Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/23/24
Area Forecast Discussion
National Weather Service Goodland KS
950 PM MDT Wed May 22 2024
.KEY MESSAGES...
- Isolated to scattered severe thunderstorms are forecast to
develop Thursday afternoon and evening.
- Cold front moves through Thursday evening and night with more
severe thunderstorms possible along the front across eastern
counties and non thunderstorm wind gusts up to 50 mph across
the western counties.
- For the holiday weekend, expecting a chance for storms both
Saturday and Sunday, with some severe storms possible.
&&
.UPDATE...
Issued at 850 PM MDT Wed May 22 2024
For the overnight hours, latest 00z guidance is showing
increasing moisture in the 700-500mb layer moving across the
area from far eastern Colorado. Its anticipated that this
moisture source will work with 2km CAPE values around 500 J/kg
and limited CIN to at least support 20%-30% chances for showers
and thunderstorms mainly along the I-70 corridor (and
neighboring counties to the north) as well as Norton/Graham
counties. Presently, severe weather is not expected.
See Fire Weather section below for updated Red Flag Warning
Thursday.
&&
.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 110 PM MDT Wed May 22 2024
Weak mid level ridging is present across the region currently with a
surface high in the lower levels; both of which are keeping the
skies virtually clear and the weather quiet. As we head into
the afternoon and evening a weak wave will move off of the Front
Range and onto the Plains. Winds will turn to the south and
begin advecting some moisture back into the area as a surface
trough develops; if everything can phase in time then some
isolated showers and storms may become a possibility around 01Z
across eastern Colorado and into NW Kansas. Little if any
rainfall is currently forecasted; will maintain with silent pops
due to concerns about the wave and the moisture return not
phasing. As the surface trough begins to deepen some tonight,
the southerly winds will become breezy with sustained winds
around 20 knots at times. This is forecast to help keep the
atmosphere mixed keeping overnight lows in the 40s to 50s.
The trough tomorrow looks to deepens into a surface low across
SW Kansas. Ahead of the low moisture will continue to return
from the Gulf of Mexico. A stout dryline will become present
through the afternoon which serve to be the focus for initiation
for the next round of severe thunderstorm potential. Confidence
is increasing in the dryline setting up near the Highway 25
corridor from Trenton through Leoti during the early to mid
afternoon. Discrete storms are forecast to develop along the
dryline with large hail around 2 inches in diameter damaging
winds being the primary threats as the NAM shows 2500+ j/kg of
MUCAPE with 40-45 knots of effective shear, steep lapse rate in
excess of 8 c/km and straight line hodographs. These hodographs
would support splitting of storms as well. If a discrete cell
can continue through 00Z (east of Highway 83) some tornado
threat may develop as the LLJ strengthens increasing the
streamwise vorticity. This scenario is seen in the 12Z NAMNEST
with elongating hodograph signature as well. I`ve strongly used
the NAM and NAMNEST for my forecast as these models have done
extremely will with convection and location of the dryline thus
far this spring. It is also interesting to note that the HRRR
has been consistently not initiating any storms along the
dryline, so that scenario is possible but at this time thinking
it is unlikely.
Into Thursday evening and night, a cold front then surges south
through the area. A second round of potentially severe storms may
occur along the cold front as well, as long as as the area remains
in the warm/moist sector (mainly east of Highway 25). Plentiful
MUCAPE and shear remains in place as more of a line/cluster pushes
south across the area. Damaging winds and hail will be the primary
threats. If any bowing segments occurs with the line then wind
driven hail may become more of a concern. Shower and storm
development back west across the front is a little more uncertain
due to the dry air in place; NAM and GFS both suggest 8-11 mb
pressure rises over 3 hours with and behind the front. Non
thunderstorm wind gusts around 50 mph looks to occur with this.
Blowing dust is also of limited concern due to the recent heavy
rains in the main dust source region of northeast Colorado.
Some fire spread potential will need to be monitored behind the dry
line as well as RH values look to fall into the low teens and deeply
mixed inverted v soundings look to help bring down wind gusts around
30 mph. After collaboration with surrounding offices, opted to hold
off on any fire weather highlights due to the continued spring
greenup and most importantly the recent rains. A portion of
western Cheyenne county Colorado also continues to lie in the
40th percentile ERC (Energy Release Component); however nothing
notable was being seen in calculating the GFDI with mid range
"Very High" fire spread numbers being seen which does lead me to
believe that the recent rains have helped the area mitigating
the burn ready fuels.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 110 PM MDT Wed May 22 2024
Post frontal stable air will be in place behind cold front as
another surface high sets up across the area to start the extended
period. Winds will remain breezy which is forecast to keep
temperatures from completely bottoming out despite dew points
in the mid 20s to low 30s. The pattern with a slight eastward
shift of the surface high would create lighter winds which would
then support frost concerns again across the west, so upcoming
shifts will need to monitor the position of the high. A very
similar day to today is forecast for Friday as the surface high
pushes off and another weak wave moves off the Front Range; not
anticipating any precipitation at this time.
Into the weekend, moisture again surges northward across the area so
will need watch for fog/stratus into Saturday. Saturday will
need to be watched for severe weather potential as a warm front
and dry line look to be in the vicinity of the CWA as another
low pressure system develops. There remains considerable
discrepancies regarding the positioning of the these features
so confidence remains on the low end regarding specific details.
However, with this being the Memorial Day holiday weekend,
those with outdoor or travel plans will want to monitor the
forecast very closely.
Into Sunday; wraparound precipitation may move into the area along
with cooler temperatures with highs in the 60s to 70s across
the area. Ridging then looks to develop during the new work week
with warmer temperatures making their return into the region.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 950 PM MDT Wed May 22 2024
KGLD...VFR conditions are expected through the period.
South-southeast winds of 12-15kts with some higher gusts are
anticipated from taf issuance through sunrise. From 12z-00z,
southerly winds will slowly veer to the southwest, gusting up to
30kts. After 01z, winds are currently forecast to quickly shift
to the northwest with gusts up to 35kts as a cold front moves
through. Presently, no precipitation is anticipated.
KMCK...VFR conditions are expected through the period. A
southeast wind up to 10kts is forecast from taf issuance through
13z. From 14z-00z, southerly winds gusting up to 30kts are
forecast. After 01z, winds are currently forecast to quickly
shift to the northwest with gusts up to 30kts as a cold front
moves through. At this time, confidence is too low to pinpoint
when/if the terminal would see showers/thunderstorms in the
vicinity or over the terminal. Presently, it appears the 23z-03z
timeframe would have the best chance based on the latest data.
&&
.FIRE WEATHER...
Issued at 850 PM MDT Wed May 22 2024
Recent coordination with our fire weather partners suggest the
continuance of Fire Weather Watches/Red Flag Warnings until
further notice.
On Thursday, the combination of dry fuels, southwest winds
gusting 25 to 35 mph and relative humidity values as low as 10
percent will create critical fire weather conditions. Therefore,
a Red Flag Warning is in effect for Cheyenne and Kit Carson
counties in Colorado as well as Sherman, Wallace, Greeley
counties in Kansas from 17z-03z.
A strong cold front will move through the warning area Thursday
evening, abruptly shifting winds to the north to northwest with gusts
generally up to 40 mph, possibly a bit higher. This will create
unpredictable fire behavior for any fires ongoing. First responders
stay up to date on the position and timing of the cold frontal
passage should any fires occur.
Despite favorable wind and relative humidity forecasts, we`ll be
leaving Yuma county and Cheyenne county Kansas out of the Red
Flag Warning. These area have been hit hard by high rainfall
amounts in Yuma county a few feet of accumulating hail in spots.
NASA Sport 0-10km soil moisture remains rather high and would
likely not support explosive fire growth at this time.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Red Flag Warning from 11 AM to 9 PM MDT Thursday for KSZ013-
027-041.
CO...Red Flag Warning from 11 AM to 9 PM MDT Thursday for COZ253-
254.
NE...None.
&&
$$
UPDATE...99
SHORT TERM...Trigg
LONG TERM...Trigg
AVIATION...99
FIRE WEATHER...
Area Forecast Discussion
National Weather Service Jackson MS
923 PM CDT Wed May 22 2024
...New MESOSCALE UPDATE...
.MESOSCALE UPDATE...
Issued at 908 PM CDT Wed May 22 2024
Cluster of thunderstorms are occuring across the Delta this
evening, with some flash flooding occuring. High res models
suggest that these storms will inch eastward through the evening
into the overnight hours before dissipating very early on
Thursday. A strong to possibly severe storm will continue to be
possible over the next few hours, but the main concern will be
flash flooding. The main area of concern for flash flooding will
continue to be generally northwest of the Natchez Trace Corridor.
Overnight lows will mostly be in the mid to upper 60s./15/
&&
.DISCUSSION...
Issued at 239 PM CDT Wed May 22 2024
Through Tonight:
Clusters of thunderstorms have begun to form along a stationary
front from Texas to Arkansas. A complex is expected to develop
from this activity and continue to move east, progged to impact
our area later this evening. Rich low level moisture is evident
across the ArkLaTex region and into northern Louisiana. Deep
shear around 40 to 50 kts is ample for organization and will aid
in the upscale growth of the MCS. A sharp instability gradient is
noted on RAP analysis from roughly Monroe LA, to New Orleans LA,
and will likely serve as a focused track for the MCS later today
with waning daytime heating. A slight/marginal risk has been
highlighted for western portions of the area, roughly along and
west of the Natchez Trace corridor. Primary threat will be for
damaging winds, but hail quarter to golf ball size and tornadoes
are also possible.
In addition, the orientation of the boundary and storm motions could
lead to some potentially greater rainfall totals. There is
potential for a 3 inch bullseye to sneak into far western portions
of the area, notably Morehouse/Richland/Franklin Parishes. Given
this potential, have added a Limited threat area for flash
flooding into the morning tomorrow.
Further east, drier air will greatly limit severe potential, as the
greater ingredients will remain further south and west. As the MCS
moves away from this source region it should decay. A few lingering
showers and storms from this complex will be possible tonight east
of the risk area, but are not expected to post a threat. The MCS
should dissipate by daybreak and could have implications on the set
up for tomorrow`s system./SAS/
Thursday through Wednesday:
There is a Marginal Risk for severe storms again on Thursday, with
a similar synoptic setup in place. A Slight Risk area closer to
the front (northwest of our CWA) remains in place, but better flow
through the atmosphere and an uptick in instability suggest the
threat for severe storms will expand into our area heading into
tomorrow as well. Realistically, the chance for strong to severe
storms resulting from daytime and evening convection will extend
through the weekend. Above-normal heights associated with the
upper-level ridge will retreat southward over the Gulf of Mexico
as broad longwave troughing dominates the western and central
CONUS. Disturbances rippling out of this wave across the country
will provide the support for this mainly diurnal activity to
organize and progress eastward each day. Any particular afternoon,
areas around the US Highway 82 corridor have the greatest chances
for storms through this time, though I wouldn`t rule out the
chance anywhere. A southern jet stream over the region should add
the flow needed for possible organized wind threat with any deep
convection. Then as we move from Monday into Tuesday, a cold front
should sweep southeast through the region. This front will also
carry a threat for strong to severe storms, but it`s too far out
to have confidence on the timing right now. Before the front
arrives, Sunday and Monday look to be HOT. The possibility of
105-110 heat index values will put residents under the threat of
dangerous heat stress. Will likely need graphics if it appears
that widespread rain will hold off those days. /NF/
&&
.AVIATION...
(00Z TAFS)
Issued at 709 PM CDT Wed May 22 2024
Showers and storm are moving across the delta this evening and
this will bring intermittent MVFR/IFR conditions to GLH/GWO.
Expect the remaining sites to remain VFR through the period,
although JAN/HKS could see some brief MVFR conditions if the
showers make it further to the east.
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 69 90 72 91 / 30 20 10 0
Meridian 68 90 69 92 / 10 20 10 10
Vicksburg 70 90 71 92 / 50 20 10 0
Hattiesburg 68 91 71 93 / 10 10 0 0
Natchez 70 90 71 92 / 40 10 10 0
Greenville 70 86 72 90 / 70 40 40 10
Greenwood 69 87 71 91 / 60 40 40 20
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
/
Area Forecast Discussion
National Weather Service Marquette MI
813 PM EDT Wed May 22 2024
.KEY MESSAGES...
- A Wind Advisory continues into this evening over the western
Lake Superior shore counties and in the Keweenaw due to wind
gusts up to 45 mph.
- Waves of 6 to 8 feet along the shores of Lake Michigan yields
a high risk of rip currents through sunset.
- Another shortwave and low pressure system will bring another
round of showers and a slight chance (around 20% chance) for
some thunder to Upper Mi late Friday into early Saturday.
- There will be more opportunities for rain next week although
model uncertainty leads to low forecast confidence on
timing/extent.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 434 PM EDT Wed May 22 2024
Current RAP analysis shows the mid level trough now over
northwestern Ontario with the associated sfc low centered just east
of it over Lake Nipigon. As the trough pivots over the UP through
this evening, some isolated to scattered light showers already
lighting up the radar data are expected continue spreading east
through late this afternoon. Showers then will lift north and
diminish this evening as drier northwest flow works its way in and
aiding isentropic ascent ends. Median of CAMs guidance is very
minimal with only a few hundreths of QPF, so little if any
accumulation is expected.
Gusty winds continue through this evening thanks to an 800-850 mb
LLJ overhead, tighter pressure gradient, and increased mixing. Gusts
up to 35-45 mph are expected along the western counties of Gogebic,
Ontanogon, Houghton, and Keweenaw where the wind advisory continues
into this evening. Elsewhere, gusts are expected up to 30-35 mph. As
the sfc low departs north-northeast toward James Bay through tonight
and we lose daytime heating, mixing diminishes and westerly winds
weaken into tonight; the Keweenaw could still see some gusts tonight
up to 30 mph. Cloud cover gradually clears from south to north
allowing for lows to settle into the 40s.
&&
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
Issued at 401 PM EDT Wed May 22 2024
By Thursday morning, the deep surface low just north of Lake
Superior this afternoon will have moved over James Bay while slowly
weakening. A mid-level ridge building over the Northern Plains
should lead to weak ridging/subsidence and mostly dry conditions
across the area on Thursday. That said, will still hang on to some
chance PoPs during the afternoon with a few of the models hinting at
a subtle shortwave rotating thru the area in the afternoon from the
storm system over James Bay. Any shower development from this weak
wave should be sparse given dry low-levels depicted in fcst
soundings. With some CAPE present in soundings, a few rumbles of
thunder will not be ruled out - but there is some capping to
overcome. Otherwise, expect sunny skies for the most part while
temperatures climb into the 70s across most of the UP, and in the
60s near Lake Superior. Though winds will come in much lighter than
today with a weakening pressure gradient, shallow daytime mixing
could still bring down some 20mph gusts across much of the UP,
potentially higher across the Keweenaw.
By Friday, the focus shifts to the next shortwave emerging from the
western CONUS mid-level trough . This shortwave lifts NE through the
Plains and Upper Great Lakes, eventually swinging into Manitoba and
phasing once more with the broader troughing over the western
CONUS/Canadian Prairies. Increasing isentropic ascent, 850 mb theta
advection and moderate q-vector convergence out ahead of the
shortwave will lead to another quick round of showers across the
area beginning late Friday afternoon in the western UP and spreading
eastward during the evening. If showers can hold off until later in
the afternoon, then we`ll stand a better chance at eroding a
building cap which would allow for some rumbles of thunder.
Otherwise, guidance continues to favor amounts largely around a 0.10-
0.25in, but ensembles are also showing around a 40% chance for more
isolated amounts around and in excess of 0.50in. Rain showers move
eastward out of the UP late Friday night, then for the most part,
Saturday should be dry with ridging behind the exiting shortwave
with much drier air working in. However, with another subtle wave
emanating out from the parent low over Manitoba, a few additional
sprinkles/light showers will not be ruled out; little to no rain
accumulations are expected. Expect otherwise partly cloudy skies and
seasonable temperatures for the rest of the day with highs mostly in
the 60s with a few cooler mid 50s readings near Lake Superior.
While models indicate weak ridging should hold on long enough to
keep Sunday dry, there is plenty of model uncertainty with what will
happen after that. Latest deterministic Canadian guidance continues
to maintain mostly dry conditions through the first half of next
week, suppressing a southern stream trough over the Lower Great
Lakes/Ohio Valley and keeping the Upper Great Lakes mostly dry. This
increasingly looks to be the outlier among the global models. The
Euro, UKMET, and now the GFS are trending toward a phased, deeper
and farther north system tracking somewhere between the central
Lower Peninsula and the Straits of Mackinac. If a more northwestward
solution verifies it will potentially be a much more impactful
system for the Upper Great Lakes into early next week with much of
the UP receiving significant soaking rainfall, and the eastern UP
potentially seeing heavy rainfall Sunday night through Monday.
Wraparound moisture in the deformation zone, comma head of the
deepening system will lead to the potentially heavy rainfall Tuesday
as well. The deep system would also lead to more wind impacts with
gales likely over Lake Superior and windy conditions across much of
the U.P. Needless to say, model trends will be watched closely in
the coming so stay tuned to possible forecast changes into early
next week. As of right now, given the uncertainty, this forecast
reflects the latest NBM solution which does bring in an increase in
wind speeds as well as better chances for rainfall early next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 813 PM EDT Wed May 22 2024
As low pres to the n of Lake Superior drifts ne during the night,
-shra wrapping around the low will move across the area this
evening, mostly affecting CMX. With the low moving away from the
area, gusty westerly winds will also diminish during the night. At
IWD, expect VFR to prevail thru the fcst period. There may be a
passing -shra over the next few hrs, but conditions will not drop
out of VFR. There is also a low potential of MVFR cigs for a few hrs
Thu morning. Included only sct clouds at 2500ft to reflect the
possibility. Westerly winds gusting to around 20kt will diminish
late evening. At CMX, a more consolidated area of -shra will affect
the terminal for the next few hrs, resulting in MVFR cigs and
potentially MVFR vis. IFR cigs are possible early. VFR will then
prevail late evening thru the remainder of the fcst period. Westerly
winds gusting to around 30kt will diminish during the evening, but
still expect gusts above 20kt thru most of the fcst period. At SAW,
expect VFR to prevail thru the fcst period. There may be a passing
-shra over the next few hrs, but conditions will not drop out of
VFR. There is also a low potential of MVFR cigs for a few hrs Thu
morning. Included only sct clouds at 2500ft to reflect the
possibility. Westerly winds gusting to around 20kt will diminish
late evening.
&&
.MARINE...
Issued at 401 PM EDT Wed May 22 2024
Deep low pressure is centered just north of Lake Superior this
afternoon, with a tight pressure gradient over the lake. SW gales of
35 knots are common across the western half of Lake Superior, but
higher gusts to 40 knots are still possible through the evening
especially closer to the shoreline of the Keweenaw. Winds are coming
in comparatively lighter to the east, mainly up to 20-25 knots. As
the low gradually lifts north through Ontario and weakens this
evening, winds should fall below gale force by midnight. Internal
probabilistic guidance indicates only around a 20% chance for gales
the rest of the night. The winds continue to diminish through
Thursday morning and afternoon, with light winds of 20 knots or less
returning to the area by evening. The period of light winds doesn`t
last long over the western lake as northeast winds will begin to
ramp up to 30 knots late Thu night into Friday in advance of another
low pressure lifting from the Northern Plains towards Lake Winnipeg.
Guidance indicates around a 30-40% chance for gale force gusts
Friday afternoon in far western Lake Superior. Winds diminish to 15
to 25 knots over the west half of the lake and becoming southwest
behind the low and the passage of its cold front late Friday night
into Saturday. Behind this system, expect light winds of 20 knots or
less across Lake Superior for the rest of this weekend as high
pressure ridging moves over the area. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
High Wind Watch from 6 AM EDT Wednesday through Wednesday
evening for MIZ001-003.
Wind Advisory from 9 AM EDT /8 AM CDT/ to 10 PM EDT /9 PM CDT/
Wednesday for MIZ002-009.
Lake Superior...
Gale Warning until 8 PM EDT /7 PM CDT/ Wednesday for LSZ162.
Gale Warning from 7 AM EDT /6 AM CDT/ to 8 PM EDT /7 PM CDT/
Wednesday for LSZ240-241.
Gale Warning from 10 PM this evening to 11 PM EDT Wednesday
for LSZ242>244-263-264.
Gale Warning from 2 AM to 11 AM EDT Wednesday for LSZ245>251-
265>267.
Lake Michigan...
None.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Wind Advisory until 10 PM EDT /9 PM CDT/ this evening for
MIZ001>003-009.
Beach Hazards Statement until 10 PM EDT this evening for
MIZ014.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Jablonski
LONG TERM...LC
AVIATION...Rolfson
MARINE...LC
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
1101 PM EDT Wed May 22 2024
...New UPDATE...
.UPDATE...
Issued at 1058 PM EDT Wed May 22 2024
MCV is quickly dissipated with only some light rain/sprinkles
across the central valley and scattered showers and thunderstorms
over far northeast Tennessee and southwest Virginia. Latest HRRR
suggests chance of rain will continue to end as the MCV moves
east. Potential of convection developing over southern Kentucky
toward daybreak that may move into the northern Plateau but
overall dry the rest of the night.
&&
.UPDATE...
Issued at 931 PM EDT Wed May 22 2024
A weakening MCV over the northern Plateau will move across the
rest of east Tennessee and southern Appalachians this evening
and generally east of the region soon after midnight. Strongest
convection is across southwest Virginia and northeast Tennessee
where modest instability remains. MLCAPES of 1000-1500 with
effective shear of 35kts. Enough instability and shear combo to
produce strong updrafts with some small hail possible over these
areas. DCAPE of 600-700 which is limited but enough for
strong/gusty winds with these storms.
Convective complex will move east with generally mostly cloudy
sky. Lowered temperatures where rain has occurred.
&&
.SHORT TERM...
(This evening through Thursday)
Issued at 308 PM EDT Wed May 22 2024
Key Messages:
1. A few strong to maringally severe storms possible in the northern
Plateau this evening.
2. Another round of potentially strong to severe storms is expected
Thursday from late morning through early afternoon, mainly north of
I-40. Potential for training storms will pose a flooding threat.
Discussion:
A line of strong to severe storms streches along a pre-frontal
trough from central KY to West TN. Mesoanalysis of the region shows
a much les favorable environment for severe over our area, with CIN
keeping convection capped and weak deep layer shear. The HRRR and
ARW are in good agreement with the progression of storms across
Middle TN through the afternoon, and show them reaching our Plateau
counties around 00-01Z. By the time they reach I-75, the storms
weaken quickly and have virtually dissipated before reaching Tri-
Cities. The forecast for the evening will have likely PoPs only in
Morgan/Scott counties, dropping to a chance in SW VA and NE TN by
midnight. This activity should end around 06-08Z once the shortwave
trough exits, but another stronger trough will be approaching from
the west.
Convection is expected to develop tomorrow morning to our west in
association with this trough and upper jet streak. The CAMS are not
in good agreement on the details of the evolution of this
convection, but the general trend appears to be showers and
thunderstorms moving into the Plateau area during the mid to late
morning hours, about 12-16Z, and crossing the TN Valley through the
early afternoon. Some additional development may occur behind this
initial activity during the mid to late afternoon. Given the model
disagreements, PoPs have been cut back from categorical, except in
SW VA where confidence is highest. CAPE values of will support some
strong to severe storms, but deep shear is rather weak. A marginal
wind threat is possible, and given the unidirectional winds and
expected storms in the same area this evening, training of storms
may pose a threat of flooding in some isolated locations.
&&
.LONG TERM...
(Thursday night through next Wednesday)
Issued at 308 PM EDT Wed May 22 2024
Key Messages:
1. An unsettled period with multiple rounds of showers and
thunderstorms for the period.
2. Some of the storms may be strong to severe at times, with the
higher chances for severe storms looking like the weekend and
possibly into Monday. Localized flooding will also be possible.
Discussion:
The period begins with flat ridging over the Gulf and a series of
upper lows over the northern plains. These conflicting sets of
features will meet overhead, contributing to disturbances that will
move in the zonal flow over us to bring convection-triggering
convective rounds for the rest of this week.
By Sunday, that northern parade of troughs will orient somewhat
further south, and begin the process of what will become a deepening
Great Lakes upper low which will usher a cold-frontal line of
convection through the area around Monday morning. This frontal
convection might be the primary risk for organized severe convection
for the period...otherwise a little something here or there is
possible on other days.
No day in particular has impressive QPF, but the repeated rainfall
will tilt the risk of excessive rainfall and localized flooding
upward by week`s end, and that will probably carry over through the
frontal passage event Monday morning.
Afterward, that 500MB low over the Great Lakes will deepen as it
slowly rolls eastward, and we look to end up on the northwest-flow
side of an omega-pattern central U.S. ridge. This will create
potential for additional disturbance-driven rounds of scattered
precip Tuesday and Wednesday, moreso around VA, before the blocking
&&
.AVIATION...
(00Z TAFS)
Issued at 632 PM EDT Wed May 22 2024
A line of showers and thunderstorms will move into the TRI and TYS
airports this evening. These storms will be weakening as the
atmosphere is more stable across the Tennessee valley. The storms
may move just north of the CHA airport.
For the rest of tonight, convection will move east and weaken by
midnight with plenty of clouds remaining mainly VFR conditions but
can not rule out a potential of scattered 1 kft clouds.
For Thursday, scattered convection will redevelop especially in
the afternoon at all TAF sites.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 68 86 67 83 / 20 30 40 60
Knoxville McGhee Tyson Airport, TN 65 80 64 79 / 40 60 50 70
Oak Ridge, TN 64 80 63 79 / 70 60 50 70
Tri Cities Airport, TN 62 78 61 79 / 50 80 50 70
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...DH
LONG TERM....GC
AVIATION...DH
Area Forecast Discussion
National Weather Service Nashville TN
809 PM CDT Wed May 22 2024
...New UPDATE...
.UPDATE...
Issued at 804 PM CDT Wed May 22 2024
All watches and warnings have been canceled for Middle Tennessee
for the remainder of the evening. So we get to relax for a few
hours before we get to do it all over again tomorrow. The mid
state is under a marginal risk of severe storms on Thursday,
mainly during the afternoon, as that`s when the HRRR brings the
bulk of the expected convection across the area. Forecast sounding
shows plenty of instability tomorrow afternoon, with steep mid-
level lapse rates, a mid-level dry later, weak shear, and plenty
of precipitable water. So the threats tomorrow will be more or
less the same as they were today. In the near-term, we may see
some redevelopment of showers and a storm or two overnight and
early tomorrow as a weak shortwave comes through our area, but
these probably won`t be anywhere close to severe.
&&
.SHORT TERM...
(Rest of today through Thursday)
Issued at 1151 AM CDT Wed May 22 2024
A few showers and storms were moving across far northern portions
of Middle TN. More storms were firing up back across West TN and
AR. Look for all this activity to increase in coverage and
intensity this afternoon out ahead of a cold front and surface
trough. Our most significant coverage and severe risk will come in
the 3 PM to 11 PM time frame as the storms from out west move our
way while coming together to form a possible MCS. Whether
individual cells or an MCS, the main concern this afternoon and
evening will be damaging winds. Some hail is possible. Very heavy
downpours should be expected, but the storms will be moving fast
enough to keep any flooding brief. Capes in our west are already
running over 2000 J/kg and short range models show values peaking
near 4000. Deep layer shear will approach 45kt, so the storms will
have a lot of energy. Thankfully low level shear is not favorable
for tornadoes, but the risk is not zero.
Thunderstorms will move east and gradually weaken late in the
evening. Some additional storms are possible overnight into
Thursday morning, but these are not expected to produce widespread
severe wx.
During the daytime Thursday, additional scattered storms will
form. Conditions will become unstable again, so severe wx is a
possibility. The setup does not look as organized for Thursday,
but still, a few storms may contain gusty winds and large hail.
&&
.LONG TERM...
(Thursday Night through next Wednesday)
Issued at 1151 AM CDT Wed May 22 2024
We continue to be concerned about stormy wx all the way through Memorial
Day. We will be in an unsettled pattern with west southwest flow
aloft bringing a series of waves across the region. The air will
continue to be unstable and moisture-rich with a deep tropical
connection. The holiday weekend will not be a total washout. There
will be periods of time and perhaps some entire days when the
balmy early summer wx beckons us outdoors. But, we must stay wx
aware, because the periods of thunderstorms could bring bouts of
severe wx and localized flooding with generally increasing hazard
potential through the weekend. Sunday and Memorial Day look the
worst at this point with all modes of severe wx in play including
damaging winds, large hail, and tornadoes.
Overall, there are a lot of moving parts in this forecast, so the
storm outlooks and forecast details are likely to need adjustment
each day. Have fun but stay aware! A drier, cooler, and much less
humid pattern is ahead just after Memorial Day.
&&
.AVIATION...
(00Z TAFS)
Issued at 624 PM CDT Wed May 22 2024
Storms continue to roll through Middle Tennessee, although CKV,
BNA and MQY are in the clear or soon to be in the clear as far as
lightning is concerned. Storms have yet to move through CSV and
SRB, so these make up the initial conditions for those TAFs.
Overnight, another shortwave will pass through the mid state and
bring additional showers and possibly a few more storms later
tonight and early tomorrow. However, the best chance for storms
will be during the peak-heating hours of tomorrow afternoon (just
like today). In the near term, we will monitor for fog as showers
end from west to east. Right now, we don`t expect widespread fog,
but the ground is wet from abundant rainfall during the
afternoon, so it`s worth keeping an eye on.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 68 83 67 84 / 100 80 70 80
Clarksville 66 81 66 82 / 90 90 70 80
Crossville 62 77 60 76 / 70 90 60 80
Columbia 66 82 65 82 / 70 80 70 80
Cookeville 64 78 63 78 / 80 90 60 80
Jamestown 62 78 61 77 / 80 90 60 80
Lawrenceburg 66 81 65 82 / 70 80 70 80
Murfreesboro 66 83 65 82 / 80 80 70 80
Waverly 65 82 65 82 / 80 80 70 80
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.......Rose
SHORT TERM...13
LONG TERM....13
AVIATION.....Rose
Area Forecast Discussion
National Weather Service Paducah KY
641 PM CDT Wed May 22 2024
.KEY MESSAGES...
- Storms are ongoing just south of the area and could move north
into the area in the coming hours. Some may be strong to
severe.
- Storm chances exist each day through the weekend. Some may be
strong to severe.
- Sunday is still the next thing to watch closely. SPC has us outlooked
at 30% (Enhanced, level 3 of 5) for severe chances.
&&
.UPDATE...
Issued at 640 PM CDT Wed May 22 2024
Updated Aviation discussion for the 00z TAF issuance.
&&
.DISCUSSION...
Issued at 247 PM CDT Wed May 22 2024
Storms are already blowing up to the south of the area this
afternoon and may evolve into an MCS that should stay south of our
area. Individual cells though may move north into the KY/TN border
counties. Aloft a shortwave is moving through the upper Midwest with
a sfc low north of MN and an attendant cold front draped through the
Midwest and on our door step just to the west and northwest. A
second round of storms may potentially form along the front
this evening and move through the area overnight. Right now the
RAP and the NAM seem to have the best handle on what is going on
with the current convection and both models suggest some slight
redevelopment along the front this evening and overnight but
nothing major. Our severe potential is there though with about
2,000-3,000 J/kg of MUCAPE, 45-50 kts of 0-6 km shear, and mid
level lapse rates around 6.5 to 7 degC/km. The main severe
threats would be hail and damaging winds with supercells being
the primary mode.
Tomorrow through the weekend multiple small shortwaves are expected
to bring storm chances each day. The aforementioned front will stall
over the area during this time and could act as a focus for storm
development. Some of these storms may be marginally strong to severe
particularly during the afternoon and evening hours. A lot will
depend on daytime heating leading to greater instability.
Sunday is still very much a day to watch closely as a more broad
double barrel trof moves over the Rockies and central Plains. There
is a little discrepancy between the EC and the GFS however as the EC
has the sfc low over the MO/KS/IA/NE region vs the GFS which has the
sfc low centered more over KS. Both models though have the waves
taking a similar track towards the upper Midwest with a front to the
south. Sunday afternoon dewpoints look to get into the 70s in both
models. The GFS has stronger MUCAPE at around 3,500 J/kg vs the EC
at about 2,500 J/kg (likely owing to earlier onset of convection).
Both models support 40-50 kts of 0-6 km shear and mid level lapse
rates around 8.5 degC/km. Once the front moves into the area it
could serve as a focus for convective development Sunday afternoon.
Another element that is concerning is the CSU Machine Learning
Program has us pegged at 60% for severe chances, this is the same as
it was on May 8th (and the CSU MLP has been performing well lately).
That being said, it`s not surprising that SPC has us outlooked at
30% (Enhanced, level 3 of 5) for Sunday.
Monday the front comes through (which could be drier than what the
NBM currently has). Aloft a double barrel low circulates over the
Great Lakes region and swings the western low down through the upper
Midwest on Tuesday evening. This could bring a few weak storm
chances to the area Tuesday afternoon and evening.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 640 PM CDT Wed May 22 2024
Convection has exited the area, and a lull in precipitation is
expected until 09-12z, when another wave of showers and isolated
thunderstorms will move into the region. Cigs will lower to MVFR
with this activity, before improving back to VFR Thursday
afternoon as we dry out again. Winds will be light and variable
through Thursday morning before becoming S-SW around 5-10 kts.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...DWS
DISCUSSION...SHAWKEY
AVIATION...DWS
Area Forecast Discussion
National Weather Service Tulsa OK
754 PM CDT Wed May 22 2024
...New UPDATE...
.UPDATE...
Issued at 753 PM CDT Wed May 22 2024
The more recent runs of the HRRR and the 18Z EC suggest an
increase in storm coverage later on tonight from SE OK up into NW
AR. The non-HRRR CAMs are quiet for tonight, but don`t have the
shower activity that`s already popping up on radar there, and the
more aggressive storms across NE TX. With plenty of elevated to
near surface-based instability and deep layer shear, any storms
that develop will pose a severe weather threat. Despite the more
favorable near surface based moisture/instability in the lower AR
River valley, weak low level shear will limit the tornado threat.
Lacy
&&
.SHORT TERM...
(The rest of this afternoon )
Issued at 132 PM CDT Wed May 22 2024
A surface boundary is slowly working its way south across far
southeast OK. Thunderstorms, any of which could become severe,
will continue to develop at times through the remainder of the day
near and north of this boundary. All severe hazards will be
possible near the boundary, with hail being the primary hazard
north of the boundary. North of I-40, elevated storms may also
pop up at times. The severe threat will be lower, but not zero,
with marginally severe hail possible in any stronger storms. Areas
of heavy rainfall will occur with any storms, so the Flood Watch
for southeast OK and parts of west-central AR will continue
through the afternoon to account for this threat.
Overnight, scattered showers and storms will continue to develop at
times, especially for southeast OK and northwest AR. But
confidence is low on exact timing and strength as CAM guidance has
been inconsistent. The overall severe threat may trend down
somewhat tonight, but isolated severe storms are still possible.
Lows will range from the upper 50s to mid 60s most areas.
&&
.LONG TERM...
(Tonight through Wednesday)
Issued at 132 PM CDT Wed May 22 2024
The same general pattern will remain locked in through Saturday with
a deep trough across the northwest and a ridge in the southeast. As
shortwaves periodically rotate through they will bring lift and
enhanced wind shear over an exceptionally moist and unstable lower
atmosphere.
One such shortwave will move through Thursday. It is unclear whether
there will be sufficient low level convergence and lift to support
convective initiation, but the upper levels show good divergence as
the area will be in the left exit region of a jet. CAM guidance is
uncertain on timing and intensity of convection, but scattered
thunderstorms will likely develop. A few of the storms will become
severe with wind and hail being the more likely threats, though an
isolated tornado may also occur. A weak boundary moves through
Friday morning, and storms should continue at times through then.
Presumably storm coverage will decrease somewhat behind the
boundary, but with plenty of moisture and instability still in
place, storm activity can`t be ruled out. The best chance for
storms Friday will be over the higher terrain of eastern OK and
northwest AR. Highs will be below normal Thursday, generally in
the upper 70s to lower 80s, increasing to the low to mid 80s
Thursday.
A stronger shortwave and associated surface cold front will move in
Saturday. Overall this looks to be the most likely day for
widespread thunderstorms and severe weather within the forecast
period. The environment will support all severe hazards within
the stronger storms. Ridging builds in west of the area Sunday
into early next week. With decent northwest flow and plentiful low
level moisture and instability, the storm chance will not be
zero, though presumably the severe weather threat should be lower
than this week. Normally we see increase nocturnal MCS activity in
this type of pattern, which is also increasingly common heading
into June, so bumped up NBM pops a bit each day to mentionable to
account for this possibility.
&&
.AVIATION...
(00Z TAFS)
Issued at 635 PM CDT Wed May 22 2024
MVFR cigs will remain localized across parts of NW AR
for the early part of the TAF period, with MVFR/IFR cigs becoming
widespread after 06z-09z. At this time, uncertainty will preclude
any prevailing TSRA this issuance, but will include VCTS at KMLC
for part of the overnight period. IFR cigs should rise to MVFR
categories by late morning, with MVFR cigs prevailing there and at
the remaining sites through the rest of the valid period.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 63 81 68 84 / 20 30 40 20
FSM 67 84 69 87 / 70 50 60 20
MLC 65 83 68 86 / 60 60 40 20
BVO 58 80 64 82 / 10 30 40 20
FYV 61 82 65 83 / 70 60 60 30
BYV 62 81 65 83 / 70 40 50 30
MKO 63 80 67 84 / 50 50 50 20
MIO 61 81 66 80 / 40 30 50 30
F10 63 80 67 85 / 40 60 40 20
HHW 66 82 68 87 / 80 50 50 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch through Thursday evening for OKZ049-053-072>076.
AR...Flood Watch through Thursday evening for ARZ019-020-029.
&&
$$
UPDATE...30
SHORT TERM...06
LONG TERM....06
AVIATION...23