Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/09/20
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
625 PM MDT Sun Mar 8 2020
.AVIATION...
00Z TAF CYCLE
Rain showers and mountain snow showers will continue through the
evening with northeast and southwest areas least favored. Models also
depict a few thunderstorms passing through central areas around
Albuquerque and Santa Fe. Some snow showers may linger in the
northern and south central mountains until around 09Z or so. Skies
will generally clear after midnight allowing some patchy low clouds
and perhaps some fog to develop. Locations that recently received a
fresh soaking and high valleys with fresh snow will be favored for
some localized fog, which will evaporate by mid morning Monday.
44
&&
.PREV DISCUSSION...430 PM MDT Sun Mar 8 2020...
.UPDATE...
Did a quick update to trend QPF values upward tonight across the
southeast. Updated NBM and HRRR guidance is suggesting higher QPF
values for this region, and this correlates well with what has
already fallen over the area.
15
&&
.PREV DISCUSSION...224 PM MDT Sun Mar 8 2020...
.SYNOPSIS...
Monday will be a nice one for the Land of Enchantment that will
feature dry weather and warm temperatures. However, an active week is
ahead as deep moisture streams into the area ahead of a large storm
system off the coast of California. The system will be slow to move
into the area, but a few disturbances ahead of it will generate
rounds of rain and high elevation snow through the week.
Precipitation on Tuesday will favor western New Mexico before
activity spreads into central New Mexico Wednesday and Thursday.
Friday will likely be the most active day of the week as the system
finally moves over the state. Significant rain totals look likely for
northern and central New Mexico. Drier weather will return for the
weekend.
&&
.DISCUSSION...
SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)...
Satellite imagery early this afternoon depicts a very impressive
plume of subtropical moisture surging northeast into the southwest
CONUS ahead of a weak shortwave trough. 00Z NAEFS mean PW values
still show record values for southeast NM thru early this evening.
Despite the highly anomalous moisture tap there is only weak forcing
to wring out significant precip across the region. Models remain in
very good agreement with developing showers and storms in the area
between Grants and Socorro by 4 pm as a frontal passage approaches
from the west with the shortwave trough. This activity then moves
northeast through the ABQ metro and across the Sandia Mts through 8
pm. Several guidance members indicate precip lingering along west
facing slopes of the central mt chain thru midnight before ending
with much drier air arriving from the west. Temps will be cold
enough for light snow above 9,000` in the northern mts with 1-2"
possible.
Flow aloft will become zonal Monday with much drier air and weak
warm advection across NM. Max temps will rebound closer to normal
for much of the area except eastern NM where breezy west winds warm
temps near 10F above normal. The next batch of mid and upper level
cloud cover will invade from the west Monday night allowing for
above normal low temps once again Tuesday morning.
Guyer
LONG TERM...(TUESDAY THROUGH SUNDAY)...
An active week is upcoming for the area thanks to a large upper-
level low that will be off the coast of SoCal by Tuesday.
Southwesterly flow ahead of this system will tap into deep sub-
tropical moisture, and PWAT values of 0.5 to 0.6 inches in the KABQ
area by Tuesday evening could be near record. The low will be slow
to move into the desert SW, but as it rides the coast of SoCal and
Baja CA through Thursday, it will send a few embedded shortwaves
ahead of it into our area that will generate rounds of rain and high
elevation snow throughout the week.
Activity on Tuesday will favor western NM, generally areas along and
west of the Continental Divide. Activity will gradually spread into
central NM Wednesday and Thursday as the low gets closer and moisture
continues to increase. The low finally ejects northeastward over the
Baja peninsula and southern AZ Thursday night. The low will continue
to move northeastward through central and northern NM Friday which
will result in likely the wettest day of the week across the area.
Temperatures will also trend downward on Friday as the low moves
through, and the cooler air will be further enforced by a backdoor
cold front that moves through the plains late Thursday. Despite this,
this warm system will keep snow levels high with any accumulations
happening above 9000 feet. The low ejects into the Great Plains by
late Friday, and the weekend looks to be quieter as drier air moves
in. The 12Z operational runs of the GFS and ECMWF and their ensembles
have come into better agreement regarding the track of this low, but
still disagree on other details such as precipitation amounts and
the timing of the aforementioned backdoor cold front. Bottom line
through, significant precipitation looks likely for northern and
central NM.
15
&&
.FIRE WEATHER...
Light rain showers with a few thunderstorms along and east of the
Cont Dvd today will exit the area tonight. Much drier air will
arrive Monday afternoon with breezy west to southwest winds over
much of the area. Thicker cloud cover will move into the area again
Monday night with a few showers expected for western NM Tuesday. A
prolonged period of unsettled weather conditions with valley rain
and very high terrain snow is expected Wednesday through Friday with
the most significant precip likely on Friday. Drier southwest flow
with warmer temps is anticipated Saturday and Sunday ahead of yet
another storm system taking shape along the west coast.
Guyer
&&.ABQ WATCHES/WARNINGS/ADVISORIES... None.
&&
$$
Area Forecast Discussion
National Weather Service Binghamton NY
748 PM EDT Sun Mar 8 2020
.SYNOPSIS...
High pressure will bring warm temperatures and dry conditions
through Monday. Showers will return Tuesday when a cold front
moves through NY and PA.
&&
.NEAR TERM /THROUGH MONDAY/...
640 pm update...
Very quiet weather continues this evening with no significant
changes made to the forecast.
215 PM update...
Clouds dissipated as they slid eastward and out of the region
this afternoon. Temperatures are quickly rising into the middle
50s.
Skies will remain mainly clear through Monday. Light winds will
allow temperatures to drop into the middle 30s tonight, still
mild for the first week in March.
With strong sunshine and warm air advection increasing,
temperatures should climb into the middle 60s along the Twin
Tiers on Monday. Dew points won`t be as low as during the last
few days.
A frontal system will drop into NY late Monday night, pushing a
few showers into the region, mainly after midnight.
1040 AM update...
Persistent mid-layer clouds continue to stream into the Southern
Tier of NY. The latest RAP guidance pushes the clouds east of
I-81 between 17z and 18z, but we expect skies will remain cloudy
or mostly cloudy in the interim.
We updated cloud cover and temperature grids to take the mid-
layer clouds into account through midday.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
245 PM Update...
A low pressure system will bring a quickly moving batch of rain
to the region for Tuesday, followed by dry weather Wednesday
courtesy of weak high pressure.
Models are in good agreement on elongated low pressure
stretching up southeastern Ontario to around the Quebec border
Tuesday morning, tracking to Maine by Tuesday evening before the
Canadian Maritime provinces Wednesday morning. The low will not
be that strong, but it will trail a cold front through our
region Tuesday afternoon-early evening during which our primary
batch of showers will occur. Amounts will be limited by fairly
progressive nature of the passage, as well as better jet support
staying closer to the international border. However, a weak
shortwave embedded in southwest flow ahead of the front, will
cause some light initial showers to advance into the area
Tuesday morning to finish moistening the lower levels. So by the
time the front itself slips through during the afternoon-early
evening, we should have plenty of low clouds to accompany the
main batch of rain. We are still figuring on total amounts of
one to two tenths of an inch from Twin Tiers southward, but more
like a quarter to third of an inch may occur to the north; even
about a half inch for northern Oneida county.
After highs mainly in the 50s Tuesday, temperatures behind the
front will drop to upper 20s-mid 30s for lows Tuesday night.
Showers will quickly wind down in the evening, but if any manage
to linger towards midnight some wet snowflakes could mix in on
its way out at higher elevations. No accumulation anticipated.
With a brisk zonal flow, weak high pressure will zip west to
east Wednesday providing a dry day. However, there will still
plenty of high clouds from isentropic lift aloft ahead of a weak
wave. The very limited opportunity for cold air advection
between waves, will mean temperatures still reaching 40s to mid
50s for highs.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
245 PM Update...
Model spread remains fairly wide late in the week with
run-to-run and model-to-model differences. GFS has gone dry
with the Thursday night-early Friday wave, shunting moisture
well south, but ECMWF and Canadian models have a more organized
batch of rain. Models agree on cooler temperatures after Friday
yet significantly differ as to whether to just be back down near
normal or a ways below. Forecast adjusted to incorporate some of
the latest guidance/multi-model blend but overall has not
changed much from prior thinking.
Previous discussion...
Model consensus not as good this period. CanNH and ECWMF are
closest with GFS flatter aloft and wetter. Have gone colder for
the end of the week as the models are bringing in a strong polar
high for next weekend.
Before that a weak surface cold front and upper level trough
comes through with some light showers. Not expecting much snow
and rain. Temperatures fall into the 20s except for the far
south in the 30s.
Thursday will be dry with a ridge of high pressure extending
south from Canada. Still mild with highs from the mid 40s to the
lower 50s.
Late Thursday night into Friday night another wet period. This
will be a stronger cold front and deeper upper level trough
centered over Hudson Bay. It is a fast mover so better moisture
stays south of the area. Precipitation will be mostly rain with
some snow to start and end the event. With the front late in the
day Friday, it will be mild again. Lows in the 30s rise to
around 50 then fall to around 30.
Lowered temperatures for the weekend as models trending toward
bringing a cold high southeast into the area. For now highs
still mainly low to mid 40s but this could be adjusted down
more.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
VFR conditions continue through the TAF period, with some high
level clouds moving through tonight before skies clear out
again for Monday. The only real concern continues to be for some
low level wind shear beginning over the next several hours
across our central NY terminals, and finally reaching KAVP after
6Z. Monday morning, the strong low level jet moves out, with a
fairly quiet day as winds come out of the southwest at around 5
to 10 kts.
Outlook...
Monday night and Tuesday... Some restrictions with rain showers
especially Tuesday. Moderate confidence.
Tuesday night and Wednesday... Rain showers ending Tuesday
night with improving conditions.
Thursday...Restrictions possible early with rain and snow
showers. VFR possible by the evening.
Friday...Restrictions possible in rain showers.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...DJP
NEAR TERM...BJT/DJP
SHORT TERM...MDP
LONG TERM...MDP/TAC
AVIATION...HLC/MPK
Area Forecast Discussion
National Weather Service Cheyenne WY
526 PM MDT Sun Mar 8 2020
.SHORT TERM...(This evening through Monday)
Issued at 300 PM MDT Sun Mar 8 2020
Front right on track this afternoon with latest position along a
line from just north of Chadron to Bill to Rock Springs at 18Z.
Have been getting rain and snow on the Rawlins...Dixon and
Saratoga ASOS/AWOS sites the past couple hours. WYDOT webcams
showing snow showers out by Elk Mountain this afternoon. Forecast
looking on track across southeast Wyoming and Nebraska Panhandle
with a few exceptions.
Did cut PoPs across the northern Panhandle for this evening as
latest guidance shows showers staying further south across the
I-80 Corridor through the evening hours. Latest HRRR showing bulk
of heavier showers down here across Laramie County out into the
southern Panhandle through 03/04Z. Kept isolated thunderstorms in
the forecast for this afternoon through mid evening as we do have
a little CAPE. Current SPC Mesoanalysis showing roughly 250-500
J/KG SBCAPE from Scottsbluff to Chugwater to Cheyenne at 20Z this
afternoon. So far...we haven`t seen any lightning strikes though.
Front moves through the Wyoming/Colorado stateline around or
shortly after 00Z today with 700mb temperatures falling to -3 to
-4C by 06Z. So any rain likely to turn over to snow after the
front moves through.
Precip comes to an end after 12Z Monday...but could continue
seeing some snow showers over the Snowy and Sierra Madre Ranges
through the day.
.LONG TERM...(Monday night through Sunday)
Issued at 300 PM MDT Sun Mar 8 2020
Weak and mainly dry cold front for Tuesday afternoon into
Wednesday morning. Most areas will remain dry or only see
sprinkles with this front as there does not look to be a lot of
moisture to work with. Do have some very low PoPs of 15-25
percent...mainly along the I-80 Corridor from Sidney to Arlington
during this timeframe.
We are continuing to monitor a low pressure system for Friday.
Looks like the GFS and ECMWF have swapped solutions now. GFS
showing possibility of moderate snow across out southern and
southeastern zones with a more northern track over central
Colorado. This is almost the same track the ECMWF showed for the
same time yesterday. ECMWF now further south with the low over
northern and central new Mexico. So...confidence remains low on
this end of week system.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 520 PM MDT Sun Mar 8 2020
Wyoming TAFS...VFR at Rawlins. Wind gusts to 25 knots after 15Z
Monday.
VFR at Laramie until 05Z, then MVFR until 11Z, then VFR. Wind
gusts to 27 knots after 17Z Monday.
VFR at Cheyenne until 05Z, with occasional MVFR from 02Z to 05Z,
then MVFR until 07Z, then IFR until 16Z, then VFR. Wind gusts to
22 knots until 02Z.
Nebraska TAFS...VFR at Chadron until 05Z, then MVFR until 14Z,
then VFR. Wind gusts to 22 knots until 01Z.
VFR at Alliance until 05Z, then MVFR until 15Z, then VFR. Wind
gusts to 26 knots until 05Z.
VFR at Scottsbluff and Sidney until 05Z, then MVFR until 16Z,
then VFR.
&&
.FIRE WEATHER...
Issued at 300 PM MDT Sun Mar 8 2020
Minimal fire weather concerns the next several days as a cold
front moves through the area this afternoon. Rain and snow showers
become more widespread late this afternoon and through tonight as
the front moves through the area. Colder temperatures next few
days will result in higher afternoon humidity and good to
excellent overnight recoveries. Unsettled weather through the
upcoming week as a low pressure system tracks across the southern
Rockies with rain and snow showers over our mountains almost on a
daily basis.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...GCC
LONG TERM...GCC
AVIATION...RUBIN
FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Dodge City KS
1100 PM CDT Sun Mar 8 2020
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
Issued at 1100 PM CDT Sun Mar 8 2020
WV imagery indicates a southwest flow aloft prevailing across the
Western High Plains. Near the surface, a cold front is pushing
southeast across northeast Colorado and southwest Nebraska.
&&
.SHORT TERM...(This afternoon through Monday night)
Issued at 1208 PM CDT Sun Mar 8 2020
Weak shortwave was located over Arizona as of midday, and this
system will influence SW KS through early Monday. Clouds will
thicken and lower quickly this afternoon/evening, as forcing for
ascent and modest gulf moisture (dewpoints into the 40s) increase.
Infrared satellite reveals a strong subtropical moisture plume
from near Amarillo back to the spur of Baja California, so this
shortwave will also have plenty of Pacific moisture. Radar shows
numerous rain showers spreading northeast through the Texas
panhandle at midday. As such, scattered rain showers are expected
to arrive in the southern/SE zones late this afternoon.
Instability is very weak, so carrying no thunder with this
activity. Models generate weak instability across the NW zones
this afternoon/evening, and the latest HRRR iterations have
consistently shown weak convective development across the west/NW
zones by 5-6 pm. Added pops for this activity; some lightning and
very small hail/wind gusts are possible from this NW zone
activity. More focused/widespread rain showers are still expected
across the SE zones this evening, with the wet 12z NAM offering
over 1/2 inch of rain locally (Barber county and vicinity). HRRR
is a little slower with this rain, showing widespread rain east
of Dodge City around 1-3 am Monday. Along with WFO Wichita,
increased pop grids for this rain tonight, into the likely
category. With an open progressive shortwave, measurable rain
will be much more difficult to achieve west of US 283. Do expect
some wraparound rain showers along the I-70 corridor Wakeeney to
Hays early Monday.
Associated cold front will follow early Monday morning, with an
abrupt NW wind shift. Increased NW winds in the grids closer to
the MAV guidance for several hours early Monday, with gusts to 35
mph. A period of stratus is also likely ahead of, and immediately
behind the advancing cold front. Expect rapidly improving weather
daylight Monday behind the exiting shortwave, with a clearing sky
and rapidly diminishing N/NW winds. Models show little temperature
change at 850 mb Monday, but show reduced thickness and about -3C
net cooling at 700 mb. With stratus scattering early and full
afternoon sun, MOS output (especially NAM MOS) seemed too cold.
Kept Monday`s high temperatures in the upper 50s along I-70 to the
lower to mid 60s elsewhere. Cooler Monday night/Tuesday morning,
with most locations falling to the mid to upper 30s.
.LONG TERM...(Tuesday through Sunday)
Issued at 245 PM CDT Sun Mar 8 2020
Tuesday promises to be a beautiful spring day beneath zonal flow
aloft, with above normal temperatures and relatively tame winds.
A weak shortwave will dive into Kansas Tuesday night, with
scattered rain showers possible across the NE/eastern zones. More
significant rainfall will be relegated toward Wichita and SE
Kansas. Most of SW Kansas will remain dry.
Yet another beauty of a spring day on Wednesday, beneath broad
ridging aloft. With afternoon temperatures in the mid to upper 60s
and very little wind, you will want to find an excuse to get
outdoors Wednesday.
Thursday will remain dry, as a closed low arrives on shore in Baja
California by late afternoon. More pleasant 60s, but clouds will
be increasing late in the day.
A major precipitation event appears likely Friday and Friday
night. The 12z medium range models are in excellent agreement,
suggesting the SW closed low will eject onto the plains rather
progressively. Both 12z GFS/ECMWF show nearly identical forecasts
for this storm system, placing a 555 dm low in western New Mexico
at 7 am Friday. This type of agreement 5 days out is rare. It
stands to reason that the model ensembles also agree well. GFS
ejects the low with a slightly negative tilt into SW KS Friday
afternoon and evening, producing widespread heavy rain and
embedded thunder (QPF well over one inch). 12z ECMWF agrees,
placing its low near Elkhart 7 pm Friday, with widespread
precipitation spreading ahead of it across SW Kansas. ECMWF tracks
the low diagonally across Kansas Friday night, with a widespread
beneficial wetting event. Clearly, likely pops from the NBM are
appropriate, even 5+ days out, and if current model tracks hold we
will eventually carry 100% pops for this event. Confidence in
precipitation is high. Confidence in rain versus snow? Well, there
are some interesting possibilities. Noted 12z ECMWF 850 mb
thermal fields beneath the cold core low (down to -4C) would
easily support heavy wet snow Friday night, especially with a
nocturnal timing. For now, grids carry some snow on the higher
terrain of the west/NW zones Friday night. This storm will need
close monitoring through the upcoming week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 553 PM CDT Sun Mar 8 2020
MVFR to IFR conditions through much of the TAF time period. Upper
level moisture will continue to stream in from the southwest which
will keep cloud ceilings in the 1,000-10,000 range through the
night into the morning on Monday. A cold front will also move
through western Kansas tonight. Winds will switch from the south
the northwest and stay strong at 15-25 kts with gusts to 30+ knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 58 39 69 / 30 10 0 0
GCK 41 58 38 70 / 20 10 0 0
EHA 43 63 38 74 / 10 0 0 0
LBL 43 63 37 73 / 20 0 0 0
HYS 41 54 35 65 / 60 50 10 10
P28 51 58 36 66 / 70 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Tatro
Area Forecast Discussion
National Weather Service Duluth MN
1059 PM CDT Sun Mar 8 2020
.UPDATE...
Issued at 1040 PM CDT Sun Mar 8 2020
As a low pressure slowly moves into Minnesota, obs are showing lowering
clouds and scattered showers are beginning to show up on radar
across the southwestern portion of the forecast area. Forecast
models originally had the clouds moving in faster, and have been
trending down in precipitation coverage. So slowed down the cloud
cover and reduced the PoPs. Also added in a slight chance of
drizzle along the North Shore between 06-12Z as winds converge
from westerly winds over the Arrowhead and northeasterly winds
from Lake Superior.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 254 PM CDT Sun Mar 8 2020
Quiet conditions this afternoon will transition to cloudy skies
overnight, with chances of light drizzle or freezing drizzle
increasing tonight into Monday morning, mainly over the Minnesota
Arrowhead and points south of Lake Superior. The main driver of this
pattern change will be an area of low pressure, currently situated
over southeastern South Dakota, that will continue to slide
southeastward away from the region. However, this will gradually
bring a tight thermal gradient/baroclinic zone across our region
overnight tonight, leading to enhanced cold air advection. Moreover,
an attendant subtle mid-level impulse will also make its way
eastward into the region overnight. Winds will remain northeasterly,
which could help support the development of low stratus for adjacent
areas of Lake Superior. This on-shore flow, coupled with the
development of a nocturnal low-level inversion, should help to
support at least slight chances of drizzle or freezing drizzle
across the aforementioned areas. The low-level depth of saturation,
per the NAM, GFS, and RAP models is hovering right around 3000-4000
feet, which would be supportive of drizzle, albeit more marginal in
nature. There appears to be too much dry air in the mid-levels to
support any deeper saturation and would also inhibit any ice
crystals that may form aloft to fall into the warm inversion layer.
Similar to the previous forecast package, we will maintain only very
small, if any, icing resulting from the freezing drizzle. This icing
could result in some slick road conditions for the Monday morning
commute, so we will have to watch for any robust low stratus/drizzle
formation. Due to the cold air advection, overnight lows will dip
into the middle to upper teens north to the middle to upper 20s
south.
Chances of drizzle and freezing drizzle will shift south over
northwest Wisconsin as winds turn more northerly on Monday. The
column remains fairly moisture starved, so don`t have much in terms
of QPF, except for along the higher terrain of northern Iron and
Ashland counties, which could result in around one- to two-
hundredths of an inch of ice accumulation. At the same time, a
southern stream upper-level trough could bring some chances of
precipitation to our far southeastern areas, mainly over Price
county in northern Wisconsin. Nearly all of the guidance is keeping
the stratiform precipitation shield to our south where the stronger
large-scale forcing will remain. For now, we have confined any QPF
to remain over the southeastern half of Price county, but this may
need to be pulled out altogether if a dry forecast continues to be
progged in the guidance. Not as warm on Monday, but still should see
highs above freezing for most locations, near 30 north to the middle
to upper 30s south. Decreasing clouds from northwest to southeast
are expected as high pressure and drier air build into the region.
Monday night will remain dry, under partly to mostly clear skies.
Overnight lows will become quite chilly, thanks to radiational
cooling from the clearing skies and light winds, in the lower teens
north to the upper teens to near 20 south.
.LONG TERM...(Tuesday through Sunday)
Issued at 254 PM CDT Sun Mar 8 2020
High pressure will be over the area Tuesday morning, then begin to
slide off to the east in the afternoon. This allows a mid level cold
front to drop into the region in the afternoon and introduce some
pops over the southern portion. Temps support a rain/snow
precipitation type, with all snow over the Brainerd Lakes.
An upper level trof moves into the region Tuesday night accompanied
by another cold front. The opportunity for precipitation spreads
north and east through the night, diminishing from west to east
overnight as the trof departs. A rain/snow mix early becomes all
snow through the night. Some light accumulation is possible in
northwest Wisconsin.
A closed low in central Canada Wednesday, and its associated surface
low, will move into northwest Ontario Thursday afternoon and into
Quebec Friday afternoon. A cold front will be dragged across the
region as a result Wednesday night through Thursday. Moisture
availability is increasing, and have increased pops Wednesday
through Thursday. Temperature profiles suggest snow at night, rain
and snow mixed in the early to mid morning, then rain in the
afternoon. A transition back through those precipitation types as
temps cool at night.
Cold high pressure from the Arctic settles into the area behind the
cold front ending the precipitation late Thursday night, with a dry
Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 655 PM CDT Sun Mar 8 2020
An area of low pressure is slowly moving east through the Upper
Midwest tonight with increasing clouds expected. VFR conditions
will continue across the region this evening with LLWS around the
HYR area until about 04Z. Low clouds will begin moving into the
region from west to east after 04Z with conditions dropping from
MVFR to IFR. LIFR conditions are possible overnight at BRD and HYR
from very low clouds and patchy fog. Skies will begin to clear
Monday afternoon across northeastern Minnesota while low clouds
will remain around the HYR area throughout most of Monday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 27 35 17 34 / 20 10 0 20
INL 14 29 6 32 / 0 0 0 10
BRD 24 34 16 34 / 10 0 0 30
HYR 30 39 20 41 / 0 20 0 10
ASX 29 36 21 37 / 10 20 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
UPDATE...KL
SHORT TERM...JTS
LONG TERM...GSF
AVIATION...KL
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1151 PM EDT Sun Mar 8 2020
.AVIATION...
For the most part, there has been some drop in sfc wind speeds with
the onset of nighttime cooling. Latest Rap soundings, with support
from regional 00Z soundings indicate an ongoing strengthening of the
winds above the developing nocturnal inversion. With 1500 to 2000
foot level winds forecast to be 45 to 50 knots, the will result is
low level wind shear conditions through much of the night/early Mon
morning hours. The onset of daytime heating Mon afternoon will then
transition conditions back to mechanical mixing, with increasing sfc
wind speeds/gusts out of the SSW as boundary layer mixing commences.
Only a few mid clouds and occasional high clouds are expected
through early Mon afternoon given the abundance of dry air in the
region. An approaching upper level wave and associated sfc low along
with an influx of moisture late Mon afternoon/evening will result in
widespread rain overspreading the region.
.DTW THRESHOLD PROBABILITIES...
* None
&&
.PREV DISCUSSION...
Issued at 354 PM EDT Sun Mar 8 2020
DISCUSSION...
Few clouds with plenty of sunshine has allowed temperatures to
quickly climb well into the 50s this afternoon supported by warm
advection under low-mid level southwest. Gusty winds above 25 mph
will remain possible as diurnal mixing heights tap into the stronger
lower level southwest flow aloft. Many sites have reported gusts
above 20 knots so far today. Expect these gusts to last until around
00Z this evening. The 12Z DTX morning sounding came in with a 0.22
inch PWAT value and do not expect much change through much of the
day. This very dry airmass from the surface into the mid layers will
make for a quiet weather conditions through tonight as overnight lows
hold mostly in the 40s.
Synoptic set up into tomorrow has deep ridging over the eastern US
with a northern stream jet passing across James Bay and a detached
southern stream jet across Baja California. A southern stream
shortwave will emerge out of the southern Rockies tonight moving
east-northeast through the central/southern Great Plains and into
the region tomorrow evening. The deeper moisture with ties to the
Gulf is currently residing across the southern plains. This moisture
will be surging northeastward towards the Great Lakes aided by
strong moisture transport within the 50-60 knot low level jet into
tomorrow. This will send a PWAT axis of around 1.00 inch into the
area by tomorrow evening. There will be good synoptic forcing with
favorable right entrance region jet dynamics and vorticity advection
to result in frontogenesis. Scattered rain showers should move into
parts of southeast Michigan during the afternoon. Then widespread
categorical PoPs arrives by the tomorrow night period as deep theta-e
advection moves into southeast Michigan between 00-06Z. Expecting
precipitation to fall as all rain with high temperatures remaining
well above normal in the 50s tomorrow with mild temperatures in the
40s again tomorrow night.
The wave will lift northeast of Michigan Tuesday morning driving a
cold front through the area allowing for a drop in high temperatures
back into the 40s. The cold air advection along with lower level
northwest flow will likely lead to a fair amount of low cloud
hanging across the area on Tuesday, though precipitation will
diminish by late morning/early afternoon. Deeper dry air advection
throughout the day will then support a clearing trend late in the
day.
Brief break in precipitation before the next chance arrives
Wednesday when a progressive Pacific shortwave moves through the
Great Lakes region. The degree of vorticity advection should be
enough to support light precipitation, but overall greater forcing is
lacking with this system. Lingering cold air and wet bulbing should
support snow as the main precipitation type with a potential
transition to rain as lower levels warm during the day. Overall
confidence remains low with this system, but early indications are
that there will be minimal snow accumulation if any at all.
MARINE...
The Great Lakes remains wedged between high pressure located across
the Carolinas and low pressure across the northern Plains which has
resulted in the formation of a moderate pressure gradient. Gusts
around 20 knots, maximized across the Saginaw Bay and northeast into
central Lake Huron will persist through the day. Isolated gusts to
20 knots are possible elsewhere, but the warmer air traveling over
the cooler waters will limit gust potential as a stable atmospheric
profile has developed. Otherwise, southwest flow expected to hold
leading into early next week before the next low pressure system
arrives by late Monday into early Tuesday. This system will bring
likely rain and also an eventually shift in wind direction from the
southwest to northwest on Tuesday.
HYDROLOGY...
Low pressure will bring widespread precipitation by Monday evening
into Tuesday morning. Favorable synoptic forcing along with deep
moisture will result in total rainfall amounts averaging near a half
inch with this system. If some convective enhancement can occur,
some locally higher amounts will be possible. Bulk of this
precipitation is expected to fall between 8 PM tomorrow and 8 AM
Tuesday. No significant flooding is anticipated with this system, but
some ponding on low lying roads and rises of local river levels will
be possible.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
AVIATION.....SC
DISCUSSION...AA
MARINE.......AM
HYDROLOGY....AA
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
956 PM CDT Sun Mar 8 2020
.UPDATE...
Issued at 956 PM CDT Sun Mar 8 2020
Continuing to watch the latest guidance come in. The latest HRRR
runs are supporting the colder NAM runs that were present in the
18z and 00z runs. Did re-run the forecast with some cooler Temps
aloft, and it did give me a wintry mix a bit further to the
south...running along the I-80 corridor and as far south as the
Hwy 6 and 34 corridor, but little to no wintry accumulation. The
HRRR continues to suggest there could be some brief accumulation.
Do think that with a quicker arrival of cooler air, this wintry
mix pushing further to the south is not out of the question. This
is a tricky forecast and some people could wake to some a wintry
mix before it melts. Don`t expect any lingering
impacts...especially with the warmth of this weekend and warm-up
expected after the precip ends Monday afternoon.
&&
.SHORT TERM...(This evening through Monday)
Issued at 257 PM CDT Sun Mar 8 2020
Turning wet tonight with chances for showers/isolated storms and
possibly a wintry mix...
We`ve rounded out the weekend with another day of warm/windy weather
with afternoon temps well into the 60s to mid 70s, accompanied by
southerly wind gusts of 25-35 mph.
In warm air advection late this aftn, the NAM suggests the
potential for an isolated shower/thunderstorm, however chances for
precip ramp up after dark and continue into Monday in increasing
lift/dynamics due to the combination of an advancing cold front
progressing shortwave trough across our region.
High resolution models are in agreement with convection developing
in our southern/western zones late this evening, with precip
expanding in coverage during the overnight hours. The presence of
elevated instability of a few hundred J/KG will be sufficient for
thunderstorm development and while severe weather is not
expected, cannot rule out the potential for small hail as the
freezing level lowers in the cooler post frontal airmass.
What`s interesting on the latest model runs is both the NAM/GFS
close a H7 low across Nebraska by 12Z Monday and the NAM maintains
a stronger and colder solution than the more progressive (and
warmer) other models. The NAM solution is concerning and brings
the potential for wintry weather mainly in the form of sleet/snow
and possible light accumulations across portions of our
western/northern cwa. The GFS/ECMWF thermal profile are more
similar and warmer but it`s hard to ignore the post frontal cold
air as depicted by the NAM and this will have to monitored
closely tonight. Attm, have went with a model blend which favors
a warmer thermal profile with less potential for wintry weather,
but still have some rain/snow/wintry mix for portions of our
western/northern zones.
The precip ends transitions to all rain again Monday morning
before ending from west to east late morning into Monday aftn as
the upper trough axis departs. Temps have trended cooler for highs
with readings averaging in the 40s/low 50s.
.LONG TERM...(Monday night through Sunday)
Issued at 257 PM CDT Sun Mar 8 2020
Behind the departing wave late Monday, surface high pressure builds
southeast across the Central Plains and heights rise aloft. In return
flow, a low level jet strengthens along the high plains providing
enhanced lift in a warm air advection regime leading to shower
development to our west Monday night. This precip is expected to
move into our area late Monday night into Tuesday morning.
Instability is lacking this far east but precip type is a concern
with surface temps near or below freezing and forecast reflects
a mixed precip type with the potential for rain/freezing rain and
sleet. Confidence is not high on how impactful this may or may
not be as temperatures will be on the upswing with increasing
clouds/moisture...then Tues the precip transitions to all rain as
temps warm.
Light precip/rain chances carry into Tuesday night with a
progressing northern stream shortwave trough, then the forecast
dries out for Wednesday. In a progressive pattern, another
disturbance brings additional rain chances Thursday, then attention
turns to the cutoff low lifting out of the desert southwest the
latter part of the workweek/into the weekend. The latest ECMWF has a
farther south track of the system than the GFS, filling/weakening
the system as it tracks across KS whereas the GFS favors a farther
north track across Neb. This will be something to keep an eye on
given the potential for widespread precip (rain/snow).
Depending on the track, precip should be moving out Saturday morning
or shortly thereafter so next weekend isn`t looking like a washout.
Temps will be noticeably cooler than what we just experienced with
readings averaging in the 40s for highs.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 638 PM CDT Sun Mar 8 2020
High clouds are moving in from the south across the area. Lower
clouds will move into the area as a cold front moves through the
region tonight. Along and behind this front, showers with a chance
for some thunder will be possible at both terminals from around
04-05z through morning. As the front moves through southerly winds
will become northerly and breezy. Ceilings during the overnight
hours are expected to become MVFR and persist into the afternoon
hours Monday before surface high pressure builds in and clouds
move off to the east.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...Billings Wright
SHORT TERM...Fay
LONG TERM...Fay
AVIATION...Billings Wright
Area Forecast Discussion
National Weather Service Goodland KS
552 PM MDT Sun Mar 8 2020
.SHORT TERM...(This evening through Monday)
Issued at 253 PM MDT Sun Mar 8 2020
Satellite imagery and 500mb RAP analysis showed a large upper ridge
centered over the Upper Midwest today, placing the tri-state region
under southwest flow. A large area of cloud cover extended from New
Mexico into southwest Kansas as a shortwave trough advanced towards
the High Plains from the desert southwest. At 3 PM MT, temperatures
ranged in the 70s with light and variable winds across much of the
region. Southerly winds were observed from a Hill City to Tribune
line around 15 mph. Light rain has begun to push into southwestern
Kansas from the Oklahoma panhandle.
As the aforementioned disturbance continues towards the region, a
few showers and thunderstorms will be possible for locations along
and south of Interstate 70 in Kansas during the remainder of the
afternoon. The limiting factor for this to occur will be the
thickening cloud cover, which may dampen diurnal heating and
convection. The better chance for precipitation will be during the
nighttime hours, which we will now turn attention towards.
The shortwave moves closer to the area this evening, providing
enough lift to generate shower and thunderstorm chances across much
of the region. Good moisture will be in place and despite
instability being limited, cannot rule out gusty winds, small hail,
and heavy downpours with a few of the stronger storms. There is
disagreement on where showers/storms will develop and which areas
are favored for precipitation. As a result, confidence in storm
placement/coverage remains low. However, guidance has suggested that
the better chance for nighttime precipitation should be north of
Interstate 70.
Meanwhile, a cold front is expected to traverse the forecast area
from northwest to southeast this evening and overnight. North winds
gusting up to 30 mph are possible behind the frontal passage.
Temperatures fall into the 30s and low 40s under mostly cloudy
skies.
Rain chances linger into Monday morning for eastern portions of the
region. Skies clear from west to east through the day as the
shortwave exits. Temperatures climb into the upper 50s to low 60s,
with north winds at 15 to 20 mph declining and becoming variable by
the late afternoon.
.LONG TERM...(Monday night through Sunday)
Issued at 240 PM MDT Sun Mar 8 2020
Mon night-Wed: An upper level low presently situated ~700 miles
west of San Francisco is anticipated to cut-off offshore the
central/southern Pacific coast early this week, maintaining a
split-flow regime over the western CONUS and confluent flow aloft
over the Central Rockies/Central High Plains. With the above in
mind, above normal temperatures are anticipated to persist, with
precipitation chances largely confined north and/or south of the
Tri-State area.
Thu-Sat: Long range guidance continues to indicate that the cut-
off upper low offshore the southern Pacific coast will become
progressive late this week -- tracking through the Desert
Southwest (Thu-Thu night) into the Central/Southern Plains (Fri-
Sat). Broadly speaking, expect increasing cloud cover, increasing
chances for precipitation, and cooler temperatures in this period.
Given that the aforementioned upper low will be a southern stream
feature and that the Central Plains will be well-separated from
anything resembling an Arctic airmass, p-type issues (if any) may
be dominated by precipitation processes rather than thermal
advection -- e.g. temperature profiles gradually become near-
freezing/isothermal as heavy and/or persistent precipitation
`melts-out` the above-freezing layer, resulting in a `rate-
driven` transition from rain to wet snow.
Sun: A drying/warming trend is anticipated in the wake of the
southern stream upper low late next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 526 PM MDT Sun Mar 8 2020
AT GLD, gusty southeast winds will turn to the north with a few
showers and isolated thunder moving across the area. Ceilings will
be lowering, but should remain VFR through 08Z. After 08Z,
showers should be diminishing, but ceilings will continue to lower
with conditions becoming MVFR through about 15Z. Winds decrease
and skies clear with conditions becoming VFR between 16Z and 20Z.
MCK will be VFR through 09Z with gusty winds associated with scattered
thunderstorms moving across the area after 03Z. Thunder
diminishes by 09Z with MVFR conditions and isolated showers and
gusty winds continuing through about 15Z. After 15Z, ceilings
raise with conditions becoming VFR and skies clearing after 18Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JBH
LONG TERM...VINCENT
AVIATION...LOCKHART
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
726 PM CDT Sun Mar 8 2020
.SHORT TERM...(This evening through Monday night)
Issued at 319 PM CDT Sun Mar 8 2020
Shorter term concern remain timing of cold front overnight and
chances for light rain Monday.
Temperatures warming through the 50s across most of the CWA this
afternoon. Still should see remains warm to the 60 to 65 degree
range over the southwest area toward east central MN(where little
snow cover remains) by late afternoon. Cold front progged to move
into far western MN by evening and spread east toward MSP by 06z
or so. Clouds should gradually develop as the front moves east
with lower colds expected to develop rapidly behind the front by
late afternoon. Little chance for precipitation with front
overnight and should have exited the CWA through 12z Monday.
Still, models develop some light QPF in FGEN zone in the vicinity
of the front and exiting short wave associated. Models shifted QPF
a but further to the east so we trimmed PoPs some on the western
fringe. This would leave PoP chances for the region during the
day Monday. Temperatures will struggle to rebound bake to the
lower 40s after 12z Monday to the east with 30s common to the
northwest with brisk northwest winds.
We expect clearing to take hold into Monday night as high
pressure ridge builds east with lighter winds. Overnight lows are
expected to drop back to some teens over west central MN to the
mid 20s over the east into western WI.
.LONG TERM...(Tuesday through Sunday)
Issued at 319 PM CDT Sun Mar 8 2020
The long term continues to be void of anything substantial, but it
will feature a few weak disturbances. The most impressive of which
will come through Tuesday and Tuesday evening. A trough axis and
associated band of vorticity tracking east across the Plains will
generate some light precip along it as it heads toward the Upper
Mississippi Valley. Atmospheric profiles support mostly rain
initially, but a transition to snow is expected to occur as the
dry boundary layer wetbulbs down and the sun sets. Maybe a tenth
of an inch or two of QPF across far southern MN, otherwise
amounts will be even lighter elsewhere. Snow totals of a half inch
are possible, if it can even accumulate. This would be the first
measurable precip event in 3 weeks at MSP.
Another cold front will approach from the northwest Wednesday
night and interact with a central Plains system Thursday. Once
again, precip will likely hold off from developing until it has
shifted east of the area.
PoPs return to the forecast Friday night and linger through
Saturday night. Two systems emerging from the Rockies (one over WY
and MT and the other over NM and TX) may attempt to phase somewhat
and bring precip to the Upper Midwest. Latest guidance suggests
these two will remain separate in a split flow pattern which would
result in a continuation of dry conditions. If these trends
continue, PoPs will need to be reduced or removed next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 726 PM CDT Sun Mar 8 2020
Main issue this period is timing the Dakotas stratus behind the
cold front in. Only minor slow downs were made with going TAFs,
with cigs generally expected between 008 and 014 as the stratus
sets in. Did delay improvements some Monday with the RAP showing
the low level moisture lingering most of the day for MKT/MSP on
east. Precip tonight into Monday looks to remain well south and
east of even EAU.
KMSP...RAP has stratus coming in closer to 10z, so a further delay
in lower cigs is possible. Could also see a brief period of IFR
cigs as stratus initially comes in. Less certainty on how long
these clouds stick around. Could see them mostly out by around 18z
or linger out to almost 3z. Went down the middle for now.
/OUTLOOK FOR KMSP/
Tue...VFR day. Chc MVFR-SN in evening. Wind lgt and vrb.
Wed...MVFR/IFR in AM, bcmg VFR. Wind bcmg SW 5-10 kts.
Thu...VFR. Wind NW 20G30 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&
$$
SHORT TERM...DWE
LONG TERM...BORGHOFF
AVIATION...MPG
Area Forecast Discussion
National Weather Service Marquette MI
1057 PM EDT Sun Mar 8 2020
.UPDATE...
Issued at 1057 PM EDT SUN MAR 8 2020
Based on the last several hrs of HRRR runs and incoming 00z models,
opted to push back timing of any pcpn into western Upper MI until
12z with some additional delay elsewhere across the fcst area during
Mon morning. Models are also trending s and e with the heavier pcpn
on Mon associated with a shortwave lifting ne across the Plains.
Only slight modifications to the fcst on Mon were made based on this
quick look at incoming 00z models. Still looks like there will be a
transition to -fzdz/wintry mix from nw to se on Mon. Upsloping will
be the main pcpn generation mechanism across the w and n, leading to
a potential glaze of ice from -fzdz.
&&
.SHORT TERM...(This evening through Monday)
Issued at 337 PM EDT SUN MAR 8 2020
Upper level ridging over the region today will give way when a
surface low moves through Monday. Before we get to that though, we
can expect the drier southerly flow to `heat` things up in the low
50s in the west half and upper 40s in the east. Some places today on
the east side of the Keweenaw Spine have gotten into the low 60s!
Given the flow off of Lake Michigan in the east, highs have been
lower. Subsidence and dry air under the ridge have kept skies mostly
clear.
Tonight into Monday, surface low will approach from the west, moving
into the region in the early morning hours. As the low moves through
Monday, expect winds to stay southerly/southwesterly ahead of the
cold front and northeasterly on the north side of the warm front.The
low shift through the region, allowing winds to back to the north-
northwest, increasing CAA with the frontal passage. So the big
questions are where precip will occur and if it does, what will the
precip type be. Models have been trending the heavier precip further
south with upslope/dz in the west. Model QPF has been spread but
settled on generally 0.01 (west) to about a tenth (central). Values
increase the closer you get to the Bay of Green Bay/Lake Michigan at
around 0.25-0.4".
Precip type has been a challenge given the warm column in place and
the CAA after frontal passage. The classic warm nose is there in
most model soundings, but given the depth of moisture, more of a DZ
is anticipated in the west before transitioning. In the south and
east, colder surface air won`t filter in until the afternoon, as
suggested by model soundings. Together this means, in general, a
transition from DZ, to FZDZ with some IP, with some flurries in the
west and north. In the south and east Monday, expecting mainly -RA
with likely a transition to -FZRA after this period in the
afternoon. Max ice accumulations are around a tenth, and given the
warmth in place ahead of this system, this may be overdoing it. Even
if the tenth is overdoing it, I`m confident in some FZDZ and this
may make some slick spots for the afternoon/evening commute
tomorrow.
.LONG TERM...(Monday night through Sunday)
Issued at 442 PM EDT SUN MAR 8 2020
Models suggest that a nearly zonal pattern will become more
amplified toward the end of the week as troughing develops from
Manitoba and over northern Ontario into the northern Great Lakes
850-700 fgen and associated upper level div with the right entrance
of the 250-300 jet lifting through nrn Ontario will support
additional pcpn over mainly the southeast half of Upper Michigan. An
elevated warm layer will linger over the southeast half after colder
air slides in resulting in a period of fzra/pl that will transition
to mainly snow as the warm layer dissipates. Ice accumulations to
near a tenth of an inch will be possible over mainly the southeast
third of Upper Michigan. There could also be some light nrly flow
lake enhanced snow or fzdz as 925 mb temps drop to around -11C.
Tue-Wed, After some nrly flow lake clouds/flurries may linger early
high pressure building into the region will bring at least partial
clearing along with dry weather for Tuesday. A period of moderate
700-300 qvector conv, strongest with the ECMWF, with a shortwave
trough moving through the western Great Lakes, will bring some
light snow to the area, mainly late Tue night into early Wed. Some
locations, especially over the south and east, could see amounts
of an inch or two.
Thu-Sun, A clipper shrtwv is expected to bring another round of
light pcpn into the area and drag a cold front through the northern
Great lakes with colder conditions through the end of the week. The
ECMWF and GEM have trended stronger/slow with the trough, bringing
greater amounts of pcpn into the area compared to the GFS/GEFS. Most
of the pcpn would likely fall as rain with the potential for a
transition to a mix as the colder air moves in Thu night.
Northwest flow LES may be possible behind the system. Colder dry air
will continue to filter into the region into the weekend as high
pressure builds from west central Canada through northern Ontario to
Quebec.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 751 PM EDT SUN MAR 8 2020
VFR conditions should prevail for a good part of the night at
KIWD/KCMX and until about mid morning Mon at KSAW. Ahead of the cold
front that will bring deteriorating conditions, LLWS will continue
thru the evening at KIWD/KSAW. Late tonight, postfrontal MVFR cigs
will develop at KIWD/KCMX with further lowering of cigs to LIFR Mon
morning. In addition, ocnl -fzdz should develop in the morning at
both terminals. Improvement to MVFR is expected in the evening with
pcpn ending. At KSAW, IFR cigs and ocnl -dz will develop in the
morning with further lowering of cigs to LIFR by aftn. As temps
fall, -dz will become -fzdz in the aftn.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 317 PM EDT SUN MAR 8 2020
Tonight through early Tuesday, expect winds to contain gusts of 20
to 30 knots, with a predominantly northern component once the wind
shift moves through overnight. From later Tuesday through at least
early Thursday, expect sustained winds to remain less than 20
knots, with more certainty in the winds exceeding 20 knots by late
Thursday into early Friday. Gusts on Friday may approach 30 knots,
slackening by the start of early next weekend.
Heavy freezing spray may be possible late tonight through at least
midday tomorrow for the far northern portions of the lake, mainly
confined to north of Isle Royale to the Canadian waters. Moderate
freezing spray is likely elsewhere for this same timeframe.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
UPDATE...Rolfson
SHORT TERM...JP
LONG TERM...JLB
AVIATION...Rolfson
MARINE...lg
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Monday)
Issued at 350 PM CDT Sun Mar 8 2020
Strong winds gradually subside tonight, with widespread rain
arriving around midnight and persisting through much of the day on
Monday.
The axis of a broad upper tropospheric ridge axis is now well
east of the forecast area this morning, with southwesterly flow
setting in ahead of an equally high-amplitude H300 trough over
the western CONUS. Current water vapor imagery shows a deep plume
of Pacific moisture streaming northeastward on a 150-kt sub-
tropical jet, which should continue to spread across the forecast
area for the remainder of the day. The left-front quadrant of
this jet amplifies a shallow shortwave/vort max ejecting
northeastward along the upstream flank of the mean longwave
trough. Lee troughing already noted in surface observation along
the Front Range transitions into a closed low by later this
evening as the upper level shortwave approaches. The pressure
gradient between this lee trough and high pressure along the East
Coast is producing the very strong winds seen this afternoon.
While the strongest, diurnally driven gusts should subside after
sunset, winds of 15 to 25 mph with higher gusts persist through
the overnight hours and only gradually subside Monday morning
before increasing from the northwest Monday afternoon behind a
cold front.
Increasing theta-e advection/isentropic ascent within a partially
modified Gulf airmass ahead of this low should lead to a broad
region of rain tonight--with the possibility of embedded heavier
showers given the low static stability (lapse rates for elevated
parcels near moist-adiabatic) noted in the RAP forecast soundings.
Near-term model guidance has slowed the onset of precipitation by
a few hours this evening, likely due to the H700-300 wedge of dry
air noted in the 12Z TOP/OUN RAOB. There is still a non-zero
chance of an embedded thunderstorm tonight, but various CAM/CPM
sounding profiles show very low or non-existent normalized MUCAPE
values tonight into Monday. Did remove the overarching mention of
thunder for tonight and Monday, but trends will need assessing
throughout the event. Rainfall amounts are still on track to range
from about half to three quarters of an inch given the strong
forcing and PWATs around one inch, with heavier amounts possible
in any showers.
The surface low pulls eastward overnight and is progged to be
centered around south-central to central Kansas Monday morning,
with the CAM guidance suite trending a few hours slower than the
NAM/GFS MSLP progs. The low lifts northeastward along the
baroclinic zone, clearing the forecast area by early afternoon.
Overnight temperatures in the warm sector should only fall into
the low to mid-50s with dewpoints likewise rising into the low
50s overnight. Highs in north-central Kansas will be reached early
in the morning, with northwesterly winds and CAA taking place
behind the front. Highs in the warm sector tomorrow will heavily
depend on the speed of the boundary and the degree of cloud cover
and precipitation. Did nudge highs slightly warmer in the warm
sector into the low 60s, but confidence in these highs is average
at best.
.LONG TERM...(Monday night through Sunday)
Issued at 350 PM CDT Sun Mar 8 2020
Periodic chances for precipitation dot the forecast through the rest
of the week, with at or above average temperatures through the
forecast period.
Monday evening should see a lull in the precipitation with
subsidence/surface ridging behind the departing H300 shortwave. A
very weak mid-level perturbation Tuesday morning may bring very
light rain along the Nebraska border, but a number of solutions
are coming in dry and impacts will be minimal. Return flow sets on
for Tuesday--allowing highs to reach the mid to upper 50s despite
the cold frontal passage the day before. A northern stream wave
drops southward Tuesday night/Wednesday, bringing another chance
of light rain to the area. The evolution of the pattern begins to
become more uncertain late in the week, but the next major chance
of rainfall will come Friday afternoon through Saturday as the
mean longwave trough and surface cyclone reflection track across
the Central/Southern Plains. Confidence in its evolution is still
on the lower side, though there is an increasing consensus that
northeast Kansas will be on the northern side of this complex,
possibly resulting in a mix of rain and snow for some areas.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 636 PM CDT Sun Mar 8 2020
Limiting conditions are expected to develop in the next several
hours. Initial impact may be from ceilings with MVFR decks
reported upstream but ahead of the precipitation shield.
Confidence remains high in precipitation reaching the terminals by
06Z with periods of precip through much of the forecast. There
continue to be some indications of IFR ceilings after 08Z though
the south to southwest flow does not typically produce such
levels. Somewhat improved conditions should take place in the
later portions of the forecast with northwest winds behind the
cold front, though low cloud will likely persist.
&&
.FIRE WEATHER...
Issued at 350 PM CDT Sun Mar 8 2020
Very high fire danger conditions will persist for the rest of the
afternoon and evening before winds slowly subside. RH values are
continuing to climb and this trend is expected to persist into
tonight.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 7 PM CDT this evening for KSZ021>024-026-
034>040-054>056-058-059.
&&
$$
SHORT TERM...Skow
LONG TERM...Skow
AVIATION...65
FIRE WEATHER...Skow