Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/01/22
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1055 PM EDT Tue May 31 2022
A cold front will move southwestward across the area and usher
in cooler conditions tonight along with the potential for some
scattered showers. Cool and cloudy weather Wednesday with
showers along with some thunderstorms during the afternoon
into the evening mainly west of the Hudson River. Some of the
thunderstorms could become strong to severe.
.NEAR TERM /THROUGH TONIGHT/...
A record high of 92 degrees for May 31 was tied at the Albany
International Airport today. It has also reached 92 degrees on
May 31 in Albany in 2013, 1937 and 1895.
Poughkeepsie was close but missed the record high by one degree
with a high of 93 today.
As of 1030 pm...Forecast remains on track. Backdoor front
making progress to the west with much cooler air being ushered
in with its passage. Isolated to widely scattered storms are
developing to our southwest as some CAMS indicated. Just some
minor adjustments were needed.
Previous Discussion [8 pm]...Backdoor cold front continues to
makes progress southwestward into the local area. Showers and
thunderstorms have been developing along the frontal zone across
western New England. The focus now is over Windham County VT.
The storms are moving to the southeast. Have maintained chance
pops across the far northeastern portion of the forecast area.
Based on some CAMS have added slight chance pops across the far
southwest portion of the area for this evening. Otherwise
adjusted temperatures and dew points based on observational data
and blended into the latest guidance. Expecting temperatures to
drop down into the 50s and lower 60s overnight in the of the
Previous Discussion [2:30pm]...A toasty Tuesday afternoon
continues with Albany already matching its daily record high of
92 degrees. The rest of eastern NY and western New England is
also quite warm and humid with most in the mid to upper 80s with
even low 90s in the Hudson Valley. Cooler temperatures in the
low 80s can be found in the higher terrain of the southern
Adirondacks with even upper 70s in the Upper Hudson Valley in
the wake of a backdoor cold front. Not only is this front coming
in from the north but it is also approaching from the east as
it tracks through eastern MA and New Hampshire. The 12 UTC ALY
sounding showed a pronounced capping inversion at about 785hPa
and latest GOES16 satellite data show only shallow cumulus as
most have already met their convective temperature with little
vertical growth detected.
The HRRR and RAP are performing the best in tracking the
backdoor front and wind shift boundary and both indicate the
potential for showers/storms in southern VT, esp near the
Connecticut River Valley, into the Berkshires and Litchfield
Hills after 21 UTC through early this evening. The main question
will be if the incoming front will be able to provide enough
lift to penetrate the capping inversion or if the inversion will
prove too strong and limit updraft growth potential and prevent
any storms from becoming strong/severe. SPC did introduce a
marginal risk over our western New England areas for today into
tonight for this exact reason and we will continue to monitor
trends. We continued to limit any thunderstorm mention only to
areas in the Upper Hudson Valley, southern VT and western MA/NW
CT since the boundary will likely only reach these areas when
their is sufficient daylight. Should any severe storms develop,
damaging winds and large hail will be the main concerns but any
strong storms will likely be isolated at best.
Any storms weaken and diminish this evening but the backdoor
front will continue marching inland, resulting in westerly winds
shifting to the north or northeast. This will allow dew points
and temperatures to drop and stratus clouds overspreading areas
from northwest to southeast after Midnight. Temperatures should
cool into the upper 50s to low 60s. Some patchy showers or
drizzle are possible as well overnight under this marine
influenced air mass. We will keep an eye on a potential "ridge
roller" or decaying MCS late tonight into early tomorrow morning
tracking over the ridge from southern Canada towards into Lake
Ontario and potentially into the western Adirondacks mainly
after 09 UTC. Showalters become negative during this period and
after collaboration with BTV and BUF, continued our thunder
mention in the grids mainly for Herkimer and Hamilton counties
through early Wednesday morning.
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
Clouds and cooler temperatures will overspread the region by
tomorrow morning. Guidance continues to indicate that a
shortwave embedded in the fast flow aloft or a "ridge roller"
will ride overtop the amplified or spiky ridge positioned over
western NY early tomorrow morning and with showalters falling
below zero as it tracks into our western Adirondack zones, this
implies we have to watch for an area of showers and
thunderstorms due to a decaying MCS. General consensus timing
wise for this to occur looks to be 10 UTC through 14-15 UTC with
potential for showers to track into the Upper Hudson Valley and
possibly southern VT; however, low stratus clouds in the wake of
the backdoor front should limit thunderstorm potential mainly to
areas west of the Hudson River. After any morning showers, most
should experience a cooler and cloudy day as moisture trapped
underneath the inversion maintain a stratus cloud deck. In fact,
limited boundary layer mixing looks to prevent temperatures from
warming up much above the morning lows. Current forecast shows
highs only reaching into the mid to upper 60s with possibly near
70 in the Hudson Valley. Western New England, especially
southern VT, should be the cool spot in the low to mid 60s.
Otherwise, forecast soundings suggest winds may be a bit breezy
in north/south oriented valleys sustained 5-15mph.
While most of eastern NY and western New England will experience
a much cooler/cloud day compared to today, the one exception
looks to be the western Mohawk Valley and the northern/eastern
Catskills where the backdoor cold front should loosens its
grips and a warmer and more humid air mass from western/central
NY can penetrate, especially after 17-18 UTC. Guidance has
struggled in showing just how north this air mass can reach with
some of the latest trends keeping further to our south and west
in BGM`s area; however, there is enough uncertainty that we
show temperatures reaching into the mid to upper 70s with dew
points spiking into the low to mid 60s tomorrow afternoon ahead
of an incoming cold front. Should this occur, a tight
instability gradient will set-up in this area (as indicated on
the latest HREF) and high res guidance suggests that showers and
thunderstorms could develop and track along or just east of
this gradient. While instability is questionable with just near
or under 1000J/kg on the HREF, deep layer shear looks strong
with 0-6km shear values near 35-45kts. Therefore, any storm
clusters that develop tomorrow afternoon could become strong to
severe with damaging winds and large hail the main hazards.
However, with the stratus deck and backdoor front nearby,
sufficient low level veering in the wind profile may be in
place to support a tornado. SPC maintains a slight risk mainly
in the Mohawk Valley, western Adirondacks and north/eastern
Catskills with a marginal risk downstream for the rest of
eastern NY. General thunder only for western New England where
the effects of the backdoor front should limit the severe
As the cold front from west/central NY advances eastward mid to
late afternoon tomorrow, showers/storms should push further into
eastern NY but instability remains questionable given the
stratus deck, limited sun and cooler air mass. We therefore only
included slight chance thunder for areas east of the Hudson with
little if any thunder mention in western New England.
With PWATs near 1-1.50" tomorrow, any storm is capable of heavy
downpours and should any area received multiple storm clusters,
urban or poor drainage flooding may result.
The cold front pushes eastward through the region Wed night with
any showers ending by or shortly after midnight. A cooler and
drier arrives overnight with lows in the 50s.
High pressure takes control of the area Thursday with partly to
mostly sunny skies and much more pleasant day as high
temperatures peak in the mid to low 70s.
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Guidance is in good general agreement with regards to the longwave
pattern. Ridging shifts eastward off the East Coast with a trough
over the Great Lakes into the Northeast as we head into the weekend.
Over the weekend the flow is expected to flatten becoming zonal
across the CONUS. Troughing is expected to develop over the Great
Lakes Region with ridging developing downstream as we move into
early next week. Also there is uncertainty about potential tropical
development in the Gulf of Mexico; please refer to products issued
by the National Hurricane Center about this potential development.
A cold front on a gradual approach from the west is expected to
finally reach and move across the region aided by short waves
rotating about an upper low positioned just west of Hudson`s Bay and
by a southern stream short wave which phases in resulting in the
development of a low along the boundary. Expecting a period of
showers Thursday night into Friday. There is a chance for some
thunderstorms across the southern portion of the forecast area.
A period of fair weather is expected Friday night through the
weekend as a surface high shifts eastward and passing over the
region. With zonal flow aloft looking at seasonable temperatures
with highs in the 60s and 70s and lows in the 40s and 50s.
Chances for showers are expected to return early next week with the
approach of a low pressure system. However, the timing is uncertain
so kept forecast simple with low chance pops Monday afternoon
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Isolated showers along a frontal zone in central and western New
England will remain mostly north and east of the TAF sites this
evening. There is a very small (less than 20 percent) chance
that one of these showers could briefly affect one of the sites
but this chance is too low to include in any of the TAFs. Cigs
will remain VFR through this evening with scattered to broken
Lower clouds will move into the area from the east after
midnight tonight as a backdoor front moves west across the
region. Scattered to isolated showers will occur across the
region Wednesday morning and these are covered with VCSH. The
best chance for rain looks to be Wednesday afternoon into the
evening, and there could even be some widely scattered
thunderstorms late Wednesday as more organized clusters of
showers move southeast along the stalled frontal zone. Cigs
should remain mainly MVFR through the day Wednesday.
Winds will be variable at less than 10 kts this evening, then
east-southeast at 5 to 15 kts late tonight through Wednesday
with a few higher gusts possible at ALB and PSF.
Wednesday Night: High Operational Impact. Likely SHRA.
Thursday: Low Operational Impact. Slight Chance of SHRA.
Thursday Night: High Operational Impact. Likely SHRA...TSRA.
Friday: Moderate Operational Impact. Chance of SHRA.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
After a dry Tuesday, some showers and isolated thunderstorms may
reach into the southern Adirondacks late tonight into early
tomorrow morning. Otherwise, tomorrow will be cooler and cloudy
with additional showers and storms possible in the afternoon,
mainly west of the Hudson River. Some storms may be strong to
severe producing heavy downpours.
Otherwise, RH values tonight rebound to 85 to 95 percent as
skies become cloudy. Clouds stick around tomorrow with cooler
temperatures and lower humidity. RH only drop to 60 to 75
percent tomorrow between the clouds, cooler temperatures and
West to northwest winds shift to the north and northeast tonight
becoming sustained to 5 to 10 mph. Winds shift to the south late
tonight into tomorrow morning and turn breezy with sustained
winds near 8 - 15mph, strongest in north-south oriented valley.
Any strong to severe storms may produce damaging wind gusts.
Mainly dry weather through tonight with the exception of the
western Adirondacks which may experience some showers and storms
late tonight into tomorrow morning which may result in a soaking
rain, especially if there are embedded storms. Then, some
patchy drizzle or light showers are possible the rest of the
morning but overall precip amounts look light.
A cold front advancing eastward from west/central NY approaches
tomorrow afternoon which looks to result in more widespread
showers and storms for the western Mohawk Valley and northern
and eastern Catskills especially for areas that break for more
sunshine. Any storm can produce downpours and should any areas receive
multiple rounds of thunderstorms, ponding of water may occur in
urban or low lying areas. River and streams should not
experience any impactful rises due to recent dry conditions.
Next chance for showers then holds off until Thursday night
into Friday, with southern areas possibly seeing over a half
inch. Mainly dry weather is expected for the weekend.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
657 PM CDT Tue May 31 2022
For the 00Z TAFs, a fairly complicated forecast with low confidence
in details through late Wednesday afternoon. Confidence is lowest
in precipitation prospects during this cycle. Based on latest model
guidance, greatest threat for precipitation is at KGUY, followed
by KDHT and KAMA. Thunderstorms are possible through tonight.
However, whether or not any terminal site will be impacted is
problematic at this time due to high uncertainty in coverage
should any storms develop. Finally, expect MVFR to IFR cigs to
develop late tonight and persist through Wednesday afternoon in
the wake of a cold frontal passage.
.PREV DISCUSSION... /Issued 259 PM CDT Tue May 31 2022/
SHORT TERM...Today through Tomorrow.
Bottom Line Up Top: Conditions will be favorable for severe
storms along and south of a quasi-stationary front this afternoon
into early this evening. The front is currently setup from near
Morton, TX to Clarendon, TX, to Seiling, OK. Very large hail and
damaging winds are the main threats, with a low tornado threat.
Flash flooding could also occur as some training of storms is
possible along the front. Another round of storm activity is
possible late in the evening and overnight and this would expand
to include most of the Panhandles with scattered coverage. These
storms would pose more of a large hail threat and could linger
into the morning hours Tuesday.
Details: The latest upper level analysis places a shortwave trough
and possible closed low over the central part of the NE/UT state
line. A belt of modest southwesterly winds extends from northern
New Mexico up into southeast Nebraska. At the surface, a cold
front has stalled near Morton to Clarendon to Seiling. Dew points
behind the cold front were in the 40s, but along and ahead of the
front dew points were in the 60 to 65 range.
A cumulus field was already noted within the moist warm sector
near the front. Lift should become sufficient for CI by around
21z, and this is when storms could erupt and quickly become
severe given large MLCAPE of 2000 to 3000 J/kg. Effective shear
early in the convective cycle is modest with values around 35 to
45 knots. This is mostly due to the veering wind profiles. The
stronger southwesterlies aloft remain north of the area. A few
supercells may develop along the front late this afternoon, but
with the mean flow being largely parallel to the front, some
training and clustering of storms is possible (which could lead to
flash flooding given PWATs in the 90th percentile range). Any
supercell that does stay discrete could quickly become capable of
baseball size hail and damaging winds of 70 mph (locally higher).
Storms will likely produce some strong outflow winds given DCAPE
on the order of 1500 J/kg and LCL values around 1500 m.
Clustering storms will likely become outflow dominant, with
additional storms possibly forming on the outflow going into early
evening. The tornado threat does not look as concerning based on
the latest data which keeps low level SRH on the marginal side
and LCLs on the high side. However, going into the evening the low
level jet does increase as surface winds become more easterly
(these easterly winds may be largely due to outflow). The net
effect is to greatly increase hodograph lengths and curvature in
the lowest 3km. If any storms become rooted at the surface, a
tornado threat would exist after dark. However, this seems
unlikely unless the most aggressive model (RAP) verifies with very
large moisture/theta-E advection. Current thinking is that the
RAP is way to high on the near surface moisture due to convective
feedback. If dew points rise to near 70 in the Texas Panhandle
late this evening, then the RAP scenario may unfold. Otherwise,
storms that form overnight behind the front would be elevated and
pose more of a large hail threat. This large hail threat overnight
could be a bit more expansive than currently advertised if
moisture advection is more robust, especially considering the deep
layer shear increases in response to a secondary 500mb jet streak
in the area.
This overnight round of elevated convection could linger into the
morning hours Tuesday, mostly favoring the northern and eastern
half of the combined Panhandles where isentropic lift will be
maximized. Widespread stratus will form overnight along and north
of the front as moisture increases (also helped by rain cooled
air). This could lead to some periods of drizzle as well through
the morning hours. There is some indication that clouds will erode
near the frontal boundary which should remain draped across the
far southeast zones tomorrow afternoon. If this does happen,
destabilization would occur quickly and another round of storms,
possibly severe, could materialize (parameters are expected to be
similar to today`s).
LONG TERM...Wednesday night through Tuesday.
For Wednesday night, latest model trends continue support the
scenario that the heaviest and most extensive precipitation will
shift southward further downstate as cool surface high pressure
builds into the region. As a result, a decent north to south pop
gradient is expected, ranging from slight chance values across the
OK Panhandle to likely values in the far southeast TX Panhandle.
Mainly light amounts of QPF are foreseen Wednesday night.
For Thursday and Thursday night, some lingering showers are possible
Thursday morning across the southern Texas Panhandle, with slight
chance pops utilized. Thursday afternoon will likely be dry for
all of the OK and TX Panhandles. The next minor upper level shortwave
trof is then anticipated to track into eastern NM and eastern CO
Thursday afternoon, and should assist in the development of showers
and thunderstorms over the higher terrain of eastern NM and eastern
CO late in the afternoon, then move eastward into the forecast area
Thursday night. Chance pops offered by the NBM for this time frame
look plausible and were incorporated into the grids.
A near repeat performance is foreseen later Friday afternoon and
night as yet another minor upper level shortwave trof tracks through
the area from eastern CO and eastern NM. Showers and thunderstorms
should develop over eastern NM and eastern CO Friday afternoon, then
head eastward into the OK and TX Panhandles late Friday afternoon
and night. NBM pops capture this scenario and were utilized.
Dry weather and warmer temperatures are forecast to return to the
area Saturday through Monday as a flat ridge of high pressure
prevails. A weak cold front may impact the region Monday night
into Tuesday with pops across northern zones during this time
period based on the progged upper level pattern.
Area Forecast Discussion
National Weather Service Grand Rapids MI
955 PM EDT Tue May 31 2022
Issued at 956 PM EDT Tue May 31 2022
The convection is behaving largely as expected. While there are a
few isolated storms over lower Michigan, mostly between MKG and
MBS, a broken line of storms, that have recently developed from
eastern upper Michigan, across northern Lake Michigan, to near MKE
to RFD. There is still 1500 to 2000 j/kg of mix layer cape ahead
of this line over WI and IL. Over MI it is more like 1000 to 1500
j/kg. There is still 30 to 50 knots of effective bulk shear but
that is forecast to decrease to under 25 knots after midnight.
I expect the storms to continue to fill in over the next few hours
as the storms head toward Southwest Michigan. Most areas should
see at least some rain overnight.
SPC has taken our area out of the slight risk for severe storms
and put is in the marginal risk and that is indeed what I am
thinking it what our risk into to the early morning hours is.
During the early morning hours the HRRR model sounding still show
1000 to 1500 j/kg of cape with an EL near 200 mb. There is
unidirectional shear and down draft capes are in the 300 to 600
j/kg range through 3 am. There is not much of a low level
inversion shown on the model sounding even at 2-3 am. This means
straight line wind gusts are still possible (20 to 40 j/kg of CIN
through 3 am). We also have enough cape in the DGZ to suggest
large hail is possible till around 3 am with a few of these
The bottom line is I still expect most area to get at least rain
showers overnight as the front comes through. Thunderstorms will
be around till 4 am (ish). An isolated severe storm is not out the
question. This would mean large hail and wind gusts to 60 mph are
still possible, if that does in fact happens at all, it will be
very isolated. After 3-4 am the showers should mostly be south of
.DISCUSSION...(This evening through next Tuesday)
Issued at 242 PM EDT Tue May 31 2022
-- Potential remains for a few strong to severe storms tonight --
A couple of light showers have tried to form this afternoon. One
formed along the edge of the lake shadow when some enhanced cumulus
have been found, and a couple of have formed up across the NW area.
They have not had much luck sustaining themselves so far. Deep layer
shear is on the weaker side this afternoon.
We continue to expect that numerous showers with scattered
thunderstorms will form later this evening. As mentioned in the
previous discussion, we do lose the sfc based instability toward
dark as one would expect. However, models continue to indicate that
we will keep as much as 1500-2000 J/kg of most unstable CAPE that
will be elevated in nature. This, combined with a better band of
convergence developing over the area with the front coming in, and
the mesoscale ridging diminishes downwind of Lake Michigan a bit.
Effective deep layer shear values are forecast to increase a bit
into the evening to around 35 to 40 knots as mid level winds
increase. This will help to increase the potential of a few better
organized storms. With elevated storms, the threat of wind and
tornadoes go down a bit. Parameters for hail are not all that
impressive as mid level lapse rates are only around 6.5 C/km
tonight. The shear may help that cause a bit. The wind threat is
there a bit, as forecast soundings indicate that the sfc based
inversion as rather shallow and weak in nature. There is some low
level shear in place, but the sfc inversion should keep tornado
potential quite limited, but not zero.
-- Chance of rain South on Thursday --
There may be a residual shower early in the morning across the far
southern portion of the area toward Jackson. The front slows down a
bit, and a weak wave of low pressure will ride along it and keep the
chance in early. We will then see clouds decrease through the day as
high pressure move in.
The front will continue to slowly sink south, but it will remain
just close enough to bring another chance of rain on Thursday. This
occurs as another short wave embedded in the flow will emerge from
the Rockies and move south of the state on Thursday. There is
general troughing over the entire state on Thursday, but the better
energy will be south of the area, and will induce some rain showers
north of the front. This rain should stay mostly south of I-96 on
-- Cooler next weekend with rain chances around Sunday --
The trough moving through the area on Thursday, will move east of
the area by Friday morning. NW flow aloft will persist, but we will
see upper heights build as the upper ridge axis builds toward the
area. At the sfc high pressure will be moving overhead, helping to
diminish the cloud cover and keep the area dry, yet cool. 850 mb
temps will be dropping to around +2 to +4C which supports highs only
in the mid to upper 60s. Return flow eventually sets up by Saturday,
and helps temperatures start to recover a bit.
At some point between Saturday and Sunday, we will see rain chances
increase. We will see another wave emerge from the Plains, and send
a nice surge of warm and moist air up over the area. This warm air
advection will be focusing along a warm front to produce showers and
storms. The chance will then hold on potentially through Monday,
before the supporting wave would exit the area. This whole scenario
is a bit uncertain, due to indirect effects from the Tropical System
Agatha. If this system emerges over the Caribbean and strengthens
like the Euro, it will slow up the upper air pattern over the area.
If it does not develop as much like the GFS, the upper air a pattern
will be more progressive up our way. Tough to say exactly how this
will pan out at a week out.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 723 PM EDT Tue May 31 2022
At 7 pm we have gusty southwest winds with cirrus clouds over
Southwest Lower Michigan. The surface cold front is over eastern
Iowa into southern Wisconsin. An area of convection is developing
as I write this, just in front of that surface cold front, near
the greatest mid level instability and best upper level shear.
I expect this area of convection to increase in coverage and move
over our TAF sites in the 03z to 09z time frame. I would think
most of our TAF sites should get at least 15 to 30 minutes of
convection in that time frame so I put a "TEMPO" group to suggest
what does happen will not last long.
Once the front comes through, a weak wave forms on the front. This
may result in MVFR/IFR cigs for the I-94 TAF sites more so than
the I-96 TAF sites. This will have to be watched to see how
extensive if gets, if it happens at all. Skies should clear by
afternoon for all TAF sites.
Issued at 242 PM EDT Tue May 31 2022
We will hold on to the Small Craft Advisory and Beach Hazards
Statement from Grand Haven and northward through tonight. As
expected, winds and waves have been just shy of criteria through
today, with no expected increase tonight. The winds and waves might
take a part of Wednesday to come down significantly, but they should
be down below criteria by daybreak Wednesday.
Our next marine headline event looks to come in the Thursday
night/Friday time frame with the next wave of low pressure riding
along the front to our south.
MI...Beach Hazards Statement until 6 AM EDT Wednesday for MIZ037-043-
LM...Small Craft Advisory until 6 AM EDT Wednesday for LMZ847>849.
Area Forecast Discussion
National Weather Service Lincoln IL
858 PM CDT Tue May 31 2022
Issued at 319 PM CDT Tue May 31 2022
Scattered showers and thunderstorms are expected to develop near
the Mississippi River this evening and track southeast tonight. A
few storms could be strong to severe, mainly west of the Illinois
River. The cold front will result in a broad range of
temperatures on Wednesday, with areas north of I-70 in the 70s and
areas south of I- 70 in the mid-80s. Showers may linger
Wednesday, with the best chance for rain being south of I-72.
Issued at 858 PM CDT Tue May 31 2022
A broken line of convection has developed along an advancing cold
front from northwest Illinois into north-central Missouri this
evening: however, the chance for severe weather continues to dwindle
as daytime instability wanes and deep-layer shear decreases. Latest
mesoanalysis indicates MLCAPEs of 1500-2000J/kg across the western
half of the KILX CWA...with much higher values in excess of 2500J/kg
noted well upstream across Oklahoma into southwest Missouri. With
instability steadily decreasing and the nocturnal low-level jet
progged to strengthen well W/SW of Illinois tonight, do not think
the current line of convection will have much fuel to work with as
it gradually shifts eastward into central Illinois. May see a few
cells with gusty winds/small hail, but overall severe threat
looks low. The more significant thunderstorm activity will focus
across Oklahoma into Arkansas/Missouri as it is fed by the LLJ.
Some of this convection may reach areas along/south of I-72 late
tonight, but will be in a much weakened state as it arrives. Made
updates to hourly PoPs, mainly to delay arrival of precip chances.
Based on current trends, areas east of I-55 will remain dry until
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 319 PM CDT Tue May 31 2022
An occluded 988-mb low pressure system remains located just north
of MN as of 2pm/19z, with its cold front remaining draped across
WI and into east-central IA. Assessing today`s convective
prospects remains a challenge. Extensive cirrus has persisted
through the day west of I-55, and has been most dense west of the
IL River. As a result, temps were only in the upper 70s (as of
2pm) west of the IL River as opposed to mid-80s near I-55 and
upper 80s across eastern IL. That leaves questions as to how much
destabilization will occur, and the latest RAP analysis shows
SBCIN still present across west-central IL, which is the area that
was originally expected to be most conducive for svr wx this
evening. There are also a few weak MCVs tracking northwest
through the area. The stronger of these tracked near the far NW
corner of the CWA as of 2pm/19z, and helped invigorate some
showers between the IL River and I-55 along a remnant outflow
boundary. However, these showers dissipated almost as quickly as
they formed as the ascent provided by the MCV shifted away.
Visible satellite has shown some thinning of the cirrus shield,
perhaps caused by subsidence behind this MCV, so there may still
be a window for sufficient destabilization to occur.
While CAMs have not had the best handle on today`s evolution, one
noteworthy trend has been a shift towards later storm development
and subsequent movement into our CWA. The latest runs now keep
most of the activity west of the CWA through 00z. Overall,
confidence in the severe threat has waned. Storms are expected to
develop later in the day, in an area that has remained beneath
dense cirrus for much of the day, and not push into the ILX CWA
until late evening when any instability that does manage to
develop is trending downward. While the severe threat isn`t zero,
the coverage of strong storms may less than initially anticipated,
especially with eastward extent into the CWA overnight.
The environment remains supportive of heavy rain, as 850-mb
moisture transport is focused ahead of the front, with 850-mb flow
nearly parallel to the front. The latest RAP shows PWAT values
around 1.7" this afternoon, and some deterministic models have
PWAT values approaching 2", which would be in the 99th percentile
relative to the climatology. The 12z HREF shows the potential for
localized QPF maximums of 2" west of I-55 through Wed AM, and just
west of the ILX CWA there are max QPF values in excess of 4",
although these values may be a tad overdone given the shift in
expectations since the 12z models ran this morning. Flash flood
guidance suggests that more than 2" of rain in 3 hours would lead
to problems. Despite a supportive environment, there are a few
factors limiting a greater flash flood threat. Antecedent soil
moisture is quite low, only 10- 20%. Additionally, the axis of
convection shifts southeast as the front advances through
overnight, keeping storms from lingering over any one location for
too long. Waning instability should result in rainfall rates
trending downward overnight as well.
Uncertainties in the frontal timing linger and impact the forecast
for Wednesday. The current expectation is that the front will be
near I-72 corridor by sunrise Wed, then shift into SE IL.
Additional showers and storms will be possible along the frontal
zone Wed afternoon/evening as a shortwave tracks from the west-
central Plains towards the Great Lakes. The presence of the front
will lead to a broad range of high temps on Wed, with areas NW of
the IL River only in the low 70s while areas south of I-70 reach
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 319 PM CDT Tue May 31 2022
Depending on where the frontal boundary stalls, some precip
chances could linger Wed night into Thurs. High pressure building
over the central Plains will result in a few cool, dry days.
Temps will be in the low 70s on Thursday, then recover into the
upper 70s by Friday as a weakening, broad sfc high shifts directly
Into the weekend, an upper level low remains anchored over the
Canadian Prairie to the north of Minnesota, while upper level
ridging builds over the Rockies. As disturbances drop through the
northwest flow over the northern Plains late this weekend and into
early next week, they could provide precip chances across central
IL. No significant heat waves are expected through the current
long term period (through June 7th), with highs in the upper 70s
to mid 80s from Saturday through early next week. That trend
appears likely to continue, as the latest CPC outlook (valid June
8-14) favors below normal temperatures. Normal highs for the
second week of June are in the low to mid 80s.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 644 PM CDT Tue May 31 2022
Main aviation forecast concern continues to focus on convective
development this evening into tonight. 2330z/630pm radar mosaic
shows scattered showers/thunder beginning to develop along a cold
front near the Mississippi River: however, areal coverage remains
minimal at this time. Think this activity will develop/spread
northeastward over the next few hours...first impacting KPIA after
03z. HRRR/NAM suggest a broken band of convection gradually
working its way further E/SE as the night progresses...potentially
reaching KBMI/KSPI by around 07z and further east to KCMI by 09z.
Given low confidence forecast, have maintained just VCTS at the
terminals until radar trends become more apparent. As was noted by
the previous forecast package, it appears a period of MVFR
ceilings will develop once the cold front passes late tonight into
Wednesday morning. Winds will initially be S/SW with gusts over
20kt at both KDEC/KCMI early, then will veer to NW and drop below
10kt after FROPA late tonight.
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
732 PM EDT Tue May 31 2022
Issued at 728 PM EDT TUE MAY 31 2022
Forecast continues to remain on-track. Updated PoP based on some
of the convective activity in Letcher and Pike counties. Also,
updated dry grids based on the latest observations.
.SHORT TERM...(This evening through Wednesday night)
Issued at 333 PM EDT TUE MAY 31 2022
The afternoon surface analysis reveals an area of high pressure
just to our east and southeast remains in control of the weather
here in eastern Kentucky. This keeps the region under generally
southerly flow at the surface and dewpoints in the low to mid 60s.
The mid-level ridging and dry are aloft will keep most dry this
afternoon and evening, but noting slightly more growth the the
cumulus nearer the VA border. However, these will remain anemic
given the aforementioned dry air and capping inversion. Any shower
(less than 20 percent chance) will relent with loss of daytime
heating and resultant loss of steeper low level lapse rates. This
will give way to mostly clear skies tonight, with slight 5 degree
cooler temperatures felt in the valleys versus the ridges. This
will result in mainly river valley developing late tonight under
weak winds and high pressure.
Wednesday, expect any fog that develops overnight to dissipate
around 9 to 10 AM. Some of the CAMs have shown signs of isolated
showers toward dawn, and cant completely rule this out with
chances generally 15 percent or less. We will see a shift in the
pattern through the day Wednesday, as stronger upper level ridging
shifts SW southwest allowing heights to begin falling ahead of a
shortwave in the Lower Ohio Valley. This in conjunction with an
approaching cold front will help to weaken the capping inversion
through the afternoon and evening. This could lead to more shower
and even thunderstorm development late Wednesday afternoon into
Wednesday evening. The greatest chances of convection Wednesday
afternoon will be in areas north of the Mountain Parkway. The
shear seems to lack, with effective shear maybe reaching 30
knots, but MUCAPE values do climb into the 1000 to 2000 J/kg range
which could lead a some more vigorous updrafts. Either way looks
like better shear to the north and west and likely little if any
severe weather expected in eastern Kentucky for Wednesday.
Wednesday night this front will sag southward and become more ill
defined as it does so. Either way continued decreasing heights
will keep shower and thunderstorm chances rolling through the
night. The coverage still seems best in the northern parts of the
CWA generally along and north of the Mountain Parkway, where
chances peak at 50 to 60 percent. Increasing clouds and showers
will keep splits under control with lows in the mid 60s for most.
.LONG TERM...(Thursday through Tuesday)
Issued at 315 PM EDT TUE MAY 31 2022
The long term period will start out with an upper level trough axis
extending from the mid Mississippi Valley, northward through central
Canada. Shortwave ridging will cover the upper Northeast while a
high pressure center sits over southwestern Texas and Mexico with
ridging extending northward through the PNW. This trough will
support a strong surface low over central Canada and a secondary low
in the Northeast. A cold front will be draped from upstate New York
back southwest through the Ohio and Tennessee Valleys, and the lower
Mississippi Valley and southern Plains. Showers and storms will be
possible along and ahead of the cold front. The SPC has placed all
of eastern Kentucky in a day 3 marginal risk for severe
thunderstorms. CAMs show scattered thunderstorms developing along
the boundary Thursday afternoon, however, the environmental set-up
is not certain at this point. Model soundings differ greatly in
terms of instability with the NAM likely overdoing the MLCAPE with
over 2500 J/kg while the RAP is more reasonable with around 1500
J/kg. Cloud cover will be on the increase ahead of the cold front
and will be a big factor in how much instability we see. The main
threat will be strong wind gusts, however, DCAPE values are marginal
across the area with the best values around 900 J/kg over the
Cumberland region. The best chance for severe weather will likely be
where models show the highest CAPE values, over the southwest
portion of the CWA. Overall, confidence in severe potential is
currently low but will continue to be monitored.
The trough axis will swing to the east through the end off the week
leaving behind quasi-zonal flow across the Ohio Valley and Southeast
US. Surface high pressure will move in from the west and will bring
a period of dry weather to the area through Saturday night. Multiple
shortwaves will move across the central CONUS and will bring the
chance for showers and storms Sunday afternoon, though models are
not in the best agreement currently. Highs will start off in the mid
to upper 70s as cloud cover and a passing cold front keep conditions
cool on Thursday and Friday. A warm up is expected this weekend and
into the beginning of the next work week with highs bouncing back
into the mid to upper 80s Monday and Tuesday.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 732 PM EDT TUE MAY 31 2022
VFR conditions will prevail through the TAF period as high
pressure continues to remain overhead. With mostly clear skies,
areas of fog will be possible at terminals KJKL and KSME. Added
VCFG to the remaining terminals. MVFR conditions will be possible
wherever fog develops. Areas of convection return tomorrow
afternoon but look to remain away from all terminals. Otherwise,
once the fog burns off; VFR conditions will be reestablished.
Area Forecast Discussion
National Weather Service North Platte NE
630 PM CDT Tue May 31 2022
.SHORT TERM...(This evening through Wednesday night)
Issued at 332 PM CDT Tue May 31 2022
An upper level disturbance swinging through UT this afternoon will
move east through Colorado tonight and briefly emerge onto the cntl
High Plains Wednesday morning and then drop south into KS and the
The model soundings show north winds in the boundary layer and moist
westerlies aloft. This strongly suggests a top down saturation
process which can delay the arrival rainfall at the sfc by several
hours. It also produces diabatic warming favoring stratiform rain
processes. The forecast guards southwestern Nebraska-along and west
of highway 61- with likely rain chances but drops rain chances north
and east. The RAP model shows strong frontogenesis developing across
KS Wednesday and this should focus the best rainfall south. The
forecast therefore discounts the northern solution- the very wet
SREF, and leans toward the HREF for QPF.
Temperatures tonight and Wednesday are based on the short term model
blend plus bias correction. The expected cloud cover during this
time favors less diurnal temperature range. The short blend is good
at this vs the guidance blend which favors a larger diurnal range.
Skies should clear Wednesday afternoon and evening and the models
show 850-300mb RH falling to around 40 percent. This should open the
window for radiational cooling so the guidance blend is in place.
.LONG TERM...(Thursday through Tuesday)
Issued at 332 PM CDT Tue May 31 2022
The models show a warm front lifting into Nebraska Friday and remaining
nearly stationary through Monday or later. The GFS model shows
cooler air to north pushing the front well south of region Tuesday
while the ECM and GEM continue to hold the front across Nebraska.
Thus, the focus for thunderstorms will be in place and given
moisture and upper level forcing, storms should develop. The models
continue to show a high latitude block forming across Canada and
this should set up a belt of strong westerlies across wrn and ncntl
Nebraska. In fact, GFS shows a low bulk Richardson number suggesting
the return moisture and instability is too low to support widespread
thunderstorm development. POPs are limited to 50 percent Friday
through Monday for this reason.
Given the instability and bulk shear developing on the cntl High
Plains in the GFS and ECM models, isolated to perhaps scattered
severe storm development is possible daily Friday and beyond. SPC
will examine this potential throughout the week.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 630 PM CDT Tue May 31 2022
Mid-level cloud cover continues tonight and into tomorrow across
southwest Nebraska with rain chances increasing toward dawn. Brief
drops to MVFR are possible mid-late morning at KLBF. Farther
north, terminals should remain in VFR and dry with primarily high
cloud cover for tomorrow. Gusty north winds early this evening
taper after sunset and stay around 10 kts tomorrow.
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
811 PM CDT Tue May 31 2022
Issued at 807 PM CDT Tue May 31 2022
Continuing to monitor a gradual uptick in showers and some storms
into the evening, with a limited/isolated severe potential.
Since 5 P.M., there has been a slow but steady increase in
showers and some storms in the confluence zone along and about 100
miles ahead of the cold front. This zone is within a plume of
high moisture in the 0-3 km layer, as sampled by the 00Z DVN
sounding, and shown by surface dew points around or just above 70.
The vertical profile on that DVN sounding was uncapped, with
1,500 J/kg of mlCAPE, but lapse rates in mid-levels are fairly
poor (6.5C/km through most of the depth). With the moisture,
including PWATs of 1.5-1.7 inches, would think there will
continue to be a gradual uptick in at least shower coverage and
probably in intensity of a few cells through 10-11 P.M. There is
35-45 kt of deep layer shear analyzed in the northwest quarter of
Illinois, so some organization has been seen with storms, even
despite meager lapse rates, and with some isolated cells, that
probably will continue. Forward motion on the cells is largely
parallel to the boundary/confluence axes, so even though shear
orientation to these boundaries favors discrete/semi-discrete
cells, it hasn`t taken long for cells to merge into small clusters
if they can sustain themselves...and thus far few have done that.
Aircraft soundings from over the Chicago metro indicate still some
capping in place, so while there have been some cumuliform clouds
along some boundaries seen on radar reflectivity, they have not
materialized into any convective cells. This also means the
activity to our west may struggle as it gets toward and especially
east of I-55. But prior to then, through 11 PM or so, there
remains a chance for a couple stronger to possibly one or two
severe storms. That includes with a couple of the clusters from
western Illinois into northeast Missouri, which on GOES-16 water
vapor imagery looks like may have a mid-level sheared wave
supporting them too. If some of those clusters track over the
same area, it would not take much for an isolated 1-2 inch
rainfall occurrence given the moist profiles.
Overall, this is more in-line with an SPC level 1 of 5 (Marginal)
Risk, and accordingly, that`s the level now with their 01Z
Issued at 315 PM CDT Tue May 31 2022
* Threat for any strong to severe thunderstorms through mid to
late evening, with threat window about 6 PM to 11 PM
The local radar picture is currently devoid of any convection,
likely owing to suppression on the backside of the core of the
MCV lifting into Wisconsin. In addition, as noted earlier,
extensive mid and high cloud cover has limited stronger
destabilization despite temperatures in the lower to mid 80s
northwest of I-55 and mid to upper 80s near and southeast of I-55
amidst dew points in the 60s. It appears likely that there`s at
least some lingering mid-level capping. Most recent HRRR run
initialized well and now focuses main convective threat toward and
Another important item of note to the late day and evening severe
weather threat is the lack of surface convergence with the cold
front draped west of the Mississippi River. The cold front
currently serves more as a moisture discontinuity with generally
southwest winds on either side of it. It thus appears that the
anticipated thunderstorm uptick in the early evening will be tied
to forcing related to upstream convection across Missouri, which
may be tied to a 700 mb wave. If any modestly robust MCV can
emerge from this area, that would certainly assist in scattered to
numerous showers and storms developing. A northwesterly wind
shift is now not expected until after midnight behind the front,
hence the above thinking on more mesoscale influences resulting in
convection blossoming and then gradually building east and
The lack of stronger large scale forcing and low-level convergence
does cast uncertainty on convective coverage this evening, though
as noted, continued message of scattered to numerous t-storms
with likely PoPs. Turning to the severe threat, the thinking
hasn`t changed from midnight shift of an overall decreased threat.
It appears that debris cloudiness will remain extensive enough to
continue limit strong with inc r destabilization through the
daylight hours, and the strongest effective shear will remain near
or northwest of the northwest CWA. With signs pointing toward
more of an evening timing, we`ll then have to contend with diurnal
decrease of SB/MLCAPE after sunset. While SPC maintained a level
2 (slight) severe risk in their 20z update, suspect trends point
to more of an isolated level 1 (marginal) severe threat for hail
and damaging winds. If convective coverage becomes widespread
enough this evening, can`t rule out an isolated/localized flooding
threat, though confidence is also low in this regard.
Assuming anticipated convective coverage this evening comes to
fruition, it should gradually wane after midnight as cold front
finally makes southeastward progress. The cold front will clear
the entire CWA to the south tomorrow morning and then slow its
progress to the south of I-70 on Wednesday. Lingering weak
elevated instability north of the surface front could enable a
few rogue thunderstorms for southeast CWA sections primarily
during the morning, but otherwise looking at a cooler but pleasant
and primarily dry day for most under partly to mostly cloudy skies.
Have some slight to chance PoPs for the southeast 1/3 to account
for isolated to widely scattered showers pushing in at times.
Highs will be in the 70s inland but only in the 60s near the lake
as onshore flow persists through the day with high pressure over
the Great Lakes. Dew points will be quite comfortable and in the
50s for most locations.
Issued at 328 PM CDT Tue May 31 2022
Wednesday night through Tuesday...
Wednesday night, a broad center of low pressure is forecast to trek
across the Ohio River basin with a swath of showers and
thunderstorms along its northern periphery. Several of these
showers will fall over the CWA Wednesday night and early Thursday
morning. The greater rain chances will exist in the southern and
southeastern portions of the CWA with far less confidence in rain
occurring along and north of I-88. This also corresponds to the
greatest potential for seeing a couple of thunderstorms with most,
if not all, of the storm activity expected to be confined to
areas south of I-80. Any storms that manage to pop up should be
just your run of the mill thunderstorms with very little
instability present inhibiting the chance for any strong storms.
The ideal timeframe for rain out of this system is roughly 2AM-
7AM meaning a few showers could accompany your Thursday morning
commute, especially if that commute is southeast of I-55.
Following this early morning rain chance, the rest of Thursday
will be dry with clearing skies as some drier air works its way in
aloft with the trough digging in.
Meanwhile, cool northerly low-level flow and height falls aloft
through the morning will keep temperatures in the lower and middle
70`s on Thursday with areas closer to the lake getting stuck in
the 60`s. With the trough axis slated to pass through the CWA
Thursday afternoon, some WAA aloft in the mid and upper levels
will help temperatures climb into the middle and upper 70`s on
Friday. A large center of high pressure descending from the
windward side of the aforementioned through will keep conditions
dry through Friday and most of Saturday. Temperatures will climb
an additional couple of degrees on Saturday, although onshore flow
will keep communities closer to the IL lakeshore down in the 60`s
Saturday evening and night, a weak, developing warm frontal boundary
will propagate into Upper Midwest and park itself over southern
Wisconsin becoming quasi-stationary through Sunday. Isolated showers
are forecast to pop up along this boundary and fall on the CWA as
early as Saturday evening with coverage expected to expand to more
scattered showers for much of Sunday. The rain chances will continue
into Monday with the broad low pressure center expected to pass over
on Monday. A second, more organized center of low pressure will pass
through central IL on Tuesday keeping shower chances rolling
through Tuesday as well. Thunderstorm chances through the weekend
appear minimal with little instability found near and south of the
frontal boundary. A fair amount of instability building in ahead
of the low pressure center makes Monday afternoon and evening our
best chance for seeing thunderstorms early next week. However, a
nearly zonal shear profile and mediocre thermodynamic profile
should keep storms light and brief. Temperatures on Sunday and
Monday will reach the middle 70`s to lower 80`s before dropping a
few degrees following the Low passage on Tuesday.
For the 00Z TAFs...
The primary aviation weather concerns through the 00Z TAF period are
- The potential for showers and thunderstorms this evening
- Winds shifting to near-northerly overnight tonight, then onto
easterly early Wednesday afternoon
Following a dry Tuesday thus far, a line of convective showers is
building across eastern IA and far northwestern IL. These showers
will be moving through the area mid to late evening with some
additional showers potentially popping up ahead of this existing
line and reaching the terminals as early as around 01Z. It appears
that there will be some thunderstorms embedded in these showers as
well, however thunderstorm coverage and intensity are still not
entirely certain. While strong to severe thunderstorms are certainly
still possible, best guess is that these will be just some routine
gusty storms with one or two isolated stronger storms. A few rounds
of showers and storms appear possible, primarily between 02Z and 06Z
over Chicagoland. Isolated light showers could then continue into
the predawn hours of Wednesday morning. VFR conditions should
prevail through this event, although some guidance suggests that we
could see cigs drop into high-end MVFR territory for brief periods
underneath some of these showers.
Meanwhile, gusts near 20-25 kts will hang on through around sundown
before winds drop below 10 kts for the overnight. Winds will then
shift from SW to NNW overnight and hang there through the morning.
By early-mid afternoon, winds will turn east of north over ORD and
MDW and continue from an easterly direction at near or under 10 kts
through the remainder of the TAF period. Following tonight`s rain
event, VFR conditions can be expected for the entirety of
LM...Small Craft Advisory...nearshore waters until 9 PM Tuesday.
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Area Forecast Discussion
National Weather Service Lubbock TX
622 PM CDT Tue May 31 2022
Overall VFR conditions are expected to prevail through much of
tonight into mid morning. Some convection will be possible at CDS
and possibly PVW and could lower VIS and CIG to MVFR or IFR
temporarily. Storms will also be capable of producing very large
hail over 3 inches in diameter and wind gusts over 60 knots. MVFR
CIGs are expected to move over all terminals mid to late tomorrow
morning after a cold front pushes through the region.
.PREV DISCUSSION... /issued 220 PM CDT Tue May 31 2022/
18Z upper air analysis depicts a vertically stacked/occluding
cyclone over the southern Manitoba/Ontario border, with a trailing
mid-level cold front extending west-southwestward into the central
Great Plains and into the Great Basin as per 12Z 500 mb objective
maps and recent RAP analysis. A secondary cyclone, although less
amplified, was centered over the central Great Basin with a series
of smaller-scale shortwave perturbations detected on the latest
water vapory imagery that were rotating east-northeastward towards
the region. At the surface, a quasi-stationary front was anchored
from southwest-to-northeast across the CWA along a line from Denver
City to Tulia and extending towards the I-40 corridor as per recent
West Texas Mesonet data and the shallow cumulus field demarcating
its position. The dryline intersects the quasi-stationary front
across far southeastern New Mexico, and is not expected to propagate
eastward this afternoon as the airmass becomes increasingly
barotropic with southward extent from the front and as larger-scale
forcing for ascent remains displaced over the west-central Great
Plains region. West Texas Mesonet data and WSR-88D VWPs from KLBB
indicate that surface-to-low-level flow is parallel to the frontal
position across the moist sector, with winds shifting to the north
in wake of the front with speeds generally between 10-20 mph across
the post- and pre-frontal sectors with steady pressure tendencies.
This has resulted in weak convergence in vicinity of the stalled
front, evident by the shallow cu field despite the influx of strong,
The 12Z MAF RAOB sampled a very moist boundary-layer with dewpoints
in the upper 60s and a mean mixing ratio of 14.6 g/kg that was
advecting northward. South of the quasi-stationary front, a plume of
dewpoints ranging from the lower 60s across the Caprock and into the
middle-upper 60s in the Rolling Plains is present with temperatures
in the upper 80s to lower 90s, contributing to strong-extreme
thermal instability as MLCAPE nears 3,000 J/kg on the latest RAP
analysis. Confidence in this prognostication with respect to the
magnitude of MLCAPE across the moist sector is high based off the
observed morning sounding from WFO MAF. Effective bulk wind
differences (EBWDs) are modest as the CWA remains beneath the
glancing influence of the mid- and high-level jet streaks to the
north, with EBWDs near 40 kt in addition to the 850-500 mb wind
vectors remaining boundary-parallel. Isolated to widely-scattered
thunderstorms are forecast to form across the South Plains with mean
storm movement governed by advection, with storms quickly becoming
severe as the large, upward-directed accelerations accentuated by
wide updrafts offsets the modest shear. Significant/2"+ diameter
hail is expected to occur in addition to severe-caliber gusts as
cells move east-northeastward. Across the extreme southeastern Texas
Panhandle and into the northern Rolling Plains, scattered convection
is expected to develop mid-to-late afternoon as low-level
convergence maximizes while quickly becoming severe. Precipitable
water content is anomalously high, as per 12Z MAF RAOB and recent
GOES-East Total Blended Precipitable Water imagery. Initial storm
characteristics are expected to be multi- and supercellular, with
weak storm-relative flow throughout the LCL-EL layer which will
enhance precipitation-loading within the wide updrafts. Severe to
potentially significant-severe/65+ kt gusts are expected as
convection morphs into a Mesoscale Convective System (MCS) with
embedded mesocyclones. MCS movement will be slow, and dictated
largely by the combination of intense cold pools and the isolated to
widely-scattered cells to the southwest merging with it which will
augment the possibility of a forward-propagating MCS. A short-lived
tornado risk will accompany any storm merger or within any mesoscale
convective vortex that develops; however, the strong/cold downdrafts
and potential steeply-sloped outflow boundaries will eventually
undercut surface-based inflow parcel trajectories, ultimately
resulting in the demise of the MCS as theta-e advection weakens and
diabatic stabilization occurs. Severe convection should wane/exit
the northeastern zones altogether near 01/06Z.
The low-level jet will strengthen overnight with the stalled front
remaining positioned in vicinity of the TX PH and South/Rolling
Plains region, though the exact position of the front may be
affected by convective outflows from the decaying MCS. The airmass
is forecast to be in a similar state tomorrow ahead/south of the
front, with the center of the sub-tropical ridge retrograding over
Mexico along with a shortwave trough pivoting across the central
Great Plains, causing mid- and high-level flow to veer. The stalled
front will begin to transition into a cold front and move southward
across the CWA by the mid-afternoon hours, with scattered, severe
convection expected to develop with a few supercells possible across
the South Plains before cold pools merge as frontogenetical forcing
increases. Localized flash flooding will once again be possible, in
addition to the potential for severe-caliber hail (possibly 2"+) and
Precipitation chances will continue through the rest of the week
after Wednesday afternoon with additional heavy rain and severe
thunderstorm chances. The cold front will continue to push through
the rest of the area Wednesday evening with expected widespread
convection ongoing through the evening hours. The weather pattern
will look slightly different for the rest of the week after that.
Zonal flow will be overhead on Thursday with weak short wave ridging
moving over the area. Southeasterly low level upslope flow will
dominate the lower levels in the post frontal air mass. Furthermore,
a weak short wave moving through the flow with the above conditions
will promote higher terrain convection in eastern New Mexico.
However, convection may struggle to reach far into West Texas.
Better lift for convection will exist from the Permian Basin into
Far West Texas and the Big Bend as a stronger upper level jet streak
noses into that area. Additionally, instability will mostly be
elevated on Thursday with cool and cloudy conditions.
Severe chances may be better on Friday with upper flow slightly more
backed. Much better instability will be available with better low
level moisture and warmer surface temperatures. Additionally,
another weak short wave may be moving through the flow aloft
initiating thunderstorms again on the higher terrain of eastern New
Mexico. However, this convection would stand a better chance at
progressing farther across the South Plains for the aforementioned
reasons. CIPS analog guidance highlights Friday as a higher
probability day for severe weather over Thursday. A sloshing dryline
will return this weekend but convective chances are doubtful at the
moment with temperatures rising back well above seasonal averages.
Area Forecast Discussion
National Weather Service New York NY
1101 PM EDT Tue May 31 2022
A backdoor cold front stalls across western New Jersey tonight.
A wave of low pressure develops on the front Wednesday and moves
back across the region Wednesday into Wednesday night. The front
then stalls south of Long Island. A frontal wave along the
stalled front will then pass to our south and east Thursday
night into Friday. High pressure builds in thereafter through
the weekend. Unsettled weather could return to the area by
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A few showers have developed with a weak shortwave rounding the
ridge this evening. With decent DCAPE values, upwards of 1300
J/kg, a few stronger wind gusts are possible with any showers
that do form. Added a slight chance for thunder through 6z,
though this will be very limited. Widely scattered showers may
persist though through much of the night, based on CAMS, maintained
a slight chance for a shower region until 9z. Adjusted temps
and dews to align better with current obs given the challenges
of the backdoor cold front that continues to move inland, making
its way through KEWR in the past half hour. Temperatures have
been falling as much as 25 degrees with the passage of the front
along with wind gusts up to 30 mph. Continued with the timing
of the HRRR through tonight for the frontal passage. Rest of
forecast remains on track.
The backdoor cold front stalls to the west of the region, across
western New Jersey, late tonight. Otherwise an upper ridge
remains to the west of the region tonight. With the easterly
flow overnight stratus will likely develop.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
A much cooler airmass will be in place for Wednesday as the
stalled front to the west remains weak and moves eastward as a
weak surface low develops on the boundary. The upper ridge does
remain in place with a couple of weak shortwaves expected to
move into and over the ridge during the day Wednesday.
Initially the instability will be weak with little CAPE, and
increase during the afternoon. The highest instability will be
across the inland areas of northeastern New Jersey and the lower
Hudson Valley. A few strong to locally severe thunderstorms will
be possible, and the Storm Prediction Center has placed the area
in a marginal risk. Leaned toward the cooler MAV and MET
guidance for highs.
The chance of showers will be ending Wednesday night as the
weak frontal wave moves east by 12Z Thursday. Stratus likely
remains in place Wednesday night.
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Upper level ridge axis slides east of the area during the day
on Thursday as a shortwave rotating around a closed upper level
low approaches from the west. At the surface, a frontal wave
will develop along a stalled front off to our west and track
just south and east of the area. How much rain we see will
depend on the exact track of this wave. This will continue to
become more clear over the next 24 hours as the event enters the
high-res CAM window. However, given the environment, there is
potential for moderate to locally heavy downpours. The
environment will be characterized by pwat values around 1.70
inches. Based on SPC`s Sounding Climatology Page, this is
between the 90% moving average and the max moving average. There
will also be deep layered lift with approaching shortwave
energy, right rear quadrant of an upper level jet streak and
nose of a lower level jet. Right now the thinking is that the
best chance for heavy downpours is just south of the area where
the greatest instability looks to be in place.
High pressure builds in thereafter through the weekend
resulting in dry weather. Unsettled weather could return early
next week with a frontal system approaching from the west.
Thursday looks to be the warmest day of the long term period
with highs in the mid 70s to low 80s. Temperatures remain
slightly above seasonable through the rest of the period. The
NBM was mainly used for temperatures, with just minor
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
A backdoor cold front works west of the area tonight, while
high pressure builds in from New England. Another frontal system
approaches from the west on Wednesday and passes through the
area Wednesday night.
VFR to start with ceilings lowering to MVFR/IFR by daybreak.
Some improvement on Wednesday with most locations improving to
MVFR and possibly VFR, especially at the eastern terminals.
There is some uncertainty overnight as to how quickly we moisten
beneath a frontal inversion. This could occur later than
currently forecast and there is a chance that ceilings never get
down to IFR. Ceilings likely lower Wednesday evening with the
chance of SHRA and a few TSRA, best chance after 00Z.
Scattered showers with gusts up to 35 mph possible between 03Z
Winds become E around 10 kt across the remainder of the
terminals the next few hours. Brief gusts up to 25 kt possible
immediately behind the cold front. E winds 5-10 kt on Wednesday
veer to the SE.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
There is some uncertainty overnight as to how quickly we
moisten beneath a frontal inversion. This could occur later than
currently forecast and there is chance that ceilings never get
down to IFR.
Scattered showers with gusts up to 35 mph possible between 03Z
.OUTLOOK FOR 03Z THURSDAY THROUGH SUNDAY...
.Wednesday Night ...SHRA likely with a few TSRA the first half
of the night.
.Thursday...Becoming VFR. MVFR or lower SHRA/TSRA Thu eve/night.
.Friday...AM MVFR or lower with SHRA, improving to VFR in the
.Saturday and Sunday...VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
A backdoor cold front will continue to move westward this
evening. Wind gusts with the frontal passage will generally be
around 20 kt, with a few gusts approaching 25 kt. Otherwise
winds and seas remain below SCA levels tonight through Wednesday
With a relatively weak pressure gradient expected, winds and
waves likely remain below SCA criteria through the beginning of
Showers and embedded thunderstorm activity will likely move
through the region Wednesday and Wednesday evening with the
potential for brief heavy rainfall. There is a chance of poor
There is potential for moderate to locally heavy downpours
Thursday night into Friday. The likely threat is for minor urban
and poor drainage flooding.
A moderate rip current forecast is expected for Wednesday for
all ocean beaches as E winds veer to the SE. A low rip current
forecast is expected for Thursday.
Vulnerable record highs for Tuesday May 31 (See RERs for records
that were tied or set today.)
EWR: 96/1987 new record set at 98
BDR: *91/2013 new record set at 94
JFK: 92/1988 new record set at 94
ISP: 92/1987 new record set at 93
*ALSO OCCURRED IN PREVIOUS YEARS
Area Forecast Discussion
National Weather Service Spokane WA
355 PM PDT Tue May 31 2022
The beginning of June will welcome 70 degree temperatures across
the region with a few spots in the Columbia Basin getting into the
low 80s by Thursday. Mountain showers will be possible on
Wednesday, but most valley locations will be dry with increasing
high level clouds. A showery pattern will return Thursday, and
some thunderstorms late in the week into the weekend may be
capable of locally heavy rain.
Tonight through Wednesday night: Diurnally driven showers will
persist into the early evening over the east slopes of the
northern Cascades, Northeast Blue Mountains, and southern to
central Idaho Panhandle Mountains. Some of these cells are
expected to develop into thunderstorms. Storms this evening will
be slow moving with brief heavy rain being the main impact of
note. Issues with heavy rain really are only expected to be a
concern if thunderstorms develop over a recent burn scar. These
chances look low as thunderstorm coverage will be isolated in
nature, but not completely out of the question. The RAP model is
analyzing a weak vorticity maximum over the Northeast Blue
Mountains that may help to give cumulus development there a little
bit extra oomph into this evening. It`s quite possible that
models may be under doing shower chances around Lewiston,
Pullman/Moscow, and St. Maries do to this mesoscale feature that
isn`t as well resolved. Showers and thunderstorms will quickly
dissipate through the latter half of the evening as we lose our
diurnal heating with the setting sun. Much of the boundary layer
moisture that was trapped in the valleys of northeast Washington
into the Idaho Panhandle will have mixed out this afternoon and
will result in lower chances for redevelopment of fog compared to
earlier this morning.
Shortwave ridging of high pressure off of the eastern Pacific will
shift in over the region on Wednesday. Temperatures aloft will
increase with higher heights building in and have an overall
stabilizing effect on the atmosphere. Even so, models still
indicate enough shallow surface based CAPE for cumulus development
over the higher terrain for Wednesday afternoon. Modeled sounding
profiles indicate equilibrium levels up to about 16,000 to 18,000
ft MSL, which would be enough for shower development but less
likely for thunderstorms; although, a one-hit wonder can`t be
completely ruled out. Temperatures will warm around 5 degrees over
today with highs topping out in the 70s regionwide. These
temperatures may feel warm (if not quite pleasant) but running
right around what is expected for the first day of June.
A weak shortwave disturbance will run up the backside of the ridge
for through the course of Wednesday afternoon/evening. This will
bring increasing moisture. The atmosphere will take some time to
moisten from the top down with mostly higher level clouds
increasing on Wednesday. Better chances for precipitation will
come later on in the week. /SVH
Thursday and Friday: A large low pressure system sitting off the
coast in the eastern Pacific will move closer to the coastline and
send pieces of energy into the region. Precipitable water values
will increase to 120-180% of average. All ingredients are there
for shower and thunderstorm development in the afternoon;
moisture, instability and a kicker. We will see good upslope flow
into the Cascades in the morning for some light rain. Then by the
afternoon heavier and stronger showers and thunderstorms will
develop across much of Washington and the ID Panhandle. The main
concern for stronger storms on Thursday will be the Cascades and
then during the evening them moving off the Cascades and towards
the Okanogan Valley and Highlands. Locally heavy rain will be a
concern, and will be closely monitoring any burn scars that are of
concern. Friday region wide thunderstorms will also be a concern.
Precipitable water values remain high, but storms will be moving
slightly faster than previous days. As of now, flooding is not as
much of a concern.
Temperatures will cool a couple of degrees due to the cloud cover,
but the southwesterly flow will keep us in the 70s, with low 80s
possible for parts of the Columbia Basin and LC Valley Thursday.
Saturday and Sunday: The low will migrate north. We will continue
to see high precipitable water values and waves of energy moving
through. Think most areas will at least see some light rain, just
pinpointing when over the weekend that will occur is a bit more
tricky. Have increased chance of precip through the weekend, with
the highest probabilities Sunday. Temps will cool down to the mid
to upper 60s.
Monday onward: The precip water tap finally leaves the area and
widespread showers will come to an end. However showers Monday
cannot be ruled out, especially in the mountains. The Columbia
Basin will get shadowed out. Tuesday showers chances decrease
further, but still a slight chance in the mountains. Temperatures
will remain on the cool side. /Nisbet
00Z TAFS: A weak mesoscale disturbance over the Pullman/Moscow
Airport and Lewiston Airport will generate showers in the vicinity
through 04Z this evening. There may even be a few lightning
strikes with embedded thunderstorms, but this possibility carries
low confidence. Isolated showers and thunderstorms are expected
into the east slopes of the Cascades and over the Okanogan
Highlands as well. This convection may produce a brief shower near
at airports from Wenatchee, Chelan, Winthrop, and Omak.
Convection will dissipate through the evening. There will be
increasing high level clouds late tonight into Thursday with VFR
conditions and light winds prevailing. /SVH
.PRELIMINARY POINT TEMPS/POPS...
Spokane 49 74 54 75 54 72 / 0 10 10 40 40 60
Coeur d`Alene 45 73 52 74 53 70 / 10 10 10 40 40 60
Pullman 46 72 52 75 54 71 / 10 10 10 30 30 50
Lewiston 51 78 55 81 59 77 / 10 10 10 40 40 60
Colville 44 76 54 75 51 71 / 0 10 10 40 40 60
Sandpoint 44 71 52 70 51 68 / 0 10 10 30 20 60
Kellogg 48 71 51 72 54 68 / 10 20 10 40 30 60
Moses Lake 49 79 58 82 54 78 / 0 0 10 30 30 30
Wenatchee 54 77 57 77 57 75 / 0 10 20 60 50 40
Omak 48 78 56 77 54 74 / 10 10 20 50 50 60
Area Forecast Discussion
National Weather Service Mount Holly NJ
949 PM EDT Tue May 31 2022
A backdoor cold front will slide into our region from the northeast
tonight into Wednesday and lingers over the area through Thursday
becoming the focal point for several rounds of showers and
thunderstorms before a stronger cold front moves through the region
Thursday night. High pressure builds into our region Friday and
Saturday before gradually shifting to our east Sunday and Monday.
Another surface low may move towards the region from the Midwest
into the early part of next week.
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
Mid-level ridging was seen on water vapor this evening with a
potent closed mid and upper level low near the Canadian
maritimes. In association with the strong low near the Canadian
maritimes, a backdoor cold front is currently heading west
across Long Island, NY. After LGA reached 93 degrees Tuesday
afternoon, temperatures have fallen into the upper 60s behind
the front. Meanwhile, a weak wave is traversing the top of the
mid-level anti-cyclone with some showers forming near Watkins
Glen, NY. These multiple weak features has made for an extremely
difficult forecast this evening.
The overall idea, is for the weak showers and isolated
thunderstorms to slide southeast mainly across northern NJ and
northeastern PA. This also happens to be where the best
saturation is forecast ahead of the backdoor cold front. Severe
weather is not expected with this initial batch of showers and
an isolated rumbles of thunder. Across the eastern zones this
evening it appears that the surface cold front will indeed head
west and progress inland. The biggest question at this time is
how far west does the cold front make it. The NAM is by far the
strongest with the front, pushing it all the way to the Lehigh
Valley. The GFS pushes the front to about the I-95 corridor. The
high res is a mix of these solutions (the HRRR bringing the
front to the Lehigh Valley while the ARW pushes the front just
west of the I-95 corridor and the FV3 follows the GFS). The
answer looks like it will be a blend of the two pieces of
guidance. The latest runs of the NAM appears to be to bold with
the QPF overnight from the convection (up to around 0.75" of
QPF near DE and northern NJ). This likely is having the affect
of reinforcing the cold front slightly to far west. The current
thinking is to have the backdoor front make it to potentially
the Lehigh Valley early Wednesday morning only to retreat
Just west of the backdoor cold front, forecast soundings
quickly destabilize with around 1500 - 2000 J/kg of MLCAPE. As
this occurs, a mid-level wave will be approaching from the west
likely causing CI across central NY. The width of the warm
sector is modest Wednesday with the best shear being just north
and east of the CWA. Given that, there still exists 30/ 35 kts
of deep layer shear which is sufficient for some rotating
updrafts. Some clustering of storms to a few discrete cells will
be possible with damaging wind gusts being the primary threat,
and hail being a secondary threat. Confidence is high that
storms will form over central NY Wednesday afternoon and head
south and east. The main conditionality to the threat across NJ
and PA tomorrow will be the placement of the cold front. As
convection crosses over to the cool side of the boundary it will
likely slowly start to decay. The highest threat area for our
region Wednesday will be towards Carbon/ Monroe counties or
closer to the boundary and warm sector. High temperatures will
also be extremely variable Wednesday with mid to upper 60s
forecast near Sandy Hook, NJ and upper 80s forecast over the
Wednesday evening the convection will push southeast and slowly
weaken. Convection will then come to an end late Wednesday night
into early Thursday morning. Expect low temperatures mostly in
the mid 60s Wednesday night.
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
...Slight Risk of Severe Thunderstorms Wednesday evening and
again Thursday afternoon and evening...
Showers and storms look to move into into portions of our
eastern PA and NW NJ zones Wednesday evening as shortwave
energy ripples along the baroclinic zone over the area. At this
time a warm front should be over eastern PA oriented NW to SE
with a trailing cold front extending back over western PA into
Ohio. ML CAPE looks to be upwards of 1000-1500 j/kg over the
area with deep layer shear around 40 knots. For this reason, the
potential for severe weather exists with the highest threat
being over NE PA into far NW NJ. The greatest threat looks to be
damaging winds followed by large hail. The main threat should be
through the evening with storms moving out overnight.
For Thursday, the first portion of the day looks fairly quiet
ahead of the second shortwave trough as it works its way across
the Midwest into the Great Lakes. This second shortwave will be
the stronger of the two with a more pronounced negative tilt
with the parent closed 500 mb low over central Canada.
After any lingering rain departs in the morning Thursday, we should
see a little clearing in the late morning and early afternoon.
However, the greater the clearing, the greater chances for
widespread severe weather into Thursday evening. With stalled
frontal boundary remaining situated over the region, there will
likely be an appreciable temperature gradient once again with cooler
highs in the upper 70s for the northern half of the region and upper
80s to near 90 south of the front. The front will attempt to move
northward as a warm front ahead of the incoming shortwave trough and
attendant surface low. The greatest risk for severe thunderstorms
remains south of the front, which looks to be mostly south of the PA
Turnpike and AC Expressway (Philadelphia suburbs southward). The
Storm Prediction Center has a Slight Risk for Severe Weather south
of Philadelphia Thursday. With CAPE values forecast to be in the
1000 to 2000 J/kg range (perhaps upwards of 3000 J/kg MUCAPE in
areas that see enough sun to the south). The greatest threats look
to be hail and damaging wind with deep CAPE well above the freezing
level and some modest dry air aloft leading to forecast DCAPE values
from 500 to 1000 J/kg. LL shear looks to be supportive of at least
some supercells initially that will morph into a broken line or
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Rain will gradually come to an end Friday as the cold front moves
offshore and drier air filters into the region. The southeastern
extent of a Canadian upper-level trough swings across the Northeast
and northern Mid-Atlantic regions to start Friday. The mid-level
flow is forecast to become more zonal as the aforementioned Canadian
trough becomes more elongated. Weak high pressure should build in
later Friday and Saturday, although some clouds may be tossed our
way as additional shortwaves track across the Great Lakes region. By
Sunday, the high moves directly overhead. It is forecast to be less
humid with surface dew points into the 50s, and high temperatures
each day get into the mid to upper 70s Friday and the upper 70s and
low 80s Saturday and Sunday.
The forecast becomes a little less certain into early next week as a
shortwave and developing surface low move across the Midwest and
towards the Great Lakes. On the other hand, some of the guidance is
trying to hint at another surface low forming over the Atlantic off
the Carolina Coast, but should remain south of our region. How far
north this reaches by Tuesday and Wednesday remains highly
uncertain, but could end up blocking the incoming shortwave if it
ends up taking a northern trek near Bermuda as the EC has favored.
Highs Monday and Tuesday look to reach into the upper 70s and low
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Tonight...Mainly VFR. However, MVFR ceilings are forecast to
push into our region from the northeast and east late tonight.
The MVFR ceilings are expected to reach KTTN, KPNE, and KACY.
There is less confidence that the MVFR ceilings will reach KPHL,
KMIV, KILG, KABE and KRDG although the potential exists. West
to northwest wind 8 knots or less, becoming northeast to east.
Wednesday...IFR to start most likely north and east,
transitioning to VFR southwest. High uncertainty on extent of
IFR cigs in the morning. Most areas see cigs return to VFR in
the afternoon. The greatest chance for showers/thunder is late
in the day and at night. Winds will depend on the location of a
backdoor cold front. Low confidence.
Wednesday night... A return to VFR with lower cigs in any
showers and thunderstorms. Low confidence.
Thursday...MVFR and/or IFR conditions possible with several rounds
of showers and thunderstorms, especially from the Philly terminals
north then spreading south through the rest of the terminals through
the night. Winds mostly from the west in the early morning 5 to 10
knots then turning to the northwest through the day from 10 to 15
knots. Low confidence.
Friday...Sub-VFR conditions possible in the morning as rain and
thunderstorms move off to the east. VFR returning into the
afternoon. Northwest winds from 10 to 15 knots. Moderate confidence.
Saturday...VFR. Winds from west-northwest from 5 to 10 knots.
Saturday night...VFR. Winds from the north 5 knots or less. Moderate
A southwest to south wind of 10 to 15 knots late today is
forecast to shift to the northeast and east tonight with the
arrival of a cold front from the northeast. Waves on our ocean
waters will likely be 2 to 3 feet. They may build near 4 feet
late tonight on our ocean waters north of Barnegat Inlet. Waves
should remain at 2 feet or less on Delaware Bay. On Wednesday,
winds will remain mostly easterly at 5-10 knots with 2-4 foot
waves, highest on the ocean north of Barnegat Inlet.
Conditions are expected to be below Small Craft Advisory criteria,
though showers and thunderstorms Thursday and Thursday night could
lead to locally stronger wind gusts and wind shifts.
A south to southwest wind is forecast to increase to 10 to 15
MPH today. Breaking waves should be around 1 foot with a short
to medium period swell/wind wave varying from south to east.
There is a LOW risk for the development of rip currents today
along the coasts of Delaware and New Jersey.
A northeast wind around 10 MPH on Wednesday is expected to veer
to the east, then to the southeast. Breaking waves should range
from 1 to 2 feet with a short to medium period swell/wind wave
varying from south to northeast. We will keep the rip current
risk at LOW for Wednesday with the waves remaining rather tame.
However, the risk could approach moderate at times due to the
Area Forecast Discussion
National Weather Service Pocatello ID
144 PM MDT Tue May 31 2022
.SHORT TERM...Tonight through Wednesday night.
Expect lingering showers and isolated thunderstorms early this
evening ending by midnight with dry conditions the rest of
tonight. Low temperatures will be in the 30s and 40s. Expect dry
conditions Wednesday with high temperatures in the 60s to lower
70s. Only area with a chance of showers and thunderstorms will be
the Island Park area near the Montana border and Yellowstone.
Wednesday night will be dry across the board with lows in the 30d
mountains and 40s valleys.
.LONG TERM...Thursday through Tuesday.
Model cluster analysis shows very good agreement among members
through Saturday. A ridge of will bring mostly dry weather to the
area. An are of low pressure off the coast of Washington will try to
send some moisture through the ridge Friday and Saturday. This will
produce a slight chance for showers and thunderstorms over most of
southeast Idaho with better chances for scattered coverage across
the central mountains into the upper Snake highlands. Temperatures
look slightly above normal with the 25th-75th percentile NBM
supporting highs in the Snake Plain and Magic Valley in the 70s with
the 75th percentile supporting near or low 80s. Ensemble members
begin to lose cohesion on Sunday as the ridge slides east and a
shortwave trough moves into the area. The main differences involve
the strength of the trough. A stronger trough supports better rain
chances as a whole, but also better chances further south into the
southern highlands. This solution produces 0.50-0.75 inches for the
high country and up to 0.25 inches for the Snake Plain and Magic
Valley. A weaker trough indicates of little if any rain for the
southern highlands into the Magic Valley/Snake Plain and only up to
0.25 inches for the high country. Currently, the NBM 4.0 50th
percentile supporter the drier solution with less than a 25 percent
chance of the wet solution verifying. Once this system passes on
Monday, models differ greatly indicating a high degree of
uncertainty amongst ensemble members and low forecast confidence.
A few showers and thunderstorms are developing over the terrain and
may affect TAF sites for a few hours this afternoon and early this
evening. Most likely locations are SUN, DIJ, and possibly IDA/PIH.
Model consensus has skies clearing through the night with light
winds. HRRR is picking up on some patchy fog over the Snake Plain,
but confidence is low if it will affect any of the TAF sites.
.FIRE WEATHER...Cold upper low finally sags southeast of the
region through tonight. Will see lingering showers and
thunderstorms early tonight ending by midnight. Expect dry
conditions Wednesday with a solid warming trend. Showers and a few
thunderstorms may return to northern regions Thursday as the
ridge begins to breakdown ahead of the next system arriving by the
.HYDROLOGY...Ample rainfall and higher elevation snow from the
past few days is expected to bring some minor rises to East Idaho
waterways as temperatures warm through midweek. The main river of
concern remains the Big Wood near Hailey. Gage still indicates
river fluctuating through action stage, and expectations keep the
river at this range for the next several days. Flood Advisory
remains in effect while minor flooding/ponding remain a concern.
Area Forecast Discussion
National Weather Service Springfield MO
702 PM CDT Tue May 31 2022
...00Z Aviation Discussion Update...
1.Thunderstorms will occur at times from this evening through
early Thursday morning as a slow moving cold front moves into and
through the area. A few storms may be severe with the main risks
being large hail, damaging winds, and flooding especially this
evening and tonight along and northwest of I-44.
2. Cooler weather is expected Wednesday and Thursday with a
warming trend this weekend into early next week.
.SHORT TERM...(This evening through Wednesday)
Issued at 250 PM CDT Tue May 31 2022
Starting to see convection increase just a bit over west central
MO where abundant low level moisture and moderate to strong
instability are present along an old outflow boundary from
earlier convection. Dewpoints in the low 70s and uncapped mlcape
values 2000-3000 j/kg. HRRR has been okay guidance in showing a
gradual uptick in storm coverage this afternoon and early this
evening. Deep layer shear (0-6km bulk shear 30-40kts) over the
northwest cwfa will be supportive of supercells. In general low
level shear is weak in the vicinity of a diffuse sfc cold front
and that will limit the overall tornado risk, but initially some
weak backing of sfc winds might contribute to some uptick in low
level helicity. Large hail/damaging winds are the main risks with
stronger storms focus near the northwest border of the cwfa
through 10 pm.
Will see storms propagate southeast with time late this evening
and overnight with an outflow modified frontal boundary. Weakening
instability later in the night will start to limit the overall
severe storm risk, but strong winds will still be possible with a
reduced hail risk. Storms increasingly get undercut by outflow as
Based on latest guidance from WPC and some high res models, will
be adding some counties to the flood watch and will monitor short
term trends for additional hydro watches/warnings. watch will be
in effect until 10am.
Will continue to see some shower/storm potential Wednesday as a
shortwave moves into eastern KS/OK with storms possible in the
afternoon/evening. Again, some storm organization with deep layer
shear of 30-35kts could produce a wind/hail risk where stronger
instability can develop, which looks to be more favorable
along/south of I-44.
.LONG TERM...(Thursday through Tuesday)
Issued at 310 PM CDT Tue May 31 2022
Thursday-Friday: Front drops south of the area with weak sfc high
moving into the region. Could see some shallow dense fog late
Thursday night but it shouldn`t last too long this time of year.
Lows around 50 deg F will be possible, and maybe some upper 40s in
low lying areas.
Saturday: Sfc high shifts off to the east. NBM is somewhat bullish
on rain chances late in the day (mostly due to the GFS ensemble
members). Guidance does move the first of a series of shortwaves
into the area, and will see some uptick in shower/storm chances,
late in the day and Saturday night. Low confidence on the timing
at this point.
Sunday-Tuesday: A fairly active zonal flow pattern looks to exist
from the central Rockies to the Mid MS Vly late Sunday
night/Monday is the next time period pinged by the NBM for a round
of convection but some differences exist, mainly in the timing
(more a question of when, not if). An additional wave looks
possible Monday night-Tuesday. Blended guidance will tend to
spread out rain chances in this type of zonal/fast flow aloft
regime, but it does look like at least a couple of waves will
move through during this period.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 702 PM CDT Tue May 31 2022
VFR ceilings will continue at the TAF sites through much of the
evening, with SGF/JLN seeing mid-level stratocumulus. A cold
front still located over eastern Kansas will slowly move into the
area later this evening and tonight, with increasing thunderstorm
chances as the front moves in. Highest thunderstorm chances will
be between 05-12Z at JLN, 09-14Z at SGF, and 12-15Z at BBG. May
see some stronger wind gusts with the storms at times, but exact
timing of the strongest winds is still difficult right now.
Expect a lull in thunderstorm activity most of tomorrow morning
into early afternoon before additional thunderstorms develop
during the mid afternoon.
Winds will veer to the northwest behind the cold front as it
slowly moves through the TAF sites during the later portion of the
TAF period tomorrow.
MO...Flood Watch through Wednesday morning for MOZ055>058-066>071-
KS...Flood Watch through Wednesday morning for KSZ073-097-101.