Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/24/20
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
950 PM CDT Sat May 23 2020
.UPDATE...
Issued at 947 PM CDT Sat May 23 2020
Made some changes to the pops to account for convection trends so
far this evening. Best chance for severe would appear to be
Missouri valley where stability progs and developing LLJ support
as much. Further east showers and some storms are likely, but the
risk for severe looks low over northeast SD. Southeast SD is
probably where the best support is for a long lived MCS with
occasional severe weather.
&&
.SHORT TERM...(This Evening through Sunday Night)
Issued at 345 PM CDT Sat May 23 2020
Storms developing this afternoon across western sd along a
stationary front. Expect thunderstorm development to be slow to the
east into our western cwa this evening and into tonight as this
focus area/front moves/pushes east with a surface low pressure area
lifting along it. The latest spc analysis and rap forecast cape and
deep layer shear show western sd with the best ingredients for
severe weather into this evening. The good instability and shear
build/move into central sd into the late evening and then weaken
diminish through the night into our eastern cwa. Therefore, expect
the best thunderstorm and rain coverage to be in our western cwa
with the storm coverage diminishing through the night into the
eastern cwa with more showers late tonight. Otherwise, there will
probably be a break in the action Sunday morning in the cwa with new
development Sunday afternoon and night with the main upper level low
pressure trough out west bringing more lift to our region. Also,
some sunshine under the colder air aloft will bring some good
buildup of instability Sunday afternoon and evening. The surface
cold front should push through most of the region through Sunday
afternoon with possible breezy conditions in the western cwa. Highs
on Sunday will range from the upper 60s far west to the upper 70s
far east.
.LONG TERM...(Monday through Saturday)
Issued at 345 PM CDT Sat May 23 2020
Differences show up right away in models in regards to Monday`s
weather. 12Z EC shows a surface wave moving northward along the
boundary and bringing showers and thunderstorms to the eastern CWA,
whereas the GFS and Canadian solutions keep things further east and
mostly dry. Have chance POPs in right now, but may need to make
adjustments over the next couple models runs based on what happens.
Otherwise, no major changes to the extended period forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
Issued at 616 PM CDT Sat May 23 2020
Terminals KABR,KATY,KPIR,KMBG
KPIR/KMBG are under the threat of showers/thunderstorms this
evening, with severe weather possible, especially around KPIR.
Further east, KABR and KATY will see some late night showers and
storms, but severe weather appears unlikely. The showers could
linger into the morning on Sunday.
***Construction to improve the taxiway for runway 13 at the KPIR
terminal may cause an occasional temporary visibility reduction due
to blowing dust (bldu), mainly during daytime hours UFN.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...TDK
SHORT TERM...Mohr
LONG TERM...TMT
AVIATION...TDK
Area Forecast Discussion
National Weather Service Binghamton NY
908 PM EDT Sat May 23 2020
.SYNOPSIS...
A weak cold front will move through Sunday night and trigger
scattered showers and storms. High pressure builds across much
of the Northeast through the week with warming temperatures and
a chance of afternoon showers and storms nearly everyday this
week.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
9 pm update...Forecast remains mostly on track. Made some minor
changes to sky cover. With all the low clouds just about gone
from the region and just a thin cirrus layer overspreading the
area that you can see stars through, so have made conditions
overnight just partly cloudy. Only exception will likely be
from Luzerne County eastward to Pike County, as easterly flow is
trying to push a marine layer into the area through the early
morning hours.
6 pm update...Shower activity has really diminished over the
past hour as upper level low continues to push off to the east.
Have lowered PoPs through this evening with the greatest chance
for any showers across NE PA until sunset. Only other changes
made at this time was to slightly decrease cloud cover based on
latest METSAT and observations.
320 pm update... Main concerns in the near term are focused on
the persistent/redeveloping showers and storms from the srn tier
of NY into ne PA this afternoon...the cool and quiet weather
tonight and the next round of scattered showers and storms
Sunday night into early Monday morning.
A trailing wing of the cut-off upper low currently off the srn
Jersey coast is sweeping east to south across the region this
afternoon...and interacting with a fair amt of instability and
available deep moisture. Latest RAP mesoanalysis shows around
500-1000 J/kg of CAPE across ne PA...steepening low level lapse
rates due to some breaks in the cloud cover, and shallow mid
level lapse rates as the upper low moves out. PWATs are still
around 1-1.3 inches and capable of supporting convection with
echo tops above 30k ft...which may be able to drop a half to 1
inch of rain in a short period of time, especially for those
storms that either train over the same area or become quasi-
stationary. So far, the convection has been fairly progressive
this afternoon, which has limited the potential for any
hydro/flooding issues. In addition, the rain this afternoon is
occurring over an area that was void of the mod/steady rain from
last night.
The trends should remain the same through the rest of the
afternoon and into the early evening as the drier and more
stable air moves in behind the departing low. Showers and storms
are expected to diminish in intensity and coverage...and come
to an end just before or around sunset.
A small scale surface high builds in off the Maine coast
tonight and combines with the low to the south to induce a solid
east wind off the Atlantic, which is expected to push all the
way into central NY. There is still some uncertainty in exactly
what this will result in, but the consensus is that a cool, but
dry air mass will create favorable conditions for temperatures
down into the 40s east of I-81 in NY and PA...but remain in the
50s to the west.
Ridging aloft and the surface high to the east will be the
primary factors in keeping weather conditions quiet through most
of the day Sunday. Winds shift to the south/se and allow for a
slightly warmer air mass. Temperatures should climb into the 70s
for much of the area with relatively low dew points...in the
50s...making it feel quite comfortable.
The next round of showers and storms is expected to arrive from
the west Sunday evening/night as an upper short wave cuts
across the Great Lakes into nrn NY and drags a weak cold front
through the area. There could be a decent amt of instability
combined with enough forcing aloft to trigger some embedded
thunderstorms through the overnight hours.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
3 PM Update...
A chance for showers, perhaps with some rumbles of thunder, will
continue through Monday afternoon as a weak midlevel trough passes
through the area. As a surface high remains in control from New
England through the mid Atlantic, precipitation will have trouble
being able to spread too far eastward, with our chances likely
staying contained to our western NY zones. Modest instability aloft
will keep a chance for thunder in the forecast, but this would have
to overcome a developing capping inversion as a ridge builds back in
behind the passing wave. This will help to wind down chances for
lingering showers overnight Monday. Much of the area will be dry for
Tuesday with the apex of the ridge generally over eastern NY and PA
and inhibiting convection over those areas. Some shower/thunderstorm
activity would be possible across our western zones, but being
diurnally driven with no real forcing mechanism, organized
convection is not expected.
Otherwise, expect a warming trend to continue into the short term
period as temperatures reach into the upper 70s and even lower 80s
across the Finger Lakes and Ontario lake plain. Temperatures fall
back into the 50s and 60s Monday night before peaking in the 80s
across most of our forecast area Tuesday - with some of the valleys
possibly reaching into the mid/upper 80s! Temperatures fall back
into the 60s Tuesday night.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
3 PM Update...
Wednesday will be much the same as Tuesday as we remain under the
control of the upper level ridge that is slowly shifting more
offshore. This will allow a chance for daytime convection mainly
across our western forecast area as temperatures peak in the 80s and
dewpoints hover in the 60s. As the ridge will be offshore Thursday
with a warm, moist airmass in its wake, any weak ripples in the flow
could touch off some showers and thunderstorms. Chances will
continue Thursday night through Friday as a trough moves into
eastern Canada. Otherwise, temperatures continue to peak in the
upper 70s and lower 80s - with some of the guidance hinting at
cooler temperatures Friday night as the aforementioned trough drags
a cooler airmass into the region.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Upper level low continues exiting out into the Atlantic. Showers
have come to an end with clearing skies across the region. Even
with the wet conditions from recent rain, have left any fog out
of the forecast tonight, as low level flow should be just strong
enough to hinder fog development. No forecast model guidance is
hinting at any valley fog at this time either. So VFR conditions
are expected through the forecast period.
Outlook...
Sunday afternoon through Tuesday...Likely VFR.
Wednesday and Thursday...Chance of showers and storms with
brief restrictions possible.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...BJT
NEAR TERM...BJT/MPK
SHORT TERM...HLC
LONG TERM...HLC
AVIATION...MPK
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
752 PM CDT Sat May 23 2020
.DISCUSSION...Updated for latest aviation discussion below.
&&
.AVIATION...Conv firing off to the west of the RGV is leaving
behind plenty of cirrus blow off over the region moving off to the
ESE. Meanwhile, vsbl satl imagery shows some SCT-BKN low clds
moving in off of the Gulf waters. Expect these MVFR ceilings to
become a little more widespread and lower later this evening and
tonight for all 3 RGV airports. The latest 88D mosaic across
the western areas of the EWX CWA extending down south into north
central Mex. A single large hail producing t-storm is firing about
115 NM WSW of the KBRO radar. This single cell is drifting
slowly SE and is not much threat to the RGV at this time. The HRRR
conv guidance seems to be initializing pretty well on this ongoing
conv. This model generally keeps the RGV clear of the conv until
closer to sunrise Sun. So for now will leave out any mention of
conv for the current TAF issuance until the later sections of the
TAFs where will include some PROB30 remarks.
&&
.PREV DISCUSSION... /issued 309 PM CDT Sat May 23 2020/
SHORT TERM (Now through Sunday Night): Satellite imagery and
surface observations continue to indicate some fair weather CU and
moderate to gusty winds across deep south Texas this afternoon.
Temperatures this afternoon generally range from the low to mid 90s
inland and mid to upper 90s near Falcon Lake. Adjusted high
temperatures a couple of degrees warmer for the rest of the
afternoon due to current trends. Brownsville radar currently shows
some convection across the higher terrain of northeast Mexico.
Latest satellite imagery indicates convection developing in
associated with a 500 mb shortwave moving over northern Mexico and
the Texas Big Bend region. This mid to upper level feature will
strengthen over central Texas through the day on Sunday. A weak
trough axis and vorticity will swing over south Texas tonight.
However, most CAMs models develop storms far west late tonight
before weakening as the convection approaches the CWA. However, low
confidence continues for rain chances for tonight and Sunday due to
differences in the model guidance.
Brownsville upper air data this morning indicate a PWAT value of
1.62 inches. PWATs will increase tonight to between 1.8 to 2.0
inches and remain high through Sunday night. Another stronger mid-
level support is expected to arrive Sunday night. Any convective
would likely contain locally heavy rainfall, with minor flooding
possible, especially in low lying and poorly draining areas. SPC Day
2 convective outlook has the entire CWA outlined in a marginal risk
for severe weather Sunday and Sunday night. Also, WPC has most of
the CWA into a slight risk for excessive rainfall Sunday into Sunday
night. The best rain chances and potential of heavy rainfall appears
to be Sunday night into Sunrise Monday as the mid level energy
passes overhead.
LONG TERM (Monday through Saturday): The long term period continues
to look wet and unsettled. A deep mid to upper level trough will dig
into the Central Plains on Monday. As it continues to deepen into
the Southern Plains, a mid level cutoff low will form at its base,
effectively detaching itself from the mid level westerly flow. This
will allow the cutoff low to camp-out over the state of Texas
through the end of the period. With ample surface moisture streaming
in from the Gulf over the region and conditional instability in
place, the nature of the convection that forms will depend primarily
on the timing and location of mesoscale interactions...namely, the
vort maxes that circulate around the low as well as any surface
features including convective outflows. While there is generally
good agreement between the models on the wet forecast through the
period because of this general pattern, the exact onset, location,
and duration of the showers and thunderstorms that may develop is
very hard to forecast at this time. The Weather Prediction Center
(WPC) has included all of Deep South Texas and the Rio Grande Valley
in a marginal risk for excessive rainfall on Monday and Monday night
as the first round of mesoscale features interact in the long term,
but the potential for local areas to receive flash flooding
conditions will likely continue through Wednesday morning.
The better rain chances look like they will be concentrated mostly
to our north through the period, but WPC`s Day 1-7 QPF shows most of
Deep South Texas receiving 2.50" to 3.0" of total rainfall through 7
AM CDT next Saturday, but locally higher amounts are possible. This
is likely to change as we get a better understanding of the mesoscale
features driving the convection through the period. The best rain
chances for our area look to be on Monday through Tuesday and again
late in the week, but at least slight chance PoPs will continue
through the entire period at this point. The potential for isolated
strong to severe thunderstorms continues for Monday through Tuesday
night when instability is the greatest for our area, but remains a
low probability at this point. The Storm Prediction Center`s Day 3
Severe Weather Outlook only has Deep South Texas in a general
thunderstorm risk.
Temperatures next week will continue to depend on the cloud cover
and any rain and thunderstorm development, areal coverage and
longevity.
MARINE: Now through Sunday Night...Buoy 42020 reported east-
southeast winds around 14 knots gusting to around 18 knots with
seas slightly under 4.9 feet with a period of 7 seconds at 1420
CDT/1920 UTC. The pressure gradient is expected to weaken as broad
high pressure across the Gulf moves further northeast. Moderate
southeast winds and moderate seas will prevail through the period.
Small Craft Caution conditions are likely across the bay Sunday
afternoon due to winds. Small Craft Caution to low end Small Craft
Advisory conditions are possible across the Gulf of Mexico waters
due to elevated winds and swell through Sunday night.
Monday through Saturday...Elevated seas of 3 to 5 feet will start
off the week and generally subside through the period to 1 to 3
feet. Showers and thunderstorms will be possible on and off
through next week, and localized winds and seas will be affected
by any outflows produced by any strong storms that may develop.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
This product is also available on the web at:
HTTP://WEATHER.GOV/RGV
Short Term/Aviation...60
Long Term/Upper Air...65
Area Forecast Discussion
National Weather Service Grand Forks ND
1007 PM CDT Sat May 23 2020
.UPDATE...
Issued at 1004 PM CDT Sat May 23 2020
Continuing to see showers with a few embedded thunderstorms
across western portions of the Devils Lake basin with HRRR
suggesting that the activity will continue for a couple more hours
as MUCAPE around 1000j/kg fuels the activity.
UPDATE Issued at 645 PM CDT Sat May 23 2020
Line of convection has developed this evening from near Leeds ND
and northward. With weak shear expecting the slow motions to the
north northeast with localized brief heavy downpours and possibly
some small hail and gusty winds. This activity will remain across
the Devils Lake basin for the evening. The light precipitation
across the MN lakes and trees has ended.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 235 PM CDT Sat May 23 2020
Lower level clouds continue dissipating this afternoon, with mid-
level cloud cover gradually diminishing from west to east. Shower
activity is currently ongoing in western portions of ND with the
expectation of a slow eastward progression along a frontal boundary
this afternoon. Ahead of the primary theta-e gradient, we could see
a few strong storms develop later this afternoon into the early
evening. CAMs and mesoanalysis indicate CAPE values in the 2000 to
2500 J/Kg range across much of central North Dakota as clearing
takes place and afternoon heating becomes a factor. Instability
sharply drops heading east, but there remains enough to facilitate a
continued mention of potentially impactful strong thunderstorms this
afternoon and evening.
Tonight will be quiet across much of the area, with the Devils Lake
possibly seeing a chance for ongoing thunderstorm activity. Lows
will fall into the 50s. Thunderstorm chances increase for Sunday
across much of the forecast area with activity stretching into
Monday morning. At this time, there is a conditional risk for
isolated strong storms Sunday afternoon, mainly for west-central
Minnesota.
.LONG TERM...(Monday through Saturday)
Issued at 235 PM CDT Sat May 23 2020
Monday through Wednesday...The upper trough moving through the
Dakotas will continue to bring a decent chance for precipitation at
the start of the week. Some showers lingering along the backside of
the surface low, but there should be enough instability by afternoon
for some thunderstorm activity, although deep layer shear stays in
the 20-30 kt range so do not think our severe chances are that high.
Clouds and some cold air advection on the backside of the surface
low will help keep temps in the 60s to low 70s Monday, with some
upper 40s Monday night as drier air moves into the area. Another
trough moving through Canada Tuesday could bring some stray
convection into our northern counties, but for the most part think
the better chances will be with the forcing to the north. The
digging trough will help push a trough axis/front into the CWA on
Wednesday, so have POPs increasing a bit for anything developing
along the boundary.
Thursday through Saturday...Northwesterly flow aloft sets up, with
some model solutions showing ridge riders and some not. The
ensembles do not have any strong signal for precipitation, so kept
the blended solution of sub 20 percent POPs going. Thursday will see
surface high pressure and temps will stay close to the 70 mark.
However, rising heights Friday and Saturday should bring readings up
to or slightly above seasonal averages.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 645 PM CDT Sat May 23 2020
Went ahead and added VCTS to DVL this evening. MVFR CIGS expected
to develop once again overnight primary at BJI and possibly at TVF
and DVL. Rain showers possibly with thunder expected to develop or
move into the DVL first overnight and then into the valley around
mid day.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$
UPDATE...JK
SHORT TERM...Lynch
LONG TERM...JR
AVIATION...JK
Area Forecast Discussion
National Weather Service Goodland KS
544 PM MDT Sat May 23 2020
.UPDATE...
Issued at 456 PM MDT Sat May 23 2020
Updated the forecast to include the Tornado watch this
afternoon/evening spanning the CO/KS border area and extending
northeast into far SW Nebraska. Increased PoPs a bit along and
ahead of the dryline where storms are starting to fire and towards
the direction of expected storm prorogation.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 200 PM MDT Sat May 23 2020
Dry line beginning to take shape over northeast Colorado with a
westerly wind component and dew points dropping into the 20s and
30s. The dry line is forecast to move eastward through late
afternoon and be the focus for isolated thunderstorms. If storms
develop, the environment will be favorable for supercells capable
of producing large hail, damaging winds and tornadoes. Isolated is
the key word here, as CAMs continue to suggest only one or two
cells developing. Cirrus is a little more persistent than
forecast, somewhat limiting instability, but latest RAP shows CIN
eroding by 21z. Unless thunderstorm coverage is more than
expected, will probably handle it with local warnings as opposed
to a watch per coordination with SPC. Further north in the
Nebraska panhandle, forcing will be stronger resulting in better
coverage, but that complex is now expected to remain north of the
local area, so will have no POPs after about 04z tonight. Cold
front will move through and just about clear the area by 12z.
Breezy northwest winds can be expected through the night behind
the front. Low temperatures will range from the upper 40s in
northeast Colorado behind the front to the lower 60s in Norton
and Graham counties ahead of it.
Sunday the area will be post frontal. There is a low chance that
the front will hang up/or be just near the far southeast part of
the area when thunderstorms develop on it around 21z. However,
think more likely the front will be clear of the area and not be a
factor. Instead will look west to the Front Range where large
complex of rain/isolated thunderstorms will develop as main upper
trough axis emerges. Those storms will move across the area Sunday
night. Main hazards will be wind during the evening hours
associated with any cold pools/bowing structures, as well as heavy
rain, especially after midnight. Global models suggesting some
areas will receive 1 to 1.5 inches Sunday night. High temperatures
Sunday afternoon will range from the upper 60s to upper 70s and
lows Sunday night in the middle 40s to lower 50s.
Upper trough will be slow to move out on Monday. It will be cloudy
and cool with lingering rain/showers likely. Not expecting severe
storms due to lack of instability. High temperatures will be in
the 60s, and may be a bit too warm with clouds all day. Coolest
guidance is in the upper 50s to lower 60s which may be in the
right direction. Precipitation will end west to east Monday night
as upper trough finally starts to move out. Low temperatures will
be in the 40s.
A few showers may linger into Tuesday in far eastern areas,
Norton to Hill City, but otherwise dry and warmer with high
temperatures in the 70s and light winds. Temperatures will dip
back into the 40s for Tuesday night.
.LONG TERM...(Wednesday through Saturday)
Issued at 216 PM MDT Sat May 23 2020
A 500mb closed low retrogrades across the southern Plains slowly
Wednesday through Saturday and weakens as ridging pushes into the
central U.S. At the surface, high pressure sits over the central
Plains. A cold front stalls over the northern Plains by Saturday.
The extended forecast period is dry but at this time, no elevated
fire weather concerns. High temperatures will range from the upper
70s to mid-80s and lows will be in the 50s. Skies will be mostly
sunny to partly cloudy throughout the extended forecast period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 507 PM MDT Sat May 23 2020
VFR conditions are expected at GLD through the 00Z TAF period.
Southeast winds overnight will turn north after 11Z with he
passage of a cold front. North winds will increase and become
gusty after 17Z. Scattered thunderstorms are expected after 21Z.
MCK will remain VFR through the 00Z TAF period. Southeast winds
tonight will turn northerly early Sunday after 08Z with the
passage of a cold front. Between 04Z-10Z, LLWS is expected with
winds at 1kft AGL of 35kts out of the southeast turning to the
southwest after 08Z. By 10Z, LLWS will diminish as winds turn
north and increase. Scattered thunderstorms are expected after
21Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Red Flag Warning until 8 PM MDT this evening for KSZ027-041.
CO...Red Flag Warning until 8 PM MDT this evening for COZ252>254.
NE...NONE.
&&
$$
UPDATE...LOCKHART
SHORT TERM...024
LONG TERM...NEWMAN
AVIATION...LOCKHART
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
621 PM CDT Sat May 23 2020
.SYNOPSIS...
Issued at 305 PM CDT Sat May 23 2020
H5 analysis from earlier this morning had an active
pattern noted across the CONUS. Closed lows were noted over central
PA, central Iowa and a third system over far northern Utah. The
third system over Utah, had a trough extending south into western
Arizona and far southern California. At midday, the Utah low, was
now located over west central Wyoming per the latest WV imagery. At
the surface: Low pressure extended from far southeastern Wyoming
into southeastern Colorado. A dryline extended from west of Limon
Colorado into the western Texas panhandle. South southeast of the
surface low in SE Wyoming, a weak convergence boundary was noted and
extended to north of Burlington Colorado. Skies were partly to
mostly cloudy this afternoon across the area and 2 PM CDT
temperatures ranged from 72 to 76 degrees.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 305 PM CDT Sat May 23 2020
Tonight thorugh Sunday night...Precipitation chances
tonight and Sunday night and the threat for severe storms tonight
are the main forecast challenges in the near term. For tonight: The
12z LBF Raob sounding from this morning indicated a strong capping
inversion with a convective temperature in the middle 80s. Highs
this afternoon are expected to reach the middle to upper 70s.
Forecast soundings from further west in far southwestern Nebraska
and the eastern Nebraska panhandle, indicate the capping inversion
remaining in place through peak heating this afternoon. That being
said, not expecting much in the way of storm initiation across the
forecast area late this afternoon. Further west though, the latest
NAM12 soln is indicating a weakening cap around 21z Saturday. The
last few hourly runs of the HRRR develops convection SE of Sterling
Colorado around 21z, approaching far SW Nebraska in the 5 to 6 PM CT
time frame this evening. Deep layer shear of 35 to 40 KTS will
adequate for supercells. Mid level lapse rates (H70-H50) are very
steep across sw and west central Nebraska. This would favor large
hail and even a very large hail threat across far western portions
of the forecast area through 01z Sunday. As for the tornado threat,
the capping inversion is problematic. Also low level helicities are
meager. That being said, the tornado threat appears limited and
confined to far western portions of the forecast area in a short
window, say 4 to 8 PM CT. As for precipitation chances, they will
remain greatest in the northern forecast area. As storms migrate off
of the panhandle early this evening, they are expected to congeal
into a convective complex, enhanced by the development of a low
level jet overnight. ATTM, not too concerned about flooding as the
heaviest rain is expected north of areas which saw the heaviest
rainfall earlier this week. Later this evening, there will be some
wind threat with the convective complex as it tracks east. The
latest NAMnest and HRRR solns indicate some bowing storm structures
within the convective complex.
The H5 low, will lift into eastern Montana overnight into Sunday
morning, forcing a front through the area by mid morning. This front
will then stall off to the south and east of the forecast area and
will be the focal point for showers and thunderstorms Sunday
afternoon/Sunday night. Other showers and storms may develop across
eastern Colorado Sunday afternoon, INVOF the front and near the base
of the H5 trough. Some of this activity may extend into SW then
Southern and portions of central Nebraska Sunday night. Have kept
pops going in the south, southeast and east Sunday/Sunday night, but
trimmed them back in the north as these areas will be well north of
the front and appreciable forcing will be very limited in these
areas. Skies will be mainly cloudy Sunday which will limit temps to
the 60s to around 70 for highs. The h5 low will weaken and meander
slowly east into the western Dakotas Sunday night. The front will
remain anchored off to the east of the forecast area, so pops will
be highest in the east with mainly dry conditions expected in the
west and northwest.
.LONG TERM...(Monday through Saturday)
Issued at 305 PM CDT Sat May 23 2020
The mid range solutions
including the ECMWF and GFS from this morning, develop a cutoff low
over central Texas into the Arklatex next week. Ridging to the west
of this feature will develop from the four corners, north into the
northern Rockies by late next week. Moisture will be locked in over
Texas with the cutoff, so am expecting mainly dry conditions across
the forecast area next week. This shows up in the latest MEX
guidance, which is well below climo for pops next week. Temperatures
will increase into the upper 70s to lower 80s next week with the
ridging off to the west. However with the axis of this feature
aligned over the Rockies, the hottest temps should remain west of
the forecast area.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 620 PM CDT Sat May 23 2020
Thunderstorm activity across the Panhandle this evening will move
east and expand in coverage across wrn and ncntl Nebraska
overnight affecting areas generally north of Interstate 80.
Isolated storm coverage is expected along and south of the
Interstate. All storm activity should exit the region by 12z
Sunday. VFR is generally expected across wrn and ncntl Nebraska
thereafter.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...CDC
Area Forecast Discussion
National Weather Service Marquette MI
815 PM EDT Sat May 23 2020
.SHORT TERM...(This evening through Sunday)
Issued at 335 PM EDT SAT MAY 23 2020
A warm, and muggy for UP standards, start across the board this
morning as increasing high- and mid-level clouds moved in from the
south. GOES imagery and RAP analysis show a sfc low across Iowa that
is essentially collocated with a shrtwv trof. This trof and assoc sfc
low is progged to lift through the Great Lakes region tonight,
bringing rain showers and the chance at a thunderstorm or two as
well. As this shortwave continues lifting northward, expect cloud
coverage to continue to increase. More locally, a few -SHRA popped
up as a wave moved across the UP and crossed over the lake breeze.
Temperatures were held down into the upper 60s to near 70 across
the west and under more sunshine the east climbed to near 80.
Tonight, models suggest that sfc low and shortwave will lift through
northern Lake Michigan. Models still show quite a bit of different
solutions, but the mean of them suggest the chance for -SHRA from
Marquette/Dickinson county east. There is a bit more agreement on
the chance of -TSRA along Menominee, Delta, and Schoolcraft
counties, though. Models show the CAPE tonight is a little elevated,
just above the nocturnal inversion, but to the tune of a few 100
J/kg. With little to no shear, and jet dynamics remaining well to
the south there isn`t much chance for anything to become
significant. As these clouds linger through the night and PWATs are
near 1.5 inches, went with a little higher lows for tonight than the
going fcst...but still should fall into the mid to upper 50s.
Included some patchy fog in this forecast as low-level moisture
lingers and weak upslope flow from WI brings an increased chance.
Models aren`t all in agreement for fog, but the best chances seem to
be across the central where low-level moisture will continue to
increase, leading to the best chance to produce some fog.
Tomorrow, there may be some linger -SHRA across the east half of the
UP in the morning, but then models suggest dry conditions in the
afternoon. As the shortwave exits east, models do suggest some
shortwave ridging to move in behind it with rising heights.
Expecting this to lead to some clearing in the afternoon from west
to east, but we shouldn`t tap into any abundant sunshine. Went with
the 50th percentile for highs which brings widespread 70s with some
low 80s across the downslope-favored areas. With weak synoptic
forcing, winds will be generally light, which should allow another
lake breeze to develop in the afternoon. Didn`t include any PoPs in
the forecast, but given the high Tds expected tomorrow, any
afternoon shower or two along the lake breeze seems possible.
.LONG TERM...(Sunday night through Saturday)
Issued at 335 PM EDT SAT MAY 23 2020
An upper level ridge will strengthen over the eastern U.S as another
blocking pattern develops for early next week. An upper level low
pressure pushing out of northern Rockies will split with a closed
low becoming cut off over the southern plains. Shortwaves
ejecting ahead of the upper level low will bring multiple chances
for precipitation to the Upper Peninsula through midweek. An upper
level trough and cold front arrive for the later part of the week
as the eastern high pressure ridge breaks down, bringing cooler
and drier air into the area.
Sunday night into Memorial Day. A steady feed of gulf moisture will
bring low level moisture into the area resulting in continued
muggy conditions, with warmer overnight lows and high temperatures
in the 70s to low 80s. Cooler temperatures can be expected along
the Lake Michigan and Superior shorelines as the lake breeze
develops in the afternoon. Ensembles are showing 1.25+ inches of
precipitable water with the deterministic GFS indicating values
of over 1.5 inches. Multiple shortwaves will affect the area
Sunday night into Monday night. These, combined with daytime
heating destabilization, should result in multiple opportunities
for isolated to scattered showers and thunderstorms, particularly
over the western 2/3 of the Upper Peninsula. Shear will remain
marginal with instability of 1000 to 2000 J/kg and therefore
widespread organized thunderstorms are not expected at this time.
The biggest threat will be heavy rain with the higher precipitable
water values. Those recreating outdoors for the holiday should
keep an eye to the sky.
Unsettled conditions continue into Tuesday and Wednesday with a
possibility for more widespread precipitation though models still
diverge on solutions with the GFS being the wetter solution.
Medium range models indicate a fairly significant faster trend with
shortwave to usher in cooler conditions late week. Fropa may now
occur as early as Wed night/early Thu which would support dry
weather returning on Thu along with cooler conditions than currently
reflected in this fcst issuance. Dry weather would then follow on
Fri, perhaps lingering Sat.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 814 PM EDT SAT MAY 23 2020
VFR cigs are expected at KIWD and KCMX with the potential for
some fog toward daybreak. A Shower may be possible at KIWD late
this evening but probability is too low for mention as VCSH and is
not expected to drop conditions to MVFR.
VFR conditions at KSAW are expected to give way to lowering cigs to
MVFR and then to IFR toward Sun morning as additional moisture moves
into the area with an approaching weak trough. Showers may also be
possible late but the main batch of rain and TS potential should
remain to the south and east. Conditions should improve to VFR by
afternoon.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 335 PM EDT SAT MAY 23 2020
Little change to the forecast as winds will be generally light
through the period. A few waves will move through the region through
the week, but winds are expected to remain on the lighter side. The
air mass lifting up over Lake Superior over the next couple of days
will gradually moisten, and could result in some areas of fog at
times. However, where any showers, and potentially some
thunderstorms, develop and track will play a large role in where fog
may develop.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JAW
LONG TERM...NL
AVIATION...JLB
MARINE...JAW
AREA FORECAST DISCUSSION
National Weather Service Morristown TN
919 PM EDT Sat May 23 2020
.UPDATE...
EVENING UPDATE.
&&
.DISCUSSION...
Convection has all but ended across the area as this was diurnal
based activity. The latest HRRR shows the showers and storms
currently across northern Alabama gradually moving toward the
southern Plateau and southern TN valley but then fading before
entering the CWA. Still have a slight chance POP in place over the
next hour or two but then a dry forecast for the rest of the
night. Added some patchy and area fog into the grids for the
early morning hours. Will send out new zones for fog addition. All
other elements appear to be on track.
SR
&&
.AVIATION...
00Z TAF DISCUSSION.
Mainly VFR at all sites. Convective activity has all but subsided
across our area as we lose daytime heating. There is still a
slight chance for an isolated shower or storm over the next hour
or two near a terminal but not high enough chances to include in
TAFs. CHA will be VFR through the period. TYS will see a brief
period of MVFR fog tomorrow morning but otherwise VFR. TRI will
also see fog tomorrow morning but will go down to LIFR before
returning to VFR through the rest of the period.
SR
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 66 88 67 86 68 / 20 30 20 50 20
Knoxville McGhee Tyson Airport, TN 65 87 65 85 65 / 20 30 20 50 20
Oak Ridge, TN 64 87 65 86 65 / 20 30 20 50 20
Tri Cities Airport, TN 60 84 62 83 61 / 20 30 20 40 20
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
Area Forecast Discussion
National Weather Service Paducah KY
958 PM CDT Sat May 23 2020
.UPDATE...
Issued at 958 PM CDT Sat May 23 2020
Although difficult to discern without question, there still
appears to be weak troughiness or low embedded near a shear zone
moving toward the Missouri BootHeel and the southeast Missouri
Delta region during the past hour. Convection across northeast
Arkansas and west Tennessee loosely support this feature.
The recent runs of the HRRR and ESRL HRRR continue to support some
northward transport of this localized moisture and instability
into west Kentucky later this evening and overnight. Kept a small
chance of showers and isolated thunderstorms in place across
southern parts of west Kentucky and into southeast Illinois
overnight.
Although the probability will continue to diminish markedly,
cannot rule out a strong wind gust with any thunderstorm that
moves into the WFO PAH forecast area. Will leave a mention of an
isolated strong storm in the Hazardous Weather Outlook for the
remainder of the evening.
Otherwise, little if any changes to the sensible weather elements
for the remainder of the tonight`s forecast.
&&
.SHORT TERM...(Tonight through Monday night)
Issued at 247 PM CDT Sat May 23 2020
Our region will remain in an unsettled weather pattern through the
holiday weekend. Coverage has been sparse today, though the HRRR
and RAP indicate a few hours of convection late this afternoon
across the Pennyrile region north into portions of southwest
Indiana. Latest radar shows a couple of cells developing just
south of our CWA in west tennessee, and visible satellite shows
increasing cumulus development in the Pennyrile, so increased
chances through 00z for this area. Will keep slight chance pops
across the rest of our area until 00z.
Loss of heating should give us dry conditions overnight. A
mid/upper level wave will cross our area on Sunday, and with
daytime heating and available moisture, we expect better chances
of showers and storms across our entire region, especially in the
afternoon hours. Small chances will linger across our western half
of counties into the early evening. Loss of heating should again
give mainly a dry overnight.
On Monday, a more substantial mid/upper level trof over the
Rockies will be pushing into the Central Plains and a cold front
making its way toward the middle Mississippi Valley. This results
in even better chances of showers and thunderstorms for Monday,
and went with likely chances for Monday afternoon. With the cold
front continuing eastward, we will not be getting our nighttime
break from the convection, though chances will decrease.
We will remain warm and muggy through the period, with highs in
the middle to upper 80s and dew points in the middle to upper
60s. Overnight lows will be in the middle to upper 60s, which is
10 to 15 degrees above seasonal normals.
.LONG TERM...(Tuesday through Saturday)
Issued at 247 PM CDT Sat May 23 2020
The post holiday week forecast continues to look like summer. As we
remain in between strong high pressure to our east, and a
closing/eventually cut off Low to our west, we will have ample
warmth and moisture in the column each day. Instability will
continue to be best during the heat of the day, so lacking any
triggers, diurnally favored pops will be a lingering trademark in
our forecast. The best chance for any assisted lift/focus would come
from mesoscale outflow, or perhaps, some energy feeding into western
portions of the FA from the Low pressure area to our west, but
really, its primary influence will be tapping moisture/producing
heavy rainfall/storms across the southern Plains and into the Gulf
coast states.
There has been some model indication that a more active/progressive
northern stream flow will allow for a cold front to slip down into
the Ohio River Valley late in the week. If this occurs, this would
offer another trigger and lift support and some cooler/drier air
post fropa, the effects of which would likely not manifest until
next weekend. This is in fact the blend`s approach with a slight
downward trend in pop and temps/dew points next Saturday...and we
offer no argument against it.
&&
.AVIATION...
Issued at 609 PM CDT Sat May 23 2020
At the beginning of the 00z Sunday WFO PAH TAF forecast period, a
some middle and high clouds will likely spread over KCGI, KMVN,
and KPAH (and possibly KEVV), associated with lift along a
deformation zone associated with a minor low/shortwave over
central Arkansas this evening. Some high resolution model guidance
suggests that there may be convection (showers and thunderstorms)
that may approach or impact the KPAH and KCGI TAF sites. Given
the uncertainty in the northward extent of the potential for
evening convection to these locations, have opted to leave any
significant reductions to visibility or ceilings out of the
forecast.
At this point in time, given the low probability of precipitation
through 18z Sunday, decided to continue with a VFR forecast of
cloud bases and ceilings and visibilities for the forecast period.
The only caveat is from 18z Sunday to 00z Monday on ceilings and
visibilities at all WFO PAH TAF sites. This time period may be
need to be reassessed in later TAF forecast issuances.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...Smith
SHORT TERM...RST
LONG TERM...DH
AVIATION...Smith
...Update to aviation forecast discussion...
.SHORT TERM...(This afternoon through Sunday night)
Issued at 328 PM CDT Sat May 23 2020
For this afternoon and early evening, there remains a conditional
chance for thunderstorms. And that condition is generally what
would cause a storm to initiate, i.e. lift or forcing. Forecast
soundings from the HRRR/RAP/NAM continue to show very little if
any inhibition to a boundary layer parcel this afternoon. With the
hot and humid air in place, forecast MUCAPE values remain in the
3000 to 4000 J/kg range. And while deep layer shear is rather
modest, effective shear around 35KT would be enough for a rotating
updraft. So there remains some concern for an isolated severe
storm into the early evening. If a storm is able to develop, very
large hail and torrential rain would be the most likely hazards.
As the low level jet increases this evening, the low level
hodograph is progged to expand suggesting there would be a tornado
risk around sunset. However confidence in storms developing is
low. The last several versions of the HRRR have backed off on
developing anything this afternoon. So chances for thunderstorms
are slight, but if one develops it could quickly become severe.
Later on in the night, there continue to be some indications from
the models for convection off the higher terrain to potentially move
far enough east to make it into the forecast. The NAM is the most
aggressive in showing storms from the dryline in southwest KS moving
through central KS. This solution doesn`t have much support from
other models. The NAM also look to have some convective feedback in
its solution which may explain the more aggressive propagation of
convection east overnight. In general there is not a lot of
confidence in storms moving this far east overnight since models
show little mid level height falls over eastern KS and the nose of
the low level jet is progged to set up over central NEB. Have
continued with some POPs overnight in case I`m wrong, but have
trended them lower. Lows tonight should not cool off to much with
good southerly flow and a moist airmass remaining over the area.
Think lows will end up in the upper 60s to around 70.
For Sunday, chances for precip will be on the increase during the
afternoon as there is good consensus for the prefrontal trough to
move into central KS by the late afternoon. Meanwhile the upper
trough over the Rockies should continue moving east with
perturbations likely to lift across the state. Given a very unstable
airmass still over central and eastern KS, storms are expected to
develop within the low level confluence of the surface trough during
the afternoon and continue moving east overnight. Initially storms
may be discrete but are forecast to eventually evolve into a linear
system. Large hail and damaging winds will be a concern with any
storm that forms on Sunday. Since I`m not that excited about
convection overnight, think there should be enough insolation
tomorrow for highs to again reach the mid 80s. Confidence in lows
for Sunday night is lower than normal since convection and cold
pools could drop temps cooler than otherwise they would be. Lows are
forecast to range from around 60 over north central KS to the mid
60s across the eastern counties.
.LONG TERM...(Monday through Saturday)
Issued at 328 PM CDT Sat May 23 2020
For Monday a frontal boundary oriented north south is progged to
remain over the area as the upper trough slowly begins to cut off.
Instability is expected to be lower since there should be less
chance for daytime heating due to cloud cover and occasional
precip. Then for Tuesday through Friday, the cutoff upper low is
progged to remain just south of the forecast area. Chances for
showers and thunderstorms remains in the forecast because of this
pattern with precip probably setting up in a diurnal pattern each
day. There are some indications the deformation zone associated
with the closed low will propagate south of the forecast area by
Friday with some dryer air working in from the northeast. So there
is some hope for dry weather to return by the end of the week.
Temps are expected to be rather seasonable given a lack of strong
temp advection. If we are able to see some sun, highs could bounce
up to near 80. Cloudy conditions with rain may keep highs in the
lower 70s. Lows should be in the upper 50s and lower 60s through
next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 545 PM CDT Sat May 23 2020
LLWS will develop after 3Z as the low level jet increases and the
boundary layer decouples. Expect VFR conds to prevail through at
least 18z Sunday with an increasing risk for tsra by late
afternoon. At this point we will not mention any precip since it
is so far out and focus on LLWS overnight.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Wolters
SHORT TERM...Wolters
LONG TERM...Wolters
AVIATION...Omitt