Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/28/23
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
612 PM MDT Sat May 27 2023
...New AVIATION...
.SYNOPSIS...
Issued at 240 PM MDT Sat May 27 2023
Severe weather expected again this afternoon across portions of
eastern New Mexico. Cloud-to-ground lightning, large hail,
damaging winds, and flash flooding will be possible. Western
locales can expect dry conditions through much of the week.
Thunderstorm activity becomes less robust on Sunday through
Tuesday before trending back up Wednesday and Thursday for the
eastern plains. Breezy conditions return to central areas on
Wednesday. Temperatures will be near to below normal through the
forecast period.
&&
.SHORT TERM...
(This evening through Sunday night)
Issued at 240 PM MDT Sat May 27 2023
Low level moisture has mixed out through much of the Rio Grande
Valley this afternoon with the main area of convection stretched
over the Northeast to Central Highlands and southward. This was
propagating northeastward with low level southeast winds across the
east central and southeast plains where a severe thunderstorm watch
is in place. The HRRR indicates the low level moisture will push
westward again tonight and into the Rio Grande Valley at Albuquerque
and Santa Fe and potentially into central Socorro county as well so
there may be a few hours this evening when a gusty east to southeast
wind is observed but it may become more northerly as the night
progresses. Models indicate the dryline will retreat farther to the
east on Sunday than it has recently as drier air aloft is expected
to make more progress into the state Sunday, although the Day 2 SPC
outlook has the marginal risk area over a smaller portion of eastern
NM with only a sliver of Union county in the slight risk area.
Convection is also indicated to fade away by late evening on Sunday.
Lows as well as high temperatures will be near to slightly cooler
than normal.
&&
.LONG TERM...
(Monday through Friday)
Issued at 240 PM MDT Sat May 27 2023
Ridging amplifies over New Mexico to start off the long term as a
deep upper level low begins to flirt with the SoCal coast. This
will work to take the previous daily rounds of showers and
thunderstorms back down to an isolated threat on Monday and
Tuesday. Previously favorable forcing will be absent in the
presence of upper level high pressure. What activity does initiate
will favor northeastern NM and will be greatly dependent on
orographics alongside moisture slosh from the dryline.
The aforementioned upper low pushes into the Desert Southwest
Tuesday night, allowing southwest flow aloft to strengthen once
again. This feature will work to enhance upper level forcing and
instability as it careens into the state Wednesday morning.
Meanwhile, the dryline will recede well into eastern NM, creating
a favorable environment for strong to severe storms once again
Wednesday and possibly Thursday. Timing on the upper low has yet
to reach agreement across models, and its evolution and departure
from Thursday afternoon forward is still unclear. The ECMWF and
CMC both show a slower progression than the GFS. Where the GFS
swings the low into CO Thursday, the others suggest it will fall
into an open wave. These differences don`t necessarily thwart this
forecaster`s confidence that a very unsettled couple days may be
in store across the east midweek. After that, however, confidence
lowers as the upper level features become messy and disorganized
across guidance. The GFS brings another low hot on the previous
low`s heels Thursday evening, a trend somewhat echoed by the CMC.
This would result in a more favorable setup for an additional day
of severe weather Friday. Meanwhile, the ECMWF tries to develop an
almost Fujiwhara situation, allowing the two disturbances to
tango in and around the Great Basin. This dance would lead to a
much drier solution for NM. These discrepancies have caused a low
confidence forecast into the weekend and therefore, did not
deviate much from the NBM.
&&
.AVIATION...
(00Z TAFS)
Issued at 553 PM MDT Sat May 27 2023
Mesoscale models show scattered to isolated showers and
thunderstorms continuing over eastern areas for much of the
night, some of which may turn severe with large hail, damaging
winds, very heavy rain, and a risk of tornadoes. The favored
location after midnight should be north of I-40. Areas of MVFR and
IFR conditions in low clouds and patchy fog are again expected
east of the central mountain chain late tonight into Sunday
morning, as well as in Santa Fe. Drier air will move into the
state from the southwest on Sunday with a downtick in coverage of
showers and thunderstorms. Isolated to widely scattered showers
and thunderstorms are expected in the afternoon and early evening
on the eastern plains, a few of which may turn severe with large
hail and damaging winds.
&&
.FIRE WEATHER...
Issued at 240 PM MDT Sat May 27 2023
An active pattern of showers and storms will continue over eastern
NM with daily rounds of locally heavy rainfall through Sunday. Drier
weather expected Monday and Tuesday under a ridge of high pressure
with northeast NM becoming the focus area for any convection.
Localized elevated to near critical conditions are possible Monday
and Tuesday mainly along and west of the Continental Divide, as high
Haines is widespread along with poor overnight humidity recovery and
sub 10 percent daytime humidities. However widespread strong winds
are not forecast.
By the middle of next week, low level moisture will begin to slosh
back and forth again with another upper trough to our west, leading
to more active showers and storms central and east for the rest of
next week. However, localized critical conditions may persist along
and west of the Continental Divide where drier air remains
entrenched.
&&
.PRELIMINARY POINT TEMPS/POPS...
Farmington...................... 43 82 45 84 / 0 0 0 0
Dulce........................... 35 77 37 78 / 5 0 0 0
Cuba............................ 42 76 44 79 / 10 5 0 0
Gallup.......................... 37 79 39 80 / 0 0 0 0
El Morro........................ 38 75 41 76 / 0 0 0 0
Grants.......................... 38 80 41 81 / 0 0 0 0
Quemado......................... 42 78 43 80 / 0 0 0 0
Magdalena....................... 51 79 49 81 / 10 10 0 0
Datil........................... 44 76 44 78 / 5 5 0 0
Reserve......................... 43 81 43 82 / 0 0 0 0
Glenwood........................ 53 85 52 85 / 0 0 0 0
Chama........................... 34 71 36 71 / 10 5 0 5
Los Alamos...................... 47 76 48 75 / 20 5 0 5
Pecos........................... 44 75 46 77 / 20 10 5 10
Cerro/Questa.................... 37 75 37 72 / 10 10 5 20
Red River....................... 34 65 34 66 / 20 10 5 20
Angel Fire...................... 33 67 32 69 / 30 10 10 20
Taos............................ 39 76 39 77 / 10 5 0 10
Mora............................ 41 73 41 74 / 40 20 10 20
Espanola........................ 42 81 42 84 / 10 5 0 5
Santa Fe........................ 47 76 48 79 / 20 10 5 10
Santa Fe Airport................ 46 80 46 81 / 10 5 0 5
Albuquerque Foothills........... 54 81 54 83 / 10 5 0 0
Albuquerque Heights............. 55 83 55 84 / 10 5 0 0
Albuquerque Valley.............. 49 84 49 88 / 10 5 0 0
Albuquerque West Mesa........... 53 84 53 86 / 10 5 0 0
Belen........................... 56 87 53 88 / 10 5 0 0
Bernalillo...................... 51 84 51 87 / 10 5 0 0
Bosque Farms.................... 52 86 50 88 / 10 5 0 0
Corrales........................ 52 84 52 86 / 10 5 0 0
Los Lunas....................... 54 86 52 88 / 10 5 0 0
Placitas........................ 51 81 51 83 / 10 5 0 0
Rio Rancho...................... 53 83 53 85 / 10 5 0 0
Socorro......................... 58 88 55 90 / 10 10 0 0
Sandia Park/Cedar Crest......... 46 76 48 77 / 10 5 0 0
Tijeras......................... 48 78 49 79 / 10 5 0 0
Edgewood........................ 46 78 46 79 / 10 5 0 5
Moriarty/Estancia............... 45 79 43 81 / 10 10 0 5
Clines Corners.................. 46 75 46 77 / 30 10 5 10
Mountainair..................... 49 78 48 81 / 20 10 0 0
Gran Quivira.................... 50 79 49 81 / 20 20 5 5
Carrizozo....................... 56 82 54 85 / 20 20 5 5
Ruidoso......................... 50 73 49 78 / 30 30 10 5
Capulin......................... 47 73 45 74 / 40 20 10 40
Raton........................... 45 78 44 80 / 40 20 10 30
Springer........................ 45 77 44 81 / 30 20 10 20
Las Vegas....................... 44 75 43 78 / 30 20 10 20
Clayton......................... 53 77 52 79 / 30 30 20 20
Roy............................. 49 76 47 78 / 40 20 10 20
Conchas......................... 51 80 49 85 / 40 20 10 10
Santa Rosa...................... 52 81 50 83 / 50 20 5 10
Tucumcari....................... 55 81 53 83 / 30 30 10 10
Clovis.......................... 55 78 54 83 / 50 40 20 10
Portales........................ 56 80 55 85 / 40 40 20 10
Fort Sumner..................... 56 83 53 87 / 40 30 10 10
Roswell......................... 60 87 57 92 / 40 30 20 5
Picacho......................... 54 80 52 85 / 50 40 10 10
Elk............................. 52 77 50 82 / 40 30 10 5
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
Flood Watch until midnight MDT tonight for NMZ231-232-234>236.
&&
$$
SHORT TERM...99
LONG TERM....12
AVIATION...44
Area Forecast Discussion
National Weather Service Amarillo TX
647 PM CDT Sat May 27 2023
...New AVIATION...
.SHORT TERM ...
(This evening through Sunday night)
Issued at 353 PM CDT Sat May 27 2023
Outflow boundaries from this mornings complex pushed south of the
area and left the Panhandle subsident all day after last of the
left over stratiform rain dissipated. That said, skies cleared
eventually and temperatures have warmed enough to produce MLCAPE
of 1000-1500 J/KG across the west and there was no cap analyzed
by the SPC RAP at 20Z. Thunderstorms are forming in the higher
terrain of New Mexico where MLCAPE is 1500-2500 J/KG with the
assistance of an approaching mid-upr level trough seen best in H25
streamlines. These storms will track east slowly through the late
aftn and evening and the million dollar question is whether the
airmass will have rebounded enough over the Panhandles for these
storms to maintain much strength. Storms will the cross the
border around 00Z and will move into a more marginal shear area
with just 25 to 30 knot bulk shear. Gut feeling is the storms
will attempt to track a bit south into the area that mostly
remained south of the morning convection and outflow, but there
are some cams that bring activity to the NW Panhandle as well and
this can`t be ruled out. The main upper trough will approach after
midnight and large scale lift may be enough to promote additional
development late tonight. RAP and NAM both hint at a repeat
performance from last night with clusters of storms near
Tucumcari to Logan drifting slowly into the western and southwest
Panhandles. This is all very uncertain given the potential
continued influence of the morning storms today, but it does
provide additional concern for flooding overnight. We have
extended the Flood Watch across the SW 4 counties through 12Z to
account for this possibility. All in all the west and especially
the SW areas are favored for the highest POPs tonight and forecast
POPs range from 40-70 in the SW corner to 20s in the far north
Leaned toward the more aggressive models wrt POPs for Sunday aftn
and evening as the main trough axis will be slowly crossing the
area due to the tough`s favorable position. The one caveat would
be morning convection stabilizing things early. There is also
potential for a little H7 drying that is indicated by some models,
but feeling is the upper support and low level moisture will be
sufficient for SCT storms. MLCAPE is actually forecast higher than
what we have seen much of the week (1500-2500 J/KG). This
combined with bulk effective shear which may peak around 30-35
knots would be sufficient to support organized severe storms.
Northern areas are favored and included in the slight risk given
better wind shear values in those areas. Of course the continued
threat for heavy rainfall is just as big if not the bigger threat
with any strong to severe storms.
Gittinger
&&
.LONG TERM ...
(Monday through next Friday)
Issued at 353 PM CDT Sat May 27 2023
Appears a weak upper trough axis will be over of just east of the
area on Monday and this should provide at least one relatively
quiet day, although can`t completely rule out a few showers or
storms especially in the east or far NW depending on exact
location of the trough axis which models are not completely in
acquirement on. A bit more robust upper level storm system will
dive south across CA from the northern stream in a split flow
pattern and will position itself across Nevada by late Tuesday.
Models are not in perfect alignment in the track and strength of
this system from there, but there is a pretty strong signature it
will provide another increase in thunderstorms to the area again
as early as Tuesday evening as a jet exit region and leading weak
s/wv potentially trigger storms in NE NM and SE CO that could
track into the area. While the GFS seems excited by the rain
prospects Tue evening, the NBM doens`t have enough members on
board to push POPs above around 20 for now Tue night.
A majority operational models continue to show a very favorable
track with the closed low passing somewhere near southern NV and
the GEFS and GEPS ensemble mean both circle the tip with an H5
closed low. From there the system tracks slowly NE or ENE weakens
but some models immediately replace it with a another system,
although again there are various takes on the details. This setts
the stage for potentially an even more organized multi-day
thunderstorm threat (Wed to Fri) than what we experienced this
week as the system taps into plenty if SFC-H7 moisture. In fact
12Z GFS is currently forecasting well into the 90th percentile
PWATs this period. While the probability for a classic upper
system evolution and track for a severe episode seems high, we
will have to see how wind fields/shear unfold. The heavy rainfall
threat might be the highest probability threat if current model
forecasts pan out. NBM is showing 50-70 percent chance of for 1
inch or great in 72 hour period ending Sunday morning and a 10-40
percent chance for 2 inches or more. Of course the blend input
can`t handle storm scale which would suggest localized amounts
well above these probs. This is definitely something to watch
closely given the saturated ground in many areas.
Gittinger
&&
.AVIATION...
(00Z TAFS)
Issued at 634 PM CDT Sat May 27 2023
VFR conditions are prevailing this evening as the region remains
storm-free for the time being. Confidence in storms this evening
is not high as guidance is a bit scattered in coverage of storms
and if they can maintain themselves as they push east from New
Mexico. Have not included any in the forecast for now, but will
monitor closely for amendments. Also low chance for MVFR ceilings
overnight and have not included in the forecast for now, but may
be something to consider in future TAF cycles.
Culin
&&
.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX 59 78 57 79 / 30 40 40 10
Beaver OK 59 80 58 82 / 20 40 40 10
Boise City OK 54 79 53 81 / 20 30 30 10
Borger TX 61 82 60 83 / 20 30 40 10
Boys Ranch TX 58 81 56 82 / 40 30 30 10
Canyon TX 59 78 56 80 / 50 40 30 10
Clarendon TX 59 75 58 76 / 40 40 30 10
Dalhart TX 54 78 54 81 / 30 30 30 10
Guymon OK 58 79 56 81 / 20 20 50 10
Hereford TX 57 79 56 82 / 60 40 20 10
Lipscomb TX 59 78 59 79 / 30 40 40 10
Pampa TX 59 78 59 78 / 20 40 40 10
Shamrock TX 59 76 59 77 / 40 40 30 20
Wellington TX 60 78 59 77 / 40 50 30 20
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...Flood Watch through Sunday morning for TXZ011-012-016-017-317.
OK...None.
&&
$$
SHORT TERM...88
LONG TERM....88
AVIATION...28
Area Forecast Discussion
National Weather Service Denver/Boulder CO
843 PM MDT Sat May 27 2023
.UPDATE...
Issued at 840 PM MDT Sat May 27 2023
Fairly strong convection is continuing over the CWA this evening,
mainly over the Palmer Ridge and Weld, Logan & Morgan Counties. A
decent portion of the CWA saw decent rainfall again this afternoon
and evening. Concerning GFE grids, will make appropriate edits to
pop grids based on reality and that the CAM models are keeping
convection going over the plains through 06Z and finally east of
the CWA by 09Z tonight. Will leave the rest of the grids pretty
much alone.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 255 PM MDT Sat May 27 2023
Storms have formed this afternoon in an environment that has ample
instability. The SPC mesoanalysis shows over 2,000 j/kg in Weld,
Morgan, and Logan counties with over 1,500 j/kg across the rest of
the far eastern plains. An 18Z sounding from the BACS team near
Nunn, CO verified this instability with most unstable CAPE of
around 2,500 j/kg. That sounding also indicated the lack of deep
layer shear. The surface to 6km bulk shear was 21 knots. The low
level shear was also lacking with surface to 3km SRH of 1 knot.
Winds in the free atmosphere were all from the southwest. As a
result, these storms are producing nice updrafts but the lack of
shear is keeping them from becoming severe at the moment. Once we
get into the later afternoon, the shear may increase slightly
along and just south of the Cheyenne Ridge which will allow a
couple storms to reach severe limits with large hail and strong
winds the primary threats. A Severe Thunderstorm Watch was issued
for Weld, Morgan, and Logan Counties. Farther south in and near
Lincoln County, it appears there will be another focus for strong
storms there. There is slightly better shear down there and a
severe storm or two is possible there. In our collaboration call
with SPC about the Severe Thunderstorm Watch, Lincoln County was
mentioned for the possible inclusion in the watch. However, since
it is a lone county that has that threat and the surrounding
counties don`t have a similar threat, there was no watch issued
there.
Models are becoming less certain now about the chance for storms
later in the evening and overnight. The NAM Nest doesn`t have much
in the way of storms while the HRRR still has good coverage. PoPs
were generally kept about the same as the previous forecast with
PoPs in the 20-50 percent range most of the night across the far
northeast corner.
On Sunday, a shortwave trough will move past our CWA with weak NVA
overhead. Ridging will develop which should limit the forcing for
storms and the storm coverage will be much lower than the past
couple days as a result. The focus for storms will be along the
Cheyenne Ridge and Palmer Divide as weak low level convergence
will aid with lift there. Over the urban corridor towards Last
Chance, there will be very few storms due to the lack of forcing
and lower instability. With winds aloft becoming westerly, the
directional shear will increase. It is not completely out of the
question that a severe storm or two forms but the threat is very
limited. Otherwise, high temperatures will be near normal.
.LONG TERM...(Sunday night through Saturday)
Issued at 144 PM MDT Sat May 27 2023
High over low (Rex) blocking pattern to prevail through the
middle of next week. This block never really breaks down. For mid
to late next week, the high amplifies as it slowly retrogrades
westward, but remains to the east of Colorado. For Sunday night
through Tuesday, a closed low slowly drifts south-southeast along
the California coast. This low will induce ridging ahead of it
over the Central and Southern Rockies. Expect this to bring
subsidence and drier air. With the drier air and ridging in place,
temperatures should be warmer for Monday, Tuesday, and possibly
Wednesday with highs in the lower to mid 80s over northeast
Colorado. Still should be enough moisture and instability around
for isolated to scattered afternoon showers and thunderstorms.
This activity should be weaker than the convection of the past few
days.
Ridging slides off to the northeast as the California low moves
inland over the Desert Southwest on Wednesday. Moisture will
increase and lead to a better chance for showers and
thunderstorms. This low weakens and lifts north across Colorado on
Thursday. A new low replaces this low over the Desert Southwest,
which will keep a southerly flow aloft over the state through next
week. Better moisture is expected to remain in place, bringing
good chances for showers and thunderstorms each day. The increase
in moisture and clouds will lead to cooler temperatures with highs
in the 70s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 843 PM MDT Sat May 27 2023
Winds are DIA are still northeasterly at this time; mainly in
response to ongoing convection. Most models get drainage winds
going at the airport between 06Z-09Z overnight. There shouldn`t
be any ceiling issues at DIA overnight.
&&
.HYDROLOGY...
Issued at 255 PM MDT Sat May 27 2023
Storms will be less intense on Sunday with lower coverage over the
burn areas. While flash flooding is not expected, there remains a
limited threat.
There will be a slight decrease in moisture for early next week,
but isolated to scattered showers and storms are still expected
each day. Better moisture is expected to return by Wednesday,
which may lead to an increase in the flash flood threat for the
burn areas starting Wednesday.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.......RJK
SHORT TERM...Danielson
LONG TERM....Meier
AVIATION.....RJK
HYDROLOGY....Danielson/Meier
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
617 PM CDT Sat May 27 2023
...New AVIATION...
.SHORT TERM...
(Tonight through Sunday night)
Issued at 259 PM CDT Sat May 27 2023
A beautiful Memorial Day weekend Saturday is in progress,
courtesy of a ridge of high pressure (albeit somewhat "dirtied"
with high clouds) aloft. A fair amount of sun is combining with
cumulus and cirrus clouds, along with a pleasant easterly breeze.
Earlier, very spotty "pop-up" variety light showers were about,
and we could still see a few more of these this afternoon, but
impacts should be minimal.
Heading into tonight, most of Deep South Texas and the RGV stays
rain-free, with partly to mostly cloudy skies and low temperatures
right around normal values in the lower 70s F. Will need to keep
an eye on any showers or thunderstorms approaching Zapata County
from the west this evening, but short-term model consensus has
this convection on a dying trend as it approaches. So, a few
showers across Zapata, and perhaps Jim Hogg/Starr, are the the
most likely outcome.
Matters become more interesting for Sunday, and especially into
Sunday night. Despite forecast precipitable water bumping up to
1.8- 2.0 inches, and a possible weak shortwave aloft moving
through in the morning, QPF signal is rather modest through the
daytime hours. NAM/GFS actually have transitory ridging at mid-
levels behind the weak shortwave, which would suggest a mainly
pleasant afternoon. HRRR runs suggest a few sea-breeze showers and
thunderstorms, which also seems plausible. With perhaps more sun
under the transitory ridging, went a degree or two above NBM
guidance for afternoon highs, putting them in the lower 80s/near
90 for most everyone.
Weather picture for Sunday night is becoming clearer, but still
some uncertainties on timing and location of heaviest rainfall.
SPC has also added a Marginal Risk (Level 1 of 5) for severe
weather for Sunday into Sunday night (would favor the evening into
overnight hours). Model consensus brings a more robust shortwave
aloft across the Rio Grande from the west in the evening. NAM and
most CAM`s comprising the HREF now congeal early activity into a
cluster or broken line of storms overnight, which steadily (if
slowly) progresses across the CWA. Current best estimate on timing
brings storms into Zapata County between 11pm Sunday-2am Monday,
then into the Lower RGV between 4-8am on Monday (Memorial Day).
WPC QPF has nudged up and then back down a bit over the past 24
hours, but general totals of 0.5-1.5 inches through early Monday
morning seem reasonable, with CAM`s (as well as GFS) suggesting
pockets of up to 2-4 inches possible along the Rio Grande, though
some of these totals could stay on the other side of the border.
NBM probabilistic guidance suggests 10-20% chances of >2 inch
rainfall totals, with 5-10% chance of >3 inches. This all lends
support to WPC maintaining a Marginal Risk for Excessive Rainfall
for all counties except Kenedy/Willacy/Cameron, though this could
all shift a bit if the cluster/line speeds up. (And all of our
counties are included in the Day 3 ERO for Monday.) Somewhat more
progressive nature, if said cluster/line develops, could mitigate
flash flooding threat a bit, but could enhance damaging wind gust
possibility.
&&
.LONG TERM...
(Monday through next Saturday)
Issued at 259 PM CDT Sat May 27 2023
Unfortunately for those who are traveling or have outdoor plans
for Memorial Day, the forecast is still looking potentially wet
and stormy for Monday. Convection will likely be ongoing at the
start of the period (see the short term discussion), and the
locations impacted on Monday will depend on that activity
overnight Sunday along with the progression of the convectively-
enhanced mid level shortwave. This activity on Monday is looking
more like a minor flooding threat for low-lying and poorly
draining areas than a severe thunderstorm threat with plenty of
available moisture (precipitable water values near 1.8 to 2
inches) and somewhat limited lift and shear. However, some models
are showing modest instability, so cannot totally rule out some
strong gusty winds in any stronger storms. Confidence is only
moderate on Monday`s forecast as it is dependent on how the storms
behave Sunday night. Temperatures will be below normal with the
expected rainfall and cloud cover.
Energy associated with the shortwave over Texas will dive south
on Tuesday, carrying rain chances at least through the morning,
mostly near the coast where there will be better moisture,
instability and lift. Diurnal heating may also help to destabilize
conditions a bit by the afternoon, and allow a slight chance of
rain to linger.
Weak ridging will try to set up behind Memorial Day`s shortwave
trough for mid to late week, but there will still be a few
disturbances that pass through the flow aloft. Overall, rain
chances will taper off Tuesday night through Friday and
temperatures will gradually increase through the rest of the week.
The mid level ridge will flatten into next weekend and a weak
shortwave will pass through South Texas on Saturday, which may
help to increase rain chances Saturday into Saturday night. With
it being at the very end of the period, have kept only a slight
chance of rain for Saturday.
&&
.AVIATION...
(00Z TAFS)
Issued at 613 PM CDT Sat May 27 2023
VFR conditions are generally expected to prevail through the TAF
period with light to moderate easterly winds. A few showers have
developed across Deep South Texas and the RGV, but no lightning as
been detected as of 2320Z. However, there remains a less than 10
percent chance of seeing one west of KMFE. Additionally, the
latest HRRR has a weakening line of showers and thunderstorms
nearing KMFE at the end of the run, or around 15Z Sunday.
Confidence wasn`t there to include SHRA or TSRA in the TAFs with
this package, but may get introduced in subsequent TAF packages if
confidence increases.
&&
.MARINE...
Issued at 259 PM CDT Sat May 27 2023
Now through Sunday Night: A weak pressure gradient over the
western Gulf of Mexico should maintain light to moderate onshore
winds and low to moderate seas along the Lower Texas Coast during
the period. Holiday weekend boaters will need to be aware of
increasing chances of showers and thunderstorms from late
afternoon Sunday through the night (and continuing into Monday).
Monday through Saturday: Showers and thunderstorms will be
possible for the end of Memorial Day weekend and into early next
week. Otherwise, rain chances should clear out beyond Tuesday
evening and seas of 2 to 3 feet can be expected with fresh to
moderate east to northeasterly winds.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE 74 89 72 85 / 10 10 30 50
HARLINGEN 71 90 70 86 / 10 10 30 50
MCALLEN 73 90 71 86 / 10 20 40 50
RIO GRANDE CITY 72 89 68 86 / 20 20 50 40
SOUTH PADRE ISLAND 78 83 74 83 / 10 10 30 40
BAYVIEW/PORT ISABEL 74 86 72 84 / 10 10 30 50
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...53-Schroeder
LONG TERM....69-Farris
AVIATION...58-Reese
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
957 PM CDT Sat May 27 2023
...Short Term Update...
.UPDATE...
Issued at 957 PM CDT Sat May 27 2023
Just a few notes regarding rain/thunderstorm chances mainly over
the next 12-15 hours (through Sunday AM):
- Based largely on consistent signals from previous HRRR runs(through
the 00Z run), have increased rain/thunderstorm chances (PoPs)
for Sunday morning, with even low-end "likely" percentages
starting very late tonight far west and expanding east-
northeastward across parts of mainly our Nebraska CWA between
sunrise and Noon.
- Earlier HRRR runs (through 00Z) also suggested some increasing
concern for heavy rain/perhaps localized flooding in mainly the
Furnas County area early to mid-morning Sunday. However, the
very latest 01Z run has backed off a bit on Sunday AM rain
amounts and shifted the potential a bit farther north. Obviously
it`s never wise to put too much stock in hour-to-hour high-
res/CAM runs, but it`s possible that SOMEWHERE in our far west
sees some localized heavy rain toward and especially after
sunrise, so this will need monitored.
- Opted against issuing a formal Flood Watch for our far west-
southwest Nebraska zones for Sunday AM given that our western
zones have received FAR less rain over the past few days than
counties JUST to our west. However, a River Flood Warning
continues for the reach of the Republican River across northern
Furnas County at this time (see latest Flood Statement/FLSGID
for more details).
&&
.DISCUSSION...(This evening through Saturday)
Issued at 340 PM CDT Sat May 27 2023
Key Messages:
* Main forecast concern is timing, coverage, duration, and
intensity of thunderstorms through the remainder of the Memorial
Day holiday weekend.
* Widespread and/or significant severe weather is not expected,
though a few strong to marginally severe storms are possible,
along with localized heavy rain and flash flooding.
* Unsettled weather pattern continues into, and likely through,
the upcoming week, but day-to-day predictability is low, at
best.
* The remarkable stretch of consistent temperatures (by late
spring standards) will also persist through the forecast.
Forecast Details:
Fairly benign day thus far weather wise - except for the fact that
western zones have dew points 10 deg higher than areas along Hwy
81 corridor, and around 20 deg higher than locations near/along
the MO River. Don`t see that every day in late May! This is due to
highly anomalous upper air pattern featuring strong upper ridging
over the Great Lakes, and stubborn, cut-off troughing over the SE
CONUS. These two features are working together to funnel dry air
in from the E, while competing with narrow zone of "return flow"
and Pacific-based moisture streaming into W zones ahead of broad
troughing in place from Four Corners region northward to N
Rockies...leaving the local area squarely within the transition
zone. Seeing yet another round of cumulus this aftn, with perhaps
some subtle hints of weak CI over far W/SW zones per GOES-16 day
cloud phase RGB. However, the greatest focus for convection this
aftn/early eve will be over the High Plains, within zone of
upslope flow and closer to upper trough axis. So can`t rule out an
iso shwr/weak storm through sunset, but by in large should be a
quiet and seasonably comfortable eve, though a bit brzy.
The low level ridging in place over the Great Lakes/Upper
Midwest is forecast to gradually break down and nudge eastward
tonight into Sun, allowing the primary moisture plume
(characterized by PWATs 125-150 percent of normal) to nudge
eastward, as well. Weak WAA/isentropic ascent, in the absence of
warm mid-level temps/capping, could lead to band of elevated shwrs
and weak storms late tonight and into Sun AM. Extended runs of the
HRRR and RRFS have shown this most consistently, so have PoPs incr
from 10-20 percent before midnight to 30-50 percent by dawn Sun
AM. Both mid level lapse rates and effective shear are weak, so
severe weather is not expected from this activity.
Conceptually speaking, there should be a relative lull from late
AM into early aftn due to weakening LLJ and localized subsidence,
but confidence is not overly high. This is mainly due to the fact
that we`ll still have the tail end of the ejecting W trough
lingering in the area through Sun eve and capping will be
essentially non-existent. CAMs are really all over the place,
which also doesn`t lend much help in the confidence department.
Nonetheless, assuming a break does indeed occur, then conceptual
model would also suggest redevelopment of scat tstms by late aftn,
most likely first in areas W of Hwy 281. SPC Day 2 Convective
Outlook places these areas within a Marginal Risk for severe
weather - which seems reasonable given moderate CAPE and weak
effective shear that would support pulse-type activity. Another
concern similar to that of the past few days further W, is the
potential for very localized heavy rain and flash flooding. Weak
mid-upper level flow and Corfidi vectors suggest slow storm
motions and don`t see any reason to believe the above avg PWATs
already in place will decr. 12Z HREF 48-hr QPF PMM isn`t terribly
concerning, but I believe this is due in part to the poor
agreement in convective timing/placement. The 48hr max QPF does
have small bullseyes of 2-5"+, and if this occurs in our more
saturated W zones then there could be iso hydro issues. Whatever
convection develops Sun aftn/eve should slowly slide E/SE and
weaken Sun night.
Shower/storm chcs continue into Memorial Day Monday, but to be
honest, confidence on coverage/timing/intensity are not great.
FWIW, latest model depictions are for subtle height rises as the
trough from Sun weakens and shifts well N of the area. A return to
weak zonal flow COULD result in a weak perturbation crossing the
area during peak heating and no cap, but without a more
substantive signal attm, believe most of Mon will be on the
drier/quiet side for most of the CWA. In fact, could be a pretty
nice day with overall-weaker winds (compared to today-Sun) and
continued pleasant temps.
Upper pattern remain that of weak, zonal flow through at least
midweek...so probably looking at the same song and dance from Mon
into Tue and Wed, as well. Perhaps a more substantive signal for
active weather comes later in the week - towards Thu/Fri - as
models bring another upper trough into the Four Corners region.
Significant "over the top" blocking persists across S Canada, and
latest EC develops yet another cut-off low over the Gulf Coast/SE
CONUS - a pattern VERY reminiscent to that of the past 5-7 days.
So the more things change, the more they may actually just stay
the same, which is off and on uncertain rain chances, seasonably
pleasant temps, and a focus for severe weather that remains
largely SW of the area over the S High Plains.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Monday)
Issued at 719 PM CDT Sat May 27 2023
- General overview (including winds):
Overall-high confidence in VFR conditions through at least the
majority of the period (and TAFs are officially VFR for now).
However, this is by no means a "sure thing" as not only are there
two "windows of opportunity" for showers/thunderstorms mainly
during the latter half of the period that could cause briefly sub-
VFR visibility and/or ceiling, but even apart from possible
convection there is at least a small chance for MVFR ceiling to
develop at times, particularly at some point between sunrise and
early afternoon (and probably favoring KEAR more than KGRI). Wind-
wise, direction will prevail southeasterly through the period
(except for any possible thunderstorm-outflow influences that
could greatly disrupt prevailing speed and/or direction at least
briefly). Sustained speeds through most of the period will average
10-15KT, but frequent gusts of 20-25KT are likely during the day
Sunday.
- Ceiling/visibility/precipitation details:
Honestly, the only portion of the period that can be declared
shower/thunderstorm-free with a relatively high degree of
confidence is right away this evening through around 11-13Z
Sunday. Beyond that, higher-res models are becoming increasingly
insistent that at least scattered convection (and perhaps even a
small convective complex?) will work through the area early in the
day Friday. Still not confident enough for any TEMPO/prevailing
groups given this is mainly during the latter half of the period,
but slightly adjusted timing of the generic "vicinity
thunderstorm" (VCTS) group to focus 11-17Z KEAR/13-19Z KGRI.
Severe storms appear unlikely with this early-day activity, but
heavy rain/gusty winds certainly possible. In theory, there is
then a lull in shower/thunderstorm potential for at least a few
hours until later in the afternoon, but this is no "guarantee".
For now, have brought in another VCTS group at 22Z for both
KGRI/KEAR to account for renewed developed of perhaps isolated,
but maybe strong to even marginally-severe storms with a threat of
at least small hail/gusty winds. The bottom line: there is at
least one if not two chances that convection could plague parts
of the daylight hours Sunday. Also of considerable uncertainty is
whether an MVFR ceiling could develop at least briefly NOT
directly associated with active convection. Model signals are
currently mixed on this, so for no will only "hint" at this with a
scattered MVFR cloud group through the latter 11-13 hours of the
period.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...Pfannkuch
DISCUSSION...Thies
AVIATION...Pfannkuch
Area Forecast Discussion
National Weather Service Indianapolis IN
920 PM EDT Sat May 27 2023
.Forecast Update...
Issued at 920 PM EDT Sat May 27 2023
* Mostly Cloudy and not as cool tonight
Surface analysis this evening shows large, broad high pressure in
place from the Great Lakes, across NY State, toward points southeast
of Long Island. A deep tropical low pressure system was found off
the SC coast. These two systems continued to provide a dry easterly
surface flow to Central Indiana. Furthermore a tropical flow aloft
between these two systems was resulting in a stream of high clouds
from the middle Atlantic States across the Appalachians to KY/OH and
Indiana. Dew points within the lower levels remained quite dry in
the lower 40s.
Overnight, little overall change is expected. Models show 300mb
moisture continued to be advected east across Central Indiana,
providing high clouds through the night. Time Heights and forecast
soundings are on board with this showing saturation well aloft with
dry air below. Thus we will expect a mostly cloudy sky overnight.
Given the expected cloud cover and weak warm air advection
overnight, temperatures should be a bit slower to fall than previous
days. Thus lows in the middle to upper 50s appear to be on the mark.
&&
.Short Term...(This evening through Sunday)
Issued at 223 PM EDT Sat May 27 2023
A complex upper level low in the Tennessee Valley area will be the
main influence for weather across central Indiana through Sunday.
Rest of This Afternoon...
Clouds will continue to overspread the area from the southeast and
east. Temperatures will be in the mid 70s to lower 80s.
Tonight...
Clouds will continue to thicken and slowly lower across central
Indiana as some weak lift occurs in the mid levels. Lower levels
will remain quite dry thanks to a continued east flow. By the end
of tonight period some rain may be falling out of the mid cloud
across the far southeast forecast area, but with the dry low levels,
only some sprinkles/very light rain would reach the ground.
Will keep some slight chance PoPs far southeast near the end of the
tonight period.
Clouds will keep temperatures warmer than previous nights, with lows
in the mid 50s expected.
Sunday...
Clouds will lower a bit more through the mid levels, and
weak isentropic lift will move through mainly the southern portions
of the forecast area at times during the day. However, the lowest
portions of the atmosphere will remain dry.
Given the weak forcing and the dry lower atmosphere, feel that odds
of anything measurable reaching the surface are low. Will have some
low PoPs across the southeast quarter or so of central Indiana,
with dry conditions elsewhere. Wouldn`t rule out a sprinkle up into
the Indy area during the afternoon though.
Thicker clouds will keep high temperatures around 70 in the
southeast, but thinner clouds will allow highs around 80 northwest.
&&
.Long Term...(Sunday night through Saturday)
Issued at 223 PM EDT Sat May 27 2023
Sunday Night Through Wednesday.
Generally dry and quiet conditions are expected for much of the work
week next week with only small chances for pulse thunderstorms
during peak heating. Skies will gradually clear during the overnight
hours on Sunday into Monday as the weak low pressure system pushes
to the east. A ridge of high pressure then will build across the
area and bring summer conditions to central Indiana as highs climb
to near 90 by Wednesday. The PBL will deepen to over 6kft Monday
through Wednesday with a weak cap at the top of the boundary layer
which will limit convective initiation but leave a fairly robust
field of diurnal cu each afternoon, especially on Wednesday. Can`t
rule out a stray shower or two but the lapse rates above the top of
the PBL are near moist adiabatic which will lead to near 0
instability. Air quality issues are likely for Tuesday and Wednesday
with a stagnant air pattern and plenty of sunshine.
Thursday Through Saturday.
Little change is expected Thursday into the early portions of the
weekend with hot but not humid conditions. By Friday most areas
will reach 90 with 90s expected again on Saturday. Flow aloft
remains weak and with the very stagnant airmass in place, air
quality concerns will continue into the weekend. Afternoon RH
values will fall to around 30 percent but with little wind, the fire
threat will be somewhat limited.
&&
.Aviation...(00Z TAF Issuance)
Issued at 630 PM EDT Sat May 27 2023
Impacts:
* VFR Conditions expected
Discussion:
Surface high pressure over the Great Lakes will keep dry easterly
flow in place across Central Indiana through the period. Forecast
soundings through Sunday show dry air within the lower levels.
Aloft, a tropical low off the Carolina coast was producing high
cloud that was streaming NW into Indiana as seen on GOES16. The
stream of upper level tropical moisture looks to remain present
through tonight and into Sunday. RAP shows continued saturation at
the 300mb level through tonight and Sunday, indicative of this
moisture continuing to flow across the area. Ultimately, this will
result in just continued high level CIGS and VFR conditions.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...Puma
Short Term...50
Long Term...White
Aviation...Puma
...UPDATED AVIATION FORECAST DISCUSSION...
.SYNOPSIS...
Issued at 416 PM CDT Sat May 27 2023
Key Messages:
- Periodic thunderstorm chances continue the next several days with
a threat of hail, wind, and very heavy rain this weekend
- Breezy south winds expected again Sunday
- Near normal temperatures this weekend, then a slight warmup headed
into midweek with a push for 90F across northern Neb
Synopsis:
Nebraska lies in southwest to nearly meridional flow aloft as the
state is bounded by closed lows in the Pacific Northwest and
Tennessee Valley. Near the surface, a trough continues to hold
against the higher terrain in CO and WY. This feature will be partly
responsible for additional thunderstorm development over the next
several hours.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 416 PM CDT Sat May 27 2023
This evening tonight... Strong south/southeasterly low level flow
will keep driving the moisture advection scheme for western
Nebraska. The winds are nearly uninhibited from the Gulf, helping
maintain dew points in the mid 50s to lower 60s. Weak isentropic
upglide is in place over southwest Neb and the Sandhills through mid-
evening, which may provide enough lift to spawn isolated showers and
storms. Otherwise, the main story will be convection approaching
from the west. Scattered activity is underway (as of 21z) close to
the divide, and guidance suggests upscale growth toward the Neb
panhandle later on. Thunder parameters such as instability and deep
layer shear weaken notably after 06z east of the panhandle, which
would suggest that activity to fizzle. However, newer storms may
develop in the southwest overnight, possibly in the form of an MCV.
More aggressive guidance like the HRRR hints at full-blown
convection barreling through near and south of I-80, while HREF
suggests scattered and less intense activity. If the former scenario
comes to fruition, heavy rain will be a major concern. Creeks are
still running high or even above flood stage in/around Hayes Co, and
flash flood guidance is relatively low. While forecast soundings do
not suggest super slow storm motion, atmospheric moisture content
remains seasonably high and above the 90%ile of climo. Forecast min
temps used a general short term guidance blend and resulted in mid
50s west to upper 50s east.
Tomorrow... Upper level flow transitions to more quasi-zonal briefly
as a progressive trough swings into the Dakotas and is accompanied
by a mid-level shortwave. These features, along with the surface
boundary hanging off to the west and a developing warm front to the
south, will present additional opportunities for thunderstorms. A
big question mark is the aforementioned MCV. Should one be slow to
erode or exit the forecast area, new development may be delayed
until late in the evening. Perhaps the greatest potential exists
toward central Neb after dark when earlier iso/sct storms merge into
a cluster or MCS-type setup. The other possibility will be scattered
storms forming by early/mid afternoon in the Sandhills. Whatever
activity occurs, the environment would support strong to severe
storms. Instability would be ripe with MUCAPE values of 1500+ j/kg
and mid-level lapse rates around 7 C/km, while deep layer shear
approaches 30 kts in the south and 40 kts in the north. Soundings
suggest a skinnier CAPE profile, which may limit large hail growth,
but very steep low level lapse rates would encourage stronger wind
gusts. Similar to the past few days, torrential rainfall will be big
concern as well. Forecast max temps hedge on the lower end of the
NBM envelope due anticipated more widespread cloud cover and
precipitation. Values range from the lower/mid 70s southern/central
Sandhills to around far north central.
.LONG TERM...(Monday through Saturday)
Issued at 416 PM CDT Sat May 27 2023
The synoptically active period continues through the workweek for
Nebraska as upper flow switches between quasi-zonal and
southwesterly. Eventually toward late week, the trough over the
Western US deepens and spreads onto the Plains, possibly spinning
off a closed low over the central Rockies. Surface boundaries will
also be in the vicinity, including a warm front passage late Monday
and a cool front Friday. Overall, periodic rain showers and
thunderstorms will be the norm. The most persistent and widespread
activity may occur Friday into Saturday with the approaching upper
low. Temperature-wise, highs will stay near normal (70s to around
80F) through the weekend, then warm well into the 80s Tue and Wed. A
few 90s may be possible in the Sandhills midweek depending on sky
cover and the strength of low level temp advection.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 625 PM CDT Sat May 27 2023
VFR conditions are expected to prevail into tonight. By late
tonight, thunderstorms will begin to progress from west to east
across the area, with MVFR possible in any thunderstorms. Behind
the storms, an expansion in low stratus is anticipated, with
widespread MVFR/locally IFR CIGs persisting into the afternoon
hours tomorrow across the area. CIGs should gradually rise to
low-end VFR by late afternoon, with VFR then expected to prevail
through the end of the period. Winds remain breezy from the south,
with gusts of 20 to 25kts possible again tomorrow afternoon.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Snively
SHORT TERM...Snively
LONG TERM...Snively
AVIATION...Brown
Area Forecast Discussion
National Weather Service Marquette MI
742 PM EDT Sat May 27 2023
.SHORT TERM...(Through early evening)
Issued at 253 PM EDT SAT MAY 27 2023
Water vapor imagery and RAP analysis show a mid-level anticyclone
centered in the vcnty of far eastern Upper MI. Air mass over the
area is extremely dry as noted on the 12z KGRB sounding which showed
precipitable water at a paltry 0.12 inches (~15pct of normal), just
shy of a record low value for the entire month of May. Typical for a
very dry column and full sun, temps soared after sunrise with
readings currently well into the 70s F widespread, except for local
cooling near the Great Lakes which is more consistent near Lake MI
since there is a gradient southerly wind. Some of the traditional
nighttime cold spots have seen temps rise around 45 degrees from
early morning mins. Some of those locations will approach a 50
degree temp swing before the diurnal rise ends late this aftn. With
the very dry air avbl to mix down, 850mb dwpt on the 12z KGRB
sounding was -30C, sfc dwpts have been falling since late morning,
but not as much as would be expected given the avbl dry air to mix
down. Still, dwpts are as low as the mid 20s F at a few spots in the
interior, and RH has fallen into the teens pct at many locations.
Fortunately, winds remain light with ocnl gusts generally to 10-
15mph.
For the rest of the aftn, temps will rise a few more degrees in the
interior with widespread RH in the interior likely to run from
around 12 to around 20 percent. Temps near the Great Lakes will see
some upward and downward fluctuations. Clear skies will continue
into the evening.
.LONG TERM...(Tonight through Saturday)
Issued at 345 PM EDT SAT MAY 27 2023
Upper level ridging persists through at least Thursday before
troughing over the Canadian Maritimes begins retrograding westward
near the end of the extended forecast period. This means a prolonged
stretch of nearly ideal beach weather with above normal temps and
below normal precip. At this time, the best chance for precip falls
on Thursday/Friday, but even that looks spotty pop-up showers or
storms.
The strong late-spring sunshine continues to moderate a very dry
surface ridge that has lingered across our area for several days
now. In fact, this mornings balloon launched at GRB had a pwat of
0.12" only slightly more moist than the record low for the month of
May (0.10"). This dry surface ridge will continue to result in large
diurnal temperature swings especially south-central and east away
from the Lake Superior shoreline. Presumably, the weak southerly
flow is insufficient to climb the slight slope resulting in ideal
conditions for radiational cooling. As a result, some patchy frost
is possible again tonight for Delta, Schoolcraft, southern Luce, and
perhaps locations farther east too. Farther north, this stable
southerly flow is able to spill into the Lake Superior basin
resulting in more mixing and warmer temps.
Full sunshine allows for a quick warm up Sunday morning with high
temps reaching into the lower 80s across most interior locations
where RH values fall below 20% once again. Despite light winds,
recent dry weather and very low RH values results in fire wx
concerns continuing through the holiday weekend. There is some
potential for high clouds to stream into our area Sunday night,
which should prevent temps from bottoming out as efficiently
suggesting the frost threat should end too. Monday should be similar
to Sunday except a few degrees warmer and still very dry (RH below
20%) with fire wx concerns.
The stubborn surface ridge finally begins shifting east Monday night
and Tuesday resulting in increasing southerly winds that should also
help to transport more moist air into our area. The combination of
more wind and continued dry conditions could result in a more
volatile fire wx regime, especially if moisture is slower to arrive
than currently anticipated. By Wednesday, EFI values >0.8 indicate
very unusual warmth and SoT values >0 indicate a few ensemble
members have temps approaching the 99th percentile of modeled
climatology. In this case, this all means there`s potential for
temps >90F across the interior on Wednesday and perhaps Thursday
too. At some point on Thursday, a cool front should sag south into
our area resulting in cloud cover and precip chances that should
take the edge off this early summer heat wave. Clouds and precip
chances could linger into Friday, but a dry Hudson Bay high builds
south next weekend bringing another dry stretch of weather.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 740 PM EDT SAT MAY 27 2023
With high pres over the Great Lakes region providing a very dry air
mass, VFR and winds mostly blo 10kt will continue at IWD/CMX/SAW
thru this fcst period. There will be variability in wind direction
at CMX as lake breezes affect the terminal, resulting in easterly winds
becoming westerly late tonight and then becoming easterly again late
aftn Sunday. Generally s to sw winds will prevail at IWD/SAW until
a lake breeze brings winds around to the e to ne Sun afternoon.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 345 PM EDT SAT MAY 27 2023
Light winds of 20 kts or less are expected across Lake Superior over
the next several days as high pressure remains across the Great
Lakes region. The next chance for winds approaching 20 knots is
Tuesday night ahead of the next trough/cool front. There could be a
few thunderstorms over the western lake late Tuesday gradually
spreading across the remainder of the lake by Thursday as this weak
cool front/trough drops into the region.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...EK
AVIATION...Voss
MARINE...EK
Area Forecast Discussion
National Weather Service Norman OK
1006 PM CDT Sat May 27 2023
...New UPDATE...
.UPDATE...
Issued at 1006 PM CDT Sat May 27 2023
Removed or lowered POPs before 09Z, but otherwise the forecast
looks to be in good shape. The current convection may wane this
evening to the west, but there is a decent signal of re-
intensification or redevelopment Sunday morning before sunrise in
the eastern Texas panhandle as a shortwave and/or MCV from the New
Mexico convection reaches an axis of deeper moisture in the
eastern panhandles. This convection is then expected to move into
the western counties near or before sunrise.
&&
.SHORT TERM...
(This evening through Sunday)
Issued at 338 PM CDT Sat May 27 2023
The main weather issue through this evening would be weak isolated
thunderstorms with a potential of localized heavy rainfall across
portions of western Oklahoma and adjacent portions of western north
Texas. Much of these storms had been developing on an outflow
boundary from earlier storms east of the dryline stretched across
eastern New Mexico. Some of these storms may track across the
Southern High Plains into our western CWA through the evening hours.
Moderate instability and ample low-level shear with increasing 850
mb flow over the Southern High Plains will keep any severe risks
mainly west of our CWA across the Texas/Oklahoma Panhandles. Any
storms that make it into our western CWA will be moving into weaker
instability keeping them below severe as they dissipate. Additional
but more elevated storms may develop tonight across the panhandles
as a shortwave propagates through a ridge in the mid-levels although
deterministic models trending these overnight storms to mainly
affect our western north Texas CWA. Models also trend a weak
nighttime shortwave across the Central Plains, as any storms that
develop across western Kansas could track into weak unstable air
across northwest Oklahoma with the latest HRRR painting isolated
rain showers. As a result, will keep storm POPs in the forecast
through the overnight hours across our western CWA. Again no severe
weather expected, although weak steering flow aloft would result in
slow moving storms, which could result in heavy rainfall underneath
leading to a potential risk for localized flooding, especially in
poorly drainage areas.
The shortwave over the panhandles will increase with stronger
vorticity moving across central Texas on Sunday afternoon with
storms breaking out ahead of a stalled warm front stretched across
across northern Texas. As a result, will keep storm POPs in the
forecast and increase them spatially further east across our CWA to
near the I-35 corridor. Weak instability along the I-35 corridor
will be sufficient for non-severe thunderstorm development, although
moderate instability over the panhandles may be sufficient for strong
to marginally severe storms through the evening across our far
western CWA, with damaging hail & winds as the main severe hazards.
Heavy rainfall with slow moving storms will possible along & west of
I-35 on Sunday as well.
&&
.LONG TERM...
(Sunday night through next Friday)
Issued at 349 PM CDT Sat May 27 2023
Current Rex Blocking pattern over the eastern U.S. will transition
into more of an Omega Block pattern next week as a closed upper low
develops over the western U.S. coast, with weak ridging inbetween
over the remaining southern half of the country, including the
Southern Plains. A series of shortwaves propagating through the
weak upper ridge will provide opportunities for rain or storms every
day next week across parts of our CWA. Not expecting any kind of
dryline convection as it will remain stretched across eastern New
Mexico/Colorado. The highest probabilities for rain/storms will be
on Monday and Friday into next weekend. Will see the stalled warm
front lift across our CWA on Monday along with a passing shortwave
aloft initiating storms, while an approaching upper trough coming
from the west will increase our POPs for Friday into the weekend. So
far not expecting any severe storms in the long term. We won`t see
much of a change in temperatures as they will remain warm and
seasonably average as we go into early June.
&&
.AVIATION...
(00Z TAFS)
Issued at 636 PM CDT Sat May 27 2023
Any showers and thunderstorms are expected to remain west and
south of the TAF sites through the night. There will be increasing
chances of scattered showers/storms Monday morning in the west
moving in from the Texas and Oklahoma panhandles. Apart from these
showers and thunderstorms with reduced visibilities and lower
ceilings, VFR conditions are expected.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 64 80 62 78 / 10 30 20 50
Hobart OK 63 77 60 77 / 20 60 30 40
Wichita Falls TX 64 78 63 77 / 20 60 40 50
Gage OK 60 78 59 80 / 30 40 30 20
Ponca City OK 59 81 61 84 / 10 20 20 40
Durant OK 62 85 64 82 / 10 10 20 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
SHORT TERM...68
LONG TERM....68
AVIATION...26
Area Forecast Discussion
National Weather Service Blacksburg VA
941 PM EDT Sat May 27 2023
.SYNOPSIS...
Low pressure off the South Carolina coast will move slowly north
tonight through Sunday night bringing widespread rain and below
normal temperatures to the region. Tuesday and Wednesday the
probability of rain decreases, but dry and warmer weather does
not arrive until the end of next week.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 930 PM EDT Saturday...
Light rain continues to overspread the region with the greatest
concentration generally in areas near and west of I-77. Coverage
gradually decreases the farther the away from this location with
only very patchy light rain across the southern Alleghany
Highlands. Meso-scale models over a small break in the activity
across the southwest portion of the region a little past
midnight, but with another resurgence of cover as we head into
the pre-dawn hours of Sunday.
Have made minor tweaks to hourly temperatures and dew points
based upon the latest observations and expected trends over the
next several hours.
As of 705 PM EDT Saturday...
Widespread light rainfall becomes heavier tomorrow...
As of this evening stacked low pressure was spinning off the
coast near Charleston, SC. A plume of moisture stretched from it
NW towards Knoxville and into the Ohio Valley. Additional
forcing NE of the low was supporting an area of thunderstorms
over the NC coast. We were getting some of the lighter moisture
being drawn in from the ENE north of these areas. The result was
light but persistent rain across northern NC and parts of SW VA
and even into SE WV. Rainfall amounts were light so far with
just a few hundredths falling every hour, and a sharp cutoff .
We will continue to skirt the deeper moisture through tonight,
and expect most to see several periods of light rain off and on.
Isentropic lift increases towards daybreak. As the surface low
lifts north along the coast, some of the deeper moisture will
work in along the southern Appalachians. This will result in
periods of heavier rainfall Sunday. Overall looking gloomy and
cool.
Adjusted PoPs and temperatures/dew points slightly for this
update.
As of 120 PM EDT Saturday...
Confidence high for rain and wind tonight...
Two closed upper lows, one over the Tennessee Valley and the
other off the South Carolina coast will merge tonight, lower
500MB heights over the Carolinas. At the surface low pressure
will track from the South Carolina coast into North Carolina by
Sunday.
Starting with a large surface temperature/dewpoint spread this
afternoon with dew points in the upper 30s to mid 40s. The air
mass will saturate from the top down and as has been the case
for the past few runs, will slow down the northern edge of the
rain with the system. Will use the timing off the HRRR and HREF
which gets the rain in to Roanoke and Lynchburg around 22Z/6PM
and not up to Lewisburg and Hot Springs until 03Z/11PM.
Surface and low level winds veer to the east and southeast
tonight and remain easterly on Sunday. As the winds become
east, the low level jet increases into the 45 to 50 knot range
leading to low level convergence and slightly better upslope
lift. Isentropic lift is still decent too, especially tonight.
Even with all the clouds and mixing this evening, temperatures
will lower and dew points will rise as low levels moisten.
Little change in temperature is expected once the humidity is
near 100 percent. Clouds and rain will also keep temperatures
unseasonably cold on Sunday. Forecast high temperature are close
to records for coldest maximum. See the climate section of this
discussion.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
As of 1220 PM EDT Saturday...
Continued cool and rainy conditions...
The upper closed low and stacked sfc low is progged to meander
slowly eastward through the period allowing for continued slugs
of enhanced Atlantic moisture advecting across the area along
the north and eventually west of the center. Despite some
warming temps compared to the weekend, there doesn`t look to be
much instability available unless some breaks in cloud cover and
daytime heating during the afternoon could locally enhance sfc
based parcels. Just hard to see anymore than a slight chance of
thunder given this setup and northeast to east fetch. Tuesday
even looks to be possibly more stable with stronger wedging
combining into the setup.
For QPF, Sunday night through Monday looks to have most of the
area with the heavier amounts generally in the 1-1.5 inch
range for storm totals, then an additional quarter to half inch
shifted to the eastern CWA for Tuesday. While these totals are
not very impressive, any localized flood threats may depend on
antecedent conditions and what precip amounts are realized from
the weekend rounds.
Forecast confidence is medium to high.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 1220 PM EDT Saturday...
Shower and storm chances for Wednesday then some slight
chances Thursday and Friday. Temps moderating warmer...
For Wednesday, as the aforementioned low dampens to the east of
the area, we still stay in a regime of some residual enhanced
moisture but with little discernible forcing mechanism present.
This with limited progged instability mainly warrants a day of
general chance pops and slight thunder mention.
For Thursday into Friday, some weak ridging could win over and
allow for a pocket of drier airmass pushing in from the north.
Guidance solutions are indicating we may be able to lessen pops
for these days. For now will keep some parts with just a slight
chance of precip.
Temps look to have a welcomed snap back to reality and moderate
even up to above climo norms by the end of the work week.
Friday forecast highs should generally range from mid 70s to low
80s in the mountains and some low to mid 80s for the piedmont.
Forecast confidence is medium.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
As of 215 PM EDT Saturday...
Two closed upper lows, one over the Tennessee Valley and the
other off the South Carolina coast will merge tonight, lower
500MB heights over the Carolinas. At the surface low pressure
will track from the South Carolina coast into North Carolina by
Sunday.
Starting with a large surface temperature/dewpoint spread this
afternoon with dew points in the upper 30s to mid 40s. The air
mass will saturate from the top down and ceilings were already
lowering. Have KDAN reaching MVFR around midnight/04Z, KBCB
around 06Z/2AM, KBLF/KLYH around 09Z/5AM, KLWB/KROA by 11Z/7AM.
Ceilings will continue to drop throughout the day Sunday
reaching IFR at all local TAFS except for KLWB by 14Z/10AM.
Widepspread MVFR rain and fog will fill in across southwest
Virginia, northwest North Carolina and southeast West Virginia
around the same time as the ceilings drop to MVFR. Rain and fog
will continue past the 18Z/2PM end of the TAF forecast period.
Surface and low level winds veer to the east and southeast
tonight and remain easterly on Sunday. As the winds become
east, the low level jet increases into the 45 to 50 knots. Wind
gusts overnight will remain in the 15 to 25 knot range.
EXTENDED AVIATION OUTLOOK...
Poor flying conditions will persist into Monday night.
Gradual improvement should take place during Tuesday as low
pressure starts to move east. The probability of precipitation
will lower but the chance of showers with afternoon
thunderstorms will continue into Wednesday.
VFR ceilings and visibilities will return for Wednesday and
Thursday.
&&
.CLIMATE...
As of 215 PM EDT Saturday...
Listed below are the record cold maximum temperatures for May
28th
Bluefield WV...51 in 1992
Danville VA....61 in 1968
Lynchburg VA.. 57 in 1992
Roanoke Va.....56 in 1992
Blacksburg VA..54 in 1997
&&
.EQUIPMENT...
As of 645 PM EDT Saturday...
The temperature reading at Roanoke (ROA) has been erroneous
since a hardware failure this morning. Electronics technichians
were evaluating the problem. Use this data with caution. Parts
of the preliminary 5PM climate report have been sent as
missing.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS/SH
SHORT TERM...AB
LONG TERM...AB
AVIATION...AMS
CLIMATE...AMS
EQUIPMENT...AMS