Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/22/22
Area Forecast Discussion
National Weather Service Burlington VT
1034 PM EDT Sat May 21 2022
Warm and muggy conditions will exist tonight and into Sunday before
a cold front sweeps through Sunday afternoon accompanied by a line
of showers and thunderstorms, some of which have the potential
to be strong to severe. Cooler and less humid conditions are
expected for Monday and Tuesday, followed by daily chances for
showers through the end of the work week.
.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 1034 PM EDT Saturday...Warming cloud tops associated with
convection across western New York will continue to lift
northeast tonight and we should see some showers and isolated
storms overnight, especially across northern New York and
northwest Vermont. Made some minor adjustments to the forecast
to account for this scenario. Rest of forecast remains
It`s taken all day but the cap has finally broken across the
entire region with RAP analyzed 3000-4000 J/kg of CAPE. While
we`re not lacking in instability, we are lacking in any deep
layer shear and a clear forcing mechanism. Upstream though,
storms have begun to fire along a lake breeze off Lake Ontario
and with the mid/upper level flow southwesterly we will see some
of this activity shift into the forecast area this afternoon
and evening before diminishing after sunset. With impressive
progged DCAPE values up to 1400 J/kg the main convective threat
will be damaging winds especially given reports from a
convective complex moving through the Ottawa Valley which
produced gusts up to 70 mph. Can`t rule out some large hail
either or some rotating supercells as storm relative helicity of
100- 150 m2/s2 should exist.
After sunset activity should quickly quiet down with a generally
quiet but muggy and warm night on tap. Residual showers from
upstream convection may shift briefly across portions of the St.
Lawrence Valley around midnight with some light shower, but
elsewhere should trend mainly dry with lows only in the mid 60s to
We`ll be looking for a repeat of severe potential again tomorrow as
a potent cold front will work through the region. Given the
overnight moisture in place it won`t take much to generate SBCAPEs
upwards of 2000 J/kg ahead of the boundary mainly from the
Adirondacks eastward, and with better deep layer shear in the
vicinity we expect more widespread showers and thunderstorms to
develop from noon onward. Once again, the primary threat would be
damaging winds and large hail, and while brief heavy rainfall will
be possible storm motions of 30-40kts should preclude any flash
After sunset, the convective show should quickly come to an end with
the loss of surface heating/instability with showers lingering
through midnight before the aforementioned cold front sweeps through
ad high pressure builds in behind in. After 2 warm and muggy nights,
Sunday night will be nice a cool with lows ranging from the mid 40s
to mid 50s.
.SHORT TERM /MONDAY/...
As of 346 PM EDT Saturday...A cool forecast for Monday. Following the
strong frontal boundary to pass through Sunday, our temperatures
will be below normal, with a steady north wind. Highs range in the
60s across the North Country.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
As of 1029 PM EDT Saturday...
Overnight Monday night there will be light winds, clear skies,
and a surface 1030mb high pressure should promote efficient
radiational cooling. Lows fall into the 40s in the valleys, with
mid to upper 30s across the Northeast Kingdom and Adirondacks,
which are approaching their median frost date, and frost
advisories may be needed.
Conditions will then remain dry through Wednesday evening as
strong deep layer ridging keeps moisture well to our west. A
surface low is expected to develop as an upper trough moves east
of the Rockies and tracks towards the Great Lakes. By Wednesday
night, that system`s warm front will lift northwards with rain
propagating east parallel to the front as moisture ridges the
crest of the upper ridge. The center of a 500 hPa high will
shift northwards and intensify a bit, which may push the bulk of
that precipitation north of the area, which is in line with the
GFS. A weaker 500 hPa high would bring moderate, perhaps heavy,
rain across our area, as the ECMWF depicts. Given it`s about 5
days out, will remain close to blended data, but probabilistic
guidance hints a bit more centered over our area. A negatively
tilted shortwave follows right on the heels of that system, with
a surface low developing along the frontal boundary of the
system ahead of it that then ejects northeastwards. This sends
another wave of high theta-E air Thursday night into Friday
morning, but precipitation seems scattered in nature at this
time. This leaves plenty of clouds lying around Friday
afternoon, but development of a modest cold front should provide
a focus for convection and additional chances for moderate to
Beyond Friday, trends in the data support a return to drier
weather and temperatures right around seasonal normals.
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...Threat for strong to severe storms has come
to an end this evening. There are some showers and isolated
storms moving northeast into far western New York this evening.
This activity may move into the area producing showers that
could result in brief MVFR ceilings and visibilities between 03z
and 12z. VFR conditions will exist between 12z and 18z and then
the potential for showers and thunderstorms will increase as a
cold front moves across northern New York. After 18z strong to
severe storms will be possible from the northern Adirondacks
eastward across Vermont with hail, strong winds, lightning, and
heavy downpours with any of these storms. This will likely
create IFR and LIFR conditions for brief periods. Winds will be
10 knots or less, but then pick up out of the south and
southwest with gusts to 20 knots after 18z.
Sunday Night: VFR. Chance SHRA.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. Chance SHRA.
Wednesday Night: Mainly VFR, with local MVFR possible. Chance
Thursday: Mainly MVFR, with local VFR possible. Likely SHRA.
Near record highs are possible today, May 21 and Sunday, May 22
as we are anticipating temperatures to reach well into the
upper 80s and lower 90s. Here are the current daily record
Date KBTV KMPV K1V4 KMSS KPBG KSLK
05-21 92|1911 89|2021 89|2021 89|1975 92|1975 94|1911
05-22 93|1977 90|1994 84|9999 89|1977 92|1977 91|1911
Area Forecast Discussion
National Weather Service Cleveland OH
1015 PM EDT Sat May 21 2022
A cold front moves west to east across the region tonight. High
pressure builds eastward across the Great Lakes region tomorrow
night through Tuesday. A warm front extending from low pressure
over the mid-Mississippi Valley will move northward across the
.NEAR TERM /THROUGH SUNDAY NIGHT/...
Low pressure over NW OH still needs to move eastward near the
south shore of the lake through the overnight hours. As this low
moves eastward it will pull a cold front with it. Still enough
upper level jet energy to provide some lift along the front but
the region has little in the way of instability remaining.
However we do think there is enough moisture and lift to at
least generate some isolated/scattered showers, maybe a few
thunderstorms after midnight, then continuing through Sunday
morning. Best chances through sunrise look to be west of I-71.
As we heat things up ahead of the cold front on Sunday there
could be a few thunderstorms along the cold front as it moves
into western PA.
The environment is primed for severe thunderstorms this
afternoon, with RAP mesoanalysis suggesting SBCAPE as high as
4000 J/kg, with projections building it up to 4500 J/kg.
Combined with effective bulk shear 30-40 kts and we have a
favorable environment for severe convection. Damaging wind gusts
are likely to be the prime culprit this afternoon and evening
with max theta-e difference of up to 30 C, DCAPE up to 1200 J/kg
and low level lapse rates of 7-8 C/km all contributing to a
favorable environment for damaging winds. However, large hail
will also be possible with moderate mid-level lapse rates of
6.5-7 and hail growth zone (-10 to -30 C) CAPE of up to 1000
J/kg. While not especially favorable, an isolated tornado can
not be ruled out with modest 0-1 km shear of around 10-15 kts,
effective SRH around 50, and LCL heights around 1000m. Flash
flooding is also pose a risk with a very moist environment in
place, especially if convection initiates off a WSW-ENE
The cold front finally pushes east of the area tomorrow
morning and precipitation will gradually taper off during the
morning and early afternoon Sunday from west to east. Cooler
air will spread into the area tonight with considerably colder
temperatures compared to this morning`s lows. Also, notably
cooler temperatures expected for Sunday. As we remain in the
warm sector today, temperatures will take a stab at hitting the
90 degree mark. However, with advancing clouds, temperatures
should hold below the 90 degree level across much of the area.
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
High pressure over the Great Lakes will foster dry weather through
the majority of the short term period. However, lingering cold air
advection will provide below normal temperatures Monday, with highs
in the low to mid 60s anticipated. By Tuesday, a building ridge
across the southeastern US will allow temps to increase and highs
will recover to the low to mid 70s. Overnight lows will be in the
40s to low 50s each night.
Pops begin to increase Tuesday night as low pressure developing over
the Mississippi Valley lifts a warm front northeast towards the
local area. The best chance of scattered showers will be confined to
the western half of the forecast area.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
An unsettled weather pattern is expected mid to late week as a
deepening upper-level trough and surface low inch eastward across
the region and several shortwaves move across the local area. This
will result in several waves of precipitation, including potential
for thunderstorms during peak heating hours. As of now, the highest
pops are Wednesday and Thursday, with slightly lower chances heading
towards the end of the week due to divergence in model guidance. A
cold front will likely move across the area Friday, allowing pops to
decrease Friday night into Saturday. However, scattered showers may
persist through the first half of the weekend as a reinforcing cold
front moves across the lower Great Lakes.
Wednesday and Thursday will most likely be the warmest days of the
week with highs in the mid to upper 70s. Temps will be slightly
cooler in the upper 60s Friday and upper 60s to low 70s Saturday.
Overnight lows will be in the upper 50s to low 60s Wednesday and
Thursday night and expect cooler lows in the low 50s Friday night.
.AVIATION /00Z Sunday THROUGH Thursday/...
Strongest thunderstorms moving across western PA. MVFR/IFR
conditions with the strongest convection. Gusts may reach 45
knots. Otherwise light rain continues in the wake of the
stronger convection. Low pressure tracks near the south shore
of Lake Erie through 06Z eventually pulling the cold front
eastward across northern OH into NW PA in the morning. may be
some MVFR ceilings in the wake of the front into Sunday
Winds variable with the convective outflows and the area of low
pressure moving eastward near the south shore of the lake. Winds
eventually shift to the west and northwest in the wake of the
cold front. Winds may reach 10 to 15 knots for a few hours with
gusts around 20 knots. Winds decrease through the afternoon.
Outlook...Non-VFR possible Tuesday night through Thursday with
showers and afternoon thunderstorms.
Thunderstorms will impact the lake this afternoon into early this
evening and any thunderstorms that move over the lake may produce
hail and strong winds. Outside of thunderstorms, expect variable
winds 6 to 12 knots this afternoon before becoming southwesterly
this evening. Winds shift to the northwest and increase to 15 to 20
knots Sunday morning and a short-fused Small Craft Advisory may be
needed before winds and waves decrease Sunday afternoon. Onshore
flow continues through the first half of next week and although
winds will remain below 20 knots, persistent onshore flow may keep
waves elevated in nearshore zones. Will continue to monitor wind and
wave forecast trends for any Small Craft Advisory conditions through
Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
902 PM MDT Sat May 21 2022
...UPDATE FOR WIND ADVISORY...
Models are trending stronger with the winds expected behind the
cold front tonight. Forecast soundings from multiple models show
mountain level winds of 30-35 knots across Southern Dona Ana and
Otero Counties and our Texas zones. The NAM NEST and HRRR
wind/wind gust parameters are showing 30G45kt for the usual windy
spots in these areas. Winds will pick up west to east with the
front passage, so the strongest winds are likely to occur between
3AM and 7AM for El Paso before diminishing.
.PREV DISCUSSION...535 PM MDT Sat May 21 2022...
...00Z AVIATION UPDATE...
.AVIATION...Skies are expected to remain mainly SKC through the period. Winds
will continue from the west and west-southwest before diminishing
some after sunset. A cold front will begin to affect the region
between 6z and 9z, which will abruptly shift winds from the east
and southeast of 10 to 15 knots with gusts of 20 to 25 knots.
Smoke has remained north of TCS, but drainage flow may allow smoke
to move into/over TCS between sunset and the front`s arrival. Left
mention of smoke in TAFs, but occurrence is uncertain.
.PREV DISCUSSION...246 PM MDT Sat May 21 2022...
A cold front will bring cooler weather on Sunday along with a
slight chance of thunderstorms for Hudspeth County into Monday.
Continued dry and warm weather is expected Monday into next week.
Breezy west winds early this week, then again next weekend.
.SHORT TERM...Tonight into Sunday...
Aloft, west flow will remain along with the approach of a subtle
system into Sunday afternoon. The story will be a frontal boundary
approaching from the east tonight, however.
Frontal boundary will move into the Borderland this evening and
tonight, across the far east after sunset, then the RGV around
Midnight, and farther west by the morning hours. Easterly winds
will be gusty (values up to 40 mph possible) across west slopes of
terrain (Huecos and Franklins especially), and breezy across most
other locations within the vicinity of the International Border.
Winds will be northeast and a bit breezy at T-or-C for a few hrs
Sunday morning as the front drains from the north. Overnight low
temps will be about 5, maybe locally up to 10 degrees cooler than
they were Saturday morning for the Rio Grande on eastward. Values
will be mainly in the 50s.
Stiff southeast winds are expected to continue on Sunday, with
more south to southwest in the vicinity of the Continental Divide.
As a result, in addition to scattered cloud cover, temps will be
pleasant, with values in the low to mid 80s across the lowlands
and 60s in the highest elevations. No precipitation is expected
during the period. However, by Sunday evening, dewpoint temps will
be in the mid 40s with increasing instability and an approaching
little perturbation aloft. See details below in the long term
Decent moisture leftover behind Sunday`s cold front will allow
for some of our region`s first rain chances in quite some time
Sunday night into Monday morning, with the best moisture and near
neutral stability indices existing east of the Rio Grande.
Scattered showers and thunderstorms will be possible over Hudspeth
County and the far eastern fringes of the CWA, generally east of
the US-54 corridor. Rain chances still don`t look good for El Paso
or Las Cruces as moisture is quickly pushed back eastward and out
of the area by midday Monday. A few additional showers will be
possible over the Sacramento Mountains Monday evening, with no
significant precipitation (spatially or quantitatively) expected.
Northwest flow aloft on the front end of a Pacific high will
drive a continued breezy, dry, and mild weather pattern through
Tuesday. Temperatures will quickly return back to seasonal normals
Monday/Tuesday as moisture is scoured out under breezy west
winds. Afternoon wind speeds look breezy (15 to 20 mph) but
nothing we haven`t already seen consistently this spring.
Disturbance aloft crosses the Southern Rockies to our north again
Wednesday morning, inducing a surface high along the western
Plains and thus another cold front down the TX panhandle and
eastern NM. Ensemble solutions disagree on the western extend of
this boundary, with consensus generally seeping into the Rio
Grande valley by Thursday morning. The disruption of lee low
formation will allow winds to be much lighter these days, but no
major adjustment to the current weather pattern is expected with
this weak intrusion. Precipitation chances will continue to be
slim to none and Wednesday`s temperatures will remain near normal
for late May.
High pressure aloft will progress over northern Mexico by
Thursday, suggesting a warming trend which is confirmed by latest
MOS guidance. Lowland highs will quickly return to the upper
90`s/near 100 Thursday into next weekend along with the return of
breezy westerlies Friday/Saturday. Fairly significant diversions
in ensemble solutions 7 days out, with several GFS members
suggesting high pressure directly overhead and the deterministic
ECMWF moving a strong trough across the Western U.S. at the same
time. Leaned this forecast toward the more seasonal GFS solution
with dry, warm weather prevailing into June.
A cold front will move into the region tonight, with an east to
southeast wind shift along with increased moisture. As a result,
overnight recoveries will be much more friendly east of the Rio
Grande (50 to 80%). On Sunday, southeast winds will remain most
areas, the exception being in the vicinity of the Continental
Divide where south to southwest winds will prevail. Much cooler
temperatures are expected east of the Continental Divide, with
values 5 to 15 degrees below average, in addition to richer
moisture. Consequently, min RH will be in the 20 to 30% across
Fire Zones 055, 056, and 113. A few showers and thunderstorms will
be possible east of the Rio Grande as well Sunday night into
Monday, mainly across Hudspeth county.
By early next week, energy across the Rockies will produce breezy
winds across the Borderland Monday and Tuesday, values 15 to 25
mph, with critical humidity most locations. The potential exists
for local Red Flag conditions with near normal temperatures both
days. By the end of the week, a ridge of high pressure will move
overhead with warming temperatures and potentially mild breezes.
Expect a mix of Poor to Fair ventilation east and Good to
Excellent out west on Sunday, then excellent early next week.
.PRELIMINARY POINT TEMPS/POPS...
El Paso 56 82 61 92 / 0 0 20 0
Sierra Blanca 51 75 57 83 / 0 0 40 20
Las Cruces 54 83 56 91 / 0 0 0 0
Alamogordo 51 83 55 88 / 0 0 10 0
Cloudcroft 35 63 43 65 / 0 0 20 20
Truth or Consequences 54 82 58 89 / 0 0 0 0
Silver City 53 79 54 80 / 0 0 0 0
Deming 50 84 52 90 / 0 0 0 0
Lordsburg 53 88 52 88 / 0 0 0 0
West El Paso Metro 56 82 61 91 / 0 0 10 0
Dell City 50 75 52 88 / 0 0 30 20
Fort Hancock 53 83 58 91 / 0 0 30 20
Loma Linda 51 75 55 83 / 0 0 20 0
Fabens 54 83 60 92 / 0 0 20 0
Santa Teresa 54 81 56 89 / 0 0 10 0
White Sands HQ 56 80 61 89 / 0 0 10 0
Jornada Range 48 81 55 88 / 0 0 0 0
Hatch 50 84 55 90 / 0 0 0 0
Columbus 56 85 56 91 / 0 0 0 0
Orogrande 50 79 57 89 / 0 0 10 0
Mayhill 36 70 45 78 / 0 0 20 20
Mescalero 37 73 45 75 / 0 0 20 20
Timberon 41 69 47 74 / 0 0 20 20
Winston 39 80 45 84 / 0 0 0 0
Hillsboro 51 81 54 86 / 0 0 0 0
Spaceport 48 82 54 88 / 0 0 0 0
Lake Roberts 45 79 46 82 / 0 0 0 0
Hurley 47 82 48 85 / 0 0 0 0
Cliff 44 88 40 90 / 0 0 0 0
Mule Creek 38 82 50 83 / 0 0 0 0
Faywood 51 80 51 84 / 0 0 0 0
Animas 51 88 50 89 / 0 0 0 0
Hachita 51 85 51 88 / 0 0 0 0
Antelope Wells 51 87 53 88 / 0 0 0 0
Cloverdale 52 83 53 83 / 0 0 0 0
NM...Wind Advisory from midnight tonight to 8 AM MDT Sunday for
TX...Wind Advisory from midnight tonight to 8 AM MDT Sunday for
Area Forecast Discussion
National Weather Service Houston/Galveston TX
636 PM CDT Sat May 21 2022
MVFR ceilings are spreading inland early this evening, and expect this
trend to continue as the evening progresses. Eyes then turn to the central
TX area SHRA/TSRA complex that has developed along the cold front. Have
the front and its convection moving into SE TX later this evening and
on through the overnight hours. Very different timing/strength/coverage
scenarios are being displayed by the most recent models, so confidence
on how this will all unfold remains low at this time. It is possible
that convection could accelerate overnight as it moves through our
area resulting in a shorter time period of TSRA risk. Timing differences
could also mess with when MVFR and possible IFR ceilings develop behind
the front and how long they persist along with where/when any development
happens on Sunday. We`ll see how this all evolves and unfolds.
Periods of SHRA/TSRA similar to tonight`s event can be expected into
the middle of the upcoming week.
.PREV DISCUSSION... /ISSUED 338 PM CDT Sat May 21 2022/
SHORT TERM [Through Sunday Night]...
Beginning to see some convective initiation to our nw in advance
of a frontal boundary. Expect shra/tstm coverage to fill in along
the front as it approaches northern parts of the CWA in the late
evening hours and eventually toward the coast around sunrise. Not
much in the way of shear, but there will be a threat of some
isolated severe storms with wind/hail the primary threat. At this
time, locations generally north of a Brenham-Trinity line will
see the better chances for any severe wx. Further south, capping
should mostly hold into the evening, then we`ll lose daytime
heating and some instability...so would anticipate that overall
intensity should begin to wane.
That said, things could eventually be run on the mesoscale. For
example, a cold pool developing behind the precip slightly
speeding the boundary up, etc, etc. Several of the 12z HREF
members showed something like this being a possibility later
tonight...with a cold pool/meso-high developing across extreme
east Tx and northern La and a healthy line of precip trekking
southward along the Sabine then eventually southwest toward the
metro area and upper Tx coastal waters in the 2-8am timeframe.
Latest HRRR runs have trended a bit different. Tx Tech WRF, on the
other hand, has been consistent showing little in the way of
meaningful precip across southern parts of the region until maybe
Sunday afternoon where the front stalls near the coast. So...a lot
of writing to say that overall fcst confidence in regards to how
things exactly evolve late tonight isn`t exactly very high.
With a lack of upper support for a continued swd push, expect the
front/wind shift to eventually stall somewhere near the coast.
Coastal areas might just see winds back to a e/ne direction in
association with some weak coastal troughing. Regardless of the
finer details, we`ll welcome the increased cloud cover Sunday,
chances of scattered precip, and a lower daytime temps.
Surface high pressure slides off to the east and the front/boundary
should begin lifting back north late Sunday night & Monday.
Deeper plume of moisture will follow so rain chances continue into
next week... 47
LONG TERM [Monday Through Saturday]...
An active weather pattern is expected to continue through mid week.
First, the weekend cold front that is to stall over the Gulf coastal
waters will move northward, back inland as a warm front during the
day Monday while a few weak shortwaves rounding the base of an upper
level trough situated over the Great and Southern Plains, move
overhead. Though there is a slight chance some capping may be
present on Monday, it does not seem strong enough to be able to
suppress our chances of rain at the moment, especially along the
northern and western sectors of Southeast TX where the greatest
instability and moisture lies. Tuesday into Wednesday, a series of
stronger upper level shortwaves will move over TX as the upper level
trough progresses eastward over Central/North Central CONUS. A cold
front will make its way into Southeast TX sometime Wednesday
afternoon/evening. Persistent onshore flow will give us plenty of
moisture to play with (PWs of 1.5 to 1.9 inches) and with sufficient
instability in place, showers and thunderstorms are most likely going
to develop ahead and along the front. The front is expected to move
into the Gulf waters Wednesday night, bringing northerly winds and
slightly cooler/drier airmass across the region. High pressure will
build across Southeast TX on Thursday, inhibiting rain chances and
resulting in light variable winds through Friday morning. Winds will
turn southeasterly Friday night into Saturday and gradually increase
low level moisture.
As for temperatures, Monday`s highs will be mostly in the mid to
upper 80s and cool down into the low to mid 80s on Tuesday. The
highs on Wednesday are forecast to increase back into the upper 80s
(mainly along the central and southern portions) but will ultimately
depend on the timing of the front. If it arrives sooner than what is
currently forecasted, then those locations will experience highs
closer to the low to mid 80s. With the intrusion on drier/cooler air
in the wake of the front, highs on Thursday will likely be in the
low to mid 80s (slightly higher along the southern counties and
coasts) and the lows will drop into the low to mid 60s Thursday
night. Expect a gradual warming trend thereafter, as onshore flow
Small Craft Advisory has been extended through 5 PM this afternoon
across Coastal waters from Freeport to Matagorda Ship Channel TX out
20 NM and Waters from Freeport to Matagorda Ship Channel TX from 20
to 60 NM due to elevated seas. Conditions will improve this evening
into the overnight hours, however, hi-res models are indicating
another round of strong showers and thunderstorms just ahead and
along a cold front Sunday morning. These storms may be accompanied
by strong gusty winds with speeds up to gale force possible and
could result in higher seas as well. The front is expected to stall
along the coastal Gulf waters Sunday, continuing the chance for
showers and thunderstorms throughout the day. Expect east northeast
winds Sunday. Light to moderate onshore flow will return Monday as
the front moves back inland. A series of upper level disturbances
will move overhead through mid week, resulting in periods of showers
and thunderstorms across the bays and Gulf waters. The next cold
front is progged to move into the coastal waters sometime late
Wednesday night or Thursday morning. Expect north northeasterly
winds in the wake of the front.
For the beachgoers, high risk of strong rip currents will continue
throughout the weekend for the Gulf facing beaches. It is recommended
to practice beach safety and swim near a lifeguard.
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 65 82 69 85 71 / 70 50 10 50 60
Houston (IAH) 73 85 72 86 73 / 70 60 30 40 50
Galveston (GLS) 78 86 78 87 79 / 60 70 30 30 40
TX...High Rip Current Risk through Sunday evening for the following
zones: Bolivar Peninsula...Brazoria Islands...Galveston
Area Forecast Discussion
National Weather Service Huntsville AL
845 PM CDT Sat May 21 2022
...New NEAR TERM...
Issued at 844 PM CDT Sat May 21 2022
Isolated to scattered showers/storms currently across the
Tennessee Valley this evening. These showers/storms developed
earlier this afternoon in the hot, humid, and unstable atmosphere.
These showers/storms were initiated along outflow and
differential heating boundaries. With the large instability in
place, a few of these storms became marginally severe earlier this
evening. These storms are having a more difficult time developing
over the last hour or so with the loss of daytime heating and
expect this will continue to be the trend over the next couple of
The focus then shifts to the MCS approaching from the northwest.
This line of showers/storms has developed ahead of an approaching
cold front. Portions of the line are currently warned as it
approaches Memphis, TN. The last few scans indicate a shift
southward in the motion of the MCS. The MCS looks to try to stay
in the area of higher instability. Still not certain how intense
the MCS will be as it moves into NW AL. So far, not seeing much
warming at all in the cloud tops. However, the latest HRRR has the
activity falling apart as soon as it enter NW AL. Would expect a
weakening trend with the loss of daytime heating but so far things
are holding somewhat steady state. For now, have the line
entering NW AL around 05z and fading quickly as it moves across
.SHORT TERM...(Sunday through Tuesday night)
Issued at 242 PM CDT Sat May 21 2022
Present indications are that the decaying MCS discussed in the near
term section will continue to translate southeastward between 12-18Z
Sunday, with abundant cloud cover and lingering light rain in the
wake of this system expected to limit instability. Nonetheless,
virtually all model guidance suggests that widespread convection will
redevelop once again by early afternoon, as a slow-moving cold front
drops southeastward into the region. There is still a good deal of
uncertainty regarding how far south the cold front will penetrate
into the region, but our best guess is that is will remain nearly
stationary and bisect the forecast area from Sunday night through
Monday morning. It still appears as if a stronger mid-level
disturbance in the southern stream will begin to lift northeastward
from the southern LA vicinity on Sunday evening, providing weak but
sufficient synoptic scale ascent for the development of widespread
showers and thunderstorms on both sides of the front. Weak shear and
only meager instability suggest that the main impact from this
activity will be locally heavy rainfall, especially as convection to
the north of the boundary will be slightly elevated.
Although the location and orientation of the front will likely not
change, this precipitation regime should spread slowly eastward on
Monday afternoon/evening as the mid-level wave lifts northeastward
and away from the region. The stalled boundary will begin to return
northward as a warm front on Tuesday morning, as an amplifying
shortwave trough digs east-southeastward across the central Rockies
and adjacent High Plains. This will place the local area within the
warm/moist sector of the trough`s developing surface cyclone, with an
increasing coverage of showers and thunderstorms expected both
periods. Highs through the short term will be in the u70s-l80s, with
lows in the l-m 60s.
.LONG TERM...(Wednesday through Friday)
Issued at 242 PM CDT Sat May 21 2022
The central High Plains shortwave trough discussed above will
continue to deepen as it tracks eastward across the Great Plains
during the mid-week period, perhaps evolving into a partially closed
low as it reaches eastern MO/western IL by 00Z Friday. Given the
dynamic nature of this system, flow throughout the lower troposphere
will strengthen considerably to levels more typical of an early
Spring system rather than one in late May. With this in mind, deep-
layer shear will quickly become favorable for organized/severe
convection during the day on Wednesday, when several clusters of
thunderstorms will begin to spread northeastward in rapidly
strengthening warm advection ahead of this system. This regime will
persist on Wednesday night and Thursday, and with the low-level jet
expected to reach the 40-50 knot range atop a very moist boundary
layer with dewpoints in the m-u 60s, all severe hazards including
tornadoes will be possible. At this point, it appears as if some form
of a QLCS preceding the cyclone`s cold front will end both the risk
for severe weather and thunderstorms as it crosses the region
Thursday afternoon. A drier and cooler airmass will spread into the
region in the wake of this system for the end of the work week.
Issued at 631 PM CDT Sat May 21 2022
VFR conditions currently across the terminals. There are a few
isolated storms across the area this afternoon/evening but they
are outside of the 10 mile radius of the airports. For now, think
they will stay far enough away from the airports to not include
VCTS over the next couple of hours. Will monitor radar trends and
make amendments as necessary. Another area of showers/storms will
approach from the northwest later this evening around 04z. These
showers/storms should be weakening as they move through but did
include VCTS at both terminals overnight. This precipitation will
come to an end after midnight. However, another round of
showers/storms is forecast after 15z. Additionally, MVFR ceilings
are forecast late in the TAF cycle.
Area Forecast Discussion
National Weather Service Indianapolis IN
1159 PM EDT Sat May 21 2022
...Updated Aviation Discussion...
Issued at 1037 PM EDT Sat May 21 2022
Severe weather has come to an end over the area. With the low
currently passing overhead, light precipitation and a few rumbles of
thunder are making its way across central Indiana. Behind this rain,
cooler air will settle in with Sunday morning lows expected in the
50s. The rain should end and exit off to the east by sunrise.
Updated the forecast to match current conditions, including upping
PoPs over the SW portion of the area where there is a swath of more
widespread rain. Across the southern edge of the forecast area is
where lightning will be most likely, but should remain sporadic
.Short Term...(This evening through Sunday night)
Issued at 305 PM EDT Sat May 21 2022
- Showers and Thunderstorms this afternoon and tonight.
- Dry weather returns Sunday and Sunday Night
Surface analysis early this afternoon shows the frontal boundary
near HUF to north of IND and NW of Anderson and Muncie. Clouds
dissipating from the departing MCS were beginning to allow for some
heating in the warm sector south of the front where temps have risen
to the lower 80s. Recent radar trends show the approaching MCS
convection continuing to make progress east toward the forecast
area...but weakening upon approach. New convection is breaking out
in the warm sector across SE Indiana and KY.
HRRR suggests the MCS crossing Indiana will be continue to make
progress to the northeast...but radar trends continue to suggest
weakening upon approach. This will be due to limited instability
across Indiana north of the frontal boundary and also due to a
worked over air mass due to earlier clouds and rain. Better
conditions for storms will be found across the southern parts of the
forecast area where CAPE is most favorable and where heating has had
a chance to occur today.
After this afternoons weather system the surface frontal boundary
should be pushed to far southern parts of the forecast area...again
limiting the source for additional instability overnight. Models
shows southwest flow in place aloft tonight with a short wave within
the flow passing well north of Indiana...across WI and the Great
Lakes. HRRR suggests another wave pushing across Indiana late this
evening and overnight...but confidence is low with that feature as
given the previous two waves...instability should be limited and
the surface boundary should be well to the south across southern
Central Indiana. Thus not all of our features are lining up well and
models seem to be having issues handling these multiple rounds of
convection. Forecast soundings show deep saturation as the storms
pass this afternoon...but fail to show deep saturation for the rest
of the night. Thus will use high pops late this afternoon...and per
the HRRR trend toward a few dry hours this evening before increasing
pops late this evening and early overnight as the final wave appears
to pass. Although will trend pops a bit lower than the NBM as
confidence is a bit low on whether this second wave of showers and
storms will come to fruition on the cold side of the boundary.
Models suggest southwest flow remains in place aloft with little in
the way of upper support available. The remains of the frontal
boundary are expected to be well south of Central
Indiana...elongated across Kentucky. Forecast soundings suggest
subsidence within the column with some lower level moisture trapped
beneath an inversion. This appears representative of cold air
advection stratocu in the wake of the departed front. As the day
progresses...strong high pressure over the plains is suggested to
continue to make progress into the Ohio valley...drying out the
forecast soundings and pushing the lingering frontal boundary
farther south and away from Indiana. Thus after some morning
cloudiness (mainly across southern Central Indiana) skies should
become partly cloudy to mostly sunny. Given our northerly winds
highs in the middle to upper 60s appear on the mark.
Little change is expected within the upper flow on Sunday night as
southwest flow remains along with little in the way of upper
support. Large high pressure over WI and IA will maintain its
influence across Indiana...with subsidence and cool northerly flow
in place across Indiana. Thus will trend toward a dry forecast under
mostly clear skies and lows in the middle 40s.
.Long Term...(Monday through Saturday)
Issued at 305 PM EDT Sat May 21 2022
Drier and cooler conditions expected as a surface high pressure
builds across the great lakes region. The surface high will likely
produce northerly flow early Monday, and veering to predominantly
easterly Monday afternoon. This will allow for lower dewpoints and
cooler temperatures. Cloud cover will begin to increase during the
day Tuesday as a Surface low begins to approach the region with
slight POPs for Tuesday afternoon. Temperatures will be slightly
below average to near average for this time of year.
Several damp days are possible as a deep broad trough slowly
approaches the region with Central Indiana remaining in the warm
moist sector for multiple days. Southerly flow will return early
Wednesday morning. This will allow for moisture to be advected into
the region with dewpoints increasing into the 60s. Likely POPs are
in place across the CWA from Tuesday night through early Friday.
precipitable water values, usually within the upper portions of a
1.00-1.80 inch range will bring the potential for locally moderate-
heavy rainfall. Embedded thunderstorms would be mainly widely
scattered and diurnally-driven, per generally modest shear and
considerable cloudiness limiting daytime heating on both
Wednesday/Thursday. High temperatures will be slightly below to near
average for this time of year due to cloud cover and rainfall. Lows
will be above average as persistent moisture will keep temperatures
The broad upper trough will finally progress eastward and push the
greater axis of gulf moisture into Ohio. This will allow for an
upper ridge to build across the region. Drier conditions expected
due to synoptic subsidence. Northwest flow will keep temperatures
below average towards the end of the long term period.
.Aviation...(06Z TAF Issuance)
Issued at 1159 PM EDT Sat May 21 2022
* Additional showers and scattered convection will continue tonight.
* Predominantly MVFR through the night, then VFR on Sunday.
Additional showers will work across central Indiana tonight. Can`t
rule out a few rumbles of thunder but not enough to include in the
Rain diminishes late tonight with dry conditions expected on Sunday.
MVFR conditions will become widespread at the beginning of the
period and will continue through the night. There may be pockets of
IFR. Improvement to VFR will occur on Sunday.
Area Forecast Discussion
National Weather Service New Orleans LA
907 PM CDT Sat May 21 2022
Have updated most grids to handle short term trends, as outflow
from thunderstorms has pushed most precipitation to the north and
west of the area...at least for now. The 00z LIX sounding was a
post-storm environment with much of the column between 950 and 500
mb comparatively dry. Precipitable water value at that point was
1.3 inches. This compares to 1.8 inches at Lake Charles and 1.5 at
Water vapor imagery shows convection firing from Arkansas
southwestward into Texas, as well as over the Gulf of Mexico to
the south of Louisiana. Latest HRRR run indicates at least some
threat of convection from either or both areas approaching our CWA
prior to sunrise, so we can`t go with a totally dry forecast.
Don`t see temperatures falling much, if any, from where they are
at, and if onshore winds return, temperatures could even rise a
few degrees before sunrise. 35
.PREV DISCUSSION... /issued 408 PM CDT Sat May 21 2022/
Upper ridging centered over Florida this afternoon with a
shortwave moving northward on the west side of it. Thunderstorms
over the Gulf of Mexico associated with this shortwave are
producing outflow that is generally moving westward with gusts to
around 40 mph. The next shortwave in the southwesterly flow is
currently moving across Colorado and New Mexico. Areas that have
received precipitation this afternoon have fallen into the upper
70s, while dry areas are generally in the lower 90s.
SHORT TERM (through Monday night)...
A weak upper low is expected to try to develop over the Gulf over
the next 24 hours or so, and then lift northeastward Monday and
Monday night. The airmass is continuing to moisten up with
precipitable water values around 1.5 inches today, which will
increase to near 2 inches tomorrow and tomorrow night before
retreating to 1.5 inches Monday and Monday night after the passage
of the shortwave. Potential for severe weather and excessive
rainfall will continue during the afternoon hours on Sunday as the
airmass will remain unstable. As the upper low lifts
northeastward tomorrow night, it may provide a focus for excessive
rainfall, especially on the Mississippi coast, as heavy rainfall
tends to focus near the center nocturnally.
Threat will likely diminish for a period Monday afternoon and
evening behind the low, but not enough for a dry forecast.
Generally kept near the NBM numbers with the exception of
overnight tonight, as NBM has been too cool on lows the last
couple nights, bumped up a couple degrees, and that might not be
LONG TERM (Tuesday and beyond)...
Southwesterly upper flow expected to continue through at least
Thursday. With differences in timing of individual shortwaves,
didn`t veer very far from NBM PoPs, as there aren`t large scale
differences. Convective threats should mainly focus on the daytime
hours, particularly in the afternoons. Precipitable water values
crash below 1 inch on Friday, so that should end the precipitation
threat. Temperatures generally in good agreement, so NBM numbers
aren`t likely to provide a significant target of opportunity. 35
AVIATION (valid through 00z Monday)...
Main concern over the next few hours will be TSRA, which should
gradually dissipate with loss of surface heating. Gusts to 35 to
40 knots possible with the strongest storms. MVFR to IFR
visibilities will be brief. Beyond midnight, likely to see some
MVFR ceilings develop as moisture gets trapped under the inversion
again. As heating commences on Sunday, redevelopment of SHRA/TSRA
is expected at most terminals with the same limitations as today.
Will extend the Small Craft Exercise Caution headlines overnight,
although some portions of the waters are likely to fall below
those levels at least briefly. Headlines may need extended
tomorrow, but more significant marine threat over the next several
days will be thunderstorms producing gusty winds. 35
.PRELIMINARY POINT TEMPS/POPS...
MCB 69 85 66 83 / 30 90 60 60
BTR 71 85 68 84 / 60 90 60 60
ASD 71 86 67 86 / 40 90 70 70
MSY 75 85 72 84 / 50 90 70 70
GPT 73 86 70 83 / 50 90 80 70
PQL 71 86 69 82 / 40 80 80 70
Area Forecast Discussion
National Weather Service Louisville KY
903 PM EDT Sat May 21 2022
Issued at 901 PM EDT Sat May 21 2022
Latest convective and environmental trends suggest our severe
weather threat is extremely low given increasing low-level CIN with
the nocturnal inversion beginning to setting in. As such, the severe
thunderstorm watch has been allowed to expire at 9PM EDT/8PM CDT. An
additional line of showers and storms are ongoing across southern
Illinois through Arkansas, but these should weaken as they approach
our region later tonight given how `worked over` the atmosphere is
from our previous storms. The latest CAMs also suggest that this
will be the case.
Issued at 650 PM EDT Sat May 21 2022
After coordination SPC we will expand in area and in time WW254 to
cover the remainder of our SE CWA and delay expiration until 900 PM
EDT. Have gone ahead and removed another row of north-central KY
counties where the threat of severe has ended.
Highest threat of severe weather will generally be along and south
of a line from Russellville northeast to Richmond. The most unstable
air and uncontaminated atmosphere is roughly south of the Cumberland
Parkway. Large MCS with expanding cold pool should push a squall
line through northern TN and far southern KY this evening. Updated
products are in production and will be available shortly.
Issued at 610 PM EDT Sat May 21 2022
Did another quick update to remove some our KY counties bordering
the River from the WW254. Also did an expansion of WW254 to the
south and east for the next hour until the original expiration of
21/23Z. Outflow boundary continues to surge out ahead of ongoing
convection across east-central KY. Atmospheric is a little worked
over up in this area (between Lexington/Louisville) from where
previous convection fired earlier this afternoon. Storms in this
area are under severe limits producing mainly heavy rainfall, wind
gusts of 30-35 mph and quite a bit of lightning.
Stronger instability continues to reside off to the south, mainly
south of the WK/BG Parkways where the atmosphere has been relatively
undisturbed. Mesoanalysis suggests around 2000 J/kg of MLCAPE along
with 0-3km lapse rates of nearly 8C/km ahead of eastward moving
complex. Overall threat continues to look mainly a damaging wind
event as cold pool gradually expands eastward. Depending on
convective trends additional EXA/EXT to WW254 may be required within
the next hour. Will coordinate those issues with SPC in a bit.
Issued at 531 PM EDT Sat May 21 2022
Did a quick update to clear our southern Indiana counties out of
WW254. Updated grids and text products have been produced and sent.
Currently we`re tracking a line of convection pushing east-
southeastward across central Kentucky. Line that moved into the
region became outflow dominant with gusts of 35-40 mph with the
actual outflow. Resultant convection that fired behind the outflow
was strong/severe as storms pulsed up and collapsed resulting in
damaging winds across our southern Indiana counties and into
portions of the metro Louisville area.
The outflow boundary currently extends from near Frankfort southwest
to just south of Elizabethtown and then back toward Greenville, KY.
We expect this outflow to continue to push southeastward with
additional convection firing up behind it. The convection behind
the outflow is just below severe levels with mainly wind gusts of 40-
50 mph, heavy rainfall, marble sized hail, and frequent lightning.
The strongest cells were located across our southwestern sections.
The strongest storm at this time is across Muhlenberg county with
another strong storm near Rough River Lake on the border of
Grayson/Breckinridge. These storms will move east-northeast over
the next 1-2 hours.
To the south of the outflow boundary, the atmosphere has continued
to warm. Temperatures from the KY Mesonet were in the lower 80s
with dewpoints in the upper 60s. This results in MLCAPE values of
2500-3000 J/kg with DCAPE values between 1200-1300 J/kg. Storms
ahead of the outflow boundary may continue to pulse up and down with
damaging winds, marble sized hail, possibly up to nickels/dimes, and
We`ll continue to watch convective trends and if convection starts
to uptick further an EXA to WW254 or possibly a new watch issuance
may be required across portions of our southern/southeast sections.
.Short Term...(This evening through Sunday)
Issued at 315 PM EDT Sat May 21 2022
Afternoon satellite imagery shows partly sunny skies across the
region. Two clusters of convection were being tracked. The first
is moving eastward across the Bluegrass region with a second line
coming in from the west. In areas not affected by storms as of yet,
temperatures were in the upper 80s. However, in rain cooled spots,
temperatures ranged from the upper 60s to the lower 70s.
In the near term, we`ll be watching these two areas of convection
closely. The first one moving eastward through the Bluegrass is
within a plume of instability where MLCAPE values of 2500-3000 J/kg
were found. Bulk shear values were less than 25 knots here. Model
proximity soundings show good instability here with DCAPE values
over 1000 J/kg. Based on CAPE/shear profiles, pulse type severe
storms will be possible with this activity. Damaging winds and hail
up to the size of quarters will be possible. Slightly higher values
of shear were analyzed north of the I-64 corridor, so in the next 1-
2 hours, the corridor of highest severe weather will be across
portions of Scott/Harrison/Woodford/Fayette/Bourbon/Clark/Nicholas
counties. Further south along the southern edge of the Bluegrass
convection, storms have generally remained linear and weaker due to
the bulk shear being less as one heads down toward Somerset.
Nonetheless, a period of showers/storms can be expected for those
areas out in the I-75 corridor.
Further out to the west, ongoing line of storms has crossed into
southwest Indiana and western Kentucky. KVWX radar shows healthy
convection moving through Evansville with outflow racing ahead of
the storms. Bulk shear across western KY is not all that strong
with values in the 0-6km layer of 20 knots or less per the KPAH VAD
profiles. Shear values are little stronger to the north from the
KVWX VAD profile where 20-25 knots of shear was noted. As the
outflow races ahead of the line, we`re likely to see further
convective development as it moves through southern Indiana and
extreme northern KY. The atmosphere out ahead of it has been baking
for a while with KY Mesonet readings in the mid 80s with dewpoints
in the upper 60s/lower 70s resulting in MLCAPE values of around 3000
J/kg. Proximity soundings from the HRRR from Owensboro east to Fort
Knox show a well mixed lower PBL with DCAPE values of 1000-1100
J/kg. The outflow should knock parcels upward and allow further
convection to develop rather quickly. Again shear values south of
the river drop off decently, so the main threats with this line as
it moves through our western areas will be damaging winds (45-65
mph), frequent lightning, and perhaps a few instances of large hail
(marbles to quarters) in the strongest cores.
The western line of convection should continue to head eastward late
this afternoon and this evening across Kentucky posing a risk of
damaging winds and scattered hail reports. We`ll probably see some
downstream watches come out as the line moves on through. However,
convective intensity should wane due to the loss of heating later
this evening. Wind shear values remain weak across our area as the
higher shear values will be found to our southwest across AR.
Nonetheless with the frontal boundary out to the west, some
additional elevated convection may be possible overnight. So, we`ll
continue with high PoPs. Cooler air will filter into the region
behind the front late tonight. Lows will range from the lower 50s
over SW IN with lower-mid 60s over much of KY east of I-65.
For Sunday, the cold front will continue to move eastward through
the region. Best chances of rain on Sunday looks to be mainly east
of I-65. Instability and shear profiles look rather weak, so
widespread shower activity with perhaps a few embedded storms out
near the I-75 corridor will be possible. Highs will range from the
upper 60s west of I-65 to the lower 70s east of I-65.
.Long Term...(Sunday night through Saturday)
Issued at 320 PM EDT Sat May 21 2022
Sunday night, surface high pressure with anticyclonic northerly
winds will limit temperatures to the 50s under mostly cloudy skies.
Suppressed temperatures will remain with highs in the low to mid 70s
on Monday before southern flow returns on Tuesday, lifting
temperatures to either side of 80.
Tuesday, precipitation chances will return to the CWA. Near the
southern tip of the axis of a large upper trough covering the US, a
surface low will begin strengthening over TX as it moves towards WI
through Wednesday. Extending east of the low, a warm front using
Gulf of Mexico moisture will work its way north increasing
precipitation chances from the south into the Lower Ohio Valley
during the day Tuesday, and with the system over MO Tuesday night,
shower and t-storm chances will increase and remain until the cold
front trailing the system passes from west to east Wednesday
afternoon and evening. Precipitation behind the front could remain
through Thursday. The GFS and Euro differ on placement of the best
forcing which plays with the timing of precipitation. The Euro is
slower with heavier precipitation going through the Ohio Valley on
Thursday. The GFS keeps heavier rain on Thursday afternoon farther
south in the southern states.
Beginning on Friday heading into the weekend, upper riding will
follow the upper trough out of our region. This along with surface
high pressure will help bring sunnier skies and drier conditions.
Temperatures will continue in that upper 70s and 80s range.
.Aviation...(00Z TAF Issuance)
Issued at 704 PM EDT Sat May 21 2022
- Showers and thunderstorms this evening
- Low cigs Sunday morning
Band of convection stretching from KBWG northeast to KLEX will
continue to slowly push off to the east-southeast over the next few
hours. Convection should diminish in intensity with the loss of
heating this evening. Some additional convection out across SE MO
will continue to push east, but this activity should diminish to
just showers later this evening as it moves across the area. Surface
cold front will push through the region late tonight and cross the I-
65 after sunrise Sunday. We expect cigs to lower overnight with
cigs dropping to FL012-FL015 by Sunday morning.
Medium on all elements.
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1051 PM CDT Sat May 21 2022
.SHORT TERM... (Through Late Sunday Night)
Issued at 247 PM CDT Sat May 21 2022
1. Showers and thunderstorms will continue this afternoon and
evening. While unlikely, I can`t rule out a thunderstorm becoming
strong enough to produce quarter sized hail this afternoon.
2. Locally heavy rain associated with individual thunderstorms,
and minor flooding continues to be a threat, particularly across
areas that have already seen heavy rainfall today.
3. Temperatures will cool drastically behind the front.
Showers and elevated thunderstorms will continue this afternoon and
into the evening along the 850mb baroclinic zone, behind the
surface cold front that now lies from KHRO to KCGI and KCUL.
MUCAPE values are weak across the region in the post-frontal
environment, but the best instability is across central Missouri
where the RAP analysis shows MUCAPE peaking near 1000 J/kg.
Effective bulk shear between 40-50 kts should be enough to
organize the elevated thunderstorms over central Missouri, and the
7.5 degree/km lapse rates make hail the primary threat with any
storms that become strong. Instability is our limiting factor with
these thunderstorms, and confidence is low that any storm will
become strong enough to produce quarter sized hail. By the evening
instability and the threat for strong thunderstorms is expected
to be very weak as the 850mb front continues to slide
Localized heavy rainfall and localized flooding associated with
these thunderstorms is a greater threat. The axis of heaviest
rainfall from this morning has fallen along a line from
Springfield, MO through St. Louis, MO, into Springfield, IL. About
an inch of precipitation, with locally higher amounts, has fallen
across this area. The showers and thunderstorms that are forming
and increasing in coverage this afternoon are following a similar
path and pose a localized flooding risk, particularly in low lying
and poor drainage areas.
The continued retreat of the cold front and advance of a surface
high into the region will help shunt lingering precipitation out of
the area by tonight, ending the hail and localized flooding threats.
Cold air advection will continue in the low-levels behind the front,
pulling the 850mb temperatures into the single digits aloft by
Sunday, translating to below normal temperatures at the surface.
Temperatures overnight will cool into the 40s to mid 50s, near to up
to -15 degrees below normal for this time of year. Despite the
clearing sky on Sunday under the influence of the surface high,
sustained cold air advection and cool 850mb temperatures will keep
temperatures stunted. High temperatures in the mid 60s will make
Sunday feel more like mid-April than mid-May.
.LONG TERM... (Monday through Next Saturday)
Issued at 247 PM CDT Sat May 21 2022
A longwave mid-level trough will continue to deepen across the
western half of the CONUS during the first half of the work week,
amplifying southwesterly mid-level flow over the mid-Mississippi
Valley. At the surface the high pressure will continue to shift
eastward across the region Monday, keeping the forecast area
precipitation free for another day in advance of our next low
system. By Monday evening a shortwave will travel up the mid-
level southwesterly flow into the mid-Mississippi Valley, mirrored
at the surface by the northeastward movement a surface low. The
warm front associated with this low is expected to lift northward
through the forecast area Monday night into Tuesday morning. Light
precipitation is possible with isentropic lift over the warm
front as moisture surges back into the area south of the front,
but confidence is not high that widespread showers and
thunderstorm will be able to form.
The next best chance for showers and thunderstorms will be Tuesday
through Thursday as the surface low, and perhaps a second surface
low, move through the region in step with the northeastward
movement of the mid-level shortwave. The NAEFS continues to
indicate PWAT values near the 90th climatological percentile in
association with this event, however the NBM viewer isn`t
currently indicating that significant rainfall will be an issue.
Severe weather conditions continue to be more favorable to the
south of our area, however I can`t rule out that threat moving
north in the intervening days. Guidance differs in how quickly the
mid-level trough will push through the mid-Mississippi Valley.
About 40% of the WPC Cluster members favor a more progressive
trough, pushing east out of the region Thursday into Friday.
Confidence is high that by Friday the trough will be retreating
from the area, with 80% of members indicating the trough will
moving into the Ohio River Valley. Rising heights associated with
the exit of the trough axis will continue into the weekend as a
ridge builds into the area.
Temperatures will be absolutely wonderful during the work week.
Cooler 850mb air will keep temperatures near to slightly below
normal with highs generally in the 70s. Periods of showers and heavy
cloud cover could stunt temperatures mid-week. By the weekend the
rising heights aloft and southwesterly low-level flow will help
warm temperatures to near normal.
.AVIATION... (For the 06z TAFs through 06z Sunday Night)
Issued at 1048 PM CDT Sat May 21 2022
The last of the light showers or drizzle are in the process of
moving out of the St. Louis terminals and expect any lingering
MVFR ceilings will be out of these terminals by 06Z. With drier
air moving into the area, have gone dry and VFR conditions with
this set of TAFs. Winds will be out of the north at 12 knots or
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1014 PM EDT Sat May 21 2022
Ridging aloft continues through the weekend. A cold front will
move into the area Monday bringing unsettled weather.
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 1010 PM Sat...Partly cloudy conditions prevail late this
evening with all convective activity well north into Virginia.
Focus for overnight convection now shifts offshore where
considerable instability still lingers. A weak signal remains
for some overnight activity to potentially drift across the
southern coast this evening, but an ongoing convective complex
off the coast of far southern SC may interfere with moisture
transport and prevent any development - the 00Z HRRR appears to
be catching onto this idea. Current PoPs are reasonable and left
them alone for this update.
Prev disc...Little change in the pattern tonight with high
pressure centered offshore. Any sct storms across the coastal
plain will dissipate this evening with loss of sfc heating, but
weak shortwave energy will be present acrs the region through
tonight, so cannot rule out a widely sct shower or even a storm,
but only a 20 pop in the fcst to account for this as most
places remain dry. Guidance is also suggesting that we could see
stratus development along the coast overnight once again. Swly
flow will keeps temps very warm with lows no lower than 70.
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
As of 330 PM Sat...Aforementioned weak shortwave energy will be
prevalent in the morning, so a sct shower or storm is possible
early in the day, esp srn half of the FA. Diurnal heating and
strengthening onshore flow will transition any convection
chances inland during the afternoon. Have lowered pops a bit,
with around 30% fcst, as best forcing is still going to be west
of the Coastal Plains tomorrow. Highs a touch lower, though
still quite humid. Expect readings in the low 90s interior to
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
As of 3 AM Sat...Unsettled weather expected through the period
with more seasonable temperatures. Front will push through the
area Monday then linger just off the coast through mid week,
with a stronger front expected to impact the area late week and
early next weekend.
Monday through Saturday...Still looks unsettled through much of
the period. Front is progged to push into the area Monday with
low pressure developing inland along it. Most guidance now
pushes the front all the way through the area, then stalling
offshore through Wednesday. This would keep the area on the cool
side of the boundary with moist low level NE-E flow. Best precip
chances still look like Monday afternoon and Monday night with
potential for locally heavy rain. Precip becomes more scattered
Tue through Thu, maybe even more isolated at times, likely
enhanced during diurnal peak heating. Cloud cover, precip and
NE-E flow will keep temps near or below normal with highs in the
70s/80s. Boundary will likely lift back north as a warm front
late Wed and Wed night while complex low pressure strengthens
over the Mid-West lifting towards the Great Lakes. The cold
front associated with this system is currently progged to push
through the eastern NC late week/early next weekend. 00z GFS and
EC are in pretty good agreement with fropa this far out in
time. Capped pops at high chance late week for now.
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /through Sunday/...
As of 735 PM Sat...High confidence in VFR conditions through the
period for TAF terminals. Shower and storm threat has largely
ended and an overcast evening courtesy of mid and high level
clouds is forecast with steady southwesterly flow, precluding a
fog threat. Low-level stratus could form again for south coastal
terminals (MRH, NJM, etc.) like last night resulting in
localized LIFR conditions overnight.
LONG TERM /Sunday night through Wednesday/...
As of 3 AM Sat...Scattered showers and thunderstorms may bring
brief periods of sub-VFR conditions Sunday night. A front will
push into the area Monday, likely stalling through mid week.
This will bring increasing chances for scattered to numerous
showers and thunderstorms along with potential for periods of
sub-VFR. Guidance shows cigs lowering to MVFR, possibly IFR
Monday behind the front and persisting through at least Monday
SHORT TERM /Through Sunday/...
As of 330 PM Saturday...High pressure remains centered offshore
bringing SW winds across the waters through the short term.
Typical thermal gradient will strengthen winds late afternoon to
early evening, and a few gusts to 25 kt are possible, before
gradient relaxes later tonight to Sunday morning with 10-15 kt.
Afternoon thermal gradient returns again for Sunday afternoon
with an inc to 15-20 kt once again. Seas will remain on the
lower side, generally 2-4 ft with a 5 second wind chop.
LONG TERM /Sunday night through Wednesday/...
As of 3 AM Sat...Moderate SSW winds 10-20 kt continue Sun,
strongest during the late afternoon and evening hours with
potential for a few gusts to 25 kt, with seas generally 2-4 ft.
Front will push into the waters Monday, then likely stall
across the waters through mid week. NE winds 10-20 kt expected
behind the front, though placement of boundary will make the
wind forecast challenging. Stronger NE winds 15-25 kt may
develop Tue and Tue night with waves developing along the front.
Which would allow seas to build to 3-5 ft across the northern
and central waters, possibly up to 6 ft. A period of SCA
conditions will be possible, with best chances across the
northern waters/sounds and central waters early to mid next
Area Forecast Discussion
National Weather Service Nashville TN
954 PM CDT Sat May 21 2022
FOR EVENING DISCUSSION.
Updated suite of forecast products per current regional
weather trends per radar, satellite, and surface observation
analysis. 22/00Z HRRR model run initialized best and has
the most realistic evolution of weather pattern development
across mid state region remainder of evening through overnight
hours compared to other CAMs. Best potential for some strong
thunderstorm activity approaching 22/03Z(10 PM CDT Tonight)
remains generally confined to southwestern portions of mid state
region. Overall trend of weakening convection strength should
continue, including line of showers and thunderstorms approaching
TN River Valley region in western TN approaching 22/03Z(10 PM CDT
Tonight), that will shortly move into western portions of our
area, as remainder of evening into overnight hours progress.
Certainly can not rule out a strong thunderstorm here or there,
but again, overall trend of convection strength will be a
weakening one. Tweaked hourly gridded temperature, dewpoint,
and wind speed/direction grids blending them with associated
previously forecasted late evening/early overnight hourly
gridded values. Current regional temperature trends generally
in line with forecasted lows across mid state region. Will be
issuing an update to the suite of forecast products shortly
after top of hour as the severe thunderstorm watch for the
four northwestern counties of mid state region will be allowed
to expire. Remainder of forecast continues to be on track.
00Z TAF DISCUSSION.
Scattered TSRA will impact the terminals (except CSV) this
evening. There will be a break after 02Z, then more scattered
showers and storms will move in after 04Z. A cold front will pass
through the area around 12Z for most sites. The front will bring
NNW winds. Scattered showers and a few thunderstorms will follow
the front throughout Sunday with mainly MVFR cigs area wide.
Area Forecast Discussion
National Weather Service Springfield MO
625 PM CDT Sat May 21 2022
1. Showers and storms likely through this evening. Few severe
storms possible along with minor flooding.
2. Cool and dry conditions Sunday.
3. More showers and storms are expected at times late Monday
through mid week, with widespread excessive rainfall possible.
4. Below average temps likely this week.
.SHORT TERM...(This evening through Sunday)
Issued at 200 PM CDT Sat May 21 2022
A surface cold front was located southeast of Springfield early
this afternoon, generally near West Plains. The front has slowed
down as low pressure was moving through northern Arkansas.
Temperatures northwest of the front were in the lower to middle
50s, with lower to middle 70s occuring along and southeast of the
front. Showers and thunderstorms were beginning to increase in
coverage as lift associated with the right entrance region of a
strong upper level jet was placed near the area. Latest RAP data
indicates about 1000-2000j/kg of elevated MU CAPE and 20-30kts of
effective bulk shear. Therefore some storms could remain
organized this afternoon behind the front with some small hail as
mid level lapse rates remain steep. Areas ahead of the front
across south central Missouri are more unstable and could pose a
threat for a severe storm or two. A moist airmass remains over the
area with PW values well above average, around 1.7 in. Minor
flooding occurred this morning and with additional pockets of
heavy rainfall developing, additional areas of minor flooding will
The front and associated precip will clear the area completely
overnight, however high clouds will remain. A drier and colder
airmass will build in with temps dropping into the lower to middle
40s by early Sunday morning. HREF guidance shows that high clouds
should begin to move out during the afternoon, however northerly
winds and slight cold air advection will only lead to highs in the
middle 60s, which is about 10-15deg below average.
.LONG TERM...(Sunday Night through Saturday)
Issued at 200 PM CDT Sat May 21 2022
Showers and thunderstorms will develop in Oklahoma and southern
Kansas late Sunday night into early Monday morning as a low level
jet begins to strengthen ahead of the next storm system. This
activity could drift into western Missouri during the day Monday.
Highest chances for rain Monday look to be west of Highway 65.
Clouds and precip will likely keep temps in the middle to upper
Another shortwave will move up from the southwest during the day
Tuesday. Ensemble clusters all show precip with this system
therefore precip chances remain quite high. Good moisture fetch
from the Gulf will be present with this system and will need to
monitor for flooding potential. Currently the NBM has high probs
for a widespread 0.5 to 1 inch of rainfall with this round.
Uncertainty increases on Wednesday and Thursday as the next upper
trough pushes into the area. It is possible that the heaviest qpf
axis shifts south of the area and this trend will be monitored.
Well below average temps are likely through mid week.
Conditions look to dry out for the end of the week as a mid level
ridge begins to develop. This should allow for temps to climb
closer to average.
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 623 PM CDT Sat May 21 2022
Main convection has shifted well east of the terminals early this
evening. A few showers lingering behind the front, but those have
decreased significantly over the past few hours. Have thrown in
VCSH for SGF/BBG for a couple/few hours this evening. IFR ceilings
should lift into MVFR this evening and eventually VFR later in the
evening and overnight.