surface troughing remains behind the low as
it exits into Quebec on Thursday.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
9:46 PM EST Update...
Most of the forecast remains valid per latest trends in obs and
model guidance. However, expanded the Wind Advisory to the rest
of our CWA as a SE`erly to S`erly LLJ of 40 to 50 knots at/near
925 mb translates NE`ward across our region Wednesday morning
through very early afternoon. Still expect mechanical mixing of
the boundary layer amidst winds increasing rapidly with height
between the surface and 925 mb to tap into portions of the LLJ
and yield SE`erly to S`erly peak surface wind gusts of 45 to 50
mph, prompting the Wind Advisory. Our official surface wind
gust forecast has been updated accordingly through early
Wednesday afternoon.
The Wind Advisory is now in effect until 10 AM EST Wednesday
from Lorain, Medina, Ashland, Knox Counties and points west. The
advisory remains in effect until 1 PM Wednesday for Cuyahoga
County, while it is in effect from 5 AM to 1 PM Wednesday for
the rest of our CWA. These changes to the advisory and official
forecast were based on latest trends in HRRR and HREF guidance.
Please see discussion below for further details.
Previous Discussion...
An active near term period in store with multiple hazards on the
table: widespread rainfall transitioning to snow showers,
strong synoptic winds, and strong to severe thunderstorms.
Deepening low pressure currently centered over the Great Plains will
move northeast into the Great Lakes region through tonight and
Wednesday. The low will lift a warm front northward across the local
area tonight before dragging a cold front eastward Wednesday
afternoon and evening. Lingering surface troughing with wrap around
moisture will continue through Thursday. We`ll remain mild
tonight as the warm front lifts northward with lows in the upper
40s to lower 50s. High temperatures will have another shot at
60 degrees tomorrow ahead of the cold front with most areas
likely seeing highs in the upper 50s to near 60 degrees. Much
colder Wednesday night behind the cold front as lows dip into
the upper 20s to lower 30s.
Precipitation:
Widespread rain showers associated with isentropic ascent along the
warm front will enter from the west and southwest late tonight/early
Wednesday morning and gradually push eastward through Wednesday
morning and early afternoon. A dry slot will move overhead during
the day Wednesday which may lead to a break in precipitation during
the late morning and early afternoon hours. Additional showers and
thunderstorms (more information below) will develop along a
surface trough axis ahead of the cold front and push eastward
through Wednesday afternoon and evening. Forecast total
rainfall amounts generally remain between one-half inch and
three-quarters of an inch, which should curb any widespread
flooding concerns. However, can`t rule out instances of
localized nuisance flooding in any heavier shower/storm or minor
rises to flood-prone rivers. As the low continues to push to
the northeast, wrap around moisture coupled with lingering
troughing over Lake Erie and CAA will cause any remaining rain
showers to transition to snow showers Wednesday night into
Thursday. More information on the snow showers can be found in
the short term discussion below.
Synoptic Winds:
There will be two distinct windows of strong winds and gusts through
the near term period. The first will occur overnight tonight as a
strong low-level jet with 850mb winds in excess of 65 knots moves
overhead. Have issued a Wind Advisory along and west of I-71 from 9
PM this evening through 5 AM Wednesday morning. Enhanced winds and
gusts in downsloping coupled with the low level jet moving eastward
will lead to elevated winds along the lakeshore to continue
Wednesday morning though the afternoon. Have a separate Wind
Advisory for Cuyahoga County and points east from 5 AM to 1 PM
as the low level jet pushes eastward and winds remain elevated
with gusts to 50+ MPH. The exception will be Cuyahoga County
where the Wind Advisory is in effect from 9 PM this evening
through 1 PM Wednesday afternoon. The next window for strong
winds and gusts will be associated with the passage of the cold
front. There looks to be a lull Wednesday morning into early
afternoon across western zones before southerly wind gusts
increase to 40-45 MPH ahead of the cold front. As the cold front
swings eastward on Wednesday night, winds turn westerly but
will remain elevated with gusts to 35-40 MPH through early
Thursday morning.
Thunderstorms:
Strong to severe thunderstorms are expected to develop along a
surface trough axis ahead of the aforementioned cold front as it
moves east across northern Ohio Wednesday afternoon and
evening. The threat of severe thunderstorms will hinge on how
much we clear out and destabilize in the dry slot late Wednesday
morning and early afternoon. Current hi-res model guidance
indicates that a few hundred J/kg of SBCAPE coupled with
massive amounts of vertical wind shear (e.g. 50 to 70 knots of
deep layer bulk shear) develop ahead of the cold front. Given
the weaker instability, but strong wind field, damaging wind
gusts look to be the primary hazard. However, the strong wind
field in addition to 0-3 km AGL SRH values around 150 m2/s2
could allow storms to produce a tornado or two across eastern
portions of the forecast area (mainly east of I-71). As such,
the SPC has continued to include eastern portions of our
forecast area in a Slight Risk (Level 2/5) for severe weather on
Wednesday. The timing for the development of strong to severe
thunderstorms will generally begin around noon Wednesday
afternoon near the I-71 corridor and will gradually move east
into western Pennsylvania through 7 PM.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
By Thursday morning, the area will be placed under the lingering
surface trough as the parent low pressure shifts northeast into
Quebec. On Thursday, a secondary cold front will swing east across
the area, presenting an additional chance of snowfall across the
eastern portion of the CWA, where upper level support lingers ahead
of the trough axis. 850mb temperatures will quickly fall behind this
secondary cold front, with -11 to -15C temperatures suggested in
models. This will allow all precipitation to remain as snow on
Thursday with some potential support from lake enhancement early
Thursday night. Snowfall totals generally should be 1-2 inches,
possibly up to 3 inches in the higher terrain of NW PA. Much cooler
temperatures will also occur on the back side of this low, with
Thursday highs climbing into the mid to upper 30s and overnight lows
falling into the mid to upper 20s.
On Friday, a surface ridge will nudge north across the area, allow
for dry conditions across the area to start Friday. By Friday
afternoon, a warm front associated with another low over the central
US will begin to nudge north towards the area. In the upper levels,
a strong jet will extend from Texas northeast towards New England,
placing the entire CWA in the left exit region. This should result
in precipitation spreading across the area Friday afternoon and
night. The biggest question is what form the precipitation will fall
as. Current models suggest the parent low moves east across the Ohio
River Valley Friday night, leaving the CWA on the cold side of the
low. This may result in mostly snow, but with some WAA expected,
opted to maintain a rain/snow mix through the period. Will continue
to monitor, but either way no significant impacts expected. Highs on
Friday will climb into the upper 30s to low 40s with overnight lows
falling into the low to mid 20s.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
A broad upper level trough will linger across the northeastern US
through the weekend with multiple shortwaves expected to push along
it. The first round of potential showers will be Saturday afternoon
as an initial shortwave pushes southeast on the back side of the
aforementioned trough. This should provide enough support, coupled
with CAA over Lake Erie, to get scattered lake enhanced snow showers
across the primary snow belt. Another short wave pushes south on
Sunday and will be associated with more moisture. This should allow
for widespread light snow showers across the area with the greatest
potential across the typical snowbelt. Overall impacts should remain
minimal. By Monday morning, high pressure returns to the area and
will allow for dry conditions to be observed across the area through
Tuesday.
High temperatures this weekend will generally be in the mid 30s to
low 40s before warmer temperatures arrive again for the start of
next week. Overnight lows will follow a similar trend with lows this
weekend in the 20s before climbing into the 30s for the start of
next week.
&&
.AVIATION /00Z Wednesday THROUGH Sunday/...
Aloft, S`erly to SW`erly flow is expected over our region
through 00Z/Thurs as a ridge exits E`ward and a potent low moves
NE`ward from near the Ozarks to near southern Lower MI. At the
surface, the ridge continues to exit E`ward as the low wobbles
NE`ward from northwestern MO to near southern Lake Huron and
continues to deepen. Accordingly, an arcing and surging cold
front is expected to sweep NE`ward across our region between
~17Z/Wed and 00Z/Thurs. SE`erly to S`erly surface winds as
strong as 10 to 25 knots with periodic gusts up to 20 to 40
knots are expected ahead of the front. Behind the front, winds
veer toward SW`erly. These winds are expected to be as strong as
10 to 20 knots with gusts up to 30 knots or so.
A moistening/ascending airstream associated with the
aforementioned surface low pressure system is expected to allow
a swath of rain, steady to heavy at times, to translate NE`ward
across our region between ~05Z/Wed and ~15Z/Wed. VFR are
expected to deteriorate to widespread MVFR ceilings/visibility
in this swath of rain. Brief IFR to LIFR are possible in pockets
of heavier rain. Behind that swath of rain, low-level ceilings
near 3kft to 5kft AGL and fair weather are expected to
overspread our region for a time. However, scattered showers and
isolated thunderstorms are expected along/ahead of the cold
front, especially roughly along and northeast of a KPCW to KZZV
line. Some storms may be severe with erratic gusts of 50 to 55
knots, especially east of I-77. Behind the cold front,
widespread light rain and MVFR ceilings/visibility are expected
to accompany the moist and ascending airstream wrapping around
the backside of the surface low pressure system and overspread
our region generally from the west.
Outlook...Periodic non-VFR expected due to the following:
widespread rain mixing with and then changing to snow Wednesday
night into Thursday morning before likely ending by 05Z/Fri;
additional periods of rain and/or snow during the daylight hours
of this Friday through Sunday.
&&
.MARINE...
Fairly calm marine conditions are expected through this evening with
winds from the southeast at 10-15 knots ahead of an approaching low.
After 06Z Wednesday, increased gradient associated with a deepening
low over the Midwest will begin to impact Lake Erie, initially
increasing southeast winds to 20-25 knots by Wednesday morning. As
the low shifts to the east, winds will also shift to southwest and
eventually west-northwest, increasing to 25-30 knots by Thursday
morning. Winds will gradually weaken to 10-15 knots from the
southwest on Friday as a brief ridge builds over the area. Winds
will shift to northwesterly on Saturday and persist through the end
of the weekend.
The upcoming low pressure system will result in an extended period
of hazardous marine conditions beginning tonight and persisting
through Thursday. The first concern is the potential for drifting
ice. Recent satellite images show a fairly large gap of ice coverage
extending from the Islands east to Willowick, including the open
waters. As a result, small craft advisories have begun again for
areas of Lake Erie that have no ice. Waves are expected to build to
3-5 feet on Wednesday, increasing to 5-7 feet Wednesday night
through Thursday, so a Small Craft Advisory is in effect for these
nearshore zones from 08Z Wednesday to 00Z Friday. The second concern
with the strong winds is additional shifting and moving of ice
across Lake Erie. Shipping lanes across the western and eastern
basins have the potential to close, ice along the lakeshore has the
potential to become detached and shift into the open waters, and
parts of the ice sheet may break off and move into areas that
currently have no ice. As a result, it is highly advised to remain
off the ice on Lake Erie tonight through Friday and for mariners to
use caution as ice is likely to shift. A Marine Weather Statement
has been issued through Wednesday afternoon, but this will likely
need expanded through the duration of the small craft.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Wind Advisory until 10 AM EST Wednesday for OHZ003-006>010-
017>020-027>030-036-037-047.
Wind Advisory until 1 PM EST Wednesday for OHZ011.
Wind Advisory from 5 AM to 1 PM EST Wednesday for OHZ012>014-
021>023-031>033-038-089.
PA...Wind Advisory from 5 AM to 1 PM EST Wednesday for PAZ001>003.
MARINE...Small Craft Advisory from 2 AM Wednesday to 7 PM EST Thursday
for LEZ144>146.
&&
$$
SYNOPSIS...13
NEAR TERM...13/Jaszka
SHORT TERM...04
LONG TERM...04/Sullivan
AVIATION...Jaszka
MARINE...04
Area Forecast Discussion
National Weather Service Quad Cities IA IL
846 PM CST Tue Mar 4 2025
.KEY MESSAGES...
- Wind Advisory has been upgraded to a High Wind Warning for
portions of the area on Wednesday.
- Beneficial rainfall between 1-2 inches expected in the next
36 hours, especially in Iowa. Within bank rises on area
streams and rivers are likely, with some localized river
flooding and ponding of water.
- Rain changing to snow Wednesday morning to bring near whiteout
conditions for 1-3 hours generally west of a line from
Dubuque to Memphis MO. This may impact the morning commute.
-Another system to bring light accumulating snow Thursday night
Friday.
-Much warmer temperatures expected next week.
&&
.UPDATE...
Issued at 846 PM CST Tue Mar 4 2025
Only some slight adjustments to the forecast for this evening,
otherwise, things are largely on track. Currently, a deepening 984
mb low pressure system, located over north-central Missouri,
will continue to lift northeastward tonight. Ahead of the
surface low, a dry slot has develop over much of the area,
giving a brief break from periods of rain over the area.
However, radar mosaic and GOES-East clean window IR satellite
imagery shows an area of cooling cloud-tops and showers
developing on the southern and eastern flank of the surface low,
which should lift northward this evening into tonight and fill
in the dry slot.
As for the winds tomorrow, guidance still looks very impressive
for an anomalously strong area of low pressure, with the ECMWF
ensemble MSLP climatological percentiles indicating values near
the very bottom of climatology. Furthermore, the ECMWF EFI/Shift
of Tails indicates values over 0.9 for wind gusts, which is
very high on the scale. I have updated the winds/gusts forecast
to near the NBM 90th percentile, giving widespread gusts between
50 to 60 MPH (could see some gusts higher than this!), which
also matches with the wind speeds near the top of the boundary
layer per HREF ensemble mean soundings. The only adjustment that
I made for headlines was to push up the end time of the High
Wind Warning and southern portion of the Wind Advisory to 00z/6
PM Thursday as guidance indicates gusts should drop off around
that time once the boundary layer decouples. I kept the end time
of the northwest Illinois portion of the Wind Advisory the
same, which ends as 03z/9 PM.
&&
.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 226 PM CST Tue Mar 4 2025
Early afternoon water vapor imagery shows a closed low tracking east
over OK, with 19z METARS and RAP surface analysis depicting a 989mb
surface low near Topeka, KS. Strong diffluent flow and moisture
transport ahead of these two features is quite evident, with 850mb
winds over 60kts and moisture vectors pointing into northern MO and
southern IA. Area radar mosaics have widespread showers lifting
north across the CWA, with only 1 lightning strike reported
near BRL attim.
A lot of weather to unfold in the next 12-36 hours across the CWA.
The latest hi-res and RAP13 model guidance all show a deepening
surface low around 978mb near the IL/WI border by 12z Wed. Checking
WPC MSLP records for March, this is approaching record low pressure
territory for ASOS stations in IL. The 00z ECMWF EFI near 1 and
shift of tails also confirms that most of its members have an
anomalous event unfolding tonight. Strong synoptic forcing in
an increasingly moist environment will keep rain going this
evening and overnight. SPC mesoanalysis page suggest the thunder
potential is decreasing this evening with lack of instability
and have removed thunder mention in the grids. An isolated
thunderstorm however, may still be possible this evening. In
addition, some models hint there may a brief lull around
midnight tonight, as the low approaches the area. Widespread 1-2
inch rain amounts will be possible by Wednesday afternoon,
especially in IA. The frost depth at NWS Quad Cities today is
now at 0, so much of this rain will soak into the ground and
hopefully provide some relief in drought stricken areas north of
I-80. That being said, within bank rises and localized river
flooding and ponding of water may still be possible.
Wind Potential Wednesday
All hi-res guidance and most deterministic model data had slightly
higher gusts and thus have upped the winds even more area-wide
closer to the 90th percentile of NBM guidance. Bufkit soundings
show 60kts at top of mixed layer tomorrow and with a very strong
pressure gradient (NAM 3-hr press change over 60 ubars/km)
yields sustained winds 35 to 45 mph, with gusts up to 60 mph on
Wednesday. As a result and after collaboration with neighboring
offices, have upgraded portions of the area to a high wind
warning. This may need to be expanded even further east and will
let the evening and overnight crew make that decision based on
newer guidance and observational trends.
Precipitation Type Wednesday AM
Winds will switch over to the northwest after 12z Wed, with strong
CAA developing on the back side of the low. Rapid dynamic
cooling of the column will switch precipitation over to snow
from west to east during the AM commute. Snowfall rates around a
0.5"/hr for 1-2 hours at any given location may result in a
quick 1-2 inches on elevated and grassy surfaces mainly west of
a Dubuque to Memphis MO line. Unfortunately this will occur
during the strong winds, sharply reducing visibility under a
mile at times creating near whiteout conditions. An SPS may be
needed and motorists should prepare for slick and hazardous
travel tomorrow AM. Be sure to slow down while traveling!
Temperatures will struggle to climb much during the day Wednesday,
with very cold readings and wind chills in the teens.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 226 PM CST Tue Mar 4 2025
Wednesday night...strong surface low to fill and move east over the
Great Lakes. Winds to finally subside after 03z, with surface ridge
moving across IA. It will still feel quite brisk however, with lows
dropping into the upper teens to lower 20s.
Thursday...A rather nice day with much less wind and plenty of
sunshine as the high pressure ridge moves across. Highs will be in
the 40s.
The next storm storm system will arrive late Thursday night through
Friday evening with mainly snow, possibly mixed with rain. Global
models indicate a fast moving Colorado Low moving due east across
central MO. This system will be acting on a rather tight baroclinic
zone draped across the forecast area. Given this system following
somewhat quickly on the heels of the departing one it will not have
as much moisture to work with and so it would appear as though
snowfall amounts would be generally in the 1-2 inch range. Did lower
temperatures from what the NBM depicted given h8 temps in the
negative numbers and pcpn falling.
This weekend into early next week: Looks dry with a northwest flow
and normal temperatures for early March. Highs will be in the 40s
with lows in the 20s. Looking a little further ahead, the Climate
Prediction Center has 60-70% chance of above normal temperatures for
the middle of March. Normal highs are in the mid 40s and normal lows
in the lower 20s.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 601 PM CST Tue Mar 4 2025
A challenging aviation forecast continues over the next 24 to 30
hours as a deepening area of low pressure just east of Kansas
City will continue to lift northeastward tonight. Light to
moderate rainfall, along with VFR ceilings east to IFR ceilings
northwest lingering over most of the area for a time, although
a dry slot is beginning to lift northward over our southern
areas. Winds will become more variable in direction as the low
lifts over the area, but as it departs, expect winds to quickly
turn more northwesterly Wednesday morning and strengthen
significantly, with gusts between 40 to 50+ knots expected
across the area. Additionally, colder air will filter in from
the west, resulting in rain transitioning to snow. Although
snow accumulations are expected to remain light (up to 2 inches
in total), the concurrent winds should lead to a period of
blowing snow and reduced visibilties, but uncertainty on the
exact time of transition and the ability for snow to blow around
due to it being more of the wet, heavy variety remains.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...High Wind Warning from 6 AM to 9 PM CST Wednesday for IAZ040-
051-052-063-064-076>078-087>089-098-099.
High Wind Warning from 11 AM to 9 PM CST Wednesday for IAZ041-
042-053-054-065>068.
IL...High Wind Warning from 11 AM to 9 PM CST Wednesday for ILZ015-
024.
Wind Advisory from 11 AM to 9 PM CST Wednesday for ILZ001-002-
007-009-016>018-026.
Wind Advisory from 6 AM to 9 PM CST Wednesday for ILZ025-034-
035.
MO...High Wind Warning from 6 AM to 9 PM CST Wednesday for MOZ009-
010.
&&
$$
UPDATE...Schultz
SHORT TERM...Gross
LONG TERM...Gross
AVIATION...Schultz
Area Forecast Discussion
National Weather Service Grand Rapids MI
641 PM EST Tue Mar 4 2025
.KEY MESSAGES...
- Rain Moves Back in Tonight; Isolated Storm Possible Wednesday
- Windy and Colder with Some Light Snow Wednesday PM, Thursday AM
- Snow Showers Possible Friday, Mainly South of I-96
- Warming Temperatures Early Next Week
&&
.DISCUSSION...
Issued at 240 PM EST Tue Mar 4 2025
- Rain Moves Back in Tonight; Isolated Storm Possible Wednesday
The short break in rain is coming to a close and more rain will
move in this evening as well as tomorrow. A deepening area of low
pressure moves overhead by tomorrow with minimum central pressure
possibly getting down into the upper 970s mb, which is quite low.
Given the track of this system, we will be solidly in the warm
sector through Wednesday afternoon with highs expected to reach
the 50s. The 12z HREF shows surface based CAPE building after 15z
Wednesday with 100-200 J/kg. 12z HRRR soundings reveal that while
we`re in the warm sector, a few hundred J/kg of SBCAPE are
possible as a few low topped thunderstorms may develop in the
midst of no convective inhibition, at least from what the HRRR is
indicating. As such, we are adding a slight chance for
thunderstorms to the forecast for Wednesday (SPC already has us in
the General Thunderstorm outlook). Other than some lightning, any
storms that develop are not expected to be significantly
impactful.
We continue to expect area rivers and streams will be able to absorb
the anticipated rainfall amounts of 0.75"-1.25" with little to no
issue, though rises will occur. Some of the snowpack across the
Muskegon River basin will melt off into the rivers and add to the
amount of water going into the overall basin, while some may still
remain and take in the rain more like a sponge. Either way, the most
likely scenario is that we hold all rivers below flood stage through
this event.
- Windy and Colder with Some Light Snow Wednesday PM, Thursday AM
Temperatures fall from the 50s Wednesday afternoon down into the mid
to upper 20s Wednesday night with rain changing to snow. The snow
won`t last long enough to accumulate more than an inch or so, but
given the abruptly falling temperatures there could be some icy
spots on roads for the Thursday morning commute as leftover
puddles may freeze and a light coating of snow could cause some
slippery conditions especially on less traveled roads.
The pressure gradient on the back side of the departing low will
crank up winds as cold advection gets underway. Both CAMs and medium
range guidance all agree on excellent potential for 40+ mph gusts
area wide after dark Wednesday night and continuing into Thursday.
The highest gust potential of 45-50 mph looks to occur across our
lakeshore region during this time. These gusts could cause some
small branches to come down leading to a few power outages.
- Snow Showers Possible Friday, Mainly South of I-96
Ensemble and deterministic guidance is split on the outcome for
Friday as an upper wave exiting the Rockies moves east and tries to
phase with upper troughing across the Great Lakes region. A surface
low underneath this feature is likely to move east in a weakening
fashion and upper heights may be amplified enough to shunt this
feature south of our region. Nevertheless, there is enough ensemble
support (mainly from the GEFS) to include a risk for snow showers
primarily south of I-96 Friday. If the northern solution of the GEFS
verifies, an inch or two of snow could occur (probabilities for 1"
or more are shown to be 60-70% from the GEFS). The ENS shows this
outcome is less likely, with a 20-30% probability.
- Warming Temperatures Early Next Week
Rising upper heights and 850 mb temperatures increasing into the +5
to +10 C range could help boost surface temperatures into the 50s or
even 60s by next Tuesday and Wednesday. The majority of ECE members
currently have highs reaching the 60s during this time frame.
Ensemble guidance does suggest an upper wave could move through as
this early spring warmth makes an appearance, and this could bring
about an increase in rain chances by the middle of next week, with
some thunderstorms not out of the question.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 641 PM EST Tue Mar 4 2025
Our initial line of rain showers is currently impacting
MKG/LAN/JXN with additional rain showers developing behind it.
VFR cigs at present will trend to IFR after midnight as widespread
rain moves in with rain and patchy fog leading to IFR
visibilities. A dry slot moves in after 12z Wednesday leading to a
brief window of diminished shower activity and allowing
conditions to rebound to MVFR. However, instability will allow
numerous showers to develop after 16z Wednesday. Isolated
thunderstorms cannot be ruled out, especially for the inland
terminals. However given low confidence in thunder will leave out
of the TAF for now. Brief periods of IFR conditions are possible
in heavier showers or thunderstorms. Strong winds aloft will lead
to LLWS at all terminals tonight through Wednesday morning.
&&
.MARINE...
Issued at 228 PM EST Tue Mar 4 2025
A Gale Warning is being issued to handle the increased winds
expected on the back side of the departing storm system tomorrow
afternoon into Thursday morning. Northwest gales could approach
45 kts at times and help generate very large wave activity of 15
to 19 feet during this period. Hazardous winds and waves are still
expected Thursday afternoon which would impact small craft.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Gale Warning from 4 PM Wednesday to 10 AM EST Thursday for
LMZ844>849.
&&
$$
DISCUSSION...Hoving
AVIATION...Thomas
MARINE...Hoving
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
725 PM CST Tue Mar 4 2025
.KEY MESSAGES...
- Scattered showers and a few storms will continue through tonight
with another band of more organized showers/storms late this
evening and overnight.
- A Wind Advisory is in effect across central Illinois Wednesday
afternoon and evening for gusts of 45 to 55 mph.
- As colder air filters into the region Wednesday, rain will
transition to snow with a dusting of snow possible (50-60%)
north of I-70.
- Another system will bring rain and a mix of rain and snow to
portions of central Illinois Friday. Minor accumulations are
possible (70% confidence) along and north of Galesburg to
Bloomington.
&&
.UPDATE...
Issued at 725 PM CST Tue Mar 4 2025
Latest surface analysis shows 985 mb surface low centered
northeast of Kansas City this hour, with the main circulation on
radar a bit further south across west central Missouri. Dry slot
has worked into areas west of I-55 where precipitation has tapered
off to some patchy drizzle. Much of the thunder activity lately
has been increasing along the southern flank of the circulation,
where low level lapse rates are steeper.
Current run of the HRRR shows the low beginning to fill in a bit
as it moves into northern parts of central Illinois after
midnight. While showers and a few thunderstorms increase again
late this evening, a few hours of dry conditions return after
midnight. Getting closer to sunrise, showers and isolated storms
increase near and south of I-70.
Most recent updates were to mainly to adjust the precipitation
trends into Tuesday based on latest guidance. No changes made to
the Wind Advisory timing, with the main thrust of the strong
post-frontal winds moving into western Illinois late morning and
sweeping eastward through the afternoon.
Geelhart
&&
.DISCUSSION...
Issued at 116 PM CST Tue Mar 4 2025
REST OF TODAY AND TONIGHT...
This afternoon, a 990mb low is located over KS/OK and will lift
to NE MO late this evening deepening to near 980mb. Mid level warm
air advection will be in place across central Illinois ahead of
the low through this evening supporting at least scattered
showers and a few storms. A better organized band of showers and
storms will develop along an occluded front to our west and move
across portions of central Illinois this evening. Guidance
suggests weak instability rooted in or just above the boundary
layer will be present with this next band supporting a few storms
along with a low but non-zero severe threat late into the evening
if low-topped supercells form within the strongly sheared
environment. HREF joint probabilities for SBCAPE >100 J/kg and
deep layer shear greater than 30kt are roughly 40-50 percent
southeast of a SPI-CMI line from roughly 10pm through 4am.
WINDY WEDNESDAY...
Low pressure will lift from northern Illinois Wednesday morning
to northern lower Michigan Wednesday evening. A tight northerly
pressure gradient will overspread central Illinois in the wake of
the low along with moderately strong pressure rises of 5-6mb/3hr.
In addition, cold air advection will drive steep low level lapse
rates with mixing up to around 800mb Wednesday afternoon and
evening. NAM forecast sounding suggest mean gusts right around
advisory criteria (45 mph) with top of the channel winds in excess
of 60mph indicating the higher end potential for wind speeds. Hi-
res models show there will be a rapid uptick in wind speeds as
southerly winds turn northwesterly from the west Wednesday morning
and afternoon. NBM indicates 70-90 percent confidence in reaching
wind advisory criteria for max gusts on Wednesday, though only
has a 20-30 percent chance of reaching high wind warning criteria
(58 mph).
MORE PRECIP LATE IN WEEK...
After a brief break in the precip Thursday under the influence of
a transient ridge, attention turns back to the west as low
pressure takes shape over the Front Range of the Rockies. This low
will track across southern Illinois Friday afternoon and along
the Ohio Valley Friday evening. There has been a slight northward
shift in the track of this system but still expect rain on the
southern side of this system with a transition to snow as you head
north across central Illinois. NBM has shifted the probability of
accumulating snow (>0.1 inch) of around 70 percent north to a
Galesburg to Bloomington line with probs tapering off to only 10
percent along a Springfield to Tuscola line. 25th-75th percentile
"goal posts" for accumulating snow is roughly 0-2 inches along the
GBG-BMI line with 75th percentile amounts quickly tapering off
south.
DRY STRETCH THIS WEEKEND INTO NEXT WEEK...
High pressure will build from the Great Plains east across the
mid Mississippi Valley this weekend and will eventually settle
south of the Ohio Valley early next week. This should keep central
Illinois dry Saturday through Tuesday. As the ridge axis shifts
to our southeast early next week, return flow will allow for a
warming trend Monday into Tuesday with highs back in the 50s and
60s to start the upcoming week.
Deubelbeiss
&&
.AVIATION... (For the 00z TAFs through 00z Wednesday Evening)
Issued at 519 PM CST Tue Mar 4 2025
Prior to 12Z:
Area of showers and some embedded thunderstorms will lift
northeast through this evening. Ceilings will quickly drop to MVFR
from west to east early this evening, with some potential for a
few hours of IFR mainly in eastern Illinois. As low pressure lifts
into central Illinois, a few hours of ceilings above 4000 feet
can`t be ruled out, mainly near KSPI/KDEC. Gusty southerly winds
will continue through the night in eastern Illinois, but some
diminishment will take place further west with the low`s arrival.
After 12Z:
A strong cold front will sweep across the area midday and early
afternoon, quickly turning winds to the northwest and gusts ramp
up to 35-40 knots for the afternoon. Ceilings will be low through
the period, mainly 1000-1500 feet, with a few hours of IFR
ceilings late morning through midday. Rain increases with the
frontal passage, and as temperatures quickly drop, a rain/snow mix
or all snow will occur late afternoon. Some potential for IFR
visibilities in the heavier snow showers.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from noon Wednesday to midnight CST Wednesday
night for ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
536 PM CST Tue Mar 4 2025
.KEY MESSAGES...
- There is a chance (20-30%) for thunderstorms this evening. A few
of the storms could be capable of producing isolated wind gusts,
1 inch or large hail, and weak tornadoes.
- A Wind Advisory remains in effect from 600 AM until 600 PM on
Wednesday due to gusty northwest winds up to 45 to 55 mph.
&&
.SHORT TERM... (Through Late Wednesday Night)
Issued at 316 PM CST Tue Mar 4 2025
Strong low pressure centered about 40-50 miles south of Kansas City
will move northeast tonight to near Chicago by 12Z Wednesday. The
low will then continue moving northeast through the Great Lakes
Region Wednesday and Wednesday night. The second wave of rain
associated with this system is currently overspreading the forecast
area from the southwest. This warm advection stratiform rain is
mostly fairly light with rates generally well under 0.20 inches per
hour. A few embedded thunderstorms remain possible with this wave of
rain, but they are not expected to be severe as instability is very
limited according to short range guidance. This rain will continue
moving northeast this evening eventually ending from southwest to
northeast by mid evening.
CAMs have been very persistent in developing discrete convection
early this evening over southwest/south central Missouri, and
rotating those storms northeast through our area from around 01Z to
06Z. Both the RAP and GFS show an area of around 200 to as much as
400 J/Kg SBCAPE moving through the forecast area. While this isn`t
a particularly high number, the concern is that 0-1km shear will be
in the 25-30kt range with 0-1km helicity around 100 m2/s2. This
raises the possibility that this discrete convection could have
rotating updrafts and possibly produce isolated damaging wind gusts,
large hail, and/or tornadoes. This is by no means a sure thing,
with severe probs at only 5 percent, but it`s a threat that can`t be
ruled out.
Attention turns to wind on Wednesday in the cold sector of the
system. Very strong pressure gradient between the low to the
northeast and high pressure building west from the Great Plains will
produce sustained winds between 25-30kts and gusts up to around
45kts, so the Wind Advisory still looks good. Could see an isolated
wind gust up to 50kts across parts of northeast Missouri for short
period during the late morning, but most guidance shows gusts lower
than High Wind Warning criteria. Beyond the wind, cold air rushing
in behind the front will turn precip in the deformation zone behind
the low from rain to snow. Most guidance shows very minor
accumulations under an inch, but warm ground temperatures should
mitigate accumulations on roads. However, the increasing winds
combined with the snow could cause the visibility to intermittently
fall to 1 mile or less. Didn`t feel the potential impacts to
visibility were great enough to issue any kind of winter headline at
this time, however this bears watching and a short-fuse advisory may
be needed if the snow is heavier than anticipated. Precip will be
ending from west to east through the afternoon, and winds will
diminish Wednesday evening.
Carney
&&
.LONG TERM... (Thursday through Next Tuesday)
Issued at 316 PM CST Tue Mar 4 2025
Quieter weather still looks like the trend for Thursday through next
Tuesday. Temperatures fall to near or slightly below normal for
most of the period from Thursday through Sunday. First a cool high
pressure system builds into the Mississippi Valley on Thursday, and
then another low moves across Missouri into the Ohio Valley Friday
into Friday night, bringing in another cool airmass in behind it.
Temperatures do come up a few degrees above normal for most
locations on Friday ahead of the low. However, medium range guidance
is showing some variability on the track of the low, and
temperatures will be highly dependent on how far north/south it
tracks. LREF 500mb EOF patterns are showing some variance in the
amplitude of the short wave driving the low across Missouri, and the
interquartile range of temperatures from the LREF is as much as 10
degrees on Friday afternoon. All this does not lend a particularly
high degree of confidence in Friday`s temperature forecast, but it
does look like the warmest day for most locations through Sunday.
Deterministic guidance shows some light QPF in the warm advection
wing of the system early Friday morning, but temperatures in the
column look warm enough for most of the precip to remain liquid,
with possibly a few wet flakes mixing in across northeast Missouri
and west central Illinois. Saturday through next Tuesday still look
dry with temperatures warming well above normal for the beginning of
the work-week as an upper level ridge builds across the Mississippi
Valley.
Carney
&&
.AVIATION... (For the 00z TAFs through 00z Wednesday Evening)
Issued at 524 PM CST Tue Mar 4 2025
A deepening low pressure system currently located in NW MO will
move east-northeast through northern MO tonight and then northeast
into the Great Lakes region on Wednesday.
Predominately MVFR flight conditions are expected tonight and
Wednesday. Tonight they will be due to a combination of lower
ceilings and another round of showers this evening. I have not
included any thunder in the TAFs for this evening but would not be
surprised for a brief period at KCOU or KJEF. Winds tonight will
veer from southeasterly to southerly to southwesterly and will be
gusty at times.
On Wednesday the deepening surface low will drive a cold front
through the area, early in the morning (around 10z) at KJEF and
KCOU and a little later at KUIN (11z) and the St. Louis terminals
(14-15z). This front will bring additional precipitation, rain
changing to snow with MVFR and occasionally IFR flight conditions.
Very strong and gusty northwest winds will also occur in the wake
of the cold front passage.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Wind Advisory from 6 AM to 6 PM CST Wednesday for Audrain MO-
Boone MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-
Gasconade MO-Iron MO-Jefferson MO-Knox MO-Lewis MO-Lincoln
MO-Madison MO-Marion MO-Moniteau MO-Monroe MO-Montgomery MO-
Osage MO-Pike MO-Ralls MO-Reynolds MO-Saint Charles MO-
Saint Francois MO-Saint Louis City MO-Saint Louis MO-Sainte
Genevieve MO-Shelby MO-Warren MO-Washington MO.
IL...Wind Advisory from 6 AM to 6 PM CST Wednesday for Adams IL-Bond
IL-Brown IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-
Jersey IL-Macoupin IL-Madison IL-Marion IL-Monroe IL-
Montgomery IL-Pike IL-Randolph IL-Saint Clair IL-Washington
IL.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Memphis TN
931 PM CST Tue Mar 4 2025
...New UPDATE...
.KEY MESSAGES...
Updated at 922 PM CST Tue Mar 4 2025
- Strong westerly winds are expected through Wednesday evening.
Expect gusts over 40 mph at times.
- Mostly dry weather and seasonal temperatures will return to the
Mid-South for Wednesday and Thursday. Scattered showers return
for Friday night through Saturday night.
&&
.UPDATE...
Issued at 922 PM CST Tue Mar 4 2025
The main complex of showers and thunderstorms has pushed east of
the Tennessee River, ending the severe threat across the region.
Another area of showers and isolated thunderstorms has formed over
northeast Arkansas. A strong storm or two is possible as this area
of convection pivots northeast through the Missouri Bootheel.
Gusty winds up to 50 mph is possible with any strong storms. The
rest of the area will remain mostly dry and windy through tomorrow
morning.
Updated the wind advisory to reflect the slightly weaker winds
through tomorrow evening. Small tweaks were made to temperature
grids based on current trends. Temperatures will cool overnight
into the low to mid 40s. A low level stratus deck will move into
the region tomorrow morning.
AC3
&&
.DISCUSSION...
(This evening through next Monday)
Issued at 138 PM CST Tue Mar 4 2025
A powerful upper low is pushing across the Southern Plains this
afternoon. The associated occluded front is moving across Arkansas
with a broad area of showers covering the Mid-South. Embedded
within the showers is a line of storms pushing into the Delta.
Gradient winds continue to be quite strong with frequent gusts to
40 mph and occasional gusts to 50 mph. A 70-80 kt low level jet
core will slide across the area in advance of the line of storms.
Showers ahead of the line could bring down some of those stronger
winds just above the surface.
The question for the late afternoon and evening remains the extent
of the severe weather risk across areas south of I-40 and east of
I-55. Instability continues to be lacking with the latest
mesoanalysis placing significant values only as far north as
northern Louisiana. Only a couple of members of the 12z HREF
bring minimal amounts of SBCAPE into parts of the north MS late
this afternoon and evening. As a result, we cannot completely rule
out a tornado along this line of storms but the threat is pretty
low. Primary risk continues to be damaging winds as perhaps
stronger winds can be transferred to the surface as the line moves
through. The WoFS shows some support for this scenario. However,
the convection needs to become more robust, like the HRRR is
depicting, for this to occur.
The line of storms will exit into Middle TN and northern AL by mid
evening. Winds will shift to the SW and remain gusty all night. As
the system moves toward the Great Lakes the gradient remains
tight across the Mid-South on Wednesday. Wind gusts to 40 mph
will be common, especially across NE AR and the MO Bootheel. A
Wind Advisory continues areawide through 6 pm Wednesday. Expect
cooler temps on Wednesday with highs in the 40s and lower 50s.
Weak high pressure will build in Wednesday night with decent
radiational cooling which will allow temps to fall into the upper
20s and lower 30s. Temps will warm toward the end of the week as
zonal upper flow returns and SW winds develop by Friday. Highs
will reach into the 60s and lower 70s by Friday.
A fast moving low will race across the northern part of the Mid-
South or the Ohio Valley Friday night with a chance of showers
across eastern areas. Another system is expected to move by to
the south with a chance of showers sometime Saturday or Saturday
night. Location and timing of these systems are still uncertain
and confidence is low. Dry and mild weather will return for early
next week.
&&
.AVIATION...
(00Z TAFS)
Issued at 529 PM CST Tue Mar 4 2025
A busy aviation period will persist as precipitation, gusty winds,
and MVFR CIGs impact the airspace. Showers and embedded
thunderstorms will persist through the next few hours, with TUP
most likely to see any TS activity. Overnight, winds will shift
more westerly and increase in speed, gusting to around 30 kts.
MVFR CIGs look to move in by sunrise and will persist through the
remainder of the period.
ANS
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Wind Advisory until 6 PM CST Wednesday for ARZ009-018-026>028-
035-036-048-049-058.
MO...Wind Advisory until 6 PM CST Wednesday for MOZ113-115.
MS...Wind Advisory until 6 PM CST Wednesday for MSZ001>017-020>024.
TN...Wind Advisory until 6 PM CST Wednesday for TNZ001>004-019>022-
048>055-088>092.
&&
$$
PUBLIC FORECAST...SJM
AVIATION...ANS
Area Forecast Discussion
National Weather Service Morristown TN
929 PM EST Tue Mar 4 2025
...New UPDATE...
.UPDATE...
Issued at 915 PM EST Tue Mar 4 2025
Radar shows rain just starting to encroach on our southwest
corner, and forecast timing is looking decent so far. The
better defined line is still to our southwest, and will begin
moving in between 11 PM and midnight. Convective energy is
lacking, but there still may be a few rumbles of thunder and a
marginal threat of severe exists with damaging winds the main
threat. Of course the Plateau, much of SW VA, and the mountains
of E TN are still under a high wind warning, so damaging winds
will likely already be occurring well ahead of the line in some
locations. We have seen wind gusts to around 70 mph already at
Cove Mountain and Camp Creek TN where mountain wave enhancement is
occurring, and wind gusts in excess of 40 mph have already been
observed even in portions of the valley. The wind warnings and
advisories will continue as they are for now.
As for the enhanced fire danger, there have been fires occurring
across the area and even though the RH values have risen
substantially, will keep the Red Flag Warning and Fire Danger SPS
going through the evening given the strong winds.
Only minor changes with this update.
&&
.SHORT TERM...
(This evening through Wednesday)
Issued at 345 PM EST Tue Mar 4 2025
Key messages:
1. Fire weather danger stays high into the evening as strong
winds overlap lingering dry air and resulting low RH values.
2. A high end mountain wave wind event, with the potential for
wind gusts up to 100 mph tonight is taking shape this afternoon
through late tonight for the east Tennessee mountains and adjacent
foothills.
3. While damaging winds from thunderstorms are not out of the
question given the strong winds aloft, overall severe weather
threat is still low tonight.
4. Strong winds continue behind the front Wednesday.
Discussion:
A strong upper low is over eastern Oklahoma this afternoon and
should reach the mid- Mississippi river valley by late tonight,
with a cold front and associated line of convection moving east
through the forecast area late tonight and early Wednesday. Ahead
of the front, a high end mountain wave wind event will occur
across our area. Lingering low humidity values this afternoon and
into the evening is making for some high wildfire danger so have
extended the Red Flag Warning until midnight. The risk for the
showers and thunderstorms along/ahead of the front to increase
winds still poses a low risk of damaging winds late tonight.
Dewpoints have now risen to the 30s and 40s in the northeast TN
valley. They will slowly rise overnight so have kept using low
guidance with respect to dewpoints today. A mix of the NBM 10th
percentile and some HRRR and CONSShort. Wind Gusts in excess of
40-50 mph have already occurred in the downslope areas of Greene
and Sevier County and should continue to increase overnight.
Gusts in excess of 30 mph have spread across the lower elevations
in the Tennessee Valley this afternoon and over the plateau around
40 mph or higher so have added the plateau counties to a high
wind warning. As far as winds go, the background wind field with
this system is quite impressive. Another aspect of the winds with
this system will be the dry slot mixing behind the front during
the day Wednesday. Advisory level wind gusts in the lower
elevations of 40-50 mph during the day tomorrow looks good due to
deep mixing tapping into the elevated winds aloft.
The chance of severe storms tonight ahead of the front remain low
mainly due to low instability when the convection arrives. Chances
aren`t zero and the winds aloft or so high that any respectable
updraft could manage to cause some wind damage. SPC still has a
damaging winds risk equal to the Marginal risk in the Day 1
convective outlook which is most of the forecast area. The highest
odds, relatively speaking, are likely going to be confined to the
far southern Cumberland plateau and southern Tennessee valley.
Temperatures also Wednesday over most of the region as cold air
advection moves in behind the cold front.
&&
.LONG TERM...
(Wednesday night through next Tuesday)
Issued at 345 PM EST Tue Mar 4 2025
Key Messages:
1. Light snow possible late Wednesday night, especially along the
Cumberland Plateau to southwest Virginia, and higher elevations
along the North Carolina border.
2. Gusty winds will be on the decline through the day on Thursday.
3. Higher uncertainty regarding precipitation over the weekend, but
snow in the mountains is possible.
Discussion:
Wednesday night will usher in our 3rd season of the week with the
return of winter to the southern Appalachians. Temperatures will
plummet Wednesday night through Thursday morning. Dropping to near
or below freezing across the region with the higher elevations
likely to drop into the 20`s. This will combine with the wrap around
precipitation on the south side and backside of the slowly departing
low pressure system moving northeast into Canada. This overnight
cross-over of sub freezing temperatures and light precipitation will
likely cause any lingering precipitation to switch over to snow for
parts of the overnight hours. Currently accumulations in the valley
still look to remain light with a dusting possible in northeast TN
and southwest VA. In the Cumberland Plateau, higher elevations of SW
VA, and southern Appalachian Mountains we`ll have a much better
chance to see accumulating snowfall. We could see up to an inch
along the Plateau and SW VA, and in the tops of the southern
Appalachian Mountains where elevations exceed 4,000 feet we could
see closer to 3 inches of accumulations by Thursday morning.
Confidence is still somewhat low at this with regards to
accumulating snowfall as the recent sun and warm temperatures have
risen ground temps that will likely melt off a good portion of the
initial snowfall, especially in the Valley locations where the temps
are expected to only briefly get down to the freezing mark
overnight. A winter Wx Advisory may be need for some counties,
especially the mountain zones once the event gets closer.
Skies clear out and temperatures will warm up a some on Thursday
which will help melt off some of the snowfall that could occur
overnight, but we`ll still hover around 10 degrees below seasonal
normals Thursday (which will be the coldest day of this forecast).
Quasi-zonal flow in the mid levels and surface ridging will help to
slowly warm up temperatures as we head into the weekend. The weekend
will see our next chance for precipitation as a fast moving surface
low and upper trough looks to zip through the Ohio Valley... Quickly
followed up by a southern stream system traversing closer to the
Gulf. Both of these systems currently are not forecasted to have a
lot of dynamics associated with them, and will hopefully bring with
it just widespread showers and rain. Temperatures during the
overnight hours Saturday into Sunday will drop low enough to warrant
the mention of snow in the higher elevations of the Plateau,
southwest VA, and the Appalachian Mountains. Currently the snow
amounts look to be lower than what we`ll get on Wednesday into
Thursday, but it will be worth keeping an eye on as the mountains
could pick up a few more inches of snow if the current forecast pans
out.
Quick warm up expected early next week as ridging and surface high
pressure combine to help drive temperatures back into the upper 60`s
or 70`s by Tuesday.
&&
.AVIATION...
(00Z TAFS)
Issued at 634 PM EST Tue Mar 4 2025
Will see a band of showers move through tonight, and there may be
a few rumbles of thunder mainly CHA. Cigs/vsby may drop briefly to
MVFR with the heavier showers, but conditions will be mainly VFR
overnight. Later in the period some additional showers will be
moving in, and cigs are expected to drop to MVFR levels at CHA and
TYS before the end of the period. Winds will be gusty from the
southeast and south, becoming more southwest Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 52 59 34 53 / 100 30 20 0
Knoxville McGhee Tyson Airport, TN 53 60 32 49 / 100 50 50 0
Oak Ridge, TN 51 59 32 49 / 100 50 50 0
Tri Cities Airport, TN 52 64 31 44 / 100 70 50 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Wind Advisory until 4 PM EST Wednesday for Cherokee-Clay.
TN...Wind Advisory until 4 PM EST Wednesday for Anderson-Bradley-
Claiborne-East Polk-Grainger-Hamblen-Hamilton-Hancock-
Hawkins-Jefferson-Knox-Loudon-McMinn-Meigs-North Sevier-
Northwest Blount-Northwest Carter-Northwest Cocke-Northwest
Greene-Northwest Monroe-Rhea-Roane-Sullivan-Union-
Washington TN-West Polk.
High Wind Warning until 4 PM EST /3 PM CST/ Wednesday for
Bledsoe-Blount Smoky Mountains-Campbell-Cocke Smoky
Mountains-Johnson-Marion-Morgan-Scott TN-Sequatchie-Sevier
Smoky Mountains-Southeast Carter-Southeast Greene-Southeast
Monroe-Unicoi.
Red Flag Warning until midnight EST tonight for Blount Smoky
Mountains-Cocke Smoky Mountains-Johnson-Sevier Smoky
Mountains-Southeast Carter-Southeast Greene-Southeast
Monroe-Unicoi.
VA...Wind Advisory until 4 PM EST Wednesday for Scott VA.
High Wind Warning until 4 AM EST Wednesday for Lee-Russell-
Washington VA-Wise.
Wind Advisory from 4 AM to 4 PM EST Wednesday for Lee-Russell-
Washington VA-Wise.
&&
$$
SHORT TERM...TD
AVIATION...
Area Forecast Discussion
National Weather Service Paducah KY
551 PM CST Tue Mar 4 2025
.KEY MESSAGES...
- A band of rain with a slight chance of embedded thunderstorms
will move east across the Quad State into the evening. The
rain should last 3 to 5 hours and should exit the region by
midnight.
- A Wind Advisory is in effect for the entire Quad State region
through 6 PM Wednesday. Gusts of 40 mph and greater will be
possible outside of the rain and thunderstorms and even
stronger winds will be possible with stronger showers or
storms.
- Temperatures will fall through the night and all day
Wednesday. Temperatures will fall into the middle and upper
30s over northern portions of the region Wednesday afternoon.
Scattered to numerous showers are expected over much of the
region Wednesday. Some of those could mix with or change over
to snow across the northern half of the region Wednesday
afternoon and evening.
- Temperatures will be on the cool side Thursday. A brief warm
up on Friday will be followed by cool conditions again over
the weekend, and then more warming early next week.
&&
.UPDATE...
Issued at 550 PM CST Tue Mar 4 2025
Updated aviation discussion for 00Z TAFs.
&&
.DISCUSSION...
Issued at 310 PM CST Tue Mar 4 2025
Very gusty southeast winds have developed today over most of the
region in response to a highly anomalous surface low center
over eastern Kansas. Frequent gusts 35 to 45 mph have occurred
over much of the region today. The rain has pressed across
southeast Missouri this afternoon and the rain and cloud cover
has helped to contain the winds a bit. Expect gusts to subside
some as the clouds and rain spread over eastern portions of the
region in the next few hours.
We are still in a Marginal Risk for severe storms/showers
through the evening. Surface instability is virtually nil, but
the HRRR has consistently developed a fine line within the rain
shield somewhere east of the Mississippi this evening. Any
damaging wind potential will likely be associated with this
feature this evening.
Some clearing is possible behind the rain tonight. However, the
HRRR has consistently developed a cluster of showers that moves
northeast across the region overnight. The HRRR is bringing
40+kt winds down to the surface associated with these showers,
so the Wind Advisory will definitely be useful overnight.
As the surface low lifts northeast to Lake Michigan by midday
Wednesday, winds over the Quad State will shift to the southwest
early in the morning and then to the west for the afternoon. The
ECMWF has been consistently indicating near 100% probability of
wind gusts for 40 mph or greater, so the Wind Advisory looks
good for tomorrow, and may even need to be extended into the
evening over the northern half of the region.
We will see scattered to numerous showers rotate east or
southeast across the region through the day Wednesday. Also,
temperatures will plummet quickly through the 40s and into the
mid and upper 30s in northern locales in the afternoon. The cold
temperatures could allow for some snow showers to mix with the
rain showers, and a dusting is possible mainly on elevated and
grassy surfaces. The ground is warm, so road surfaces should
remain wet, and once it comes to an end in the east in the
evening, the wind should quickly dry off the roads, before they
could freeze up.
Thursday will be cool and dry, as the flow aloft relaxes. By
Friday we will be in strong west southwest flow aloft and winds
at the surface will quickly become southerly. There will be a
split flow situation, with a northern stream disturbance
tracking from the Missouri Valley into the Ohio Valley Friday
night. This could give a glancing blow of some light showers
across the north and east. A southern stream system will then
slip by to the south of the Quad State Saturday and Saturday
night. Guidance has shifted farther south and generally keeps
our area dry.
In the wake of these two systems, a large upper ridge will
develop out west Sunday, and then build over the center of the
country early next week. South winds will crank up and
temperatures will climb well above normal levels early next
week. Surface high pressure will have the Gulf tied up, so as
south winds crank up, elevated fire concerns may develop Monday
and Tuesday.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 550 PM CST Tue Mar 4 2025
An area of showers will continue to move east across the area
this evening, yielding a temporary reduction to MVFR and briefly
IFR conditions. Winds should be more subdued this evening, but
a localized gust of 35 knots or greater is possible with the
heaviest showers and any isolated thunder. A period of VFR
conditions is expected behind the rain later this evening into
the overnight hours. MVFR conditions and scattered showers will
spread back southeast across the area late tonight and through
the morning Wednesday. Winds will shift to the south tonight and
then to the west in the morning. Gusts over 30 knots will be
possible after sunrise.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...Wind Advisory until 6 PM CST Wednesday for ILZ075>078-080>094.
MO...Wind Advisory until 6 PM CST Wednesday for MOZ076-086-087-100-
107>112-114.
IN...Wind Advisory until 6 PM CST /7 PM EST/ Wednesday for INZ081-
082-085>088.
KY...Wind Advisory until 6 PM CST Wednesday for KYZ001>022.
&&
$$
UPDATE...RJP
DISCUSSION...DRS
AVIATION...RJP
Area Forecast Discussion
National Weather Service Springfield MO
544 PM CST Tue Mar 4 2025
.KEY MESSAGES...
- Marginal (1 of 5) risk for severe storms through the evening.
Quarter-sized hail, wind gusts up to 60 mph, and a low
potential (2% chance) for tornadoes with any afternoon storms.
- Wind gusts of 45-60 mph late tonight and Wednesday with the
highest gusts north of a Columbus, KS to Warsaw, MO line.
Isolated to scattered power outages possible.
- Rain transitions to snow overnight with snow persisting into
Wednesday morning. Slushy accumulations of a dusting to an
inch with localized amounts up to 1.5". The combination of
falling and blowing snow will reduce visibilities to less than
a half mile at times.
- Winter Weather Advisory in effect from 3 AM to 9 AM generally
north of a Fort Scott, KS to Ozark, MO to Ft. Leonard Wood
line. The advisory is in effect due to the expected slushy
snow accumulations, reduced visibilities, and these
conditions occurring during the morning commute.
&&
.MESOSCALE...
Issued at 110 PM CST Tue Mar 4 2025
Redevelopment Potential This Afternoon:
Surface observations depict a rapidly intensifying low pressure
(~990mb) system across portions of south central Kansas. The
initial showers and thunderstorms associated with the occluded
front are currently lifting north and east of the area. On the
backside of this activity, a wake low has been observed
supporting wind gusts upwards of 40 to 50 mph. This will
gradually weaken on its eastward trajectory. Meanwhile, visible
satellite imagery depicts a large clearing across south central
Kansas into central Oklahoma. This clearing is associated with
the dry slot of the low pressure system. The cold front is
draped just behind this clearing, and will shift east over the
next few hours.
Recent mesoscale trends would suggest some marginal
destabilization to occur in the clearing to the west, and will
be the focus for potential redevelopment of isolated showers
and a few thunderstorms as it nudges into far southeast Kansas
and southwest Missouri through mid-afternoon. However, the
remaining uncertainty is the extent of destabilization. RAP
analysis would suggest upwards of 250-500 J/kg CAPE nosing into
our area by late afternoon. This begs an additional question, is
there enough forcing present to overcome an existing cap and
subsidence? While that it is to be determined as the mesoscale
environment shows its cards, there remains a favorable shear
environment across the Ozarks region to sustain convective
updrafts.
Exploring the scenario further of isolated showers and a few
thunderstorms successfully developing, what are the associated
hazards? The background environment in the wake of the
departing line is quite overworked. But, as previously
mentioned, can we modify that environment to the west. In the
scenario we do, a few isolated cells develop across southeast
Kansas into southwest Missouri by late afternoon. A few CAMs
highlighted this potential over the last 12 to 24 hours, but
have sense become less aggressive in the extent of coverage,
with less consistency from run to run. A modified environment
with modest mid-level and low-level lapse rates would support
some stronger updrafts, generally low-topped supercells in
nature. Potential hazards with an established low-topped
supercell include hail up to the size of quarters, damaging wind
gusts up to 60 mph, and an isolated tornado. Overall,
confidence has decreased in the development of low-topped
supercells. However, an additional concern is any cells that do
develop may produce a stray landspout or two given the presence
of 0-3km low-level CAPE with high amounts of surface vorticity.
Overall, we are not looking at widespread strong to severe
thunderstorms. Rather, a low confidence scenario in an
isolated strong to marginally severe thunderstorm remains
plausible, in addition to the landspout potential. This activity
dissipates beyond the early evening hours after sunset, as
instability is already a factor working against development.
Localized heavy downpours may accompany any isolated cells,
though flooding is not a concern at this time.
&&
.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 258 PM CST Tue Mar 4 2025
See MESOSCALE section above for severe thunderstorm expectations
through this evening.
Synoptic Setup Overnight and Wednesday:
Strong surface low pressure will continue to rapidly deepen
overnight as it tracks east across northern Missouri. Short
term ensembles then have the low dropping below 980 mb as it
swings northeast into the southern Great Lakes on Wednesday. A
strong cold front will trail the low and will reach the KS/MO
state line by 9 PM. The front will steadily march east across
the area overnight and will clear the eastern Ozarks by 3 AM.
Wind Speeds, Gusts, and Potential Impacts:
Surface winds will shift to the west and then northwest behind
the passing cold front with speeds increasing as strong
pressure rises begin to overspread the region. Isallobaric
accelerations in combination with the strong low-level pressure
gradient will support sustained winds of 25-35 mph.
Wind gust potential is particularly concerning as strong cold
air advection mixes out the low-levels and increases momentum
transfer. 925 mb winds will increase into the 45-55 knot range
which will be supportive of surface wind gusts of 45-60 mph. The
strongest gusts will occur north of a Columbus, KS to Warsaw,
MO line where the Wind Advisory has been upgraded to a High Wind
Warning. We also moved the start time to 10 PM. Scattered power
outages will be possible in the warning area. A Wind Advisory
is in effect for the remainder of the Missouri Ozarks and
southeast KS from midnight through Wednesday. Isolated power
outages are possible in the advisory area. Travel will also be
difficult for high profile vehicles.
There are a few other factors worth mentioning which may lead to
some alterations to wind headlines (and speeds contained
within). We will have to watch higher terrain along the Ozark
Plateau for potential expansion of the High Wind Warning given
that there will be less vertical distance to cover with momentum
transfer. Another low-end probability to at least consider will
be the potential for the development of a sting jet within this
rapidly deepening cyclone. If this feature were to develop, the
location would be closer to the surface low track near the I-70
corridor (north of our area). A sting jet would result in even
stronger momentum transfers from higher levels in the
atmosphere.
Potential Winter Impacts:
Confidence is then very high (90-100%) that rain will change to
snow on the back side of this system. Surface temperatures will
plummet through the 30s with most locations in the 28-33 degree
range by sunrise on Wednesday. HREF output does reveal that a
brief period of freezing rain and/or sleet may accompany the
transition from rain to snow. Inspection of HREF members does
indicate that heavy pockets of snow will be embedded within the
broader region of wrap-around snow. This scenario corresponds
well with increased omega in the 285-290K potential temperature
layer (near and just south of the 700 mb low track). This gives
us three concerns regarding potential impacts:
1) Minor slushy snow accumulations from a dusting to an inch
with localized pockets up to 1.5".
2) Visibilities reduced to less than a half-mile with brief
periods of less than 1/4 mile visibilities.
3) The main impacts will occur during the morning commute.
Regarding accumulations, most areas will see at least a dusting
of snowfall within the wrap-around band. However, areas that
experience heavier bursts of snow will push an inch of
accumulation with localized amounts up to 1.5". Areas that
receive these heavier rates will have increased potential for at
least some road impacts, especially on untreated roadways.
The combination of falling snow and the strong and gusty winds
will cause significant restrictions to visibilities over
localized areas, especially where brief moderate to heavy
snowfall occurs. HREF probabilities of less than 1/4 mile
visibilities (a proxy for near blizzard-like conditions) are
running from 20-60% with the highest values between I-49 and
Highway 63 and generally north of Highway 60.
Given the potential for slushy road conditions, significant
visibility reductions, and these impacts occurring during the
morning commute, we have opted for a Winter Weather Advisory
generally north of a Fort Scott, KS to Ozark, MO to Ft. Leonard
Wood line. The Winter Storm Severity Index shows the potential
for Minor to Moderate impacts within this area, largely due to
blowing snow.
We ran the advisory from 3 AM through 9 AM to cover the peak
potential impact period. We may need to add counties farther
east towards Rolla and Salem if the wrap-around snow band (and
associated impacts) persist.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 258 PM CST Tue Mar 4 2025
Thursday-Sunday: Ensemble guidance depicts an upper-level ridge
building into the central CONUS by Thursday, with return flow
at the surface. This will support a rebound of temperatures to
near normal for early March, with highs in the lower 50s. This
warming trend continues into early Friday. However, as quick as
one trough passes, another digs into the the desert Southwest.
This trough and an associated low pressure system are progged to
sweep through the central CONUS on Friday into Saturday. While
some timing differences still exist, the daily highs are
expected to occur earlier in the day. For this reason, NBM
continues to highlight a larger spread for temperatures on
Friday. An initial analysis of the synoptic pattern suggest
minimal moisture return ahead of this trough and associated
frontal passage. As a result, rain chances remain low (10-20%).
Gusty northwest winds funnel in behind the frontal passage on
Friday. This sets the stage for a return of near normal
temperatures through the weekend with highs in the 50s and drier
conditions.
Next Week: Confidence continues to increase in a warming trend
building across the region into early next week as we approach
mid- March. This is supported by CPC 6-10 and 8-14 day
temperature outlooks. Ensembles suggest departure from normals
around 10 to 15 degrees above normal. This would support highs
at least in the middle to upper 60s, with 70s plausible.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 530 PM CST Tue Mar 4 2025
Showers and thunderstorms will continue to remain near the TAF
sites through this evening. Rain will then transition over to
snow at JLN and SGF after 06z, continuing through 12z then
decreasing. Ceilings will gradually lower through MVFR then into
IFR overnight. West to northwest winds will increase tonight
with gusts of 35-45kts after midnight through Wednesday morning
which will reduce the visibility in the snow at SGF by 9-12z.
Low level wind shear is likely at the sites overnight.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...High Wind Warning from 10 PM this evening to 6 PM CST
Wednesday for KSZ073-097-101.
Winter Weather Advisory from 3 AM to 9 AM CST Wednesday for
KSZ073.
MO...High Wind Warning from 10 PM this evening to 6 PM CST
Wednesday for MOZ055-066-067-077.
Winter Weather Advisory from 3 AM to 9 AM CST Wednesday for
MOZ055-056-066>070-077>081-088>092-094-095.
Wind Advisory from midnight tonight to 6 PM CST Wednesday for
MOZ056>058-068>071-078>083-088>098-101>106.
&&
$$
MESOSCALE...
SHORT TERM...Schaumann
LONG TERM...Perez
AVIATION...Burchfield