Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/25/20
Area Forecast Discussion
National Weather Service La Crosse WI
612 PM CDT Sun May 24 2020
.SHORT TERM...(This evening through Monday)
Issued at 345 PM CDT Sun May 24 2020
Main forecast concerns for this evening are on the potential for
strong to severe thunderstorms in the 6 PM to Midnight timeframe.
Warming and increasing southerly flow has commenced this afternoon
in the wake of this mornings line of showers and embedded
thunderstorms. MLCAPE values at 3 PM this afternoon have increased
into the 500 to 1000 J/kg range across potions of northcentral Iowa,
with even higher values of 1500 to 2500 J/kg noted over southern
Iowa. A cold front is edging southeast stretching from south central
Minnesota, southwest into northern Nebraska. Meanwhile, an MCV
was lifting north out of southeast Nebraska/northeast
Kansas/Northwest Missouri, generating a clusters of severe
thunderstorms. The MCV will have plenty of MLCAPE for it to
sustain strong to severe convection into Iowa, and likely into
northeast Iowa later this evening. Shear isnt` impressive and will
be weakening as the MCV moves into the forecast area. Storms will
likely struggle to organize but given the MLCAPE values in place
and steep mid level lapse rates of 7.5 to 8 C per km, large hail
looks to be the main concern. Also, with the lower levels
possibly being well mixed early this evening as the storms move
in, localized damaging winds could be a concern early on. The
storms will also be capable of producing brief heavy rainfall.
Convective Allowing Models are in fairly good agreement that the
thunderstorms should be on a weakening trend in the 03Z to 06Z
timeframe.
The frontal boundary edges into the area from the west during the
day on Monday. Showers and thunderstorms are possible again along
the front and across much of the area Monday afternoon as afternoon
MUCAPE values increase into the 1200 to 1500 J/kg range. Shear is
on the weaker side again with 0-6 km bulk shear values of 20 to
30 kts. Cannot rule out a few stronger storms again on Monday with
the potential for some large hail and possibly localized damaging
winds and brief heavy rainfall.
.LONG TERM...(Monday night through Sunday)
Issued at 345 PM CDT Sun May 24 2020
Main forecast concerns are on continue chances for showers and
storms through Wednesday.
The frontal boundary meandering southeast across the region and
southwesterly flow aloft will keep continued chances for showers and
thunderstorms across portions of the area through Wednesday,
possibly into Thursday. High pressure then look to build into the
region for the end of the week as flow aloft turns northwest. We
should see some drier weather return for the end of the week into
next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 612 PM CDT Sun May 24 2020
Watching showers and storms advancing north across southern Iowa
ahead of a short wave trough. As the short wave trough continues
to lift north/northeast overnight, the showers and storms should
move into the area as well. However, the timing of this activity
looks to be after dark when the CAPE will be on the decrease and
the last few runs of the both the HRRR and CR-HRRR show the
activity on a decreasing trend as it comes in and may not survive
long enough to impact either airport. For now, will continue to
carry at least a VCTS for late this evening until trends are
clearer on what is expected. Mainly VFR conditions are expected
with the exception of MVFR ceilings are KRST starting after
sunrise Monday morning.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Wetenkamp
LONG TERM...Wetenkamp
AVIATION...04
Area Forecast Discussion
National Weather Service Bismarck ND
946 PM CDT Sun May 24 2020
.UPDATE...
Issued at 945 PM CDT Sun May 24 2020
Current observations and model soundings suggest much of the
precipitation that will fall through the night will be more in the
form of drizzle than rain showers, so have trended the forecast in
that direction. The exception to this is currently in northwest
North Dakota, where models are struggling to simulate the
persistence and northward extent of precipitation. Interestingly
though, diagnosis of mid level RAP fields does show proper
placement of the closed low, and positive vorticity advection in
the RAP matches well with observed reflectivity. Also continued to
increase cloud cover through the night, as model consensus sky
cover algorithms continue to struggle with the extend and duration
of low to mid level cloud cover. Another minor addition to the
forecast was a patchy fog mention along and east of Highway 83,
mainly due to the expected drizzle. Dense fog is not expected at
this time.
UPDATE Issued at 643 PM CDT Sun May 24 2020
Not much needs changing for this update. The main adjustment was
to increase cloud cover now through tomorrow. There seemed to be
a mismatch between vertical RH fields in models and the algorithm
that calculates model consensus sky coverage. Think clouds will
be more prevalent through at least tomorrow morning given the
proximity of the closed upper low.
Left a slight chance of thunderstorms in the forecast east of
Highway 83 and south of Highway 200 for the evening due to the
presence of up to 1000 J/kg MUCAPE. However, no lightning has
been observed for several hours.
&&
.SHORT TERM...(This afternoon through Monday)
Issued at 150 PM CDT Sun May 24 2020
As an upper low continues to spin over eastern Montana, a surface
low continues to drift east across northeastern South Dakota. As
this surface low continues to move into Minnesota, precipitation
will gradually diminish this evening and tonight. Modest
instability (500 to 1000 J/kg of SBCAPE) will develop this
afternoon, possibly leading to a few isolated to scattered
thunderstorms mainly east of the Missouri River and south of US
highway 2. Anomalously high precipitable water values coupled with
various weak shortwaves rotating around the upper low may still
lead to a few pockets of heavy rain in some of the stronger shower
cores, mainly north of Interstate 94 and east of the Missouri
River. But generally, the trends this afternoon and tonight will
be diminishing precipitation.
The main upper low moves into North Dakota on Monday, leading to
some lingering wrap around showers mainly over the central and
east. These showers will be hit or miss and models suggest there
will be little to no instability available for thunderstorms with
this activity. Expect highs in the 60s.
.LONG TERM...(Monday night through Sunday)
Issued at 150 PM CDT Sun May 24 2020
Any lingering showers should move out the area or diminish by
Monday evening. The upper level trough propagates up into Ontario
leading to a zonal flow regime aloft, warmer temperatures with
highs Tuesday in the mid to upper 70s, and dry weather. Wednesday
looks similar to Tuesday, but maybe a tad cooler.
After Wednesday, broad ridging develops across the Rockies.
Mainly dry weather conditions are forecast to continue, with
seasonable temperatures Thursday followed by warmer weather with
the ridge for next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 945 PM CDT Sun May 24 2020
UPDATE...Areas of drizzle have developed from central into eastern
ND. Expect periods of MVFR to IFR visibility restrictions. VFR
conditions are expected across western ND through the forecast
period. Elsewhere, MVFR/IFR will continue through most of the
night, especially farther south.
PREVIOUS DISCUSSION...Most areas will see at least MVFR ceilings
through much of the night. The exception is northwest ND, where
KXWA is expected to remain at VFR through the forecast period.
KBIS and KJMS will likely see a period of IFR ceilings later this
evening into Monday morning. Expect ceilings to improve from
northwest to southeast on Monday. Chances for showers will
gradually decrease this evening, with a slight chance continuing
over south central into southeast ND into Monday afternoon.
Northwesterly winds will diminish to around 10 kts or less this
evening and remain so through the forecast period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Hollan
SHORT TERM...ZH
LONG TERM...ZH
AVIATION...Hollan
Area Forecast Discussion
National Weather Service Caribou ME
910 PM EDT Sun May 24 2020
.SYNOPSIS...
High pressure over the region will slowly move southeast across
the western Atlantic south of Nova Scotia through Thursday.
Meanwhile, a series of disturbances could impact the area
Monday through Thursday. A cold front will push across the area
on Friday.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
9:10 pm update: Satellite pictures continue to show cirrus
moving from west to east across the area. Lower clouds are
confined to Cape Cod and parts or northeast MA and now inching
up toward coastal NH. Not expecting anything more than cirrus
for the remainder of the night across the majority of the FA.
Toward morning there is the possibility that some of the lower
clouds to our south may approach parts of the Hancock County
coast or the outer islands. Confidence is not high, but the
21Z SREF and last few runs of the HRRR have fairly high
probabilities of lower clouds between 09-12Z along the Hancock
County coast. Increased the sky grids some along the coast
after 09Z, but otherwise just an upload of the past few hours
of observed data and minor edits to the temperature trends this
evening.
Previous discussion:
High pressure will continue to drift out to the south and east
of Nova Scotia through Monday. Mainly clear skies can be
expected overnight along with milder low temperatures, in
response to a light south wind around the departing high to our
east.
An increasingly moist southerly flow will continue on Monday
around the high offshore. Ocean stratus is expected to develop
and begin to push into the Downeast coast by later Monday
afternoon. Otherwise, expect partly sunny skies for most areas
on Monday. The warmest temperatures will be found across the
north, where high temperatures will top out around 70. It will
be a different story Downeast, especially the coast, where the
combination of an increasingly moist southerly flow off the
chilly Gulf of Maine, and increasing lower level cloud cover,
will only keep highs in the upper 50s to lower 60s across
interior Downeast areas, and only in the lower 50s along the
coast.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
A large subtropical ridge will be building to our south, both
surface and aloft, early this coming week. This will be
channeling much warmer and more humid air into the region on
southwesterly winds with a mild night Monday night then inland
temperatures climbing into the low 80s on Tuesday. The challenge
through mid- week will be in determining whether any showers or
thunderstorms may result from the initial push of warmer and
more humid air. The GFS is showing a weak collapse in the upper
ridge gliding across our area Tuesday night which, coupled with
the warm advection, may result in some showers across the
region. The NAM is indicating deep but narrow cape, especially
over the far north early Tuesday evening which could allow for
some thundershowers as the weakness in the ridge slides across.
The ECMWF, however, does now show this weakness in the flow
aloft and just has some clouds with little or no showers.
Tuesday into Tuesday night will likely be dry and a bit breezy
as the subtropical ridge becomes anchored to our southeast
building heights and continuing to advect warm air into the
region. The northern edge of the ridge will be nearby to the
north Tuesday night possibly allowing a shower to stray down
across our area. The GFS carries a chance for a few stray
showers Tuesday night. However, the ECMWF has us deep in the
ridge with a warm and dry night. The deep subtropical ridge,
both surface and aloft, will be anchored south of the Maritimes
and extending west back into the Mid-Atlantic region on
Wednesday keeping the area in a deep and very warm southwesterly
flow on Wednesday pushing temperatures into the mid to upper
80s over the area. There continues to be difference in the GFS
and ECMWF Wednesday with the GFS showing enough moisture and
weakness in the northern rim of the ridge to reflect a risk of
showers while the ECMWF has a stronger, less "dirty" ridge
keeping it dry. Either way, Wednesday is destined to be very
warm and noticeably more humid.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Southwesterly flow around the subtropical ridge to our south will
continue to keep the air very warm and humid. As the ridge begins to
break down to our north, some showers may stray across northern
areas with the GFS continuing to be more aggressive with the chances
of showers than the ECMWF. The increase in moisture and approach of
a trough and accompanying cold front will bring a chance of showers
Thursday, mostly north, with very warm and humid conditions
continuing. A southwesterly breeze will continue Thursday night as
the cold front draws closer. Some isolated showers will be possible.
Otherwise, Thursday night will be very warm and humid. The cold
front will push into the area Friday bringing a much stronger chance
for an organized band of showers and possibly some gusty
thunderstorms. Winds will be strong aloft and capes of 1000 J/Kg
possible bringing a chance for strong gusty winds in any storms. The
front will press south across the area early Saturday carrying
showers south with it. Significantly cooler and dryer air should
then follow for early next week.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR tonight at all terminals overnight, but there is
the chance of patchy stratus/fog at BHB for a time toward
daybreak, but confidence is low. Low stratus is expected to
begin to push in off of the Gulf of Maine during Monday
afternoon with MVFR cigs expected to begin to affect KBGR/KBHB
by afternoon, and likley IFR at BHB toward evening. A light S
wind expected through Mon.
SHORT TERM:
Monday night: VFR to occasionally MVFR. SW wind.
Tuesday: VFR. SW wind. Patchy fog may lower conditions to IFR at
times along the coast.
Tuesday night: VFR, except for any patchy coastal fog. SW wind.
Wednesday: VFR, possibly briefly MVFR early. Patchy fog possibly
lowering conditions to IFR along the coast. SW wind.
Wednesday night: VFR to MVFR north, VFR inland Downeast. IFR in
fog along the coast. SW wind.
Thursday: VFR, except IFR in fog coast. SW wind.
Thursday night: VFR inland IFR fog coast. SW wind.
Friday: MVFR to IFR. Risk of strong thunderstorms. SW wind, possibly
gusty at times in storms.
&&
.MARINE...
NEAR TERM: Winds/seas are expected to remain below SCA levels
through Monday. Patchy fog is expected across the waters by
Monday afternoon with visibility lowering to 1 to 3 NM.
SHORT TERM:
A southwesterly wind may gusty to 25 kt Thursday into Friday.
Warmer and more humid air lifting north over the waters has the
chance to bring fog, possibly dense, Tuesday through much of the
week.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.
&&
$$
Near Term...CB/Duda
Short Term...Bloomer
Long Term...Bloomer
Aviation...CB/Duda/Bloomer
Marine...CB/Duda/Bloomer
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1103 PM CDT Sun May 24 2020
.UPDATE...
Squall line has move east of I-35. As a result, will cancel Severe
Thunderstorm Watches 222 and 223. An area of light to moderate rains
with occasional lightning will continue over the Hill Country and
I-35 corridor for a few hours as a wake low forms. Severe
Thunderstorm Watch 224 continues as the squall line moves to the
east. However, with the speed of the line, expect it will be
cancelled prior to the 4 AM expiration time. Have lowered or dropped
POPS for the Rio Grande areas for the overnight. Multiple Hi-Res
models show some thunderstorm redevelopment over the Hill Country to
southern parts of the I-35 corridor overnight and will retain POPs
across those areas.
&&
.PREV DISCUSSION... /ISSUED 912 PM CDT Sun May 24 2020/
UPDATE...
Squall line extends from near Brownwood to Llano to San Antonio to
Pearsall to Carrizo Springs. Have updated for new Severe Thunderstorm
Watch 224 ahead of the line and have dropped most counties behind the
line. Remainder of forecast is generally on track, for now.
PREV DISCUSSION... /ISSUED 711 PM CDT Sun May 24 2020/
UPDATE...
Added a new Severe Thunderstorm Watch for Comal up to Williamson
county and westward into the Hill County.
PREV DISCUSSION... /ISSUED 643 PM CDT Sun May 24 2020/
AVIATION...
Clusters of Thunderstorms are ongoing over Austin, west of San
Antonio and South of Del Rio as of Friday evening. Models show these
clusters of storms generally moving eastward through the evening. Due
to their isolated nature exact timing will be difficult to predict
but the best chances will run through 07z-09z tonight. Behind the
storms MVFR cigs should build in through mid-morning on Monday.
Showers will linger through mid-day as well. Looking ahead another
round of showers and storms will be possible late tomorrow afternoon
into Tuesday morning.
PREV DISCUSSION... /ISSUED 603 PM CDT Sun May 24 2020/
UPDATE...
New Severe Thunderstorm Watch issues for the counties along and west
of US HWY 281. This should be the focus of severe weather through the
first part of the evening and overnight hours. Recent runs of the
HRRR show the complex of storms slowly developing across the Rio
Grande moving eastward towards the I-35 corridor.
Additional storms are ongoing from Austin to Bastrop. These storms
have produced some quarter to half dollar sized hail. The threat with
these storms is more transient as updrafts quickly form, drop the
hail, and then collapse.
PREV DISCUSSION... /ISSUED 249 PM CDT Sun May 24 2020/
SHORT TERM (Tonight through Monday Night)...
An area of showers and storms along the Highway 77 corridor
continues early this afternoon. Deeper moisture along with daytime
heating has allowed for scattered convection, some likely producing
heavy rainfall, to develop and move northward over the mentioned
area. Hi-res models generally show this convection continuing for
another couple hours, then gradually weakening. We will need to
monitor for the possibility of any outflow boundaries propagating
westward to serve as an additional focus for convection for counties
along and east of I-35/I-37.
Farther west, convection continues to develop over the higher
terrain of Mexico to the west of the Rio Grande. The overall setup
is fairly similar to yesterday, with steep mid-level lapse rates,
plenty of instability with MLCAPE around 3500 J/kg but with a
marginal amount of shear. Despite the lack of shear, the chance for
severe weather along the Rio Grande plains and southern Edwards
Plateau looks decent this afternoon and evening. Val Verde county is
already under Severe Thunderstorm Watch #218 until 8 PM this
evening.
As we head into the late evening and overnight hours, the activity
moving out of the Rio Grande plains should manage to develop into a
complex of thunderstorms while moving eastward. The global models
are in fairly good agreement in showing this scenario and indeed the
latest GOES Differential WV loop does show what appears to be a
shortwave trough axis moving through the Big Bend and northern
Mexico. The mesoscale models differ in where the convection will
initially develop, but do all show some activity developing near the
Rio Grande and moving eastward overnight. Suspect we could see a few
severe storms during the overnight hours, especially if the
convection congeals into an MCS. While there would be a concern for
large hail, damaging thunderstorm would be also be favored. Frequent
lightning and heavy rainfall will also accompany the stronger
storms.
On Monday, the flow aloft manages to strengthen some as a trough
axis drops southward into far west Texas. The models again show a
similar scenario where convection develops over the Rio Grande
plains or southern Edwards Plateau during the early evening hours.
Convection chances look very good as we will also have additional
lift provided by a cold front moving in from the northwest. We will
again show high rain chances across most of south central Texas from
late Monday evening, through the overnight hours and into early
Tuesday morning.
LONG TERM (Tuesday through Sunday)...
As model trends have shifted the more elevated period for higher QPF
potential along the cold front and larger upper disturbance, so goes
the increase in QPF for Tuesday morning over southeast counties.
Otherwise the daily QPF trends should not show much change in the
long-term part of the forecast.
As the past several rounds of convection have been driven by winds
and thus pushing activity eastward faster, concerns for cumulative
precipitation runoff concerns have eased in the medium range as well.
In hindsight, the weekend period continuing through Wednesday should
reflect several broad areas of 2-5 inch with isolated higher
pockets mostly as projected, but the lower end of the forecast
totals should end up being more common, and a few locations may end
up with totals below half an inch through the period. This is a
typical dilemma for late May upper trough patterns, and especially
those that are temporarily cut off from the polar westerlies aloft
and driven by MCV influences. With the front on the heels of the
late Monday night storm complex, there is a good chance that rain
chances will wane further for the period from Tuesday afternoon
through Wednesday. Mid week rain chances should continue to contract
News towards the now more compact upper low forecast over the Red
River Valley by 00Z Thursday.
Unstable NW flow aloft on the back-side of the upper low late in the
week as it leans east to the Ark-La-Tex; then, Friday, a high
amplitude pattern over the SWRN US results in a retrogression of the
upper low that by this time is showing a good signal of filling in
and weakening. After low PoP slight boost of mostly slight chances
carry into Thursday night, Friday and Saturday PoPs show a slight
bump in rain chances, but mainly for the air mass diurnal variety.
The ECM trends for next weekend continued an even more stable
picture, with the 12Z run depicting a large upper ridge establishing
dominance over Central and West TX by Saturday.
Given the expectation of more reductions in the long term, a subtle
bump was given to high temp forecasts versus the guidance blends
from Tuesday onward.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 69 84 66 81 64 / 70 50 70 60 30
Austin Bergstrom Intl Airport 68 83 66 81 63 / 70 50 70 60 30
New Braunfels Muni Airport 66 84 65 81 63 / 70 40 70 60 30
Burnet Muni Airport 67 82 63 78 61 / 80 40 70 60 20
Del Rio Intl Airport 68 88 67 86 64 / 60 20 60 30 10
Georgetown Muni Airport 68 82 65 79 64 / 70 50 70 60 30
Hondo Muni Airport 64 85 65 85 63 / 70 30 70 40 20
San Marcos Muni Airport 68 83 65 81 62 / 70 40 70 60 30
La Grange - Fayette Regional 69 85 67 82 64 / 70 60 70 70 40
San Antonio Intl Airport 66 85 66 82 64 / 70 40 80 60 20
Stinson Muni Airport 64 85 67 82 65 / 70 40 70 60 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term/Aviation...04
Long-Term...KCW
Decision Support...Treadway
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1054 PM EDT Sun May 24 2020
.SYNOPSIS...
An upper ridge will continue over the East Coast to start the week
while a weak back door cold front arrives tonight. A moist wedge-
like weather pattern will set up through at least midweek. Unsettled
weather will continue through the end of the week, as another cold
front approaches from the northwest.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 1050 pm Sunday: Shower and thunderstorm activity has mostly
been relegated along the fringe of the forecast area late this
evening. A weak disturbance approaching from the south and a
backdoor cold front will converge on the are later tonight to bring
another shot at a bit more widespread showers. The latest model
guidance isn`t too threatening at this time, but there could be a
few heavier showers or even an isolated thunderstorm. Given the
latest wet conditions, isolated minor flooding can`t be ruled out.
A back door front will slide across the forecast area tonight into
early Monday. There remains a concern for the potential of training
cells/localized heavy rainfall as this boundary pushes steadily SW
across the area overnight. However, guidance is sending out very
mixed signals regarding this possibility, and in fact, only the HRRR
and the operational NAM is signaling a heavy rain threat across the
area (mainly the Piedmont) late tonight. Much will likely depend upon
to what degree convection this afternoon/evening will stabilize the
air mass. Nevertheless, a non-zero locally heavy/perhaps excessive
rainfall threat will exist through the overnight, esp across the
Piedmont.
Cooler temps/enhanced cloud cover will yield less unstable air
across the area Monday afternoon, except perhaps across southwest NC
and the upper Savannah River Valley. At the same time, PWATs will be
increasing to above 1.5, while a SE upslope flow (albeit a weak one)
becomes established. The end result should be scattered to numerous
convective coverage across the entire area beginning as early as
late morning. However, intensity of convection...including rainfall
rates should be less than what we`re seeing this afternoon.
Nevertheless, a non-zero threat for excessive rainfall will persist.
Max temps will generally be cooler than climo.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 1205 PM Sunday: An abbreviated disco as convection has
developed over the NC mtns and staffing is limited. Not much change
was made to the going fcst. Still expect a stg mlvl ridge to
dominate the pattern early on...before giving way to lowering
heights as trof axis swings arnd a closed upper low across TX. This
trof will aide in bringing a tropical wave north along the Atl coast
thru the period. Expect deep convec and high rainfall associated
with this feature which will aide in limiting moisture flux to our
FA Tue. Expect mostly cloudy skies nonetheless each day, which will
limit sfc max temps a couple cats below normal and keep instability
on the low end. Easterly llvl flow will interact with the mtns and
the added lift will generate afternoon tstms which could be good
rain makers Tue in a high PWAT environ over the srn escarpment.
Deeper moisture will moves in across all non/mtn areas Wed and more
widespread showers with isol thunder will develop as the moist flow
interacts with an existing sfc ridge. Some isol hydro issue may be
had across the srn BR by the end of the period.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 1245 PM Sunday: Starting at 00Z Thursday with the omega block
breaking down and starting to shift east while a 500mb closed low
will be located over eastern Texas. A return of unstable afternoon
and evening subtropical air will replace the wedge-like pattern. The
closed low over east Texas weakens from Thursday into Friday and
begins to get absorbed into the main flow as the trough drops down a
bit from the Great Lakes. A surface cold front will be approaching
our area from the north as plenty of moisture will be in place for
mainly afternoon and evening convection. Expect CAPE values from
1000 to 1500 along and south of I-85 late in the day until the front
moves south. The front is expected to move through our area from VA
to GA during the day Saturday and should be located roughly from
ATlanta to Charleston Sunday morning. Max temperatures near normal
Thursday through Saturday then dropping slightly below on Sunday.
Min temps a few degrees above normal.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
At KCLT and Elsewhere: Low confidence in 00Z TAFs, especially
between 08Z and 15Z when IFR or lower cigs/vsbys are expected to
develop along and ahead of a approach weak cold front from the NE.
An uptick in shra is possible along and ahead of this feature from
the north and a disturbance approaching from the south by 12Z
Monday. Moist easterly flow will mean only slow improvement in
cigs/vsbys between 12Z and 18Z, which may hinder TSRA chcs,
especially along and NE of a line from KCLT to KHKY.
Outlook: Afternoon to evening showers and thunderstorms will be
possible through Thursday. Restrictions are possible each morning
from low clouds and fog, and again later each day under any
thunderstorms.
Confidence Table...
03-09Z 09-15Z 15-21Z 21-00Z
KCLT High 98% Med 76% High 91% High 88%
KGSP High 100% Med 68% High 90% High 100%
KAVL High 100% Low 46% High 83% High 86%
KHKY High 98% Med 78% High 93% High 92%
KGMU High 100% Med 60% High 90% High 100%
KAND High 100% High 86% High 90% High 98%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JDL/65
SHORT TERM...SBK
LONG TERM...DEO
AVIATION...65
Area Forecast Discussion
National Weather Service Wichita KS
810 PM CDT Sun May 24 2020
.SHORT TERM...(This evening through Monday night)
Issued at 309 PM CDT Sun May 24 2020
A compact convectively-induced mid-level circulation is currently
rotating northeast across northeast KS. This feature coupled with an
increasingly moist/unstable and uncapped airmass is supporting
scattered thunderstorm activity, mainly across northeast KS and
points northeastward. Thinking brunt of activity associated with
this feature will likely remaining northeast of the forecast area
this afternoon.
Attention then turns to scattered/numerous thunderstorm potential
this evening and overnight after about 4-5 PM, especially northwest
of the KS Turnpike corridor. The culprits are a strong frontal zone
approaching from the northwest, in concert with a deep western CONUS
trough approaching slowly from the west, amidst a
moist/unstable/weakly capped airmass. Combination of strong/fat
instability and weak to modest deep layer shear should support at
least embedded supercell structures, with a large hail/damaging wind
threat, especially before about 10 PM. Additionally, per latest
observational trends and RAP short-term forecast soundings, cannot
rule out an isolated tornado threat across central KS, where
enhanced backed flow exists just north of returning rich
moisture/instability.
Over time through the evening, veer-back deep layer shear profile in
concert with big cold pools and mid-upper flow oriented parallel to
the frontal zone should support numerous storm mergers, with main
hazards transitioning to pockets of marginally severe hail, damaging
winds, and very heavy rainfall. Localized flash flooding is
possible. Severe threat should continue to drop off through about 2
AM.
Scattered to numerous showers and thunderstorms are likely Monday
through Monday evening across much of the area, as the frontal zone
continues to move slowly east across the region, amidst a moist and
uncapped airmass. Rather meager instability owing to poor mid-level
lapse rates should limit the severe threat, although pockets of very
heavy rainfall are likely given the deep warm and moist
atmosphere.
.LONG TERM...(Tuesday through Sunday)
Issued at 309 PM CDT Sun May 24 2020
Seasonably cool temperatures and periodic shower/thunderstorm
chances will persist across the region Tuesday through Thursday, as
the western CONUS upper trough eventually stalls across the Southern
Plains. The threat for widespread heavy rainfall and severe weather
will likely be low during this period given meager instability,
shear, and forcing. Daytime high temperatures look mostly in the
70s. Mostly dry and warmer weather should return Friday through next
weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 647 PM CDT Sun May 24 2020
Challenging aviation forecast. Anticipating storms to be in the
vicinity of KRSL/KGBD/KSLN this evening then rolling into
KHUT/KSLN/KICT later. There is also a chance for storms to either
move into or develop in the vicinity of KCNU around daybreak as
hinted by a couple of models. Still expect storms to redevelop
around midday in southeast KS along front. Models continue to be
rather generous with MVFR ceilings, and based on recent track
record have mostly discounted it for now. -Howerton
&&
.HYDROLOGY...
Issued at 309 PM CDT Sun May 24 2020
Slow-moving scattered to numerous thunderstorms will likely
support a handful of areal and/or flash flood warnings across
mainly central KS this evening and overnight. The heavy rainfall
threat will shift and expand eastward for Monday afternoon-
evening, with additional flood and/or flash flood warnings
possible through central and eastern KS. Modest rises on area
rivers and streams are likely, which could support some river
flood warnings. Worst case scenario rainfall brings numerous river
forecast points into minor and moderate flooding across central
and eastern Kansas. Will continue to monitor area rivers and
streams for possible flood warnings.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 63 71 58 73 / 50 80 50 40
Hutchinson 61 68 56 73 / 80 80 40 30
Newton 62 70 57 72 / 60 80 50 40
ElDorado 63 71 58 73 / 50 80 70 50
Winfield-KWLD 64 71 58 73 / 50 80 60 50
Russell 57 64 51 75 / 90 60 20 20
Great Bend 58 64 52 74 / 90 60 20 20
Salina 61 69 56 73 / 80 80 50 30
McPherson 61 69 56 72 / 80 80 50 30
Coffeyville 65 75 62 76 / 50 80 70 70
Chanute 65 75 62 75 / 50 80 80 70
Iola 66 75 62 76 / 50 80 70 70
Parsons-KPPF 65 75 62 75 / 50 80 80 70
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Monday evening for KSZ032-033-047>053-
067>070-082-083-091>094.
&&
$$
SHORT TERM...ADK
LONG TERM...ADK
AVIATION...PJH
HYDROLOGY...ADK
Area Forecast Discussion
National Weather Service Lincoln IL
849 PM CDT Sun May 24 2020
.SYNOPSIS...
Issued at 258 PM CDT Sun May 24 2020
Summer like heat and humidity will continue across central
Illinois through the holiday weekend and most of the upcoming
week. Highs into the 80s are expected each day through Thursday
along with daily scattered shower and thunderstorm chances, though
there will be plenty of dry weather each day.
&&
.UPDATE...
Issued at 848 PM CDT Sun May 24 2020
An abundance of outflow boundaries from earlier storms have become
the focal point for additional storm development in the last hour
or two. The RAP and HRRR are starting to pick up on the line of
storms from Taylorville to Mattoon. That line is expected to fill
in farther east and progress northward with time. Additional
showers/storms reaching Schuyler to Scott counties will shift east
over the next few hours as well. The overall trend by midnight is
for a much reduced coverage of any precip, so will continue that
in the forecast. Cloud cover will likely remain across our CWA
until well after midnight, mainly due to a veil of high clouds
from convective debris.
Update this evening was primarily to the coverage and timing of
storms this evening. The remainder of the forecast appears on
track.
&&
.SHORT TERM...(This evening through Monday)
ISSUED AT 258 PM CDT Sun May 24 2020
Hot and humid conditions will continue today and tomorrow across
central Illinois. An amplified upper ridge centered over the Great
Lakes will persist in the near term along with H85 thermal ridge
with temps of 17-19C draped across the mid Mississippi Valley.
Despite some filtered sunshine today, temps were easily able to
achieve mid 80s this afternoon across most of central Illinois
with a few spots topping out in the upper 80s. Temps will be
fairly similar on Tuesday with mid 80s expected area wide again,
though thicker cloud cover may temper temps a few degrees in some
locations.
Convective chances for the rest of today into Monday remain a bit
nebulous, but CAMs are at least honing in on a couple
possibilities through tonight. Convective initiation is ongoing
across portions of north central MO along a remnant outflow
boundary from earlier MCS and ahead of an upper level disturbance
lifting across the mid Missouri Valley. NAMNest and WRF models
show a line of storms congealing in the next few hours and pushing
east into central Illinois then decaying. Limited deep layer
shear may make cold pool balance a bit of a limiting factor for
this scenario, but CAMs do hint at this or at least scattered
storms associated with this system making their way east into
Illinois later this evening.
Meanwhile, a couple clusters of storms ongoing across southern
Illinois are progged to lift north across portions of southeast
and east central Illinois this evening and overnight. These are
associated with an area of modest mid-level theta-e advection and
has the best chance to persist overnight as a weak low level jet
forms.
Overall synoptic forcing remains weak on Monday, but hot and humid
conditions will again lead to modest diurnal instability with
scattered afternoon convection possible. Coverage may increase in
the evening as low level jet again increases.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 258 PM CDT Sun May 24 2020
A summer like pattern will prevail through much of the week ahead.
Strong upper ridge will remain anchored just off the mid Atlantic
coast for several days with favorable trajectories off an open
Gulf streaming moisture across the Midwest. While an upper low
cutting off over Texas adds some uncertainty to the amount of
moisture transport, guidance continues to favor daily shower and
thunderstorm chances along much of the Mississippi River Valley on
the western periphery of the upper ridge. Moderate instability is
expected to form each day, but within a weakly sheared and weakly
forced environment. Each day will have many more dry hours than
wet, and forcing will likely be on smaller scales associated with
remnant MCV activity or outflow boundaries making details hard to
pin down at this time.
On Friday, a cold front is expected to push across the region,
eventually settling south of the Ohio Valley over the weekend.
This will usher in less humid air across Illinois and will mark
the end of precip chances through the weekend. Temperatures are
expected to top out near or just below 80F Friday through the
weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 654 PM CDT Sun May 24 2020
Isolated showers and thunderstorms could linger this evening, as
residual outflow boundaries trigger additional convection. One
boundary just progressed north through SPI, triggering a shower
just east of the airport. That line remains active with a few
stronger updrafts farther east in eastern Sangamon County. Shower
and storm activity near CMI has shifted to the north and east.
A few high resolution models still are showing storms
redeveloping just south of I-72 this evening. Have not indicated
that in the current TAFs, but will monitor for any needed updates.
Winds are still gusting from the southeast at the start of this
TAF period, but those gusts should subside by 03z at the
latest. Winds are expected to become southerly on Monday, with
pulse afternoon storms on tap once again.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SYNOPSIS...Deubelbeiss
SHORT TERM...Deubelbeiss
LONG TERM...Deubelbeiss
AVIATION...Shimon