Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/02/22
Area Forecast Discussion
National Weather Service Billings MT
705 PM MDT Sat Oct 1 2022
.UPDATE...
As expected, wave lifting out of WY has spread showers w/ some
embedded lightning to south central parts...roughly an area from
Red Lodge to Fort Smith and Sheridan...as of 7pm. Precip will
spread northward and westward over time as the upper low moves
slowly from the ID/WY border to over our SW mountains. This will
allow for dry slotting into our east overnight as precip becomes
focused over our west. There also is a greater chance of more
widespread fog across the area tonight...initially in our western
upslope areas then spreading to our east where the aforementioned
drying will be. The HRRR is very suggestive of fog in our east
tonight once the precip ends, and this seems reasonable if there
is even partial clearing.
Overall forecast is in good shape. Have adjusted pops/wx per
current and expected trends tonight, and have added fog across the
forecast area. Late afternoon web camera showed snow on Mt
Washburn in YNP...so no doubt the higher peaks (above 9 kft or so)
in the Beartooth/Absarokas are seeing wet snow w/ these bands of
showers.
JKL
&&
.DISCUSSION...
Tonight through Sunday Night...
There will be a bit of a break in the rain going into the
evening. Water vapor satellite imagery shows a dry slot that has
pushed most of the precipitation north of the area. However, there
is an area of showers and thunderstorms in central Wyoming,
closer to the center of the low. This will slowly continue to
drift to the northeast through the remainder of the short-term.
With the higher instability, with the thunderstorms. There could
be some better rain totals over night as the next round moves in
around the Bighorns.
Through Sunday, the rainfall should start to tapper off from west
to east, but this will still be fairly slow as the low is not
moving fast. With the core of the more in Montana, expecting a
little more thunderstorm activity tomorrow, mainly in the
southeast. Overall the rain totals over the next 36 hours are
mainly less than an inch, with the highest totals still near the
foothills and mountains.
Expect additional accumulating snowfall above 9000 feet overnight.
Additional amounts of up 6 inches some some locally higher amounts
near 8 inches before the system moves on. The Winter Weather
Advisory continues for the Beartooth Pass. Reimer
Monday through Saturday...
SREF showed the upper low as an open trough on Monday shifting E.
The Clusters and SREF had the trough off to the SE on Tuesday.
Noted the SREF had some MLCAPE and Bulk Effective Shear over the
SE late on Monday and NBM PotThunder had low chances in for
thunder. High PWAT`s continued on Monday as well. Expect scattered
to numerous showers, with thunderstorms in the SE, on Monday. The
precipitation shifts into SE MT Monday night, with low chances in
the far SE continuing for Tuesday. Temps will be near normal on
Mon. and a little warmer for Tuesday. Brief upper ridging with dry
weather moves in for Wednesday, then NW flow and mainly dry
conditions are expected Thursday. The NW flow allows a backdoor
cold front to move into the area, so Thu. will be cooler than
Wednesday. Friday and Saturday will be mainly dry with just some
mountain PoPs. The Clusters differed with the pattern, but the
gist of the pattern was NW flow. Fire weather is not a concern
through the period. Arthur
&&
.AVIATION...
Second round of rain moving through most terminals this evening,
with a small chance for thunderstorms this evening before becoming
all rain showers overnight. Very localized fog and drizzle
occurring at KBIL this evening that should lift later tonight. Fog
will at least be in the vicinity of all terminals overnight, with
best chance to experience it early Sunday morning before sunrise,
and at terminals KSHR and KMLS. Overcast conditions will persist
the next 24 hours. Vertz
&&
.PRELIMINARY POINT TEMP/POPS...
Sun Mon Tue Wed Thu Fri Sat
-----------------------------------------------------------
BIL 049/062 048/065 046/071 046/071 044/062 041/062 041/065
86/R 54/W 10/U 00/U 11/B 11/B 11/U
LVM 043/060 040/065 039/072 039/072 039/067 038/067 037/067
76/T 43/W 00/U 00/U 10/B 11/B 11/U
HDN 045/065 045/066 042/072 041/072 040/063 037/064 037/066
75/T 45/W 10/U 00/U 11/B 10/B 11/U
MLS 049/067 049/065 047/071 046/069 040/057 036/061 037/064
33/R 45/W 20/U 00/U 11/B 10/U 00/U
4BQ 048/068 048/064 046/068 045/070 041/058 036/061 038/064
53/T 46/T 31/U 00/U 11/B 11/B 01/U
BHK 047/070 048/064 046/069 045/066 035/052 031/057 035/061
33/R 65/T 31/B 01/B 11/B 10/B 00/U
SHR 043/064 042/063 041/069 041/071 039/063 039/063 038/065
+4/T 47/T 21/U 00/U 11/B 11/B 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect until noon MDT Sunday FOR
ZONE 67.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Charleston SC
1158 PM EDT Sat Oct 1 2022
.SYNOPSIS...
A weak cold front will move through tonight. Mainly dry weather
and below normal temperatures will then prevail under high
pressure into mid next week.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RAP 1.5-2 km moisture progs suggest stratocumulus will linger
for much of the night, possibly thinning a bit closer to
daybreak as moisture begins to strip out. Given the increased
cloud cover, lows were nudged up a degree or two for many
locations. Lows will range from the mid-upper 50s inland to the
lower-mid 60s at the coast. Dry conditions will continue as a
weak cold front meanders offshore.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
High pressure will prevail at the surface with an upper trough
aloft. Mainly dry weather is expected but can`t rule out a few
light showers at times, especially around/north of Charleston,
as upper shortwave energy rotates through the trough. It will
also become a bit breezy Monday and Tuesday as the pressure
gradient tightens, especially at the coast. Temperatures will
stay below normal, generally in the 70s during the day and 50s
at night.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Generally dry high pressure is expected mid to late next week,
although a cold front should pass through Friday night. Moisture
will still be lacking with the frontal passage so do not expect
much in the way of rainfall, if any. Temperatures should start
out the period below normal but get back closer to even a bit
above normal through Friday until the cold front passes.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
KCHS/KJZI/KSAV: VFR.
Extended Aviation Outlook: Moderate to high confidence for mostly
VFR conditions at KCHS/KJZI/KSAV through Thursday. However, there is
a moderate risk for at least periodic MVFR restrictions from low
clouds Sunday night through Monday night, especially at KCHS/KJZI.
&&
.MARINE...
Overnight: Winds will turn northerly 10-15 kt as a cold front
pushes offshore. Seas will average 2-4 ft.
Sunday through Thursday: Conditions will go downhill Sunday
night as the pressure gradient tightens due to incoming high
pressure and Small Craft Advisories will be possible into mid
week for winds and/or seas, especially for the waters beyond 20
nm.
&&
.TIDES/COASTAL FLOODING...
Astronomical tides will increase again next week due to the
lunar perigee and full moon and positive tidal anomalies may
develop as well due to the N/NE winds. Thus, can`t rule out at
least some minor coastal flooding, especially in
Charleston/Colleton Counties starting as early as the Sunday
afternoon high tide.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
Area Forecast Discussion
National Weather Service Cheyenne WY
549 PM MDT Sat Oct 1 2022
.SHORT TERM...(This evening through Monday night)
Issued at 200 PM MDT Sat Oct 1 2022
Upper low currently located near the Wyoming/Idaho state line. Low
is spinning off another piece of energy into Carbon and Albany
Counties this afternoon. Have been getting moderate rain reports
out of Rawlins and Dixon late this morning and early afternoon.
This band has shifted east and is now located along a line from
Muddy Gap to Elk Mountain to Laramie. More convection in north
central Montana moving northeast along this boundary and will
likely bring rainshowers and isolated thunderstorms to the Laramie
Range and points east as the afternoon progresses.
Looking at simulated radar from the HRRR and RAP...line of showers
and storms slowly shifts east across the Laramie Range into the
I-25 Corridor by 23Z or so...shifting further east to
Lusk/Scottsbluff/Kimball by 01Z. Showers persist in the Panhandle
through 06Z tonight. Tried to reflect this in the PoP forecast
this afternoon and evening.
Upper low tracks northeast into western Montana Sunday. 80kt jet
max moves across the CWA late morning into the afternoon.
ECMWF/SREF and NAM showing another active afternoon Sunday with
showers and isolated thunderstorms. Did go pretty high on PoPs for
Sunday.
One more day of unsettled weather Monday as low tracks into
eastern Montana and trough axis moves across the CWA. Still have
good chances for afternoon and evening showers and storms as
this trough axis moves through.
.LONG TERM...(Tuesday through Saturday)
Issued at 200 PM MDT Sat Oct 1 2022
The extended forecast includes near seasonal temperatures with
multiple opportunities for precipitation across the cwa. The cut-off
ULL will ultimately become absorbed in the steering flow aloft and
begin to push to the east across the Central Plains by late Tuesday.
CAA will continue to be present on Tuesday as cloud cover will be
slow to move out of the region. 700mb temperatures will range from
+2C to -2C on Tuesday and +4C to -2C on Wednesday. Daytime highs
struggle to reach the 60s by the afternoon hours across most of the
forecast area as there will likely be a weak cool front sagging to
the south. Lingering rain showers will be possible during this time
until the upper level low pushes east. Wednesday will see a return
of mostly sunny skies, which will likely be the first day to see a
full day of mostly clear skies since the previous weekend. This is
in response to an upper level ridge amplification across the Four
Corners region of the CONUS toward our cwa. Afternoon highs will
range from the 60s to the low 70s across the lower terrain, and
slightly cooler in the higher elevations. The upper level ridge will
begin to become flattened by Thursday, and northwest flow aloft will
allow for a weak shortwave to potentially clip the cwa by Thursday
night into early Friday. More of the same is likely for Friday into
Saturday as the northwest flow aloft will assist with another
potential shortwave bringing moisture to the area. Additionally,
tropical moisture from the Pacific will be lingering across the Four
Corners area by next weekend, per the extended model guidance, and
could act as a monsoon surge for precipitation opportunities to
round out the first 10 days of the month.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 544 PM MDT Sat Oct 1 2022
A line of showers and thunderstorms is currently moving across the
area, and is about to cross the WY/NE border. Expecting VCTS near
Nebraska terminals as this moves through with winds turning
westerly as it comes through. Timing looks like 0030z-02z for
KBFF, then between 02z and 04z for the other NE terminals, but a
few showers/storms could develop both in front of and behind this
line. Expect shower activity to wane in the NE panhandle after
midnight. An area of low clouds could develop near KBFF/KAIA
around 10z through 14z, but confidence is low at this time. Quieter
in Wyoming overnight, but could see shower activity re-
developing around around 08z. Another round of scattered showers
and thunderstorms is expected on Sunday afternoon.
&&
.FIRE WEATHER...
Issued at 200 PM MDT Sat Oct 1 2022
Minimal fire weather concerns through at least Tuesday with cool
temperatures and high humidity. Cold front moved through last
evening...bringing fairly widespread rainfall and cool
temperatures. Upper low with this front takes its sweet time
moving through northern Wyoming and southern Montana...which will
bring continued chances for wetting rains and cool temperatures
into Monday. Finally dry out Tuesday...but cool temperatures and
higher humidity remains. No fire weather concerns expected.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...GCC
LONG TERM...BW
AVIATION...MN
FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
737 PM EDT Sat Oct 1 2022
.AVIATION...
A secondary area of surface high pressure is building aggressively
southward through much of northern Ontario this evening. Models show
an enhanced pressure gradient at the edge of this secondary high
pressure which is now positioned over the northern Great Lakes. This
enhanced pressure gradient is forecasted to release southward
through Southeast Michigan late tonight taking on the form of a weak
cold front. Model soundings show a good amount of shallow cold air
advection centered between 1.5 and 3.0 kft agl after 06Z tonight
from north to south. This caa may be good enough to result in
saturation and development of stratus/stratocu. The inherited tafs
were aggressive with this cloud and will continue the mention for
BKN MVFR north of the Detroit taf sites. Northwest wind direction
theoretically enhances the potential for additional Lake moisture to
duct into the area. The parent air mass remains dry and will favor
very clear skies then once daytime heating occurs Sunday.
DTW THRESHOLD PROBABILITIES...
* Low for cigs aob 5000 feet tonight and Sunday morning. Low to
Moderate potential late Sunday morning or early afternoon.
&&
.PREV DISCUSSION...
Issued at 304 PM EDT Sat Oct 1 2022
DISCUSSION...
There will be a persistence of light northeast low level winds
tonight as the region lies between strong high pressure across nrn
Ontario and the now extratropical remnants of Ian lifting into
Virginia. The result will be some shallow cold air advection through
the night. Model soundings suggest this will result in a deepening
low level inversion. Both RAP and the 3km NAM indicate the moisture
flux off Lake Huron will result in some low stratus ducting off the
lake under this inversion, supporting the likelihood of an inland
expansion of stratus overnight into early Sun morning. This and the
lingering gradient flow will limit nocturnal cooling, supporting
nighttime mins in the mid 40s to lower 50s.
The blocking pattern over the upper Midwest/Great Lakes will persist
into early next week. Mid level ridging will actually amplify across
the Great Lakes Sunday into Monday, enhancing low to mid level
anticyclonic flow. There will be an initial surge of low level dry
air from the northeast on Sunday, clearing any lingering status
during the afternoon. Deep layer dry air and sfc high pressure will
then influence Se Mi thru Tuesday night. Light winds with ample
clear sky will result. Model soundings and ensemble guidance suggest
mainly seasonal highs in the 60s to low 70s. Conditions will however
be favorable for good radiational cooling which will support some
cool nights. Some nighttime fog, especially considering the lingering
light easterly flow off the lakes, will be the only potential
weather concern for the next few days.
A highly amplified northern stream wave is then forecast to break
down the blocking pattern, driving a potent fall cold front across
the Great Lakes. There is not only strong model agreement in this
long wave pattern shift, ensemble members do not show too much
spread in timing the system into Lower Mi despite this being around
day 5 (Thursday). The approach of this upper wave/sfc front will
bring the next chance for rain on Thursday. 850mb temps are forecast
to drop into the negative single digits behind this wave, resulting
in a period of respectable early October cold air during the end of
the forecast period.
MARINE...
Northeast winds continue to strengthen this evening as the region
remains in between the remnants of Ian and strong high pressure over
northern Ontario. Strongest winds still anticipated late
evening/early tonight over central Lake Huron and the Saginaw Bay
where gusts top out in the 25-30kt range. There still appears to be
a brief window where gusts could approach entry-level gales over the
central open waters of Huron late this evening however strength and
duration not expected to warrant any headlines. Small craft
advisories continue for all nearshore waters into Sunday before
winds and waves gradually begin to relax as the Ontario high sags
south into the Great Lakes. This weakening high drifts south across
the region through the first part of the next work week bringing a
return to favorable marine conditions.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until 4 AM EDT Monday for LHZ421-441>443.
Small Craft Advisory until 10 PM EDT Sunday for LHZ422.
Lake St Clair...Small Craft Advisory until 10 AM EDT Sunday for LCZ460.
Michigan waters of Lake Erie...Small Craft Advisory until 10 AM EDT Sunday for LEZ444.
&&
$$
AVIATION.....CB
DISCUSSION...SC
MARINE.......KDK
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Quad Cities IA IL
634 PM CDT Sat Oct 1 2022
...00Z AVIATION UPDATE...
.SYNOPSIS...
Issued at 251 PM CDT Sat Oct 1 2022
At 2 PM, eastern Iowa, northwest Illinois and far northeast Missouri
remained on the southern edge of high pressure across southern
Ontario. A surface low sits in west central South Dakota with a
warm front eastward along the Iowa and Minnesota border. There are
some mid clouds spilling into the area along and east of that front
from Minnesota and Wisconsin where some showers were occurring.
Temperatures are in the upper 60s to lower 70s.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 251 PM CDT Sat Oct 1 2022
Key Messages:
1. Quiet weather continues across the area over the next 24 hours.
Discussion:
Stagnant weather pattern continues across the area with a
blocking pattern in place aloft across the region. This is resulting
in persistent ridging across the southern Plains that
extends northward into the Mid Missouri River Valley. A shortwave is
forecast to move to our north and east tonight with mid level
cloudiness expected across the area. The GFS and HRRR do
show rain showers across the area early Sunday morning but soundings
and model time-height cross sections show a very dry lower
atmosphere so do not think that any precipitation will make it to the
ground. Low temperatures on Sunday morning will be a little warmer
with low in the mid to upper 40s. Skies will become sunny by Sunday
afternoon with high temperatures once again in the upper 60s across
northwest Illinois to the lower 70s west of a Independence to Macomb
Illinois line.
.LONG TERM...(Sunday night through Saturday)
Issued at 251 PM CDT Sat Oct 1 2022
Key Messages:
1. Pleasant fall weather continues into midweek before temperatues
turn colder.
2. Model blends continue to go back and forth on chances of
precipitation on Thursday.
Discussion:
Ridging will continue across the Upper Midwest through the middle of
the week as the overall 500 mb pattern slowly shifts eastward.
An approaching 500 MB closed low Tuesday into Wednesday will
slowly turn surface winds across the area to the south. This
will increase warm air advection Tuesday into Wednesday resulting in
slightly warmer temperatures.
By Wednesday night into Thursday, a shortwave trough digging
southward along the western edge of a broader trough in eastern
Canada will finally push the closed low to our west eastward and
drive a strong cold front across the area on Thursday. Models
disagree on the amount of moisture available and thus disagree on
the chances of precipitation for Thursday but in general these
chances are along and east of the Mississippi River and only 20 to
30 percent chances.
Behind this storm system, a broad 500 mb trough will sit across the
eastern CONUS. Cooler temperatures will spread into the area for the
end of next week resulting in high temperatures for the end of the
week in the 50s with lows in the 30s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 630 PM CDT Sat Oct 1 2022
Predominantly VFR conditions expected through the period with
light east to northeast winds. There is a chance for patchy fog
and low clouds with IFR/LIFR/VLIFR conditions after 11z through
17z at DBQ and MLI with lake enhanced moist easterly low level
flow. However, most of the guidance keeps this just east of the
terminals owing to low confidence. As a result, have left out any
mention of fog and low clouds with this TAF issuance but this will
need to be monitored with later TAF forecasts.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...Cousins
SHORT TERM...Cousins
LONG TERM...Cousins
AVIATION...McClure
Area Forecast Discussion
National Weather Service Goodland KS
505 PM MDT Sat Oct 1 2022
.SHORT TERM...(This evening through Monday night)
Issued at 329 PM MDT Sat Oct 1 2022
At the start of the short term period, the latest RAP analysis shows
an upper air low over the ID/WY border giving the CWA a west-
southwesterly flow aloft. Current satellite imagery shows some
scattered high clouds mostly in the east-central portion of the CWA
with surface observations reporting dry conditions with southerly
winds gusting up to around 30 kts. Going into Saturday night, models
show the upper air low moving eastward a bit turning the CWA`s flow
more southwesterly overnight. At the surface, the gusty winds look
to continue until the evening hours causing near-critical to locally
critical fire weather conditions for a few more hours though minimum
RHs look to be generally just above criteria. Models show areas
along and west of the CO border seeing chances for a light shower
during in the late evening along a boundary in eastern CO. Overnight
lows expect to be in the upper 40s to middle 50s.
For Sunday, forecast guidance depicts the upper air low moving
eastward along the southern MT border throughout the day causing a
west-southwesterly flow over the CWA being between the low to the
northwest and a ridge to the west. At the surface, elevated to near-
critical fire weather may be possible east of the CO border due to
another day of gusty southerly winds around 25 kts. Minimum RH
values look to reach the upper teens in the eastern portions of the
CWA, but also look to be closer to 20 percent during the afternoon
hours. During the evening hours, there are chances for showers and
thunderstorms for areas along and west of the CO border that move
into the northwestern quadrant of the CWA overnight. Similar to
Saturday, current QPF values look to be less than a tenth of an inch
if rain occurs. Severe weather is not anticipated currently
though may see faster wind gusts with thunderstorms. Sunday`s
daytime highs expect to be in the upper 70s to middle 80s followed
by overnight lows in the upper 40s to middle 50s range.
On Monday, models show the upper air low moving into the MT/SD/WY
border area by the evening hours causing the CWA to have a stronger
southwesterly flow aloft. At the surface, a low pressure system
looks to move eastward in southeastern CO bringing good chances for
showers and a few thunderstorms to the CWA during the afternoon and
evening hours. Current forecast model CAPE values look to be a
little low for severe weather though some showed values around 500
J/kg in the southwestern quadrant with bulk shear around 35 kts. So
while thunderstorms may be expected, severe weather is not currently
anticipated though this will be monitored in future model runs.
Current QPF values look to be around a quarter inch in some
locations. Fire weather conditions do not look to be a concern on
Monday. Monday`s daytime highs look to range between the middle 70s
and middle 80s with overnight lows between 45 and 55 degrees.
.LONG TERM...(Tuesday through Saturday)
Issued at 223 PM MDT Sat Oct 1 2022
For the long term, a fair amount of uncertainty of exists. However,
temperatures will likely be near to below average with a few chances
for rain.
For the mid part of the week, the forecast will largely be dependent
on the upper trough that has been northwest of the area. The
forecast is for it to remain northwest of the area until the mid
part of the week when it will finally begin to move off to the east.
Models are currently forecasting that the moisture with the trough
will move through around Tuesday which will help keep some cloud
cover over the area and bring some chances for rain with forcing
from the upper trough and associated surface low. Wednesday would
then clear out and be slightly warmer as the features move slightly
off to the east. Highs are forecasted to be in the 70`s though
Tuesday could be slightly cooler if the cloud cover remains over the
area the entire day.
For the later part of the week, it will all depend on another
smaller wave that is forecasted to move south from Canada. Current
forecast has the main part of that trough swinging through the Great
Lakes, but the surface front and higher pressure are forecasted to
move into the Plains. Guidance currently disagrees on how much of
the cold air will make it south, but well below average highs and
lows are possible including frost/freeze lows on Friday morning.
Also with system, more rain chances will be possible but when and
how much will depend on the timing of the system. If the colder
forecast doesn`t verify, temperatures will likely be near to
slightly below average.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 504 PM MDT Sat Oct 1 2022
Both terminals expected to see VFR conditions through the
forecast period, with gusty winds and some shear being main wx
issues.
Winds for KGLD, south-southwest around 15-30kts through 02z
Sunday, then south 10-15kts. By 14z increasing to around
20-30kts. LLWS 02z-10z Sunday 170@45kts and again 10z-14z
200@40kts.
Winds for KMCK, southeast around 10-15kts. Gusts up to 30kts from
00z-02z Sunday and again from 16z onward. LLWS 07z-14z Sunday
180@40kts.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...076
LONG TERM...KAK
AVIATION...JN
Area Forecast Discussion
National Weather Service Green Bay WI
1041 PM CDT Sat Oct 1 2022
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Sunday
Issued at 243 PM CDT Sat Oct 1 2022
The latest RAP analysis and satellite/radar imagery show mid and
high clouds spilling over the top of a mid-level ridge positioned
across the eastern Dakotas and the northern Mississippi Valley. As
has been the case for the past several days, dry air associated
with high pressure has prevented much eastward progression of
showers that have impacted Minnesota and western Wisconsin.
Meanwhile, strong cold advection via northeast winds is occurring
behind a cold front that is dropping south across Lake Superior.
Forecast concerns mainly include small shower chances, followed by
clouds, temps, and fog potential.
Tonight...The mid-level ridge will continue to build northeast
into Wisconsin, and models insist on spreading mid-level clouds
over top the ridge and across the forecast area. Meanwhile,
northeast winds will push the cold front into far northeast
Wisconsin late. Neither feature is expected to produce precip.
However, after watching showers over-perform over western
Wisconsin and Minnesota over the past few days, wonder if some
showers or sprinkles could reach into north-central and central
WI. In addition to the mid-clouds from the west, the cold front
will likely bring in some low clouds to far northeast WI late. The
clouds should result in warmer temps tonight, but did lower mins
at the cold spots compared to the NationalBlend. The clouds should
also reduce the chance of fog late tonight as well.
Sunday...High pressure will build into the region, but should see
considerably more cloud cover from the mid and high clouds, and
also low stratus than today. Combined with northeast winds,
should see a cooler day with highs in the low to mid 60s, locally
cooler near Lake Michigan.
.LONG TERM...Sunday Night Through Saturday
Issued at 243 PM CDT Sat Oct 1 2022
The main forecast concerns occur during the latter half of the
next work week, when a strong cold frontal passage brings rain,
possible lake-effect snow, gusty northwest winds and possible gale
force gusts on Lake Michigan.
The forecast area will remain on the west to northwest periphery
of a large high pressure system Sunday night through Tuesday
night. Most of this period will be dry, though weak WAA and a
short-wave trough may bring a few light showers to north central
and central WI late Sunday night. There may also be some fog in
northeast and east central WI Sunday night. Temperatures will be
at or above normal through Wednesday.
A cold front will approach the area on Wednesday afternoon, and
bring scattered showers to the northwest half of the forecast
area. Showers will increase, especially across northern WI, as
the frontal passage occurs Wednesday night and a strong short-
wave moves through on Thursday. Strong CAA will occur in the wake
of the front, with NNW flow and lake-850 mb delta-t`s around 20 C
leading to lake-effect in NC WI from Thursday afternoon through
Friday morning. The first snow of the season is expected in north
central WI Thursday night into Friday morning, though it is too
early to say if accumulations will occur. Winds will likely gust
to 25 to 35 mph at inland locations Thursday into Thursday night,
with gusts to near gale force on Lake Michigan. Temperatures will
drop well below normal, with highs only in the 40s and lower 50s
by Friday. Have adjusted the model blended forecast for higher
wind speeds/gusts during this period, and higher pops in NC WI
for the expected lake-effect.
Generally dry conditions should return on Saturday, but cool
temperatures will persist.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1041 PM CDT Sat Oct 1 2022
Veil of mid and high clouds continued to push across the area
during the evening hours, and will continue through much of the
TAF period. It will encounter drier air over eastern WI, so some
eroding of the clouds are expected. These clouds will help reduce
the fog potential tonight, but still could get some ground fog
where skies remain clear the longest. That does not appear to be
likely at any one TAF site, so will not include any fog. If skies
do clear out more than expected, the fog will be more widespread
with lower visibilities at times.
Models continue to be aggressive with bringing in a IFR/MVFR
stratus deck into parts of the area overnight into Sunday
morning. Best chance will be across north central and central WI
and near Lake Michigan. These clouds continue to expand across
Upper Michigan and should expand south through the night. The
lower clouds will lift/scatter out Sunday morning. Can`t rule out
a sprinkle or two across central and north central WI tonight into
early Sunday but will have no impacts.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM.....MPC
LONG TERM......Kieckbusch
AVIATION.......Bersch
Area Forecast Discussion
National Weather Service Tucson AZ
230 PM MST Sat Oct 1 2022
.SYNOPSIS...After a chance of showers and thunderstorms this
through this evening, we`ll keep enough moisture around for isolated
storms this coming week. Temperatures will remain near seasonal
averages for early October.
&&
.DISCUSSION...Radar was showing a few showers and thunderstorms
developing early this afternoon across mainly Cochise county. A weak
upper low over Sonora, Mexico combined with the daytime heating will
support additional showers and thunderstorms today. Latest HRRR
solution depicted more isolated in nature activity through this
evening before dissipating by midnight. Thereafter, the tail end of
a system tracking north of the region will swing through the area
and interact with enough moisture to keep rain chances in the
forecast. Models were in fair agreement with a portion of this
northern system hanging back and forming another weak low near SE AZ
by Thursday. This feature along with daytime heating and lingering
moisture will support rain chances through much of next week,
especially south and east of Tucson. High temperatures will hover
near seasonal readings.
&&
.AVIATION...Valid through 03/00Z.
FEW-SCT clouds (locally BKN) at 7k-11k AGL thru 02/05Z and again aft
02/18Z, with clearing skies between 02/05Z and 02/18Z. ISOLD-SCT
TSRA/SHRA thru 02/03Z and developing again aft 02/19Z. Brief MFR
conditions possible with the TSRA and wind gusts to 40+ kts. Outside
of thunderstorm outflows, SFC wind generally SELY/SLY at 8-13 kts,
with higher gusts during the afternoon hours. Aviation discussion
not updated for TAF amendments.
&&
.FIRE WEATHER...Isolated to scattered afternoon and evening showers
and thunderstorms are expected through the end of the next week,
mainly from Tucson eastward. The main threats will be strong and
gusty outflow winds, isolated areas of heavy rainfall and dangerous
lightning. Outside of thunderstorm outflow winds, 20-foot winds will
remain less than 15 mph through Wednesday. There is the potential
for elevated east/southeast winds Thursday and Friday of next week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
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Area Forecast Discussion
National Weather Service Las Vegas NV
714 PM PDT Sat Oct 1 2022
.SYNOPSIS...Low pressure stalled over the Intermountain West coupled
with a weak low in northwestern Mexico will provide enough moisture
and lift to keep chances of showers and thunderstorms in parts of
Mohave County each afternoon through Monday. Meanwhile, clear skies,
light wind, and above-average temperatures expected for the
remainder of the forecast area.
&&
.UPDATE...The thunderstorm activity over Mohave County has mostly
ended, except for a few isolated storms near Pipe Spring National
Monument. This activity should end over the next few hours, and
quiet conditions are expected area-wide for the remainder of the
night. Additional thunderstorm activity is still forecast tomorrow
afternoon, with most of the activity expected across eastern Mohave
County. Coverage could be more widespread in this area, but moisture
levels are not exceptional and significant impacts are not likely.
The current forecast grids look good, and no changes have been made
this evening.
&&
.DISCUSSION...Today through next Friday.
Another afternoon of isolated shower and thunderstorm activity
expected across portions of Mohave County today. Latest HRRR
reflectivity forecasts highlight few storms... one east of Kingman
(already observed on radar along Interstate 40), one east of Dolan
Springs, then sporadic light convection along the Arizona Strip. Not
expecting much in the way of impacts today, as moisture is not high
enough in the expected storm areas to result in efficient rain-
makers, and a DCAPE around 750 J/kg is not impressive enough for
widespread, destructive downburst winds. Will continue to keep an
eye on storms that form today, but as of 11:50am PDT, no lightning
nor measurable precipitation observed with this cell east of Kingman.
Otherwise, dry conditions, sunny skies, and above-average
temperatures persist over the remainder of the forecast area going
through the weekend due to northwest flow aloft and a building area
of high pressure in the Eastern Pacific.
Slight to scattered PoPs remain over Mohave County Sunday afternoon,
reaching portions of eastern Lincoln and Clark counties. Again, this
moisture is anomalous for this time of year, but in and of itself is
not overly impressive. The upper-level low in the Intermountain West
will remain relatively in-place through the weekend, providing some
weak forcing and allowing moisture to linger across northern
Arizona. Ensemble means continue to feed moisture up the Colorado
River Valley via a weak area of low pressure in far northwestern
Mexico that will help escort vicinity tropical moisture from
Hurricane Orlene northward into Arizona. We are not expecting direct
impacts from Orlene. Current track has it pushing inland into Mexico
north of Guadalajara. Simply, moisture originating from the
(currently weak Category 1) hurricane will be escorted northward as
the aforementioned weak low approaches the Arizona state border.
Weak forcing from the upper-level low in the Intermountain West (and
associated vort lobe) will work with this moisture, resulting in
shower and thunderstorm chances on Sunday and Monday afternoon. Both
the ECMWF and GFS ensemble means have backed off substantially
regarding moisture lingering through midweek, in part due to a speed-
up of the approaching ridge of high pressure that will shove
moisture eastward out of our area.
Above-average temperatures will continue elsewhere through the bulk
of the forecast period, with Las Vegas experiencing 90+ degree high
temperatures each afternoon. There is an indication in the extended
forecast that an area of low pressure will cut off over northwestern
Mexico / southern Arizona late-week that will help reduce
temperatures while reintroducing precipitation chances to the
forecast.
&&
.AVIATION...For Harry Reid...South-southwesterly breezes return this
afternoon, with gusts up to 20 knots. Gusts will taper off after
sunset. Winds remaining from the southwest through the evening,
becoming light and variable late tonight. Mostly clear skies with
just a few clouds around 15 kft this afternoon. Similar conditions
expected tomorrow.
For the rest of southern Nevada, northwest Arizona and southeast
California...Winds expected to favor a southerly direction at the
Las Vegas Valley sites today, with gusts up to 20 knots. Gusts will
taper off this evening. Typical diurnal wind patterns forecast
for KBIH and KDAG. Another round of breezy south winds today for
sites in the Colorado River Valley, with gusts of 15-20 knots this
afternoon. Mostly clear skies across the area, with just a few
mid- level clouds in the eastern sites. Similar conditions
anticipated tomorrow. &&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
UPDATE...Planz
DISCUSSION...Varian
AVIATION...Woods
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