Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/03/22
Area Forecast Discussion
National Weather Service Bismarck ND
956 PM CDT Mon May 2 2022
.UPDATE...
Issued at 953 PM CDT Mon May 2 2022
Recent trends in the GOES-16 Nighttime Microphysics RGB show
gradual westward expansion of stratus, as previously discussed.
With this update we increased cloud cover in sky grids through
Tuesday morning. Fog was also trimmed to keep most coverage west
of stratus, in western North Dakota. There may need to be an
adjustment in coverage of fog depending on how it develops
tonight, but will leave that for upcoming updates.
UPDATE Issued at 634 PM CDT Mon May 2 2022
23Z satellite picture remains consistent to this afternoon, where
stratus was placed across eastern North Dakota with more broken up
mid-level clouds in the southwest. The question tonight will be
the westward progression of stratus as RAP and NAM forecast
soundings show saturation in the low levels overnight, though less
so towards KDIK-KXWA. With southeast winds it looks likely that
stratus should expand overnight given relatively higher dew points
southeast and the upslope component to the flow.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 130 PM CDT Mon May 2 2022
Current surface analysis places lows over eastern Ontario and
over the southern plains, with ridging over the northern plains.
Upper level analysis shows a variety of compact lows, with one
over western Ontario, one over the central plains, and a deeper
one affiliated with a broader trough over the Pacific Northwest.
Over our area, westerly flow continues with a weak ridge to the
west. For us, rather quiet weather continues, though a broad area
of low cloud cover continues to stretch from the Turtle Mountains
into the James River Valley and points eastward with light flow
and ample low level moisture.
For the rest of this afternoon into this evening, quiet weather
will continue. Low clouds over the east may end up spreading
towards the west tonight with the low level easterly flow. To the
west of the cloud cover where skies will be clear, some patchy
fog may develop late tonight.
On Tuesday, quiet weather continues with weak ridging ahead of the
aforementioned Pacific Northwest low which will meander over the
Great Salt Lake area through the day, into the central Rockies
overnight.
.LONG TERM...(Wednesday through Monday)
Issued at 130 PM CDT Mon May 2 2022
Aforementioned compact low works its way over the central plains
Wednesday into Thursday. Precipitation should stay south of our
area as this system continues on its way, but we may see an
increase in cloud cover, primarily over southern areas.
Temperatures will be on a gradual warming trend, which will
continue through Friday.
This weekend a deep Pacific trough will work its way into the
western CONUS, bringing increasing precipitation chances this
weekend into the start of the upcoming work week. In addition,
temperatures will start to cool, but not greatly. There is still
much question as to the location and timing of some key features,
but the overall message is that a wetter pattern is probably on
tap.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 953 PM CDT Mon May 2 2022
MVFR to IF stratus continues over eastern North Dakota, including
KJMS tonight. There good indications that this stratus will spread
west overnight, likely impacting KBIS-KMOT. KXWA-KDIK somewhat
questionable if stratus makes it that far west, however if it
doesn`t there will be the possibility of fog development and
visibility reductions. Occurrence of this will likely hold off
until 06Z or after. Conditions should improve in the west and
central through the morning, and possibly at KJMS by Tuesday
evening.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AE
SHORT TERM...JJS
LONG TERM...JJS
AVIATION...AE
AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
1037 PM CDT Mon May 2 2022
.SHORT TERM...(This Evening through Tuesday)
Issued at 256 PM CDT Mon May 2 2022
Expansive rain shield across much of NE into southwest IA
associated with a well-defined surface low across west-central KS
is really struggling to move north of the MO River this afternoon.
Latest RAP soundings show a substantial dry wedge above 3000 ft
agl and this is not likely to moisten much over the ensuing
hours. Best chance for measurable rain is now for areas along and
south of line from Vermillion to Storm Lake, but even here
amounts are not likely to exceed a half inch. Farther north,
expect little to no accumulation with communities along the I-90
corridor now expected to remain dry through the evening.
Temperatures tonight will be highly dependent on cloud cover. If
some clearing can occur late for areas west of the James River,
sub-freezing temperatures are possible. Otherwise, cloudy areas
will generally dip into the mid to upper 30s.
Surface high pressure drifts across the forecast area on Tuesday,
resulting in gradually clearing skies, light wind, and warming
temperatures. Afternoon highs are expected to climb into the mid
to upper 50s.
.LONG TERM...(Tuesday Night through Monday)
Issued at 256 PM CDT Mon May 2 2022
Clouds and rain chances return Wednesday and Thursday as a slowly
meandering 500 hPa closed low moves across the Central Plains.
Areas south of I-90 stand the best chance of seeing measurable
precip with drier conditions to the north. With instability
bottled up across the Central/Southern Plains, any precipitation
will fall as light rain showers. Not expecting to see much change
in daily temperatures with afternoon highs remaining in the 50s.
A warming trend commences Friday into the weekend as 500 hPa
short-wave ridging builds across the region in advance of a
substantial Pacific trough. For the most part, late week looks dry
with highs rising into the mid 60s to lower 70s.
Saturday night into Sunday, rain/possible thunder chances return
as aforementioned Pacific trough moves east. Multiple short-waves
within nearly meridional flow are ill-resolved at this point, so
will lean on current NBM POPs for the late weekend period, which
are in the 50 to 60 percent range.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1037 PM CDT Mon May 2 2022
Low level stratus remains across majority of the region, though we
are starting to see pockets of clearing occurring so will likely
continue to see improvements throughout the overnight period. Still
have some light rain showers occurring across NW Iowa, but that
activity will be moving into central Iowa over the next couple
hours. Otherwise, expect light winds to continue into tomorrow,
starting off north-northeasterly during the morning turning to east-
southeasterly by the afternoon hours.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...Rogers
LONG TERM...Rogers
AVIATION...APT
Area Forecast Discussion
National Weather Service Lincoln IL
800 PM CDT Mon May 2 2022
.SYNOPSIS...
Issued at 310 PM CDT Mon May 2 2022
A rainy night is on tap for central Illinois, as low pressure
arrives in central Illinois by late Tuesday morning. This storm
system will spread showers and a few thunderstorms northeast
across central Illinois this evening, with shower chances
continuing into Tuesday. Dry conditions return Tuesday night and
Wednesday before the next storm system brings more showers and
isolated thunderstorms back into the area overnight Wednesday
night through Friday.
&&
.UPDATE...
Issued at 800 PM CDT Mon May 2 2022
An area of light rain has been advancing across the forecast area
this evening. However, our evening sounding shows plenty of dry
air below 700 mb, so much of this has been more along the lines of
sprinkles. Regional radar mosaics show a large break in the rain,
though some of it in the southeast CWA may be enhanced a bit
longer by an MCV moving across southern Illinois. However, a
larger area of showers and scattered thunderstorms is located over
western Missouri, with the latest HRRR bringing it into west
central Illinois closer to midnight. There still looks to be some
breaks in the rain toward daybreak into Tuesday morning south of
I-72, south of the low track.
Recent forecast updates were done for some timing adjustments on
rain chances. Temperatures were generally on track, but some
tweaks were done to the hourly temperatures on Tuesday due to
gridding tool errors caused by the non-diurnal trend across the
northwest half of the CWA.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 310 PM CDT Mon May 2 2022
A brief period of high pressure has provided some filtered
sunshine and light winds this afternoon. However, a stationary
front draped from the Plains across Missouri and southern Illinois
will begin to lift north tonight. It`s parent low pressure will
track from N Oklahoma this evening across central Illinois on
Tuesday.
Forecast soundings are pointing toward a relatively rapid
saturation of the boundary layer with rain developing late this
afternoon in our SW counties. Satellite images already indicate
saturation in progress below the cloud-bearing layer. Surface
dewpoints are projected to climb from the 40s this afternoon into
the mid-upper 50s tonight and into the low to mid 60s Tuesday
morning. While that usually ties to increasing instability, the
timing of that surge of moisture will be at an unfavorable time
for surface based CAPE. However, the models are indicating that low
level helicity will be 400-600 m2/s2 tonight in the southern half
of our CWA, as a 45-50KT 850mb LLJ noses into IL. Any storms that
do develop could have some rotation develop. However, the
marginal instability should preclude the development of severe
weather from those storms.
A dry slot is expected to push across our southern counties
Tuesday morning, shutting down precip in that area by early
afternoon. Our northern counties could see rain showers linger as
the center of the surface low passes directly over that area,
along with the upper trough axis. A wide range of high temps are
expected, with morning highs in the low 70s south of I-70, while
areas near Galesburg/Lacon struggle to climb into the mid 50s.
&&
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 310 PM CDT Mon May 2 2022
A break in the rain will occur Tuesday night as NW winds usher in
some cooler air. Lows will drop into the low to mid 40s in most
areas, with below normal highs on Wednesday.
The next long wave trough will arrive late Wednesday night and
Thursday, producing another period of widespread rain and
scattered storms. The rain on Thursday will be associated with
synoptic lift north of the warm front, while Thursday night and
Friday precip will come with the passage of the occluded low. The
system looks to be an efficient rain producer, with QPF amounts
around 1.25 to 1.75 inches Thursday into Friday.
The upper trough should shift east of Illinois Saturday, helping
bring an end to the rain shortly after sunrise Sat. Depending on
the timing of the clearing of clouds, high temps could reach near
70. Forecast highs for now are in the mid 60s Sat. ECMWF and
Canadian are advertising a Rex Block setting up for Sunday and
Monday, while the GFS keeps the ridge very narrow and not in a
blocking pattern. The ensemble spread is relatively high as a
result of the spread. However, a robust warming trend is likely
early next week, with 80s possible for highs on Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 606 PM CDT Mon May 2 2022
Ceilings expected to steadily decrease, dropping to MVFR from
05-08Z and to IFR before 12Z, as rain moves into the area. A
period of thunder is expected overnight and have continued VCTS
mentions for about a 3-5 hour period at each site. Once ceilings
drop below 1,000 feet, they should largely stay there or perhaps
nudge up into low MVFR territory at best.
Wind forecast will be tricky, as low pressure tracks directly
across central Illinois early Tuesday morning. While gustiness
picks up around toward late this evening, it will drop off for a
few hours with the low passing overhead, before returning with
winds shifting to the north/northwest during the afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SYNOPSIS...Shimon
SHORT TERM...Shimon
LONG TERM...Shimon
AVIATION...Geelhart
Area Forecast Discussion
National Weather Service North Platte NE
719 PM CDT Mon May 2 2022
.SYNOPSIS...
Issued at 253 PM CDT Mon May 2 2022
The current storm system is centered over far northwest KS. A
large deformation existed to the north of the low across the
southeast panhandle and southwest NE into the central Sandhills. A
look at area webcams shows light snow continuing across much of
these areas, with moderate to heavy snow continuing across western
Custer County. Snow accumulations so far are around 2 inches
parts of western Custer County, and from 1 to 2 inches portions of
the west. Some areas however have not accumulated, including
Tryon. With snow and reduced visibility still lingering across
the west, will keep the existing Winter Weather Advisory in effect
across the western Sandhills until 5 pm MDT.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 253 PM CDT Mon May 2 2022
The closed upper low will track east northeast this evening to
near Omaha by midnight. Chance to likely POPS across the east
through early evening, then ending far eastern areas by around
midnight CDT. Do not expect much for accumulations this evening,
except for a dusting of wet snow possible parts of Custer County.
Expecting some clearing overnight across the northwest Sandhills,
as the remainder of the area remains cloudy. This will help keep
lows up a few degrees overnight, from the upper 20s northwest to
the lower 30s southeast. The precipitation received today and
support from the 15Z SREF and RAP models indicate that patchy fog
is expected across the southwestern half of the area. This is
expected from 09Z until 15Z Tuesday. Upper ridging briefly builds
in Tuesday with some clearing skies into the afternoon. Highs to
mostly range in the mid 50s. The next upper trough and closed low
will move into CO and WY Tuesday night, bringing increasing
chances for showers across the west.
.LONG TERM...(Wednesday through Monday)
Issued at 253 PM CDT Mon May 2 2022
The upper trough and closed low will move slowly eastward across
Nebraska and Kansas Wednesday and Thursday. This will bring a
chance for showers through the period. Temperatures will be cool
in the mid 50s Wednesday and the upper 50s to low 60s Thursday.
Friday expected to be dry and warmer and the system moves east of
the area and weak warm air advection returns. Highs return mainly
into the 70s. A broad upper trough will deepen across the western
U.S. Saturday thorugh Monday. This will bring a chance for showers
each day, with thunderstorms also possible during the afternoon
and evening hours. Southwesterly flow aloft will increase. The
area is expected to remain in the "warm sector" each day. This is
shown more substantially by the 12Z ECMWF than the 12Z GFS.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 719 PM CDT Mon May 2 2022
Lingering precipitation across north central Nebraska will slowly
come to an end this evening. In the wake of the departing
precipitation, some patchy fog is possible, mainly across southwest
Nebraska and the eastern Panhandle. Fog may impact KLBF Tuesday
morning with visibility down to 4 miles. Fog will dissipate by mid-
morning giving way to partly sunny skies with gradual increasing
ceilings through Tuesday afternoon.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Roberg
SHORT TERM...Roberg
LONG TERM...Roberg
AVIATION...Kulik
Area Forecast Discussion
National Weather Service Louisville KY
848 PM EDT Mon May 2 2022
.Forecast Update...
Issued at 849 PM EDT Mon May 2 2022
A weakening cluster of showers and storms is moving NE toward our
CWA from western TN/KY at this hour. Cloud tops in IR satellite
imagery have been steadily warming, and the convection will be
running into some much drier air over our CWA. So, given that plus
latest HRRR runs showing the activity dissipating across our SW CWA
tend to agree with that solution. Previous forecast already had the
pops in our SW to cover this, so no changes planned at this time.
There is a left mover that had a history of severe hail across
western TN that is now moving into Christian county, but it has
steadily weakened and isn`t expected to be a threat when it arrives
in our CWA.
&&
.Short Term...(This evening through Tuesday)
Issued at 340 PM EDT Mon May 2 2022
...Strong to Severe Storms Possible Tuesday Afternoon and Evening...
A beautiful afternoon is in progress - warm, dry, and low humidity.
Temperatures have warmed into the mid 70s under increasing cirrus
streaming in from the west. Sfc low pressure is rotating into
western Oklahoma on the southeastern flank of a compact mid/upper
level trough near the CO/KS border. This low pressure system will
continue ENE tonight into Tuesday, with the sfc low forecast to
track across central MO/IL late tonight and Tuesday morning.
A warm front gets pulled northward across the CWA with a 40+ kt
southwesterly LLJ arriving after 06z tonight. Expect scattered to
numerous showers to move through late tonight through early Tuesday
morning, with the highest PoPs/QPF concentrated near and north of
the Ohio River. The northern CWA will see stronger forcing for
ascent and low-level moisture transport closer to the core of the
low-level jet. Isolated rumbles of thunder are also likely, though
any storms will remain elevated in nature through Tuesday morning.
Warm advection showers are already exiting off to the northeast by
12-14z (mid-morning) Tuesday. A lull in shower activity is then
likely into early afternoon, during which time the atmosphere will
destabilize ahead of the impinging cold front. HREFv2 and v3 data
supports a high likelihood for greater than 1000 J/kg MLCAPE with
the greatest instability axis from Bowling Green to Lexington. Deep-
layer shear on the order of 30-40 kts will be supportive of strong
to severe convection - the more marginal 30 kt values will be across
south-central KY. Forecast soundings and hodographs show little
directional shear, but fairly impressive 0-1 km speed shear.
Multicell storm clusters organized into linear segments look possible
along and just ahead of the cold front.
A veered wind profile, steep low-level lapse rates, marginal mid-
level lapse rates, and some mid-level dry air all point to damaging
straight-line winds as the primary threat. There is a low risk for
an isolated tornado and marginally severe hail.
Timing: The main time frame of concern for severe weather is 2-10 PM
EDT. These storms will be initiating overhead, likely near the I-65
corridor. The area with the greatest (relative) chance for severe
weather is roughly east of a line from Scottsburg, IN to Bowling
Green, KY.
Confidence: Agree with SPC`s Slight Risk for severe weather, so any
severe weather will remain isolated in nature. Given that
definition, confidence in severe weather is low-medium. Confidence
in isolated damaging winds is medium. Confidence is low for
tornadoes, large hail, and flash flooding.
.Long Term...(Tuesday night through Monday)
Issued at 320 PM EDT Mon May 2 2022
Synopsis...In the wake of the lifting shortwave trough, a brief
period of drier weather is anticipated as mid-level ridge moves
overhead and the surface cold front washes out in the lower
Tennessee Valley. Thereafter, global model guidance hasn`t changed
enough to agree in an unified solution. The GFS output keeps
depicting the translation of the upcoming closed low much faster
than its CMC/ECMWF counterparts. These differences might prove
significant when comparing the expected storm total QPF as the
latter favors a greater flooding risk. Besides, there is potential
for another round of strong/severe storms during the Thursday-Friday
interval. Nonetheless, given the aforementioned model uncertainty,
it is still of low confidence. Overall, an slower, more amplified,
and detached scenario is preferred for this part of the forecast.
Finally, it seems that model differences are reconciled by next week
as the GFS catches up with the CMC/ECMWF in portraying an Omega-type
blocking pattern as an elongated mid-level ridge extends from the
Gulf of Mexico to the Great Lakes and into Canada, flanked by
distinct troughing.
Wednesday...Although some light showers might manifest in the KY/TN
border at sunrise, most of the frontal heavy rain would have already
moved further south while subsidence and mid-level dry air prevail.
As a result, anticipate a drying trend for the middle of the week
along with low/high clouds and light northerly surface winds.
Thursday-Saturday...The next system in store for the lower Ohio
Valley will be better organized and with more dynamic support. An
occluded and vertically stacked surface low could potentially track
near or north of the KY state line Friday into Saturday. Initially,
a warm front could bring the first elevated chance of rain/storms
during Thursday afternoon and evening. CAPE/Shear space parameters
could boost the potential of discrete organized convection, so
elevated weak supercells cannot be ruled out. The slower model
solutions promote a northern storm track which augments the
possibility of warm-sector convection over central Kentucky, even
though this could happen after losing some diurnally-driven
instability. The next chance of storms and heavy rain comes with the
actual cold front passage, probably between Thursday night-Friday
morning. Aside from any severe weather concerns, it is also
reasonable to talk about flood risks, especially if the Tuesday rain
episode leaves non-negligible accumulations. Some factors to weigh
in are the slow movement of the system which enhances training
showers and low one- and three-hourly FFG in the Cumberland and some
parts of the Bluegrass regions. Although storm total QPF is not
impressive, it did increase since the last package. Also, suspect
that global models` spatial resolution might not be adequate to
resolve the embedded convective elements that usually support the
greatest rain rates. That`s why, CMC QPF (highest guidance) could be
the most representative of this period rainfall, which currently
depicts 2-3+ inches area-wide.
Sunday-Monday... Rain-free weather for this part of the medium range
as strong high pressure and elongated upper ridging become
established over the central CONUS. After a couple of days
registering normal or slightly below-normal temperatures,
southeasterly flow will warm up the mercury as highs on Monday might
reach the low 80s.
&&
.Aviation...(00Z TAF Issuance)
Issued at 753 PM EDT Mon May 2 2022
A low pressure system is expected to move from the eastern Great
Plains to the eastern Great Lakes through this TAF period. As this
occurs, a warm front will lift NE across our TAF sites tonight, and
then a cold front will sweep through by Tuesday evening.
TAFs will go valid in a VFR regime with Bkn-Ovc upper sky cover and
light E winds. Ceilings will gradually lower overnight, but will
stay VFR. Numerous showers with embedded thunder will accompany the
warm front later tonight into tomorrow morning, before a brief lull
in activity takes hold by late morning into the early afternoon. A
second round of showers and storms is then possible ahead of the
cold front from afternoon through evening. Surface winds will
steadily veer from SE tomorrow morning, to SW by tomorrow afternoon,
gusting in the afternoon up around 25 knots.
Tried to include best timing for prevailing or tempo showers and
storms, and also mentioned a low level wind shear threat mainly at
HNB/SDF tonight.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Update...BJS
Short Term...EBW
Long Term...ALL
Aviation...BJS
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
635 PM CDT Mon May 2 2022
.SHORT TERM... (Through Late Tuesday Afternoon)
Issued at 246 PM CDT Mon May 2 2022
The primary focus for tonight and Tuesday is severe thunderstorm
chances and the possibility of heavy rain across parts of northeast
Missouri this evening. Latest deterministic guidance is showing a
relative lack of strong instability tonight with less than 500 J/Kg
MUCAPE on the GFS and a bit more on the NAM, but generally less than
1000 J/Kg. The RAP has somewhat more, with 1000-1500 J/Kg, and with
40+ kts of deep layer shear, its solution would give us the greatest
chance for severe storms. CAMS do show some relatively strong
convection tonight, primarily west and southwest of our forecast
area, but by the time it gets here it`s weakening. With this in
mind, I think the probability for severe storms tonight is low. I
wouldn`t be shocked if there was some hail or a localized wind gust
in a few storms, but widespread/large hail does not seem very
likely. Turning attention to heavy rain, WPC forecast has over an
inch across parts of northeast Missouri this evening. GEFS and
ECENS situational awareness plots do highlight that area tonight as
anomalously high on P-wats, IVT, and QPF, however none of these
parameters are maxed out, and our 1 hour FFG guidance values are 1.5
to 2 inches. Given that the ground seems able to absorb the 1-1.25
inch QPF we`re forecasting, will hold off on issuing any hydro
headlines at this time.
As this first system moves east tonight and Tuesday, it will drag a
cold front through the region. Cooler and drier air will move in
behind the front which will shut the rain off from west to east
through Tuesday morning. There may be some lingering showers over
southeast Missouri into the afternoon, but most of the area should
be dry by 18Z Tuesday.
Carney
.LONG TERM... (Tuesday Night through Next Monday)
Issued at 246 PM CDT Mon May 2 2022
The next short wave in line will have crossed the Rocky Mountains by
Wednesday morning, forcing lee-side cyclogenesis over the Oklahoma
Panhandle. Low level flow will turn back to the south and southwest
across Missouri and Illinois by Wednesday evening. It should take
most if not all of Wednesday to moisten the atmosphere over our area
enough for precipitation, but overnight Wednesday night into
Thursday morning looks wet. Deterministic guidance shows a 40-50kt
low level jet with moderate to strong moisture convergence pushing
into eastern Missouri and western Illinois between 06-12Z Thursday,
with plenty of QPF, so the likely to categorical PoPs that the NBM
builds across the region Wednesday night into Thursday look entirely
appropriate. The 02/12Z GFS and ECMWF are now in much better
agreement with the speed and strength of the low as it drifts across
the Mid Mississippi Valley through the end of the week. The GFS is
much slower, and is nearly in lockstep with the ECMWF now. WPC
cluster analysis is also showing much less variability on speed and
strength with this system on the EOF plots...though there is still
some speed difference in the ensemble clusters on day 4 and 5
(Saturday/Sunday). The primary impact of a faster or slower system
will be rain chances or lack thereof on Saturday, and cooler/warmer
temperatures on Sunday. Regardless, Sunday should be dry and warmer
and Monday looks downright balmy as another deep trough digs into
the southwest U.S. and south-southwest flow is re-established over
the Mid Mississippi Valley.
Carney
&&
.AVIATION... (For the 00z TAFs through 00z Tuesday Evening)
Issued at 629 PM CDT Mon May 2 2022
The primary concerns during the 00Z TAF cycle will be
progressively lowering ceilings, as well as the potential for
thunderstorms overnight tonight.
While it appears likely that both things will occur and impact
most local terminals, confidence is low regarding the timing of
each. While precipitation is diminishing temporarily this evening,
ceilings have begun to lower at COU/JEF, and this is expected to
continue over the next several hours, and also spread eastward to
affect additional terminals. IFR ceilings are likely overnight,
with very gradual improvement expected tomorrow morning through
the afternoon.
Showers and scattered thunderstorms are expected to move into the
region late this evening through the early overnight hours.
Confidence is highest that storms will impact central Missouri
terminals (COU/JEF), but there is at least a reasonable potential
for thunderstorms to impact all areas. Hail and gusty winds will
be possible with the strongest storms. Precipitation should
largely cease very late tonight aside from a few light showers..
BRC
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 60 63 50 68 / 90 40 5 10
Quincy 54 58 45 62 / 90 50 0 10
Columbia 52 56 49 66 / 90 20 0 30
Jefferson City 53 57 49 66 / 90 20 0 30
Salem 62 68 49 68 / 90 30 5 5
Farmington 60 66 49 69 / 90 30 10 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1058 PM CDT Mon May 2 2022
.UPDATED for 06Z Aviation Discussion...
Issued at 1058 PM CDT Mon May 2 2022
&&
.DISCUSSION...(This evening through Monday)
Issued at 237 PM CDT Mon May 2 2022
KEY MESSAGES:
- Temperatures near to even a little above normal expected to return
this weekend.
- Weather pattern looks fairly quiet this week, but looks to turn
active again next week.
Tonight through Tuesday... Strong shortwave on water vapor imagery
spinning across CO and into KS will be our primary weather driver
during this period. It will remain to our south, but tonight we will
see an area of rain build north across IA. The question remains with
how far north precipitation makes it. Trend from the 12z guidance
was to keep the northern edge of the precip shield a bit farther
south, so have basically confined precipitation chances tonight to
the I-90 corridor. We may see some clearing of the low clouds into
central MN tonight, but those clouds will just be replaced by
mid/upper clouds from the system to the south. Tuesday, a surface
ridge axis will move into the area and although we are advertising
mostly sunny skies by the afternoon, forecast soundings from the RAP
do cause a little concern as they show the stratus deck remaining in
place through much of the day. At the very least we`ll start the day
with the stratus deck still overhead, with the current expectations
being that it will clear out through the morning, leaving us with
mainly sunny skies by the afternoon. The sun will also allow us to
warm up, but the CAA on the north winds will keep highs in the 50s.
Wednesday through Friday... Mid to late week, we will see split flow
develop. The northern stream will head north into Canada, with the
southern stream sending another slow moving closed h5 low across the
central Plains and into the Ohio Valley. This will result in another
multi-day severe weather episode to our south, with the main impact
for us being the threat of some light rain once again on Thursday
sneaking up into southern MN. There wasn`t a huge change to this
precip chance with this update outside of a small reduction to PoPs
on Thursday. With us being stuck between the northern and southern
streams, we`ll at least see temperatures continue to moderate back
closer to seasonal normals.
The weekend into early next week... The big story here is a
significant pattern change to what we have seen much of this spring.
GEFS/EPS mean h5 forecasts show a strong ridge building over Quebec
this weekend, with a trough digging into the Rockies. This will set
us up into southwest flow. At the very least, this will lead to our
first prolonged stretch of what one might call spring-like weather
of the season. Where uncertainty reigns is with how quickly we start
seeing energy move out of the western trough and into the upper MS
Valley. The GFS continues to be the most aggressive with bringing
energy from the western trough in on Sunday, though even it has
slowed down closer to the ECMWF, which hangs most of that energy
back until next week. Given the strength of the ridge and its
possible development into a rex block over eastern NOAM, the slower
solution is more likely at this point. With that said, given current
model spread, stayed with the NBM forecast, which didn`t change much
from the previous forecast with chance PoPs spreading across the area
on Sunday that continue into next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1058 PM CDT Mon May 2 2022
VFR conditions continue to become more widespread this evening, so
have kept this trend going in the TAFS and removed most of the MVFR
ceilings except at KMKT and KEAU where they could see a bit more low
level moisture from the system to the southeast. Otherwise expect
light northeast winds becoming a bit more easterly Tuesday night.
KMSP...
VFR conditions should continue throughout the TAF period. There is a
chance for some MVFR at times, but overall the clouds have trended a
bit higher the last few model runs. Winds will be northeast, and
eventually easterly Tuesday night.
/OUTLOOK FOR KMSP/
Wed...VFR. Wind SE at 5-10 kts.
Thu...VFR. Wind ESE at 5-10 kts.
Fri...VFR. Wind SE at 10-15 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...MPG
AVIATION...JRB
AREA FORECAST DISCUSSION
National Weather Service Morristown TN
1009 PM EDT Mon May 2 2022
.UPDATE...
EVENING UPDATE.
&&
.DISCUSSION...
The convection south and west has been moving northeast and
weakening/dissipating so far. The hi res models have generally
backed off on overnight convection. Cannot rule out thunder but
think the chance is rather low given the very limited convective
energy and forcing. Will make a few tweaks to the low PoPs and
remove thunder overnight. Will also make some minor adjustments to
temps and dew points with this update.
&&
.AVIATION...
00Z TAF DISCUSSION.
Will carry VCTS for a few hours CHA as convection is not too far
off to the south and southwest, but probability of TSRA occurring at
the airport still looks low this evening. Cannot rule out a
shower or even thunder later tonight into early Tuesday at any
site but again it looks too unlikely to impact the airports to
include for now. However, by afternoon will include a prob30
group for thunder at TRI. Outside of any thunderstorm, VFR
conditions are expected all sites for the period. Winds will be
light overnight then become gusty from the southwest Tuesday.
&&
.PREV DISCUSSION...
/ISSUED 325 PM EDT Mon May 2 2022/
SHORT TERM...(Tonight Through Tomorrow)...
Key Messages:
1. How much if any precip do we see overnight?
2. Breezy afternoon winds Tomorrow with gusts up to about 25 mph
areawide.
Discussion:
This afternoon, visible satellite imagery shows a CU field just
south of the TN state line down into GA/AL. This is the current
location of the warm front associated with an area of low pressure
across the central Great Plains. A much drier airmass is currently
across our area with dewpoints only in the upper 40s to low 50s.
Tonight, this warm front will lift northeast through our forecast
area, reaching northeast TN by tomorrow morning. Our airmass becomes
more saturated as the front brings higher PWs in from the
southwest.
As the front lifts through, we could see a few isolated showers and
storms. However, models are having a really hard time with how much
if any precip we actually see overnight. A quick look through the
CAMs confirms this. Currently have slight chance POPs in through the
night, timed around the frontal progression. If the forecast
busts, I think it will be toward the wet side as the HRRR shows
quite a bit of coverage overnight.
Our best chance at showers and storms will be from late tomorrow
morning through afternoon up across northeast TN and southwest VA.
These areas will be closest to the warm frontal boundary. Currently
have chance POPs in for these locations. Believe that most other
areas will be dry due to being firmly within the warm sector with
little forcing. There is also a slight chance POP along the
Cumberland Plateau and east TN mountains. While not expecting severe
storms, any thunderstorm(s) that develop tomorrow could produce
small hail due to steep lapse rates and gusty winds due dry air at
the surface up through 850 mb.
Also, southwest flow around 30 kts at 850mb will be in place through
the day tomorrow. This is due to the pressure gradient tightening
ahead of an incoming cold front to the west and high pressure to our
east. Soundings profiles show a well mixed boundary layer so expect
gusty winds during the afternoon hours for all areas up to 25 mph.
SR
LONG TERM...(Tuesday Night through Monday)...
Key Messages:
1. Multiple rounds of showers and thunderstorms into the weekend,
with best coverage currently looking to be Wednesday and Friday.
2. Warm temperatures will continue through Thursday, with relatively
cooler conditions Friday through Sunday.
Discussion:
This long term period will begin Tuesday night as surface low
pressure advances across the Great Lakes region. Much of the
southern and central Appalachian region will be well within the warm
sector of a warm front lifting to the northeast while a cold front
approaches from the west/northwest. This cold front will continue to
be the focus for scattered showers and thunderstorms into Wednesday
evening. There will be some surface instability present, however,
the lack of upper level support will inhibit any strong/severe
storms. In fact, it looks as though weak convergence aloft will be
working against the frontal forcing and instability. Additionally,
high pressure anchored offshore of the Carolinas will lead to the
surface front weakening as it transitions across the region. This
can be seen by the fact that no significant CAA sets up post FROPA,
resulting in relatively cooler temps that still remain a few degrees
above seasonal normal Wednesday.
For Thursday, there still remains some uncertainty in timing among
long term guidance. Another system will be progressing across the
central Plains towards the Great Lakes with an initial warm front
advancing across the region, followed by another surface cold front.
The ECMWF suggest slightly stronger high pressure to the northeast
resulting in Thursday remaining dry, whereas, the GFS does have some
PoPs around. Stuck fairly close with NBM given these discrepancies.
Either way, the best coverage of showers and storms will be Friday
with the approaching cold front.
The closed upper low will slowly encroach on the eastern coastline
heading through the weekend. This will result in some chance/slight
chance PoPs for the end of the weekend. In regards to temperatures,
warm conditions will linger through Thursday. Conditions will begin
to cool Friday due to the cold front and associated precip.
KS
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 64 86 65 84 61 / 20 20 40 50 10
Knoxville McGhee Tyson Airport, TN 61 86 64 80 58 / 20 20 50 40 0
Oak Ridge, TN 60 86 62 80 57 / 20 20 60 40 10
Tri Cities Airport, TN 52 84 62 77 55 / 10 50 60 50 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
403 PM PDT Mon May 2 2022
.SYNOPSIS...
Showers and locally breezy winds will gradually decrease this
evening as a weather system pulls away from the region. Warmer and
drier weather is forecast for Tuesday and Wednesday. A much
cooler and wetter pattern is likely Thursday through the weekend.
&&
.DISCUSSION...
Tonight through Tuesday Night: A large closed low over Central OR
will continue to drop southeast...reaching southern Idaho
tonight. A band of rain on the northeast side of this low
stretches from the Blue Mountains up into the Wenatchee area but
this will weaken and dissipate as the low drops south of the area.
Meanwhile ahead of this band of rain a boundary of cooler
southwest winds from the rain cooled air has been pushing north
and east. As of 1 pm there was a sharp contrast in temperatures
with some locations receiving rain such as Wenatchee and Pullman
in the 40s while areas further north like Omak and Sandpoint were
in the 60s. RAP analysis shows 400-700 J/KG of surface based CAPE
from the Camas Prairie up into the Central Panhandle Mountains.
Isolated thunderstorms have already developed over far NE Oregon
with additional shower development in the Clearwaters. This
combined with some forcing with the rain cooled boundary should
provide a trigger for additional isolated thunderstorm development
into the early evening. The main thunderstorm threat is expected
east of Lewiston and Coeur d`Alene.
Tonight southwest winds will advect an abundance of boundary
layer moisture from SE Washington up towards the Spokane/Coeur
d`Alene areas and northern valleys. This will result in increasing
stratus and patchy fog tonight into Tuesday morning. The stratus
will lift and become a stratocumulus deck for Tuesday afternoon
due to daytime heating as a short wave ridge moves over the area.
Afternoon sun breaks will allow for near seasonal high temperatures
on Tuesday in the upper 50s and 60s. JW
Wednesday: Most of the Inland Northwest will experience the
warmest day of the spring so far on Wednesday. Afternoon temps
will top out in the upper 60s to low 70s. That sounds quite warm
after such a chilly April, but compared to average, Wednesday will
only be about 5 degrees above normal.
Thursday through Saturday: Spring is typically the season for
showery and breezy conditions associated with the passage of cold
upper lows. The series of storms depicted by the models Thursday
through Saturday are wetter than we often see this time of year
with a deeper plume of subtropical moisture. Integrated Water
Vapor Transport (IVT) values directed into Oregon and southern
Washington are sufficient to qualify as a weak atmospheric river
Thursday into Friday so we are looking for unusually wet
conditions along with periods of wind.
*Precipitation amounts: Three-day precipitation totals (Thu, Fri,
Sat) are expected to be in the 1 to 2 inch range for the Cascades
with up to an inch and a half for the mountainous portions of the
Idaho Panhandle. Climate anomaly tools highlight this as being
quite unusual for this time of the year. The good news is our
base flows in our creeks and rivers aren`t particularly high
prior to the arrival of rain. Melting snow will contribute to
runoff, but a trend toward cooler temperatures by the weekend
will limit some of this runoff by Saturday and Sunday. We will be
monitoring creeks and small streams, but at this time our rivers
do not appear to show rises to action or flood stage. Some of us
may be tired of the rain, but moisture will continue to benefit
our dryland farm country of the Columbia Basin and Palouse.
*Mountain Snow: Snow levels through Friday should be high enough
over the Idaho Panhandle to yield rain for our passes including
Lookout Pass. Saturday night will be worth watching however as
snow levels drop with the arrival of chilly air. For the
Cascades, snow levels may be low enough at times Thursday night,
Friday night, and Saturday night for accumulations at Stevens
Pass.
*Windy Weather: ECMWF guidance forecasts a high probability of
west winds gusting 30 to 35 mph Thursday, Friday and Saturday.
At this time, our typically windy areas including the Columbia
Basin, Palouse, and West Plains look to be the windiest during
this three day period of potentially windy weather.
*Chilly Temperatures: Temperatures will trend down each day from
Thursday to Saturday. By Saturday night, overnight lows in the
30s will be a good bet across most of the Inland Northwest. We
may be looking at frost for a good portion of the region by
Sunday morning.
Sunday and Monday: Mothers Day will be chilly and breezy. Much of
the Inland Northwest will experience high temperatures in the 50s
which is about ten degrees below average. Monday should trend
drier as trough responsible for our active weather late this week
digs into the southwestern US. Frost will be possible once again
Monday morning with afternoon readings in the mid 50s to low 60s.
/GKoch
&&
.AVIATION...
00Z TAFs: Rain cooled air has moistened the boundary layer over
Eastern Washington and southwest upslope boundary layer winds will
result in increasing MVFR stratus and local IFR conditions into
Tuesday morning across the eastern third of WA/N Idaho impacting
KGEG/KSFF/KCOE/KPUW. Showers associated with the low pressure
system around Wenatchee, Pullman, and Lewiston will come to an
end later this evening as the low pressure system pulls away from
the area. There also remains a slight chance of thunderstorms
through 03z mainly east of Coeur d`Alene and Lewiston. The
stratus will lift into a stratocumulus deck for Tuesday afternoon.
For KMWH/KEAT downslope westerly winds in the boundary layer
should keep conditions VFR through the period. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 41 63 41 68 48 62 / 20 0 0 0 10 40
Coeur d`Alene 41 61 42 67 47 59 / 20 0 0 0 20 60
Pullman 41 57 39 67 47 59 / 30 10 0 0 0 50
Lewiston 46 65 44 74 53 67 / 70 0 0 0 0 60
Colville 39 68 42 68 46 63 / 0 0 0 0 10 60
Sandpoint 41 62 42 64 46 57 / 10 0 0 0 20 70
Kellogg 43 57 42 66 48 57 / 50 0 0 0 20 70
Moses Lake 40 69 42 71 50 67 / 20 0 0 0 0 20
Wenatchee 44 67 45 70 51 64 / 20 0 0 0 10 30
Omak 44 70 47 70 50 67 / 10 0 0 0 10 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Topeka KS
542 PM CDT Mon May 2 2022
...AVIATION UPDATE...
.DISCUSSION...
Issued at 255 PM CDT Mon May 2 2022
Key Points:
- Increasing coverage of showers and thunderstorms late this
afternoon through evening, a few severe possible south of I-70
- Dry Tuesday, then another round of rain and storms Wednesday
through Thursday
As of 19Z this afternoon, shortwave trough is propagating out of CO
and into western KS with VWP data showing a mid-level speed max
rounding the base of the trough. The sfc low is centered over
western OK near the TX panhandle, with the dryline near the TX/OK
border. The warm front has been slow to move northward and remains
draped over northeastern OK. Another sfc boundary extends out of the
center of the low through central KS across our far southern
counties, which has been pretty stationary throughout the day. Cloud
cover has kept our area mostly stable so far with scattered showers
area-wide and isolated thunderstorms in north central KS where we
have about 500 J/kg of MUCAPE and steeper mid-level lapse rates, per
SPC mesoanalysis. Between the cloud cover and slow northward
movement of the warm front, have knocked afternoon highs down to the
50s across most of the area. Also am less excited about the
potential for severe weather this afternoon and evening. Guidance
keeps enough MUCAPE (500-1000 J/kg) mainly south of I-70 with enough
effective bulk shear (50+ kt) to support elevated storms with a hail
threat. For this reason, still cannot rule out a few severe storms
with the strongest updrafts, but think the warm front looks to be
too far south for tornadoes to be a concern for us at this point.
Most CAMs have the activity out of our area into MO by around
midnight aside from a few lingering showers possible.
Low-amplitude ridging will be overhead for Tuesday, though CAA and
cloud cover should keep conditions fairly cool. Highs are forecast
near 60, but could remain cooler still with clouds overhead.
The next mid-level low will impact the area Wednesday through early
Friday as it slowly moves from the Rockies across the Central
Plains. There is some slight model variation in where exactly it
tracks, but at this time there remains a possibility for a few
severe storms in southern parts of the area on Wednesday as well.
Pwat both tonight and Wednesday looks to reach around 1.35", which
is above the 90th percentile from sounding climatology, so heavy
downpours within thunderstorms are possible. Flooding could become a
concern for locations that see repeated convection Wednesday through
Thursday, especially with east central KS seeing this activity
tonight as well.
Any wrap-around showers should move out Friday morning as the system
moves east, with ridging and southwest flow bringing warming
temperatures back to the 70s and 80s for the weekend along with a
return to dry weather.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday)
Issued at 542 PM CDT Mon May 2 2022
The terminals are likely to remain north and west of the surface
low tonight. This should keep the low clouds in place with TSRA
remaining elevated. Some of the models try to clear things out by
the afternoon, but given the pattern with high pressure building
in and a north wind keeping the boundary layer cool think the RAP
and GLAMP keeping MVFR CIGS in through 00Z is the more likely
solution. CAMs seem to have a decent handle on the convection so
will try to be a little more precise with timing precip.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Picha
AVIATION...Wolters