Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/24/23
Area Forecast Discussion
National Weather Service La Crosse WI
1000 PM CDT Tue May 23 2023
.DISCUSSION...(This evening through Tuesday)
Issued at 142 PM CDT Tue May 23 2023
Key Message:
- Slightly cooler (for most) tomorrow and Thursday, otherwise
warm and dry conditions continue.
Tonight - Wednesday...
There looks to be a small chance for some showers late tonight into
Wednesday for areas generally north of Interstate 94. A cold front
over northern Minnesota and Lake Superior this afternoon will slide
south into the area. Some convection was developing along the front
ahead of a short wave trough approaching from central Canada. This
wave is expected to track across the Canadian Border and as the
front pushes south it should eventually outrun this upper air
support. As a result, some of the developing showers may survive
into the norhtern parts of the area before they loose support and
dissipate. Measurable rainfall amounts will be light and expected to
be under a tenth of an inch.
Looking ahead...
The main forecast concern for later in the week continues to be very
low relative humidity with the prolonged absence of moisture feeding
into the region. Minimum relative humidity is forecast to fall into
the low 20s on Thursday, Friday, and Saturday with the possibility
of falling into the upper teens if mixing or temperatures exceed the
current forecast.
Another day of seasonable temperatures Thursday before warm air
advection kicks back in causing gradual warming Friday through the
weekend. High pressure dominates the synoptic environment into early
next week. This will generally lead to clear skies, light winds, and
dry conditions.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1000 PM CDT Tue May 23 2023
CIGS: high smoke will continue to keep milky skies across the region
into Wed, but RAP model suggests thinning/improving as we move into
Thu. Passing, backdoor cold front toward 12z Wed could bring in a
few hours of a bkn mid level (VFR) deck. Will hold with SCT for now.
WX/vsby: passage of cold front looks dry at this time. No impacts
anticipated.
WINDS: light south/southeast tonight, becoming more easterly by 12z
Wed. Could see gusts into the upper teens Wed afternoon with tighter
pressure gradient/daytime mixing.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
DISCUSSION...KAA/04
AVIATION.....Rieck
Area Forecast Discussion
National Weather Service Binghamton NY
941 PM EDT Tue May 23 2023
.SYNOPSIS...
A weak disturbance will bring a chance for isolated showers and
thunderstorms this afternoon, mainly over Central New York.
More widespread showers and thunderstorms will arrive on
Wednesday as a cold front passes through the region. Cooler and
drier conditions will round out the week, with a risk of frost
and localized freezing temperatures Wednesday and Thursday
night.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
940 PM Update...
The showers never developed as what was indicated by most model
guidance, though that was not surprising given the dry
conditions. No changes were needed to PoPs as they were already
too low to mention. The only changes that were needed with this
update were the temperatures and dewpoints. These were touched
up to better match obs.
600 PM Update...
Skies continue to be shower-free this evening. Some of the CAMs
and short-range model guidance continues to show showers for
this evening, while others like the HRRR have very little.
Soundings do hint at some mid-level moisture but near the
surface, conditions are far too dry for anything to reach the
ground. If this observational trend continues, it seems unlikely
that anything will develop and if it does, it may not even
reach the ground. Still, there is hesitation to completely
remove PoPs given what some guidance is showing. PoPs were
decreased even more but this update continues with the slight
chance PoPs across CNY. The other main change to this forecast
was to the dewpoints. With the drier conditions, the forecast
was higher than what is being observed. A blend of short-range
guidance got the forecast closer to observations. The rest of
the forecast remains on track and needed little change.
250 PM Update...
Smokey skies over the region again this today, giving the sky a
milky white appearance. The smoke is reducing heating this
afternoon, and this reduction is heating is likely why we are
seeing less shower activity than previously forecast. With
reduced instability, I have removed thunderstorms from the
forecast this afternoon and have reduced PoPs to only slight
chance.
Any shower activity will dissipate after sunset. For tomorrow,
a cold front with a strong upper level shortwave trough will
push through the area. This will kick off a band of rain
showers and thunderstorms. Instability will be limited again
tomorrow with CAPE topping out near 500 J/kg, but 0-6 km bulk
shear will be decent, approaching 40 knots so it is possible
that a few stronger storms would produce gusty winds and small
hail tomorrow afternoon.
Front exits the region tomorrow evening with strong CAA behind
it. Temperatures will drop into the low to mid 30s tomorrow
night, but winds will likely prevent frost development. However,
we may still need freeze headlines, as a few locations in the
sheltered valleys of the Catskills and in Northern Oneida County
may reach or drop below freezing.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
230 PM Update...
After a cold front moves through Wednesday, gusty northerly
winds will keep temperatures on the chilly side for Thursday.
Winds will calm down overnight Thursday, allowing for frost to
occur across Central NY and along the Twin Tiers, with low
temperatures in the mid- to high-30s. Temperatures will warm
back up into the mid- to high-60s across the area on Friday.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
230 PM Update...
High pressure begins to build back over the area Saturday, and
we`ll see an increasing temperature trend through Memorial Day.
Model guidance disagrees quite a bit on the overall synoptic
pattern heading into Memorial Day, with the ECMWF developing a
separate low pressure system over Michigan, and the GFS
propagating a shortwave off of a pre-existing system that is
over North Carolina. The general consensus is a slight chance of
showers on Sunday afternoon.
On Memorial Day, temperatures are expected to warm up to the
high-70s/low-80s, with a slight chance of thunderstorms and
rain showers in the afternoon.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions are expected through Wednesday morning. By
Wednesday afternoon, showers and possibly a few thunderstorms
will pass through the region, which will bring at least MVFR
restrictions at all Central NY terminals (KAVP likely remains
VFR). Confidence is too low for thunder at this range, and
therefore this was left out of the TAFs for now. This may be
added with upcoming TAF issuances if confidence in thunderstorms
increases. Gradual improvement is expected by late Wednesday
afternoon/early Wednesday evening.
Outlook...
Wednesday night through Sunday...Mainly VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...MPK
NEAR TERM...BTL/MPK
SHORT TERM...KL
LONG TERM...KL
AVIATION...BJG
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
914 PM CDT Tue May 23 2023
.UPDATE...
Issued at 858 PM CDT Tue May 23 2023
Occasional storms continue along a boundary from Hettinger to
near Courtenay north of Jamestown (with the greatest coverage over
northern Stutsman County and eastern Adams County), though a few
storms are starting to develop along a northward moving outflow
over Bismarck to the north of Steele. Plenty of instability
remains in place, but deep layer shear is lacking. With that said,
the storms have been very slow moving, which has actually led to
some minor flooding over northeastern Stutsman County. Expect the
threat for heavy rainfall to continue for a few more hours given
the slow storm motion and even back building occurring, combined
with plenty of moisture available.
UPDATE Issued at 647 PM CDT Tue May 23 2023
Main area of thunderstorms at this time stretch from the tail of
Sioux County east-northeastward to the north of Jamestown, though
occasional additional activity over the west has been noted. The
storms have been slow moving, possibly bringing some heavy rain.
Another concern, along with small hail given the instability, is
gusty winds which have been reported just to the east of our area,
which is supported by the latest forecast Jamestown soundings. Not
thinking severe at this point, but still something to note.
UPDATE Issued at 500 PM CDT Tue May 23 2023
A quick update has been sent out to expand precipitation chances
through northwest and south central North Dakota as some showers
and thunderstorms are starting to develop.
&&
.SHORT TERM...(This Evening through Wednesday)
Issued at 320 PM CDT Tue May 23 2023
A chance for showers and thunderstorms this evening and tonight,
highest in the south central and James River Valley, is the focus
of the short term forecast.
This afternoon, a double barrel upper low was located over the
Pacific Northwest into the southern Canadian Prairies, with a
ridge axis centered over the central CONUS. At the surface, the
center of a low was analyzed over west central South Dakota, while
a strong high pressure sat over northern Manitoba and Ontario. A
back door cold front has been sliding south through the day,
meeting a weak warm front that has been drifting north from South
Dakota. This intersection is where CAMs continue to initiate
convection late this afternoon and into the evening, in a
southwest-northeast oriented line from the Grant/Sioux County area
to the Stutsman County area. Daytime satellite imagery shows some
cu beginning to develop from Stutsman back into Logan and Kidder
Counties, but as of 2000 UTC it`s still quite shallow.
The 12Z HREF advertises a ribbon of 1000-2000 J/kg of CAPE
oriented around the frontal boundary, but 0-6km shear is very
weak, only around 10-15 knots. This is also seen in HRRR forecast
soundings, where shear is around 10 knots and hodographs are
basically an overlapping circle. With how weak the shear is, our
thought is that pulsing thunderstorms are the most likely outcome
with the present instability and strong lapse rates. Would not be
surprised if the strongest storm or two end up with nickel to
quarter sized hail, but this would be more likely with initial
storms before convection gets clustered and consequently weaker.
The other main concern with any strong showers or thunderstorms is
the potential for heavy rainfall. Abnormally high PWATs combined
with slow storm motion means there is potential for locally heavy
rainfall, which could lead to minor flooding, especially in urban
areas.
As the combined frontal boundary washes out overnight, chances for
showers and thunderstorms drift north and lessen, tapering off
Wednesday morning. We do have a slight chance for showers and
thunderstorms across parts of western North Dakota on Wednesday
afternoon, but the bulk of precipitation looks to stay on the
Montana side of the state line.
Behind the cold front, breezy east-northeast winds will expand
south through the entire forecast area, continuing through the day
Wednesday. RAP smoke forecasts are showing near-surface smoke to
be slowly diminishing from central to west through tonight and
into the morning. Smoke aloft will persist, so expect hazy skies
to continue. Overnight lows tonight will be in the 50s. Highs on
Wednesday will be in the mid 70s to mid 80s.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 320 PM CDT Tue May 23 2023
Above average temperatures and on and off chances for showers and
thunderstorms highlight the extended forecast.
The synoptic pattern during the extended period is characterized by
weak but broad ridging over the central and eastern Canadian
Prairies and troughing over the western CONUS, leading to
southwest flow aloft across the forecast area, as well as
southerly low level flow and warmer than normal temperatures.
Although flow aloft is weak and diffuse, surface flow is expected to
be moderately strong, as a surface low coming off the lee of the
Rockies is expected to deepen on Thursday. A modest surface pressure
gradient and strong low-level winds will lead to continued breezy
winds across the entire area through Thursday and Friday,
diminishing some but still staying a bit breezy central and east
through most of the holiday weekend.
Chances of showers and thunderstorms are persistent through the end
of the week and into next week, as multiple shortwaves move through
the southwest flow aloft. As is typical this time of year, there is
relatively low predictability in specific timing and location of any
precipitation. No single day looks like a washout but there could be
scattered convection each day, so something to be aware of,
especially through the holiday weekend. Additionally, deterministic
guidance continues to advertise weak shear through this time, which
is not surprising given the diffuse pattern aloft. This would keep
the severe thunderstorm potential relatively low, although with
warmer temperatures and some instability present, there could
certainly be a few stronger storms. This sentiment is echoed in both
CIPs Severe Analogs and CSU machine learning probabilities.
Temperatures look to stay similar through the extended period,
with NBM 25/75th percentiles consistently in the upper 70s to
upper 80s from Thursday through Tuesday. CPC outlooks also
highlight above average temperatures favored to start the month of
June, so this pattern is expected to continue through next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 647 PM CDT Tue May 23 2023
Isolated to scattered thunderstorms expected through tonight over
western and central North Dakota. Gusty winds possibly by any
storm, along with the threat of some small hail. In addition,
easterly winds may become gusty this evening over northern areas.
Drier weather expected over most locations through the day on
Wednesday, but gusty southeast winds will develop.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...JJS
SHORT TERM...Jones
LONG TERM...Jones
AVIATION...JJS
Area Forecast Discussion
National Weather Service Caribou ME
946 PM EDT Tue May 23 2023
.SYNOPSIS...
High pressure will exit the area to the east tonight. A cold
front will cross the area late Wednesday. An upper low meanders
over the region from Wednesday night into Friday. Meanwhile,
high pressure builds in at the surface into the weekend, then
slides offshore early next week.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
930pm update...Ongoing forecast continues to look good with the
coldest temps tonight Downeast. Winds will be fairly steady in
northern zones ahead of the approaching front and prevent a
radiation inversion. As a result, temperatures in northern zones
remain above 60F at this hour. An inversion will develop due to
strong warm air advection above the boundary layer tonight.
High clouds gradually increase from the north tonight. Smoke has
entered the area at this time as detailed in the previous
discussion.
Previous discussion...
High pressure will drift east of Nova Scotia this evening as a
cold front approaches from Quebec. Mainly clear skies intially
expected across the state with some clouds over the terrain of
the Longfellow Mtns. Visible satellite shows an area of Canadian
Wildfire smoke pushing southeast over Quebec. RAP Vertically
Integrated Smoke model is showing this arriving between 7pm-9pm
across our western skies. RAP Model shows this becoming a very
thick layer lasting into tomorrow likely. Tonight, again mainly
clear skies but clouds will also increase after midnight from
the west over the North Woods. Given the southerly flow
expecting a warmer night with temperatures falling back into the
40s but with winds relaxing some across the Downeast and Bangor
region expect the coolest lows to be there.
Tomorrow, expecting a very hazy (smoke) sunrise across much of
the area with clouds increasing along the Quebec border. Showers
will be developing in Quebec early on in response to the surface
lift. There still remains some slight timing differences between
the Globals and Hi-Res CAMs. Made some minor tweaks to slow the
arrival time of increasing POPs to mid morning across the
northern and northwestern zones. Mostly sunny south with skies
becoming overcast across the north. As the front pushes
southeast expect showers to increase in coverage with some areas
becoming steady rain especially as the 500mb trough tilts
neutral and begins to close off over Northern Maine. This will
ensure precip turns stratiform especially over northern areas.
Cannot rule out some isolated thunderstorms where some daytime
heating can generate some SBCAPE over mainly the Moosehead
Region. A strong 850mb inversion will develop late afternoon
likely shutting down any convection so mainly expecting just
rain. Strong ascent especially over the mountains into Northeast
Aroostook will enhance rainfall totals with 0.5-1 inch likely in
many locations along this stretch. Expect highs to be held down
across the North Woods due to clouds and rain with low to mid
60s. Southerly flow will keep the Downeast coast in the 50s to
around 60F. Bangor Region into Northeast Aroostook can expect
mid to upper 60s with a few 70F.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
A closed low slowly meanders across far SW Quebec and Northern New
England from Wednesday night into Friday.
Anafrontal rain will cover the area Wednesday night behind a
departing cold front in response to the upper low. The precipitation
will become gradually more showery and more likely concentrated
across the north Thursday and Thursday night. For now it appears
showers should tapper of from SW to NE on Friday as the upper low
begins to exit into the Maritimes. There is the potential for a
total of .5 to 1.5 inches of rain mainly across the North with this
system through Thursday afternoon. Generally expecting at this time
less than a half and inch of rain. Give it has been relatively dry
over the past few months and this rain will be spread out over 24
hours, no significant hydrologic impact is expected.
Lows Wednesday night should be near to slightly below normal,
ranging from the mid 30s across far NW portions to the lower 40s
across Downeast Maine. Highs Thursday should be around 10 degrees
below normal, mainly in the 50s. Lows Thursday night should be
around 5 degrees below normal and highs on Friday should be a few
degrees below normal.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Split flow sets up over the eastern US from late this week into
early next week, with northern stream ridging over a southeastern
closed low. Other than possibly some lingering showers Friday
evening as the first closed low continues to depart, it should be
dry.
It should be noted, that there is still quite a bit of uncertainty
with this pattern, with some clusters showing different placements
of the upper ridge and low. So the confidence in the forecast Friday
night-Tuesday is not all that high.
After near normal temperatures Friday night, temperatures should
be above normal Saturday-Tuesday.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR conditions expected through Wed AM. Cigs will
lower tomorrow with showers developing by midday into the
afternoon. Steady precip likely across the N terms. Mostly dry
during the day at BHB. S winds tonight 10-15kts with gusts
20-25kts across the N terms this evening. LLWS likely at FVE,
CAR & PQI tonight. S winds 10-15kts tomorrow will shift late day
NW.
.SHORT TERM:
Wednesday night...IFR or lower probable from KBGR on north,
with MVFR or lower possible at KBHB.N-NE winds G15-20KT
possible.
Thursday-Thursday night...MVFR or lower possible, with best
chance at northern terminals. N-NW winds G15-25KT possible.
Friday...Becoming VFR from SW to NE. NW-WNW winds G15-20KT
possible.
Friday night-Sunday...VFR. W-WNW winds G15-25KT possible Sunday.
&&
.MARINE...
NEAR TERM: Southerly winds and seas remain below SCA through
tomorrow. Chance of showers tomorrow afternoon across the
waters. Waves generally 2-3ft with a period of 7-8sec.
SHORT TERM: Conditions should be just below SCA levels Wednesday
night into Thursday night, then well below SCA levels Friday-
Sunday.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.
&&
$$
Near Term...MCW/Sinko
Short Term...Maloit
Long Term...Maloit
Aviation...MCW/Sinko/Maloit
Marine...MCW/Sinko/Maloit
Area Forecast Discussion
National Weather Service Cleveland OH
908 PM EDT Tue May 23 2023
.SYNOPSIS...
A cold front plunges south across the area on Wednesday. High
pressure builds in behind the cold front Wednesday night and
remains in control of the weather through the holiday weekend.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
Minimal impact weather through the near-term, though a rather
strong cold front will plunge out of Canada and slide through
the area from north to south on Wednesday. This front may pop a
few showers or thundershowers across our far southern / eastern
counties early Wednesday afternoon before quickly exiting to the
south. Otherwise, it will bring a surge of somewhat gusty
northerly winds behind it Wednesday afternoon to go along with a
notable airmass change by Wednesday evening.
In terms of some specifics...after a careful deliberation,
elected to remove the small slight chance shower mention across
parts of Northeast OH for late this afternoon. A nice cumulus
field has developed along and just south of a well-defined lake
breeze, but cloud top temperatures on IR imagery have struggled
to cool below 0C. Forecast soundings show a warm nose at around
700mb near the freezing level, and it seems the cumulus are
having a hard time punching through that given a lack of any
amount of forcing outside of the lake breeze boundary. In
addition, dew points have lowered just a bit this afternoon due
to slightly deeper mixing, somewhat more in-line with the HRRR
and RAP models (which do not develop any showers) than the NAM
(which does try to develop a few showers). Will all of this in
mind, will optimistically go with a rain-free forecast this
evening. High pressure surface and aloft should then provide for
a tranquil night with half decent radiational cooling
conditions. Some of the nooks and crannies in our inland/eastern
zones will cool into the low-mid 50s, with upper 50s/lower 60s
more common farther west and closer to the lake.
Boosted temperatures just a bit ahead of the cold front on
Wednesday given a fairly warm start and dry low-levels that will
be ripe for quick mixing, though temperatures will level off if
not drop a bit behind the front on Wednesday, especially closer
to the lake. The bulk of the forcing with the shortwave trough
forcing the front across our area will remain to our
north/northeast, though enough skinny CAPE is projected to
develop by the time the front clears our southeast/eastern
counties to warrant a slight chance or low chance mention of
showers, with a rumble of thunder not entirely ruled out.
Northwest OH and locations closer to the lake farther east will
likely observe a dry frontal passage, though the wind shift will
be sharp and coincide with a noticeable increase in wind speed.
A much cooler/drier airmass will allow temperatures to dip into
the 40s beneath mainly clear skies Wednesday night. Parts of
interior Northeast OH and especially inland Northwest PA may dip
into the 30s, but a fairly strong pressure gradient and some
continued cold air advection is expected to keep winds from
decoupling, which should preclude frost formation.
Enough elevated smoke from Canadian wildfires will remain ahead
of the cold front to keep skies quite milky/hazy so opted for at
least partly cloudy wording ahead of the front...the smoke is
projected to get swept out behind the front, which should allow
for much clearer skies to return later Wednesday and beyond.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
The post-cold frontal environment for Thursday will be quite dry
both at the surface and aloft. Surface high pressure spanning the
Great Lakes and eastern Canada will be in control with cooler
northeasterly flows across the region. While likely not
representative in real life, the NAM takes the CLE dewpoints around
the 850mb level down below -60C according to BUFKIT forecast
soundings. Whether that value is exaggerated on the low end or not,
expecting a very dry day with low relative humidity, and dropped
dewpoints manually from guidance numbers during the heating hours
Thursday. Friday will have similar issues with very dry air mixing
to the surface, but will be slightly less pronounced. All in all,
expecting fire weather risks to increase with fuels likely
continuing to dry out and again, the low RH values. Winds
northeasterly 15-20mph over the western third of the CWA, 10-15mph
further east each day. Again, this is a cooler airmass, and will be
below average Thursday, but will have slow airmass modification with
good insolation into Friday, and will see max temperatures 8-12
degrees and 3-7 degrees below normal respectively.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
Upper level system moves in late weekend, but will largely continue
to be moisture starved in the low/mid levels resulting in low POPs
only Sunday into Monday. Details to emerge on how much instability
there is and can it ultimately find enough layer moisture for
cumulus cloud growth. It is likely that most locations remain dry or
experience only brief passing showers. Thunder chances are low but
still non-zero for the southeastern CWA. Continuing to warm each day
and should be above normal by Monday.
&&
.AVIATION /00Z Wednesday THROUGH Sunday/...
Generally VFR conditions expected through the TAF period. A cold
front moves south across the area late Wednesday morning into
the early afternoon. Isolated rain showers and some scattered cloud
cover is possible with the frontal passage, with brief, MVFR
ceilings possible in Northwest Pennsylvania. Mostly clear skies
expected by Wednesday evening. Light winds overnight become
northerly with the frontal passage, strengthening to 10-15 knots
with gusts in the 20-25 knot range.
Outlook...Non-VFR is possible with isolated rain showers Sunday
afternoon.
&&
.MARINE...
The light, onshore northeasterly flow this afternoon gives way to
southerly flow tonight ahead of a cold front dropping in from the
north that will track across Lake Erie Wednesday morning. With the
pressure gradient tightening behind the cold front, expect
northerly/northeasterly winds to increase Wednesday into Wednesday
night and early Thursday to 15-25kts. This will result in building
wave heights to the 4-6ft range in the near shore zones. Winds will
persist out of the northeast from later Thursday through Sunday with
winds diminishing to 5-15kts and wave heights down to the 1-3ft
range.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...Small Craft Advisory from 4 PM Wednesday to 4 AM EDT Thursday
for LEZ142-143.
Small Craft Advisory from 10 PM Wednesday to 8 PM EDT Thursday
for LEZ144>147.
Small Craft Advisory from midnight Wednesday night to 11 AM
EDT Thursday for LEZ148-149.
&&
$$
SYNOPSIS...Sullivan
NEAR TERM...Saunders/Sullivan
SHORT TERM...26
LONG TERM...26
AVIATION...Saunders
MARINE...26
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
622 PM CDT Tue May 23 2023
...New AVIATION...
.SHORT TERM...
(Tonight through Wednesday night)
Issued at 249 PM CDT Tue May 23 2023
The short term forecast is a challenging one as the region remains
under northwest flow aloft with an upper ridge sitting near the
TX/NM border.
This afternoon into tonight: Thunderstorms are expected to develop
across portions of west TX, mainly across the Panhandle, along/near
a surface trough and dryline. These storms are expected to cluster
and move southeastward through the evening and overnight hours as an
MCS/MCV. The tricky part of the forecast is how far southeast will
the storms maintain severe intensity, and how far southeast will
they go before they diminish entirely. The HRRR seems to be the most
aggressive solution at this time, especially for north and eastern
portions of the CWA, but other CAMs also depict the line of storms
reaching the I-35 corridor during the early morning hours tomorrow.
While the storms will likely produce gusty winds until they
completely diminish, the greatest severe threat should stay to the
north and west across the Hill Country as depicted by the current
SPC Day 1 Outlook. Despite what the CAMs are showing, we cannot rule
out storms entirely dissipating before reaching the I-35 corridor
due to the increasing convective inhibition overnight, and the
forecast PoPs are fairly conservative to account for this
possibility.
Tomorrow and tomorrow night: There may be some lingering showers
through the morning hours tomorrow behind the decaying MCS/MCV, but
this activity should be isolated at best. Additionally, there is
potential for areas of low ceilings and patchy fog to redevelop in
the morning as well, mainly across the Coastal Plains and I-35
corridor, though the convective evolution overnight could play a
role in this (e.g. storm outflow). Wednesday afternoon-night will
see a similar setup as today with storms once again firing across
west Texas and then potentially drifting into the area during the
early morning hours Thursday, though there is even less confidence
in the Day 2 activity than Day 1 at this time.
&&
.LONG TERM...
(Thursday through Tuesday)
Issued at 249 PM CDT Tue May 23 2023
Northwest flow aloft will remain firmly in place across south central
Texas through Saturday. Timing of mid-level shortwaves embedded in
this flow aloft will be the main forecast challenge with regard to
timing and location of precipitation chances. For Thursday through
Saturday, the medium range models keep mid-level shortwave activity
to our north and east. Based on this, we will keep the forecast dry
for the mentioned period. However, we may need to add some low rain
chances across the I-35 corridor, Hill Country and southern Edwards
Plateau pending future model data.
The flow aloft trends to a more southwest to westerly direction
Sunday through Tuesday as the subtropical ridge axis to our west
weakens while moving eastward. Rain chances will be favored over the
Rio Grande plains Sunday, with perhaps some isolated activity moving
into the Hill country and I-35 corridor on Monday and Tuesday.
As far as temperatures through the period, MOS guidance continues to
remain very steady in day to day trends. We will keep highs generally
in the mid 80s to mid 90s with lows in the mid 60s to lower 70s.
&&
.AVIATION...
(00Z TAFS)
Issued at 622 PM CDT Tue May 23 2023
A bit of a complicated TAF forecast with the potential for early
morning thunderstorms at I-35 sites and possible MVFR ceilings
tomorrow morning. Isolated storms near AUS are slow moving to the
southeast and expected to weaken by 02-03Z. The other complex of
storms may move across I-35 sites by 11-12Z Wednesday, with model
trends favoring AUS and less certain of impacts at SSF/SAT. MVFR
ceilings are also possible at DRT and San Antonio sites tomorrow, but
storms will have a big impact on what actually happens.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 90 69 88 68 / 10 30 30 10
Austin Bergstrom Intl Airport 89 67 87 67 / 10 20 20 0
New Braunfels Muni Airport 89 67 89 66 / 10 10 20 0
Burnet Muni Airport 88 66 85 66 / 10 30 30 10
Del Rio Intl Airport 93 72 93 72 / 0 10 10 10
Georgetown Muni Airport 89 66 86 66 / 10 30 30 10
Hondo Muni Airport 89 66 90 67 / 0 10 10 0
San Marcos Muni Airport 89 67 87 66 / 10 20 20 0
La Grange - Fayette Regional 87 69 86 65 / 10 10 20 10
San Antonio Intl Airport 89 68 89 68 / 0 10 10 0
Stinson Muni Airport 90 69 90 69 / 0 10 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...Gale
Long-Term...Platt
Aviation...27
Area Forecast Discussion
National Weather Service Goodland KS
548 PM MDT Tue May 23 2023
.SHORT TERM...(This evening through Friday)
Issued at 255 PM MDT Tue May 23 2023
Pattern through the short term period will not change, with an
upper trough stuck over the Great Basin and southwest flow aloft
ahead of it over the Rockies and plains. Embedded shortwaves in
the flow aloft will result in daily chances of showers and
thunderstorms beginning tomorrow. Severe chances appear marginal
at best, with only weak to moderate instability forecast and deep
layer shear values of 20-30 kts, with the best parameters
occurring on Thursday. At the surface a moist southeasterly flow
will persist, yielding anomalously high precipitable water
values, which combined with relatively slow storm motions may
present a limited risk for heavy rain and/or flash flooding.
So for this afternoon and tonight, seeing a few very light showers
pop up over southeastern portions of the area, where CIN has
eroded and MLCAPE values approach 1000 j/kg. HRRR seems to have
the best handle and shows this activity probably already peaking
and gradually weakening through this evening. Overnight, cannot
completely rule out a few showers redeveloping, but should be
isolated. Stratus and fog will develop over western areas after
09z and persist through about 15z Wednesday morning. In the
afternoon, expecting showers and storms to develop along the Front
Range by 21z and slowly make their way eastward. Due to slow storm
motions, this activity may not arrive at the Kansas border until
the 00-03z time frame. By then, there should be a fairly large
cluster of showers and embedded thunderstorms moving through the
western portion of the area with a low risk for damaging winds
(DCAPE 500-1000 j/kg) and locally heavy rainfall, primarily in
northeast Colorado. HREF mean shows some 6-hour rain amounts in
the 1-2 inch range tomorrow evening. This area of rain will
continue eastward overnight but weakening after 06z.
The area of rain may persists into Thursday morning as it slowly
moves into eastern portions of the area. Provided the environment
can recover, storms should redevelop Thursday afternoon in western
areas with the next shortwave trough. As previously mentioned,
parameters may be slightly better for severe storms compared to
previous days, particularly deep layer shear which is forecast to
be closer to 30 kts, combined with MLCAPE values 1500-2000 j/kg.
Storm motions remain slow, 10 kts or less, suggesting heavy
rainfall/flash flooding will also be a potential hazard. Some
decrease in activity can be expected overnight Thursday.
Friday sees the same pattern continue. Severe parameters weaken
slightly, with deep layer shear 20-25 kts and weak to moderate
MLCAPE, highest in western areas. However, there is some increase
in storm motion forecast, up to 20 kts, which may mitigate the
risk for flash flooding.
Temperatures change very little through the period, with highs in
the 70s and lows in the 50s.
.LONG TERM...(Saturday through Tuesday)
Issued at 1241 PM MDT Tue May 23 2023
The long term forecast period begins with an upper level high
pressure over the Great Lakes region while an upper level low
remains centered over the southeastern CONUS. An upper level trough
is moving into the western CONUS, and with us sandwiched between
systems, ample moisture continues to be drawn into the region with a
generally southerly flow. A surface low is situated over
southeastern Colorado. Depending on its exact position, may make for
some gusty southerly winds (approx. gusts of 25-30 mph) for portions
of the Tri-State Area over the weekend.
With PWAT values generally ranging from around 0.75 west to
around/just over an inch to the east and shortwaves moving
through the area, will continue to see chances for showers and
storms to impact the Tri-State Area each day of the long term
period. Looking at severe parameters, may have sufficient (but not
overly impressive) instability and shear in the afternoons-
evenings Saturday to Monday for portions of the area to see a risk
of severe weather. Quite a bit of disagreement remains between
models in this timeframe so will need to continue to monitor as it
nears for details to become clearer. For now, given the
expectation of continued showers and storms, excessive rainfall
and flooding may remain the largest concern.
High temperatures in the mid to upper 70s on Saturday will climb
into the mid 70s to low 80s Sunday-Monday, then into the upper 70s
to mid 80s. Overnight lows continue in the 50s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 544 PM MDT Tue May 23 2023
KGLD...VFR conditions begin the 00Z TAF period with south-
southeasterly winds around 13 kts that decrease to around 9 kts by
02Z. At 06Z, IFR conditions begin at KGLD with clouds dropping to
around 500 ft. By 11Z, visibilities at KGLD start to drop to
around 1SM with LIFR ceilings at 300 ft. VFR conditions expect to
return to KGLD at 16Z with visibilities increasing and clouds
decreasing in coverage as well as rising. At 21Z, KGLD winds look
to become more southeasterly at 13G18 kts.
KMCK...VFR conditions also begin the 00Z TAF period for KMCK with
south-southeasterly winds at 10G18 kts that slow to around 8 kts
at 02Z. At 06Z, models show winds becoming variable around 6 kts
at KMCK before becoming southeasterly around 10 kts at 14Z and
then increasing to 13G20 kts at 21Z.
Going to continue to watch future model runs for how low
visibilities at KGLD will get due to potential as well as timing
for when the lower clouds begin as there still is some model
discrepancy. Will also monitor for signs of KMCK becoming sub-VFR
though latest runs look to keep lower clouds to the west.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...024
LONG TERM...CC
AVIATION...076
Area Forecast Discussion
National Weather Service Grand Rapids MI
1054 PM EDT Tue May 23 2023
LATEST UPDATE...
Update
.UPDATE...
Issued at 1054 PM EDT Tue May 23 2023
Back door cold front timing is for an early Wednesday morning
fropa and a stark change to the currently calm/mild conditions.
Expecting a surge of cool northeast winds to sweep through around
12Z, with wind gusts to 30 mph at times on Wednesday behind the
front and temps only in the 60s. (May even stay stuck in the 50s
downwind of Saginaw Bay.) Precip chances are very low along the
front given all the dry air, with low chc pops for light showers
or sprinkles restricted to mainly just the Clare/Mt Pleasant
areas.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 237 PM EDT Tue May 23 2023
The high pressure that has dominated the last few days will shift
westward as a upper level trough swings through. Though it will be
mainly dry, there is a slightly chance of rain north of I 96. The
front will drop temperatures below normal. It will also bring
gusty winds.
The front will move quickly through with temperatures behind the
front in the mid to upper 30s. While patchy frost will be
possible, especially along and north of US 10, easterly winds
should remain strong enough and mixed Wednesday night into
Thursday to preclude widespread frost development. However, area
where winds go calm, frost could form.
.LONG TERM...(Thursday through Tuesday)
Issued at 230 PM EDT Tue May 23 2023
A mid level high pressure system remains over the region into the
start of the holiday weekend. Models are in good agreement on this.
The subsidence and associated drying of the the atmosphere will
support keeping rain out of the forecast through then. With the
850 mb thermal trough in place Thursday, the temperatures will end
up cooler than normal. The feature builds east Friday into
Saturday...allowing for gradually warming 850 mb temperatures.
That will translate to a warming trend with the surface
temperatures each day with above normal values looking likely for
Saturday as 850 mb temperatures approach 10 deg C. Ensemble max
temperature plots from the models support a steady warmup over the
weekend and into early next week, but the ECMWF does show a fair
amount of spread Sunday into Monday.
For Sunday and Monday, the ECMWF is showing a weak mid level low
building in from the south while the GFS and Canadian keep this
feature stronger and well through of the CWA. The ECWMF is dry even
with this feature around so the main impact of it would be to hold
back temperatures. PWAT values are progged to start climbing early
next week, but overall instability and RH fields look too limited to
support any rain. Very little qpf is seen in the ensemble forecasts,
even early next week when several of the members start to show
precipitation.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 750 PM EDT Tue May 23 2023
Smoke layer persists aloft otherwise VFR conditions continuing
tonight with light and variable winds. A sfc cold front drops down
from the north early Wednesday with a fairly abrupt wind increase
and shift to the northeast. Gusts around 20 kts are expected at
times for much of the day.
A band of clouds will accompany the cold frontal passage but at
this time mainly VFR cigs are expected with only a slight chance
for a period of MVFR cigs. Some near sfc smoke cannot be ruled
out Wednesday with the frontal passage but no vsbys restrictions
below 6 miles are expected at this time. Any near sfc smoke as
well as the smoke aloft will clear out of the area from north to
south Wednesday afternoon/evening.
&&
.MARINE...
Issued at 1012 PM EDT Tue May 23 2023
Some modifications have been made to the small craft advisory,
specifically south of Whitehall. While the stronger northerly
flow behind the front will firmly impact Big and Little Sable
Points on Wednesday, latest HiRes HRRR and NAMNest guidance does
not show those stronger winds impacting areas south of Whitehall.
(Keeps the stronger flow well offshore.) However, there is a
signal for strong easterly flow developing Wednesday evening in
these locations and gusting to 30 kts at times, so have simply
delayed/extended the advisory south of Whitehall to be for the
Wednesday night time frame.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory from 8 PM Wednesday to 8 AM EDT Thursday
for LMZ844>847.
Small Craft Advisory from 10 AM to 10 PM EDT Wednesday for
LMZ848-849.
&&
$$
UPDATE...Meade
SHORT TERM...Ceru
LONG TERM...MJS
AVIATION...Meade
MARINE...Meade
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1040 PM CDT Tue May 23 2023
.UPDATE...
Issued at 548 PM CDT Tue May 23 2023
Scattered showers with a few thunderstorms are slowly oozing
northwest in east-central Missouri at this hour in an unorganized
line along some weak surface convergence. Thunderstorms that form
quickly collapse with no deep shear to separate the updrafts and
downdrafts. The cumulus field is dissipating in the vicinity of
the convection as the sun begins to set, and this weakening trend
will continue into the early evening when all convection will
likely cease.
MRB
&&
.SHORT TERM... (Through Late Wednesday Afternoon)
Issued at 220 PM CDT Tue May 23 2023
Light easterly flow across the area is producing orographic lift
over the Ozarks this afternoon. RAP soundings show around 1500 J/Kg
in that area this afternoon, and a decent Cu field has developed. So
far there hasn`t been much showing up on RADAR, probably due to weak
upper level ridging over the Mid Mississippi Valley producing broad
scale subsidence. There are still several hours of daytime
heating left, so the slight chance PoPs in the going forecast for
the rest of the afternoon into early evening continue to look
reasonable. 0- 6km shear is virtually non-existent, so any storms
that form will go straight up, and straight back down. While
there could be a brief heavy downpour, and perhaps some gusty
winds with these storms, they are not expected to be severe.
Convection should dissipate during the evening, but redevelop again
on Wednesday, most likely over central Missouri in response to some
weak low level moisture convergence along a dewpoint boundary. This
boundary will be the first manifestation of an east-to-west moving
cold front which will move through the Mid Mississippi Valley. The
truly colder air won`t reach us until Thursday, but this first wave
of drier air will move westward from the Mississippi River Wednesday
morning into central Missouri by the afternoon and provide a focus
for convection. CAPE values Wednesday afternoon are similar to
today`s, as are the shear values. Storms may be a little more
numerous with the boundary to focus on, but the storms are not
expected to be severe.
Carney
.LONG TERM... (Wednesday Night through Next Tuesday)
Issued at 220 PM CDT Tue May 23 2023
The deterministic GFS and ECMWF models are in good agreement from
Thursday through at least Saturday, and the WPC LREF analysis is
very similar to to these solutions, lending high confidence to the
forecast into the weekend. A cool surface high drops into the Great
Lakes Region and Ohio Valley and shoves the cold front through
southwest Missouri into the plains by Thursday night. The Mid
Mississippi Valley will then be under the influence of the surface
ridge for the rest of the week into the weekend. Temperatures
immediately behind the front will drop to near or a few degrees
below normal in the 70s on Thursday and Friday, but the airmass will
modify into the weekend bringing 80+ degree temperatures back for
Saturday and Sunday.
The pattern aloft becomes highly amplified and blocky with a strong
ridge over the Great Plains and long wave troughs to either side.
This omega block evolves into a rex block by the end of the week as
the eastern long wave trough fractures and cuts off an upper level
low over the Southeastern U.S. and the northern portion of the ridge
gets pinched off to form a closed anticyclone that drifts east into
the Upper Midwest and Great Lakes region. There are 3 clusters in
the ensembles, all with very similar solutions at least through
Friday. One cluster doesn`t develop the rex block in the Friday-
Saturday time frame, and is overall less amplified and a little
more progressive than the other two. Ultimately, one solution over
another will probably only affect precipitation chances starting
early next week. The going forecast has slight chance-low chance
beginning late Sunday night into Monday and this still looks
reasonable given the uncertainties with the progression of the
pattern...or lack there of.
Carney
&&
.AVIATION... (For the 06z TAFs through 06z Wednesday Night)
Issued at 1033 PM CDT Tue May 23 2023
Mostly VFR conditions are expected to persist through the 06Z TAF
period with only a few possible exceptions. A couple of small,
weak thunderstorms continue to percolate near St. Louis area
terminals as of 330Z, but this activity does not appear likely
to impact local terminals in the area. Instead, these cells are
likely to diminish within an hour or so, and by the start of the
06Z period they will more than likely have diminished. Overnight,
some patchy fog may develop in low lying areas, with some
potential to reduce visibilities at mainly JEF, SUS and CPS.
Confidence is low that terminals will be significantly impacted,
but the increase in humidity and expected light winds overnight
has increased confidence that at least patchy fog will develop in
the area. Any fog that develops should diminish shortly after
sunrise.
Otherwise, a weak cold front will move through the area tomorrow,
reinforcing east to northeast winds. A few showers and weak
thunderstorms will again be possible in the vicinity of JEF and
COU in the afternoon, but confidence is too low for mention in the
TAF at this time.
BRC
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 64 86 60 79 / 20 5 0 0
Quincy 59 83 54 74 / 5 10 5 0
Columbia 61 82 58 81 / 5 20 0 5
Jefferson City 61 83 60 83 / 10 20 5 5
Salem 60 83 56 75 / 5 5 5 0
Farmington 58 81 57 79 / 20 5 0 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Midland/Odessa TX
553 PM CDT Tue May 23 2023
...New AVIATION...
.SHORT TERM...
(This afternoon through Wednesday night)
Issued at 114 PM CDT Tue May 23 2023
500mb RAP analysis shows subtle ridging across southern AZ/NM,
providing northwest flow of around 25-30kts across our area. With
prevalent low level moisture in place across the eastern zones (55-
65F dewpoints), this westerly flow helps sharpen up a dryline late
this morning along the TX/NM state line, stretching southward
through the Big Bend. The dryline mixes eastward towards the central
Permian Basin through the early afternoon, pushing the 60F dewpoints
into the far eastern zones. Efficient insolation this morning has
sent temperatures well into the 80s already, pushing the low 90s in
some spots. This and the good moisture combine into 1000-2000 J/kg
of MLCAPE, with the better instability located east of the dryline.
Between convective temperature being reached and localized lift
along the dryline, convective initiation is expected around first
across western Stockton Plateau 19-20z, followed by the plains
around 20-21z. Ultimately, the placement of the dryline will be key
to the location of CI in the plains. Storm coverage will not be as
great as yesterday, but the focus for severe storms is across the
northeastern Permian Basin and western Low Rolling Plains where the
better CAPE is found. Environmental shear gradually increases from a
measly 15-20kts to around 30kts by the early evening but
convectively driven cold pools may locally enhance bulk shear to 40-
50kts. All modes of severe weather are possible with storms today
with the primary threats being very large hail and damaging winds.
If storms linger beyond 00z, SRH becomes enhanced by a strengthening
LLJ which may aid in isolated tornado development across the far
eastern zones. Depending on outflow boundary-based development, all
storm activity should move out of the area by 06z tonight.
Northwest flow persists through tomorrow as well, with the dryline
having retreated up against the higher terrain tomorrow morning.
Thanks to plenty of low level moisture in place scattered
thunderstorms are possible initially off the higher terrain of the
Davis Mountains and high New Mexico plains. From there,
northwesterly flow could allow for upscale growth as storms move
southeastward into the Permian Basin. Where storms initially develop
in eastern New Mexico and available environmental instability and
shear will determine where a potential MCS may move through tomorrow
evening, whether it will hit the central/eastern Permian Basin, clip
the eastern edge, or not develop at all remains to be seen. Any
lingering boundaries from today`s convection may locally enhance
storm development as well.
As for temperatures, lows tonight and Wednesday night will be right
around normal with highs tomorrow being a touch cooler than today
across the northern/northeastern Permian Basin owing to any
precipitation from today/tonight.
-Munyan
&&
.LONG TERM...
(Thursday through Monday)
Issued at 114 PM CDT Tue May 23 2023
Upper ridge over Mexico Thursday will extend northward across the
region with a low over WA/OR and its trough extending southward to
CA. This pattern will continue Friday and Saturday. A cut off low
develops over CA Sunday moving down across the state Monday...
wobbling over Srn CA Tuesday and into Nrn Mexico Wednesday. On
Thursday upper ridge builds over the western half of the country.
High temperatures mostly in the 80s Thursday through Sunday with 90s
along the Pecos and Rio Grande. Temperatures warm early next week
with 90s becoming more widespread. Lows mainly in the 60s with a
few 50s for higher elevation and Nrn Lea Co.
SE wind Thursday and Friday will help to keep moisture in place with
dewpts in the 60s. Been active this week with thunderstorms around
the area... this will continue Thursday with a Marginal Risk running
N-S along the NM/TX border. Thunderstorms continue over the higher
elevations and Nrn Permian Basin Friday through Sunday shifting more
to the east Monday.
&&
.AVIATION...
(00Z TAFS)
Issued at 546 PM CDT Tue May 23 2023
VFR conditions will prevail next 24 hours. Convective chances this
evening look best KMAF/KHOB, but chances too low to include attm.
NAM brings in a stratus deck overnight, w/cigs as low as IFR
KMAF/KHOB, but this is an outlier, and we`ve left them out for
now, as well. Otherwise, return flow persists, but on the light
side. Forecast soundings develop a cu field late Wednesday morning
KFST, spreading through other terminals by mid-afternoon, w/bases
6-11kft agl.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 62 86 62 85 / 30 20 30 30
Carlsbad 61 94 63 89 / 0 10 10 30
Dryden 67 93 68 90 / 30 20 10 10
Fort Stockton 66 95 65 89 / 10 20 10 30
Guadalupe Pass 63 88 62 84 / 0 0 0 20
Hobbs 59 88 61 85 / 10 10 30 30
Marfa 55 90 56 87 / 10 10 10 30
Midland Intl Airport 63 89 63 87 / 10 20 20 30
Odessa 64 90 65 88 / 10 20 20 30
Wink 64 95 66 90 / 0 10 20 30
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
TX...None.
NM...None.
&&
$$
SHORT TERM...16
LONG TERM....72
AVIATION...44
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1049 PM CDT Tue May 23 2023
.DISCUSSION...(This evening through Tuesday)
Issued at 240 PM CDT Tue May 23 2023
KEY MESSAGES:
- Seasonable temperatures on Wednesday.
- Warm, above normal temperatures Thursday through early next week.
- A slight chance of rain tonight into early Wednesday over central Minnesota.
Otherwise, dry conditions persist for the next week or so.
This Afternoon through Friday... Another warm day with
temperatures in the 80s for most locations. Western MN has the
warmest location as Madison (MN) hit 90 at 2 PM. The warm
temepratures and stagnant surface pattern has led to an Air Quality
Alert for most of the MPX forecast area that goes through this
evening due to elevated surface ozone pollutants. The hazy skies
have become a stable so far this month due to the Alberta wildfire
smoke. The smoke will remain in place, but recent rainfall over the
source region has limited additional smoke formation this week. So
what will the smoke do over the next few days? Well an elevated
layer will continue to linger over the next 2 days. The 15z RAP
extension suggests we will see a gradual improvement into Thursday
as elevated layer gradually thins and any surface smoke is pushed
out overnight by the cold front. A cold front will slowly move
through region overnight. This will lead to a brief period of chance
PoPs tonight into early Wednesday, primarily across central MN where
better forcing and moisture is available. The FROPA will bring
cooler temperatures on Wednesday and an improvement in air quality.
Highs will be in the 60s (WI) and 70s (MN) but locations southwest
of the Minnesota river could see temperatures back into the low 80s
as the cold front stalls/weakens along the river. High pressure will
settle into the region with a return to mostly sunny skies on
Thursday and Friday. This will set up a warming trend that continues
into the weekend.
Saturday through Tuesday... High pressure looks to stick with us
both at the surface and aloft on Saturday and Sunday. Previous
forecast was too quick with the departure of the ridging, but 12z
guidance maintains the influence from the high pressure into Monday.
Monday and Tuesday is less certain. 12z guidance is in surprisingly
solid agreement now that we will end up on the western edge of the
upper level ridge. So this should lead to additional hot and dry
weather as long as the upper level ridge holds over the Upper
Midwest. If we look just beyond the forecast period, the 12z ECMWF
brings through a weak system next Thursday. This would be our next
chance for any widespread precipitation over the next 7 to 10 days.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1044 PM CDT Tue May 23 2023
Cold front will just be moving into the northeast sections of the
MPX area at 6z. The front is already slamming on the breaks it will
slowly lumber across southern MN Wednesday, stalling out over western
MN Wednesday night. Still not antipating any precip with this front,
with even the cloud cover on a diminishing trend over most of MN for
Wednesday. The only thing to watch is as the flow behind the front
comes off of Lake Superior, it is bringing some MVFR/IFR cigs with
it and there`s an outside chance some of these lower cigs could make
into western WI Wednesday morning. Other than that, it`s VFR
conditions with east winds this period.
KMSP...No additional concerns.
/OUTLOOK FOR KMSP/
THU...VFR. Winds SE at 10-15kts.
FRI...VFR. Winds S at 10-15kts.
SAT...VFR. Winds S at 10-15kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...BPH
AVIATION...MPG
Area Forecast Discussion
National Weather Service Marquette MI
743 PM EDT Tue May 23 2023
.SHORT TERM...(This evening through Tonight)
Issued at 243 PM EDT TUE MAY 23 2023
A cold front is dropping south across Lake Superior this afternoon
with clouds and a few showers north of the boundary. There were a
few elevated thunderstorms across the far northern lake this
morning, but the only thunder this afternoon is well west/northwest
of the lake. Am struggling with timing of the wind shift and precip
chances this afternoon/evening since a band of light showers reached
the tip of the Keweenaw by late morning and hasn`t moved for several
hours since. Additionally, latest radar imagery shows a lake breeze
knocking on the WFO doorstep as of 2 PM, but surface observations
suggest the temperature gradient is fairly weak. An agitated Cu
field is bubbling UP along this lake breeze and HREF guidance shows
a non-zero chance of shower activity developing boundary this
afternoon. The latest 17z RAP mesoanalysis shows a localized pocket
of >250 J/kg CAPE southeast of Munising where HREF highlights some
light QPF. At this time, thunder chances are too low to include in
the grids.
Much cooler temperatures spread across the area this evening as the
reinforcing cold front moves through with a long fetch of NNE winds
coming off the still cold lake water. Some light shower activity
should accompany the FroPa, but measurable precip is tough to come
by and is most likely across the east. Despite temps falling into
the upper 30s by Wednesday morning, steady northeast winds and some
cloud cover should prevent any frost formation (though tomorrow
night is a different story). In fact, model soundings indicate the
incoming air mass is cold enough to support a shallow ~2kft layer of
lake-induced instability by tomorrow morning. Once low level clouds
burn off, abundant sunshine is expected with the layer of smoke also
blowing south and west of our area.
.LONG TERM...(Wednesday through Tuesday)
Issued at 249 PM EDT TUE MAY 23 2023
Upper air pattern consists of 500 mb troughs on the west and east
coasts and a broad ridge over the northern and central plains 12z
Wed. The pattern changes little through 00z Sat with the ridge
building over the upper Great Lakes.
In the extended, the GFS and ECMWF shows 500 mb troughs in the
western and eastern U.S. and a ridge across the plains into the
upper Great Lakes 12z Sat. The ridge remains over the upper Great
Lakes into Tue. Temperatures look to be above normal for this
forecast period. One problem with temperatures though will continue
to be smoke from fires in western Canada and this could knock
temperatures down a few degrees. Will continue dry for this
forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 742 PM EDT TUE MAY 23 2023
Cold front is current dropping s across Upper MI. Lagging the front
is a band of -shra and lwr cigs. As this band sinks, expect VFR to
fall to a period of MVFR at IWD late this evening and to a period of
IFR at SAW late this evening where upsloping will be strongest under
ne winds. At CMX, ne winds don`t have much of an upslope component,
so VFR may be able to prevail thru the evening. NE winds thru the
night should be gusty at times to around 20kt at all terminals. Much
drier air arriving overnight will cause lwr clouds to clear out with
all terminals returning to VFR, though upsloping may lead to IFR or
low MVFR cigs persisting to around sunrise. VFR will then prevail
for the remainder of the fcst period.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 249 PM EDT TUE MAY 23 2023
Cold front will drop southward across Lake Superior early this
evening. Significant pressure rises behind the front will yield
gusty north and northeast winds as the front passes and behind it.
The strongest winds will be over the western Lake where a favorable
northeast wind direction will result in gusts up to 30 knots tonight
through Wednesday afternoon. As surface ridge settles over the
Upper Lakes Wednesday night and then to the lower and eastern Lakes
late week through the weekend, winds will diminish and remain below
20 knots from Thursday through Memorial Day.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...EK
LONG TERM...07
AVIATION...Rolfson
MARINE...07
Area Forecast Discussion
National Weather Service Las Vegas NV
903 PM PDT Tue May 23 2023
.SYNOPSIS...Showers and thunderstorm chances will become more
confined to central Nevada through the week. Breezy afternoons will
be prevalent each afternoon through this week, otherwise,
temperatures will drop a few degrees late-week before increasing
back to above average once again through the weekend.
&&
.UPDATE...Thunderstorms were persisting over central Nevada
including Esmeralda County where training storms were occurring
ahead of an upper level vort max rotating into the central/southern
Sierra as it moves through the base of a broad quasi-stationary
trough over the Pacific Northwest and California/Nevada. Scattered
showers were lifting up through Lincoln County this evening, but
little potential for lightning. The latest HRRR indicates
thunderstorms may continue to develop between Silver Peak and
Tonopah the next few hours before dissipating. Emseralda County will
again be the focus for afternoon showers and thunderstorms Wednesday
afternoon as it remains near the center of the southern branch of
the aformentioned trough. This is reflected in the going forecast
and no immediate changes are needed. -Adair
&&
.PREV DISCUSSION...
1118 AM PDT Tue May 23 2023
.SHORT TERM...Today and Tomorrow.
As of 17Z, GOES18 satellite showed thunderstorms developing just
north of Lincoln county with increasing cumulus development over
the high terrain areas north of the I-40 corridor. 12Z HREF and
latest mesoanalysis depicted a very conditional convective setup
for locations south of the HWY 95 corridor whereas areas north
should see scattered thunderstorms this afternoon and early
evening. Shortwave energy will put central Nevada in a favorable
dynamically lifted environment, coinciding with better deep layer
moisture than farther south where low level dry air is progged to
filter in from the south and southeast, eroding almost all surface
based instability south of the 95 corridor. That being said,
marginal mid level moisture still exists enough to keep PWAT
values above normal for the column, so can`t completely rule out
convection for Clark, Inyo, and San Bern...but those areas will
highly depend on high terrain to convect. Would expect these
storms to orphan immediately after coming off the terrain, but not
before dropping some impressive outflows if they can can maintain
coherent updrafts above -50C. Ended up bumping up PoPs for
Nye/Lincoln and left slight chance PoPs for high terrain locations
farther south to account for this. For any storms that develop,
again the main concern will be strong outflows and cloud to ground
lightning. The 12Z HREF 35+mph thunderstorm wind fields paint a
very reasonable picture for where the stronger gusts could occur
with 30+% probabilities encompassing Ewill move fully into northern
Nye County over the next hour or two then smeralda, Nye, and
Lincoln, with lesser chances to the south.
Moving into tomorrow, the shortwave from today should be re-
enforced by another round of vorticity maxima in the same general
area, but lesser overall moisture availability compared to today
(per GEFS/EC mean PWAT). This should serve to further lessen
convective potential across southern Nevada, perhaps staying just
as cumulus across higher terrain with a very low end chance for a
shower or storm south of the Highway 6 corridor.
.LONG TERM...Thursday through the Weekend.
Moving into the latter half of the week and weekend,
the 500mb synoptic setup and moisture situation more or less
remains unchanged in the 06Z GEFS/EC and this was seen in the 00Z
clusters as well. This would increase confidence of southwest wind
gusts each afternoon heading into the weekend but there is general
agreement that this shortwave energy will shift off to the east,
leaving generally weak southwest flow across the west. Marginal
height increases will allow for temperatures to recover a few
degrees, by the weekend, into the mid 90s for KLAS but long range
NBM temperatures seem to plateau at that point for the next
several days. CPC 6-10 day outlook from yesterday has a rather
high probability of above average precip central CA and NV, but
would expect this to shift farther north given the latest trends
in the long range models.
&&
.AVIATION...For Harry Reid...Expecting south to southwest winds
to increase this afternoon with speeds between 15-25 knots, with
some localized gusts up to 30 knots possible. There could be some
isolated convection this afternoon over the Spring Mountains, but
overall most of the thunderstorm activity will remain well north of
the terminal. Any outflow winds are unlikely today. Winds to
decrease by 04z-06z.
For the rest of southern Nevada, northwest Arizona and southeast
California...Winds will gradually shift to the south to southwest
over most area by early afternoon with most locations seeing speeds
between 15-25 knots with a few locations seeing gusts to 30 knots.
Afternoon showers and storms look to largely remain north of
terminals. There is about a 10% chance of storms at KBIH, but any
storms should generally remain east over the White Mountains.
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
DISCUSSION...TB3
AVIATION...Gorelow
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