Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/26/22
Area Forecast Discussion
National Weather Service Des Moines IA
638 PM CDT Wed May 25 2022
...Updated for the 00z Aviation Discussion...
.DISCUSSION.../Tonight through Wednesday/
Issued at 320 PM CDT Wed May 25 2022
Key Messages:
-- Showers lifting into northern Iowa tonight, possible strong
storm in the southeastern Iowa 5-8pm
-- Turning drier, but still cool Thursday
-- Friday into next week warm, breezy, highest storm chances
northern Iowa and north of the state
Details: It has been a dreary day thus far with cloudy conditions
and intermittent light showers to drizzle. A more broad shield of
rainfall has been over eastern and central Kansas and now is more
even into southeastern Nebraska. This rainfall is all in the
deformation zone of the mid-level closed low that is centered
over Oklahoma and will slowly spin northward into eastern Kansas
before advancing eastward on Thursday. Associated with this mid-
level closed low is a surface low approaching Kansas City. Recent
visible satellite imagery shows limited breaks in the clouds over
northern Missouri with even more substantial breaks over the
Ozarks. Day Cloud Phase Distinction RGB better diagnoses and
distinguishes between low clouds and more convective clouds and
shows breaks that have entered into our southeastern forecast
area. Regional radar shows a line of showers and storms over
central Missouri with most of the lightning in far southern
Missouri. While recent runs of the HRRR have this falling apart as
it lifts northward, extrapolating timing if it holds together
would be close to 22z. 17z and 18z runs of the Experimental Warn
on Forecast System (WoFS) has similar timing as well reaching the
southern Iowa border of Appanoose and Davis counties by 2230z.
Further, HRRR updraft helicity tracks have been near if not just
east of Davis/Wapello counties more so in DVN`s area. SPC 18z
mesoanalysis did not show much in the way of surface based
instability, but did expand northwestward with 500 to 1000J/kg in
our far southeast forecast area at the 19z analysis. Both the 18z
and 19z analysis is farther northwest than the RAP has modeled.
HRRR and RAP forecast sounding runs this morning starting at 12z
through about 17z have shown good turning below 1km aided by
southeast or easterly winds at the surface. However, winds become
unidirectional/straight around and above this level. As noted
yesterday and last night, the saturated sounding results in weak
lapse rates and not enough instability for concerns of hail or
wind. So, the threat if one materializes will be a tornado and
likely between 5 and 8pm. Funnel clouds cannot be ruled out with
convergence in southeastern Iowa with Oskaloosa and Ottumwa having
southeast winds at 3pm and Pella and Knoxville having northeast
winds along the boundary. This along with low LCLs lends itself to
this idea, but will need instability to have sufficient 0-3km
MLCAPE for funnel clouds and stretching to occur. Showers are
expected to become more focused over northern Iowa through the
overnight hours and fog could develop in southern areas with the
low level moisture and light winds.
Scattered showers will largely come to an end as the deformation
zone transitions eastward tonight into Thursday morning with
subsidence sliding into the state. 18z HRRR does show storms
redeveloping north of the mid-level closed low over Missouri
Thursday afternoon. While this may back into our southeastern
forecast area, the more robust activity once again seems to be
east of our forecast area.
Ridging will begin to move over the region on Friday, which will
bring higher heights and warmer conditions to the state. The ridge
axis will be pushed east of the state on Saturday with more
southwesterly to at times southerly flow Sunday into the middle of
next week. It also looks to be breezy with sustained surface winds
of 15 to 25 mph and gusts of 30 mph or higher (especially on
Sunday with higher gusts) during the daytime hours each day
Saturday through Memorial Day. Shortwave troughs will eject
through this southwesterly flow and look to be mostly north or
northwest of the state through Memorial Day as well. However,
looking at ensemble guidance from the 00z runs of the ECMWF, GFS,
and CMC, it`s possible storms could pass over portions of the
state with this most likely being northern Iowa, which will be
closer to the shortwave and jet stream track. Thus, initial NBM
guidance showing chance PoPs over northern Iowa does not seem
unreasonable at this time horizon. Compared to yesterday`s 00z
runs of the Colorado State`s machine learning random forest
outlook and the CIPS Experimental Analog-Based Severe Probability
Guidance, both have backed off their widespread probabilities
over Iowa on Memorial Day with higher chances north and west of
the state. As mid-level high pressure develops over the Tennessee
into the Ohio Valley early next week, this will bolster and
amplify the ridge with higher heights over Iowa compared to this
weekend Monday into Wednesday. This may help to push storm chances
north of the state and temperatures remaining above normal.
&&
.AVIATION.../For the 00Z TAFS through 00Z Thursday evening/
Issued at 634 PM CDT Wed May 25 2022
Most of Iowa is under stratiform cloud cover and this has brought
IFR and LIFR ceilings to several of the TAF sites. Some clearing
is possible at OTM later, but for most of the other sites expect
IFR ceilings to last nearly the entire 00z TAF period. More rain
shower clusters are expected through Thursday morning. Heavier
rainfall may result in IFR visibility in some locations. Isolated
thunderstorms are possible in southeast Iowa. This may reach
within the vicinity of OTM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Ansorge
AVIATION...Krull
Area Forecast Discussion
National Weather Service Lincoln IL
846 PM CDT Wed May 25 2022
.SYNOPSIS...
Issued at 245 PM CDT Wed May 25 2022
A slow-moving weather system will keep plenty of clouds along with
scattered showers and a few thunderstorms around central and
southeast IL through Friday. More sunshine and much warmer
conditions will arrive in time for the holiday weekend with highs
in the low to mid 80s on Sunday, and around 90 on Memorial Day
and Tuesday.
&&
.UPDATE...
Issued at 846 PM CDT Wed May 25 2022
0140z/840pm radar imagery shows a band of convection extending
from Peoria...to Lincoln...to Effingham. The storms have been
producing 45-55mph wind gusts as they lift northward through the
area, with sporadic wind damage being reported. With daytime
instability waning, think the threat for wind damage with this
line is quickly coming to an end. Will continue to monitor for
gusty winds for the next 1-2 hours as the storms exit the ILX CWA.
Once the storms depart, it appears only isolated showers will be
on tap for the remainder of the night.
&&
.SHORT TERM...(This evening through Thursday)
ISSUED AT 310 PM CDT Wed May 25 2022
Mid afternoon surface analysis shows 1000 mb low pressure just
south of Kansas City with its warm front arching through se IA
into far northern IL just north of I-88. Aloft a 559 dm 500 mb low
was over north central OK, while a 589 dm 500 mb subtropical ridge
was off the Southeast Atlantic coast. Scattered showers and
isolated thunderstorms had developed in past 1-2 hours over
portions of central and southeast IL and lifting northward. The
stronger storms with heavier rains were from southeast Clark
county and southeast into Indiana. Unstable airmass in place over
CWA with surface based CAPES of 1500-2200 j/kg, highest east of
I-57. Modest wind shear values of 25-35 kts. Also tropical level PW
values were ranging from 1.6-1.8 inches with 850 mb southerly
35-40 kt jet overhead. Temps ranged from lower 70s from Galesburg
to Jacksonville west, with upper 70s and lower 80s over central
and eastern CWA, with Champaign airport the hot spot at 85
degrees.
SPC day1 outlook continues marginal risk of severe storms over CWA
into mid evening, with slight risk ne CWA, from Bloomington to
Paris ne with all hazards risk including brief tornadoes. The
stronger storms currently appear to be tied to the warm front in
northern IL. Scattered convection likely to continue through mid
evening and then wane as instability weakens after sunset. Cutoff
mid/upper level low to move slowly into southeast MO by sunset Thu
while surface low weakens to 1005 mb as it tracks over the IL
river valley Thu afternoon. Gets unstable again on Thu as CAPES
rise to 1000-2000 j/kg over much of area by early Thu afternoon
along with the stronger wind shear over central and eastern CWA.
SPC day2 update entire CWA into the marginal risk Thu afternoon
for wind and hail while tornado threat is further east/se of IL.
Lows tonight in the low to mid 60s, coolest over western CWA.
Highs Thu 70-75F, warmest near the IN border.
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 330 PM CDT Wed May 25 2022
Slow moving mid/upper level low tracks into the lower Ohio river
valley by dawn Friday and into the eastern Ohio river valley Fri
evening. It will still be close enough to influence central/se IL
with more low cloud cover along with chances of rain showers and
isolated thunderstorms, highest pops in eastern IL. NNW winds on
back side of system to bring cooler temps, with highs Fri 65-70F,
warmest near the Wabash river and over far western CWA to the MS
river valley where some sunshine could appear during Fri
afternoon.
12Z forecast models continue to show upper level ridging into IL
by midday Saturday and bringing a nice late spring day to the
area, with more sunshine, lighter winds and temperate highs in the
mid to upper 70s. GFS shows a disturbance with some qpf moving
over IL Sat night and Sunday morning, while other models like GEM
and Ecmwf are keeping IL dry which this forecast reflects the
drier solution. A strong 590-594dm 500 mb high builds over the
southern Great lakes and Ohio river valley Mon/Tue bringing our
2nd heat wave of the season 1st half of next week. Highs in the
low to mid 80s Sunday, rise to around 90F monday and lower 90s Tue
and Wed. Will also be humid with dewpoints in the upper 60s/lower
70s. A cold front will be pressing se into the upper Midwest Wed
and possibly get close enough into nw IL Wed night to bring next
chance of showers and thunderstorms.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 622 PM CDT Wed May 25 2022
Widely scattered showers/thunder continue to lift northward across
the area early this evening...with the most significant convection
noted within a band from KUIN southeastward to KPAH. The band is
pivoting northward and is expected to impact the central Illinois
terminals over the next couple of hours. Based on radar timing
tools and latest HRRR output, have included a period of VCTS at
all TAF sites...ending by 03z-04z along I-74. Once the initial
band passes, a mostly dry night and early Thursday morning will be
noted before additional showers/thunder develop and lift northward
into the area from mid-morning into the afternoon hours. Ceilings
are presently VFR, but are expected to lower to MVFR later this
evening once the showers/storms exit. Winds will initially be S/SE
with gusts of 20-26kt, then will decrease to 10-15kt by late
evening into the overnight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SYNOPSIS...07
SHORT TERM...07
LONG TERM...07
AVIATION...Barnes
Area Forecast Discussion
National Weather Service Paducah KY
648 PM CDT Wed May 25 2022
.UPDATE...
Issued at 648 PM CDT Wed May 25 2022
The AVIATION section has been updated for the 00Z TAF issuance.
&&
.SHORT TERM...(Tonight through Friday night)
Issued at 140 PM CDT Wed May 25 2022
The short range guidance indicated another wave will move
northeast across the area this afternoon, with a band of showers
and thunderstorms. Coverage at the moment is isolated. We
anticipate additional destabilization through the afternoon. WoFS
data shows a band of organized, broken convection forming and
moving into southern/southeast MO in the 230-330 PM time frame.
This is in line with 12z CAM`s guidance. The WoFS takes the axis
just east of the MS River around 6 PM. CAM`s from there moves it
across the Evansville Tri-State area toward 7-8 PM. SB CAPE is
near 2000 j/kg with ML CAPE up over 1000 per the latest RAP data.
The severe weather chance remains marginal. The overall shear
parameters late today and this evening actually become slightly
less favorable for low level rotation. Having said that, the WoFS
does hint at isolated near 50 kt gusts with modest 0-2km UH swaths
coincident with the main convection. This should be the most
likely hazard. It is a non zero chance in terms of a brief weak
tornado. Most of the activity will be sub severe.
Tonight through Thursday, the upper low over the central Plains
will move east, and end up over southern Missouri by Thursday
afternoon. We will continue to see on and off chances of showers
and a few thunderstorms moving through with any instances of upper
level support rotating around the low.
The upper low will move over the area Thursday night and east of
the area Friday, continuing our chance of showers, maybe an
isolated thunderstorm. The overall heavy rain aspect with this
system will be limited. There will be appreciable amounts in a few
places. But, the odds of any hydrologic impacts are slim.
Temperatures will remain a blend of existing numbers and the
latest NBM.
.LONG TERM...(Saturday through Wednesday)
Issued at 322 PM CDT Wed May 25 2022
Model consensus appears to be good with a depiction of a dry
forecast for the vast majority of the extended forecast period. This
will be due to a progressively building longwave ridge, at the
surface and aloft, over the eastern half of the CONUS (with a
longwave trof in the west).
At the surface, there will be a light wind regime initially, but the
pressure gradient is progged to tighten just a bit over the weekend
and into Mon as low pressure systems move northeastward across the
central Plains. Into midweek, the ridge is expected to continue
strengthening, with the surface and winds aloft over us becoming
slack. As a result, surface dewpoints should creep up from the
middle 50s to the middle and upper 60s, while temps go from about
average to about ten degrees above average (highs around 90/lows
around 70). There is some possibility in some model solutions that a
weakness in the ridge, coming out of the Deep South could allow
enough erosion of the cap for a few showers or tstms by Wed
afternoon (Day 7).
&&
.AVIATION...
Issued at 648 PM CDT Wed May 25 2022
One cluster of showers may impact KMVN at the beginning of the
period, and another one may impact KEVV and KOWB around 02Z.
Otherwise, the forecasts are dry, but a SHRA/TSRA could pop up at
just about anytime through the period.
South to southeast winds will gust this evening, and then subside
a bit overnight before picking up again Thursday. MVFR ceilings
are expected to develop over the area later this evening and
overnight. The MVFR ceilings will likely prevail until a subtle
wind shift/cold front moves east through the region from late
morning into the afternoon.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...DRS
AVIATION...DRS
Area Forecast Discussion
National Weather Service Pendleton OR
841 PM PDT Wed May 25 2022
.UPDATE...
Quiet night and morning in store as high pressure over the region
slowly moves eastward. Only changes were to lower temps in some
areas based on latest guidance. with not much in the way of clouds
and generally light winds.
Did not make adjustments to Tursday`s forecast as the only 00Z
guidance in at this time is the NAM. The RAP and HRRR do not go
out that far and the HREF and the NAM continue to suggest that the
majority of the precipitation will be after 27/00Z, and most
suggest it will be east of PDT/ALW, and mainly over the mountains.
&&
.AVIATION...
06Z TAFS...VFR conditions are expected through the night and into
much of Thursday. The main question still is what res SHRA and
TSRA chances Thursday afternoon and evening. While the latest
guidance is still being analyzed, it appears that the best TSRA
chances are east of PDT and ALW. Therefore, no TSRA will be placed
in the TAFS at this time due to lower confidence. SHRA chances
will be low until around 27/00Z then increase, so have inserted
SHRA chances toward the end of the TAF period.
Winds should be generally be 10 kts or less until around 27/00Z
when the SHRA approach and winds could become gusty to around 20
kts. Also any heavier SHRA or TSRA could, of course, bring gustier
winds.
&&
.PREV DISCUSSION... /issued 447 PM PDT Wed May 25 2022/
AVIATION...
00Z TAFS...VFR conditions are expected through Thursday morning.
Then, there will be SHRA and TSRA developing Thursday afternoon,
with the best chances at PDT, ALW and points east. Overall chances
are still low enough for thunder to not include in the individual
forecasts at this time, but with later issuances, may need to
include. Also, as later guidance comes in, will further assess
rain chances as well.
After initial wind gusts to around 20 kts early this evening,
winds will be less than 10 kts through the period outside of any
TSRA.
PREV DISCUSSION... /issued 235 PM PDT Wed May 25 2022/
.STRONG TO SEVERE THUNDERSTORMS THURSDAY AFTERNOON AND
EVENING...
SHORT TERM...Now through Friday Night...
An active stretch of weather is expected over the near term as
increasing moisture and southerly flow develop ahead of a powerful
shortwave trough. This will bring a period of active weather to
the region beginning Thursday and continuing through the end of
the week.
For the remainder of today, rather warm temperatures have
developed with mostly clear to partly cloudy skies and broad upper
ridging. The presence of this ridge and increasing cloudiness
will likely maintain mild temperatures into tonight, with lows in
the 50s to lower 60s most areas outside of the cooler mountains.
The more active weather will take place on Thursday as a
shortwave trough approaches the coast of British Columbia, taking
on a negative tilt as it intensifies. This will result in
substantial south/southwesterly flow and a robust transport of mid
and upper level moisture. This is well handled by the Hi-res
ensembles (HREF), which depict ensemble mean precipitable waters
of 0.8 to 1.2 inches, in the 90th plus percentile range for this
region when viewing climatologies for Boise and Spokane. Despite
this infusion of mid/upper level moisture, low level moist
transport looks to be somewhat limited, which may limit the degree
of instability. Still, The ECMWF Extreme Forecast Index indicates
unusually large instability with values of 0.7 to 0.8 mainly over
northeast Oregon and far southeast Washington. The combination of
modest instability (1000-1500 J/Kg of CAPE), along with
increasing wind shear as a mid level jet approaches, will yield a
favorable environment for strong to severe thunderstorms. These
look to occur mainly in the 3-9 pm timeframe, before activity
eventually lifts northeastward into Idaho and Montana. The main
threats with the stronger storms will be large hail to the size of
half dollars and wind gusts of 60 to 70 mph. In addition, given
the high moisture content in the atmosphere, heavy rainfall will
be a concern, especially in any areas that see training
thunderstorms. Based on HREF and other model output, this appears
most probable in the mountains of northeast Oregon and southeast
Washington, where complex terrain and rocky soils can lead to
rapid runoff. ECMWF EFI values for precipitation of 0.7 to 0.8
also support the potential for unusually wet conditions. Showers
and a few thunderstorms are likely to linger into the overnight
hours with a general downward trend in intensity, thought showers
will likely persist near the Cascade crest most of Thursday night.
On Friday, showers and afternoon thunderstorms remain in the
forecast as a weak stalled front resides across Oregon ahead of
another potent storm system set for the weekend. This will bring
continued bouts of moderate to heavy rainfall mainly to the
Cascades and mountains of eastern Oregon. With any luck, some much
needed moisture will be felt in central Oregon, where exceptional
drought continues. While there will be a chance for thunderstorms
Friday afternoon, conditions do not look to support severe
weather, though lightning, heavy rains, and small hail will
accompany any storm. Breezy to locally windy conditions will
overspread the Columbia Basin and Columbia Gorge during the
afternoon hours, with generally cooler daytime temperatures owing
to widespread cloud cover and occasional showers and storms.
Austin/79
LONG TERM...Saturday through Wednesday...
Most of the extended forecast period looks to be wet and
unsettled as a strong weather system and an upper low pressure
system moves across the region. On Saturday another large broad
upper trough will move southeast into the PacNW from the northeast
Pacific. This system is expected to form a cutoff upper low
pressure system by Saturday night and continue through early
Monday morning. This system looks to bring a long duration rain
event, with possible heavy rainfall amounts. Storm total QPF
amounts are expected to reach or exceed an inch over the Blue
Mountains, Wallowa Mountains, the OR Cascades and southern WA
Cascades (mainly near the crest). Elsewhere, a half inch to three
quarters of an inch of rain can be expected over the Blue Mountain
Foothills (both north and south). A quarter to a half inch can be
expected over central OR, north central OR, and the Simcoe
Highlands. One to three tenths of an inch are expected over the
Lower Columbia Basin and the Yakima/Kittitas Valleys.
There will also be a slight chance of afternoon and evening
thunderstorms on Saturday from central OR, eastward across the
Ochoco-John Day Highlands and southern Wallowa county. These
storms will end after 00Z Saturday afternoon over central OR, but
they will continue well into the evening along the SE border of
the forecast area. Showers, which may be heavy, will be numerous
over all of the OR zones Saturday evening. The showers will begin
to decrease over central areas late Saturday night, but will
continue over the Cascades and the eastern/northeast mountains
through Sunday. There could be an isolated thunderstorm or two
Sunday afternoon, but confidence is low at this time, and will
therefore leave them out of the forecast for now.
The latest cluster analysis of the ensembles show some variance
through these time frames, but the overall concensus is for a
closed upper low to form over the CWA Saturday continuing into
early Monday morning. In addition, the ECMWF EFI index is showing
6 to .8 index values (moderate to high) for QPF from Saturday
through late Sunday, which increases confidence that there will be
a potential for unusually high amounts of QPF with this event.
On Tuesday the upper low pressure system will be moving away to
the southeast, but there will still be a slight chance of showers
over the eastern mountains. This will be followed by dry
conditions on Wednesday.
Temperatures will be much cooler than normal on Saturday and
Sunday, and then a warming trend will begin on Monday. Maximum
temperatures are not expected to get out of the 60s in the lower
elevations on Saturday and Sunday, but then they will rebound to
the mid 60s to lower 70s on Monday, and continue warming to the
mid 70s to around 80 by Wednesday. Breezy to windy conditions will
also develop from Saturday afternoon through early Monday morning
over central OR, the eastern Columbia Gorge, the Kittitas Valley,
the Lower Columbia Basin, and the Blue Mountain foothills. They
will be the strongest during the afternoon and early evening
hours. However, these winds are not expected to reach advisory
criteria. 88
AVIATION...18Z TAFS...VFR conditions are expected through the next
24 hours. There will be abundant mid and high clouds this morning at
all terminals except KRDM and KBDN. These clouds will thin out by
afternoon. Next weather system will begin to spread clouds over the
area again on Thursday, with a chance of afternoon showers and
thunderstorms possibly creating MVFR conditions at times, especially
at KPDT, KALW, KRDM and KBDN. Winds will be locally breezy after 18Z
today at KDLS, KPSC, KPDT and KALW. Elsewhere winds will be light
and under 10 kts. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 52 77 54 67 / 0 20 50 60
ALW 56 80 57 70 / 0 20 60 60
PSC 54 82 60 74 / 0 10 30 30
YKM 50 78 52 71 / 0 10 30 30
HRI 52 81 57 72 / 0 10 40 40
ELN 48 74 51 66 / 0 20 40 30
RDM 47 77 48 65 / 0 20 30 30
LGD 50 78 52 64 / 0 20 70 70
GCD 50 81 51 69 / 0 30 50 40
DLS 53 78 57 70 / 0 20 60 50
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
SHORT TERM...77
LONG TERM....88
AVIATION...77