Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/08/23
Area Forecast Discussion
National Weather Service Dodge City KS
523 PM CST Tue Feb 7 2023
...Updated Aviation...
.SHORT TERM...(This evening through Wednesday night)
Issued at 1246 PM CST Tue Feb 7 2023
Key messages in the short term
-Upper level low will bring cloud cover and small chances of rain
in south central Kansas
-Winds increasing in wake of a cold front moving through Wednesday
night
18Z observations are showing an upper level low situated in
southern New Mexico with the upper level winds generally out of
the southwest. The jet stream currently is split flow with the
polar jet entrenched over Canada. At the surface a 1026 mb high in
eastern Colorado is keeping the winds light and the skies mainly
clear.
Tonight as the upper level low moves into west Texas mid level
clouds will build in from south to north during the overnight
hours. Winds should continue to stay light and stay generally out
of the north to northwest as the surface low moves towards
Dallas. Overall conditions should stay quiet as lows fall into the
20s.
Wednesday the main forecast challenge will be where (if any) rain
should fall during the day. The upper level trough will turn
neutral as the upper level low moves into northwest Texas. The
main mid level lift from the RAP and NAM keeps the best lift
mainly in Oklahoma and eastern Kansas. As the 700 mb low
approaches Oklahoma City towards mid afternoon this will give the
best chance of rain around Barber county. Temperatures will cool
on the backside of the low towards late afternoon which may
introduce a brief mixed phase period around southeast Barber
county. Most of the precipitation should be out of the CWA after
sunset.
Wednesday night as the first system exits another upper level
trough will rotate in from the northwest. This will bring in a
cold front during the night and post frontal winds will increase
as we get towards Thursday morning. By sunrise we could already be
experiencing wind speeds of 20-30 mph with higher gusts and wind
chills could be in the teens.
.LONG TERM...(Thursday through Tuesday)
Issued at 129 PM CST Tue Feb 7 2023
Key messages in the long term
-Strong surface winds on Thursday
-Warm up and elevated fire risk far southwest on Saturday
-Rain potential early next week
Thursday will be a cold windy day as strong northwest winds pick
up from the late morning to early afternoon. EFI and shift of
tails are both showing a higher end wind event for areas
especially along the Colorado border which could be approaching
high wind criteria. Widespread wind speeds look to be 25-35 mph
with gusts over 50 at times especially for our western counties.
Otherwise with northwest flow aloft and some lift in the 700 mb
zone coming in during the day we could see some scattered
sprinkles/flurries during the day. 850 mb temperatures will be
around -5 (C) and high will only get to the middle 30s to low 40s.
Friday into Saturday should bring the return of warmer
temperatures as an upper level trough moves into the central
plains. Towards Saturday with winds increasing out of the
southwest and drier air coming in from New Mexico we could see
elevated fire danger for areas south and west of Garden City
during the afternoon. Forecast updates are showing RH values below
15% around Elkhart. High temperatures on Saturday should reach
into the upper 50s to mid 60s.
Early next week deterministic and ensemble models are showing an
upper level low moving into the southern plains on Tuesday and
increasing chances of rain especially for Oklahoma and Texas.
Confidence in southwest Kansas getting rain is low at this time
as there is a wide spread in ensemble output QPF along with the
convective parameters favoring a large thunderstorm event in Texas
which would track the upper level low further south and lower our
POP chances and QPF output.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 523 PM CST Tue Feb 7 2023
VFR flying conditions this TAF cycle for all terminals. Current
NNE winds in the 8-12 kt range will relax to light and variable
over the next hour or two, and persist through the end of the
period.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 24 51 28 41 / 10 10 0 10
GCK 22 49 27 38 / 0 10 0 10
EHA 27 52 27 40 / 10 0 0 10
LBL 24 51 26 42 / 10 10 0 10
HYS 24 51 29 41 / 0 10 0 10
P28 29 49 30 47 / 10 40 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from Thursday morning through Thursday afternoon
for KSZ061-074-084.
&&
$$
SHORT TERM...Tatro
LONG TERM...Tatro
AVIATION...Springer
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
536 PM CST Tue Feb 7 2023
...New AVIATION...
.SHORT TERM...
(Tonight through Wednesday night)
Issued at 212 PM CST Tue Feb 7 2023
Per latest mesoanalysis and radar imagery, the frontal boundary has
raced out to the east of Del Rio already, but remains held up to the
north of the Hill Country from a Rocksprings to Kerrville to Mason
to San Saba line. This boundary will likely get held up a bit due to
strong moisture advection north and westward from the Gulf of Mexico
up through the I-35 Corridor and into the Hill Country and Southern
Edwards Plateau. Rich surface moisture for early February, with
dewpoints in the 60s east of this boundary are already in place. Add
in the fact that PWATs will be approaching 1.2 to 1.4", a good 2
SD`s above the norm, we can expect some rather decent rainfall rates
with any showers that can become more convectively driven.
At the moment, most of the activity over the region remains showery
in nature, but as daytime heating continues and instability
increases with some breaks in the overcast, we should see some more
lightning strikes here and there through the afternoon hours. Latest
CAMs have a pretty good handle on the timing of the front, with the
HRRR likely the top dog when it comes to current positioning of the
frontal boundary. As we move into the later evening hours, the front
will finally start to push southward into the Hill Country/northern
CWA, making it`s way into the Austin and San Antonio metros between
02Z-05Z. The latest 18Z HRRR indicates instability will be somewhat
lacking despite deep moisture, but this is probably largely due in
part to a lack of substantial surface heating. With a positively
tilted 500mb trough set to swing through the CWA tonight into
Wednesday, the severe threat is fairly limited, but with some
stronger winds aloft, any storm that can get rooted in the boundary
layer and tied to the advancing cold front could result in some
damaging wind gusts in excess of 60 mph. Hail does not appear to be
a threat at all with this setup, while the tornado threat is quite
low as well, although not non-zero. If a storm were to spin-up, the
window would be quite narrow, primarily between 12Z-15Z as the front
moves east of the I-35 Corridor and into the Coastal Plains tomorrow
morning. Ultimately, the bulk of the severe threat should be over
the Coastal Plains and out of our CWA on Wednesday afternoon, with
locally heavy and much-needed rainfall looking like a good bet
tonight over a large portion of the region.
Once the front moves through, expect some rather gusty winds out of
the northwest, likely 15-25 mph with higher gusts to 30-35 mph out
over the Rio Grande Plains where some elevated fire weather
conditions may develop Wednesday afternoon. Temperatures will be
cooler for most, but we are not expecting a significant drop off
behind this front. However, you will definitely notice a drop in the
humidity as much drier air filters into the region. Highs will range
from the mid to upper 50s north to the mid to upper 60s south.
Wednesday night looks to be much cooler with lows dipping into the
mid to upper 30s and lower 40s, as the pressure gradient relaxes
with a sfc high sliding through. The light winds won`t last long as
our next front is progged to arrive just beyond the short term
forecast.
&&
.LONG TERM...
(Thursday through Tuesday)
Issued at 212 PM CST Tue Feb 7 2023
Thursday into Friday will see an upper trough push from near the
Four Corners region and into the southern Plains, bringing a
stronger cold front into south-central Texas. This frontal passage
appears to be dry as moisture will be lacking behind the Pacific
front we are seeing in the short term, but we can expect stronger
northwesterly winds, possibly reaching or exceeding wind advisory
criteria based on what forecast soundings show potentially mixing
down to the surface. The front`s likely arrival during the evening
and early overnight hours may help mitigate how much mixing we see
within the boundary layer, however. Colder and drier air will filter
in behind the front, with highs on Friday ranging from the low 50s
to low 60s and lows early Saturday morning ranging from the upper
20s to low 30s. We will have to monitor for elevated to near-
critical fire weather potential on Friday afternoon across our
western counties where relative humidity could dip as low as the
teens and northwesterly winds may remain elevated until the evening
hours.
Upper level ridging then builds in for the weekend with a warming
trend heading into early next week. Meanwhile, another strong upper
trough/closed low will be moving down the California coast,
eventually making its way into the southern Plains by early Tuesday.
Chances for showers and storms will be on the increase once again
ahead of this upper low and associated Pacific front, with clearing
and drying conditions in its wake heading into Wednesday of next
week.
&&
.AVIATION...
(00Z TAFS)
Issued at 534 PM CST Tue Feb 7 2023
Gusty northerly wind will continue at DRT through the period as it
sits behind the cold front. Could see some showers between 08-10Z,
but conditions should remain VFR through the period. More
complicated weather for I-35 sites as showers and thunderstorms
continue tonight into Wednesday. IFR ceilings are expected at all
sites around 02-03Z, with possibly some MVFR visibilities with
showers or storms. Isolated thunder will be possible after 02-03Z,
but the best chances for prevailing TSRA will be after 05-06Z,
possibly later as we see how storms progress. Ceilings improve to VFR
after 18-21Z Wednesday. Northwesterly wind will be breezy behind the
front, decreasing close to 23Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 49 59 41 71 / 80 80 0 0
Austin Bergstrom Intl Airport 49 58 38 70 / 80 80 0 0
New Braunfels Muni Airport 50 62 38 71 / 80 80 0 0
Burnet Muni Airport 46 56 39 68 / 80 80 0 0
Del Rio Intl Airport 48 68 41 75 / 30 20 0 0
Georgetown Muni Airport 48 57 39 68 / 80 80 0 0
Hondo Muni Airport 49 64 38 71 / 70 60 0 0
San Marcos Muni Airport 49 60 37 70 / 80 80 0 0
La Grange - Fayette Regional 54 60 39 69 / 80 70 0 0
San Antonio Intl Airport 50 61 41 69 / 80 80 0 0
Stinson Muni Airport 52 64 42 71 / 80 70 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...MMM
Long-Term...Gale
Aviation...27
Area Forecast Discussion
National Weather Service Goodland KS
732 PM MST Tue Feb 7 2023
.UPDATE...
Issued at 726 PM MST Tue Feb 7 2023
Overall forecast remains on track. Went ahead and added in patchy
blowing dust across southern portions of Kit Carson county and
throughout Cheyenne County Colorado for Thursday as office dust
parameters continues to indicate the potential. The relative best
area to see blowing dust will be across SW portions of Cheyenne
County Colorado where snow has already been absent for the past
few days. The other change that was made was to extend slight
chance pops east (mainly along and north of Highway 36 for
Thursday morning as Hi-Res guidance is picking up on a convective
band of snow showers originating from the Nebraska Panhandle and
traversing southeastward across the area.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 242 PM MST Tue Feb 7 2023
At the start of the short term period, the latest RAP analysis shows
an upper air low over the central AZ/NM border with a ridge over the
Pacific Northwest. Current satellite imagery and surface
observations display sunny skies and dry conditions across the
region with some snow cover still seen in a good portion of the CWA.
Forecast guidance show the low advancing northeastward into NM with
the ridge moving over the Northern Plains. On Wednesday, models
depict the upper air low moving over the CWA by the afternoon and
then opening up into a wave as another trough moves into the Pacific
Northwest. During the evening hours, this trough moves eastward into
the Northern Plains with the wave being absorbed into the trough
overnight.
At the surface, dry conditions are expected for the remainder of
Tuesday for the CWA with a localized surface high expected to move
into the CWA causing light winds as well. On Wednesday, models show
a surface low moving from eastern TX up through central MO
throughout the day. With this system, a cold front looks to move
through the region bringing chances for a wintry mix to the
western portion of the CWA that will transition to all light snow
showers overnight. Snowfall accumulation for late Thursday expect
to be a few tenths at most. Behind the cold front, winds become
north-northwesterly and start to speed up overnight particularly
in the western half of the CWA with soundings showing potential
wind gusts up to around 40 kts. Will continue to monitor this as
winds look to increase more beyond the short term period.
The Tri-State Area looks to see overnight lows in the upper teens to
the lower 20s. Daytime highs on Thursday expect to be in the lower
40s to lower 50s followed by overnight lows in the upper teens to
upper 20s.
.LONG TERM...(Thursday through Tuesday)
Issued at 223 PM MST Tue Feb 7 2023
Main focus for this part of the forecast is the high wind potential
Thursday behind the cold front.
An upper level low will move south across the Plains Thursday behind
the cold front from Wednesday night. Ahead of the upper level short
wave trough northwest winds will increase. Data is indicating the
low level winds will be strongest during the morning, then decline
through the afternoon as the trough shifts into the Southern Plains.
The peak wind gusts look to be around the 800mb level, which is
close to the top of the mixed layer. Soundings in East Central CO
show the gusts of 60 MPH or higher being in the top half of the
mixed layer. One complicating factor is the uniform cloud deck
expected during the day. However lapse rates are rather steep, so
am thinking there should be some mixing occurring. Another
complicating factor is the influence the snow field over Northern CO
will have on the winds. The CAA off the snow could cause an
inversion to form just above the surface which could limit the wind
gust potential. There is also the unknown influence of how much
snow will melt today and tomorrow ahead of the high winds.
Looking at the potential for wind gusts of 60+ MPH, models have high
likelihood of these winds occurring over East Central CO, extending
into West Central KS. Given the above considerations, was initially
skeptical of issuing a watch. However the model potential for high
winds was enough reason to atleast issue a watch.
Regarding wind potential, the strongest gusts look to occur over the
western part of the forecast area. The strongest gusts look to
occur during the mid to late morning, maybe into the early
afternoon, before the winds begin to trend down.
There will be some weak lift occurring during the day along with
steep lapse rates. Am thinking the steep lapse rates will be the
main contributor to snow showers forming. Given the high winds, we
could see snow squalls occur.
Blowing dust may occur, however the main threat area looks to be
more over Southeast CO. Over East Central CO the surface winds may
not be quite strong enough, and the lapse rates may not be steep
enough to allow the dust to go very far vertically.
Beyond Thursday a short wave ridge moves over the forecast area for
the weekend. This will allow warmer weather into the forecast area.
Early next week another upper level moves across the Southern
Plains. The GFS continues to move the trough well south of the
forecast area, while the ECMWF has it further north over the TX/OK
Panhandles. This setup looks like a split flow pattern, which is
usually not favorable for precipitation for the forecast area. As
such am skeptical of the current forecast for precipitation.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 334 PM MST Tue Feb 7 2023
VFR conditions are forecasted for the entire TAF period as high
pressure settles in across the area leading to the clear skies and
light/variable winds. Winds will slightly strengthen mid to late
morning Wednesday with sustained winds around 13 knots out of the
SW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...High Wind Watch from late Wednesday night through Thursday
afternoon for KSZ027-041.
CO...High Wind Watch from late Wednesday night through Thursday
afternoon for COZ090>092.
NE...NONE.
&&
$$
UPDATE...Trigg
SHORT TERM...076
LONG TERM...JTL
AVIATION...Trigg
Area Forecast Discussion
National Weather Service Grand Rapids MI
1011 PM EST Tue Feb 7 2023
LATEST UPDATE...
Update
.UPDATE...
Issued at 1010 PM EST Tue Feb 7 2023
Forecast is on track tonight. The clearing line is steadily moving
across the forecast area. By 1am, most areas will be clear based
on the current movement. Winds will subside a bit late tonight,
falling below 10 knots in the lowest 2,000 feet. As this occurs,
we may see some light fog develop, especially down towards I-94.
At this point, we are not expecting fog to become a significant
issue. Normal lows for tonight are in the teens in most areas. We
will be warmer than normal tonight with lows in the 20s.
&&
.DISCUSSION...(This evening through next Tuesday)
Issued at 308 PM EST Tue Feb 7 2023
- Freezing rain risk later Wednesday night into Thursday morning
The pattern becomes favorable for an increased risk for freezing
rain later Wednesday night into Thursday. High pressure will be
situated over eastern Ontario...funneling shallow colder air into
central Lower MI. At the same time a warm front will be lifting
northward into Lower MI leading to overrunning precipitation.
Forecast soundings around Big Rapids and Clare show an above
freezing layer at 850 mb with a subfreezing layer below at 10z
Thursday. Further south...surface temperatures are expected to
remain above freezing. By 14z Thursday...above freezing surface
temperatures should exist throughout the CWA. I don`t see the
Ludington...Baldwin to Clare region getting out of the mid 30`s
Thursday given this setup. If the freezing rain persist longer
than expected...impacts would increase accordingly. SPC HREF FRAM
shows freezing rain amounts remaining below a tenth of an inch for
this region.
- Strong wind gusts Thursday afternoon and evening
We are seeing a trend in the models for a possible trop fold
event Thursday afternoon. A PV anomaly shifts up the west side of
Lower MI during this time. Cross sections through it show a lower
of the 2 PVU heights here in lower MI then. The 500 mb winds are
running 80 to 100 knots. Winds at 850 mb increase to 50 to 60
knots and 925 mb values 40 to 50 knots. It`s interesting to see
some of the models showing 0 to 3 km CAPE moving in from the south...which
may enhance the low level mixing. Either way most models are
showing southern parts of the CWA featuring surface winds topping
35 knots with some showing over 40 knots. Thus confidence is
increasing that we will see wind related impacts then and we
appear to be headed toward a wind advisory.
- Heavier qpf Wednesday night into Thursday with small thunder risk
A strengthening warm front will be lifting northward into the CWA
Wednesday night. PWAT values along this front are modeled to be
over an inch. Stronger FGEN is noted as well with favorable upper
level divergence. All this will lead to a band of steady
precipitation that will be moderate in intensity at times. A dry
slot will work in from the south Thursday but the upper low tracks
in for Thursday night. Ensemble forecasts for Grand Rapids show 24
hr mean values of 0.75 to near an inch from the ECMWF...GFS and
Canadian models. In addition...there is a small potential for a
thunderstorm or two. MU CAPE values from several models like the
Namnest and RAP are showing several hundred joules in the
southern zones 09z to 12z Thu. This instability looks to be
elevated.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 725 PM EST Tue Feb 7 2023
An area of MVFR ceilings persist across much of Southern Lower
Michigan at 00z including all of the TAF sites. We should see a
clearing take places as these clouds are not lake generated. A
clearing out of the low clouds is expected to occur from west to
east from MKG around 03z to the eastern TAF sites of LAN and JXN
between 06z and 09z. Mainly clear skies are then expected late
tonight and on Wednesday. Not out of the realm of possibilities to
see some light fog or haze due to a moist boundary layer (via a
melting snow pack) late tonight and on Wednesday.
&&
.MARINE...
Issued at 308 PM EST Tue Feb 7 2023
We will issue a gale watch. Based upon the strengthening winds and
increasing mixing heights confidence is growing that we will see
gale force winds for at least parts of the nearshore zones.
Southern zones will be closer to the core of highest winds with
this system. The main window for the stronger winds will be during
the day on Thursday.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Gale Watch from Thursday morning through Thursday evening for
LMZ844>849.
&&
$$
UPDATE...Duke
DISCUSSION...MJS
AVIATION...Duke
MARINE...MJS
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
856 PM CST Tue Feb 7 2023
...New MESOSCALE UPDATE...
.MESOSCALE UPDATE...
Issued at 856 PM CST Tue Feb 7 2023
In the wake of light showers earlier today, areas of dense fog
quickly developed across portions of the Pine Belt this evening.
While fog may modulate to low clouds at times, high res guidance
has been consistently progging a broad area of dense fog across
southeast MS overnight as winds still remain rather light at many
locations. We have posted a Dense Fog Advisory for much of this
area, as some evening travel is already being impacted. Fog may
potentially spread more northward closer to daybreak. Otherwise,
the area of light showers is beginning to make its way out of the
area, so PoPs for the rest of tonight have been adjusted
accordingly. We can`t rule out additional isolated light showers
through the rest of the night, but low clouds and fog will be the
prevailing condition over a larger area. Forecast updates have
been posted. /DL/
&&
.DISCUSSION...
Issued at 333 PM CST Tue Feb 7 2023
Tonight and Wednesday. Light rain continues to spread north and
east across the area. Leaned heavily on the HRRR for the rain
forecast which has the rain tapering off by early morning.
Guidance was also showing fog for tonight, mainly in the I-59
corridor, so went with it. Wasn`t confident in widespread dense
fog at this time, so went with patchy fog in the zones. Could see
stratus or fog developing at this point. QPF amounts for tomorrow
were less, so opted to remove the flood risk for the afternoon.
Overall, not real changes to the short term forecast. Guidance
pops and temps were good.
Models continue to show the surface low deepening as it tracks
northeast. Looking for more warm advection type showers to develop
ahead of the system in the morning, so left slight chance values
in the east through noon. Looks like most of the convection won`t
move in until the late afternoon, generally hi-res models shows
CAPE increasing in the afternoon with values around 1000 ahead of
the boundary. There were a few other instability parameters
increasing into the late afternoon that suggests the southwest
portions of the area generally south of I-20 may be primed by the
late afternoon. Right now, it doesn`t look like much convection
will develop ahead of the boundary, so expecting most of the
activity in the later afternoon. /07/
Wednesday night into next week ...Showers and storms will be
ongoing to start the mid and long range forecast period Wednesday
night including the risk for strong to severe storms through the
overnight. Heavier rains are possible south of I-20 where a
locally higher likelihood for isolated flash flooding remains
possible. In this area, deeper moisture, somewhat slower storm
motions, and a less meridionally orientated band of storms could
result in both higher rainfall rates and longer duration of
thunderstorm activity. Urban and low lying areas, as is typically
the case, would be most at risk for flash flooding. With local
rivers remaining high, additional rainfall may prolong river
flooding issues across the area.
As storms clear with the passage of the cold front, a seasonably
cool and and dry airmass will become entrenched into the weekend.
Temperatures Thursday will be 10-15 degrees cooler than Wednesday
amidst steady northwest flow and cold advection with overnight
lows down into the 40s F. Friday temperatures continue to trend
cooler with surface high pressure in control with highs mostly in
the 50s F and lows by Saturday and Sunday morning near and below
freezing for much of the area. By Sunday afternoon, the center of
the surface high migrates east of our area and southerlies return,
resulting in moderating temperatures and highs near 60 F.
The next chance for rain likely holds off until next week when an
upper trough will be approaching Monday into Tuesday. This is
around a week out and forecast confidence is low with considerable
differences amongst the forecast guidance, but there does appear
to be a risk for thunderstorms and we will be monitoring for any
strong/severe weather risk particularly after we get through the
mid- week event and the eventual outcome becomes more clear. /86/
&&
.AVIATION...
(00Z TAFS)
Issued at 540 PM CST Tue Feb 7 2023
VFR conditions prevail across the majority of the area, with
patchy IFR/MVFR conditions in fog and light rain over mainly east
MS. This area of rain will move out of the area through the
evening, but may be accompanied by ceiling/visby reductions around
MEI/GTR. Overnight into Wed morning, fog and low clouds will
spread northward across the area, with widespread IFR/LIFR
conditions around daybreak. Visibilities will quickly improve in
most areas by mid-morning, but ceilings may be a bit slower to
improve. Though most areas will return to VFR by the afternoon
hours, MVFR ceilings may hang around, especially across east MS.
Additional showers are possible across south MS in the morning,
then generally along and west of the MS River during the
afternoon, with some thunder also possible by that time. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 59 77 51 65 / 10 40 100 20
Meridian 57 75 55 66 / 30 30 80 50
Vicksburg 59 79 48 65 / 10 50 100 10
Hattiesburg 60 77 59 65 / 20 50 80 60
Natchez 60 78 51 66 / 10 60 100 10
Greenville 57 73 46 63 / 10 70 100 10
Greenwood 57 74 51 63 / 10 60 100 10
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Dense Fog Advisory until 9 AM CST Wednesday for MSZ055>058-
062>066-072>074.
LA...None.
AR...None.
&&
$$
DL/07/LP
Area Forecast Discussion
National Weather Service Memphis TN
846 PM CST Tue Feb 7 2023
...New UPDATE...
.UPDATE...
Issued at 824 PM CST Tue Feb 7 2023
A quiet night before shower and storms move into the area for
Wednesday. We are still in a Marginal to Slight Risk of Severe
Weather on Wednesday. Greatest chances for storms will be
Wednesday afternoon with damaging winds and heavy rain being the
main threats. No major changes made to the forecast.
&&
.SYNOPSIS...
Issued at 345 PM CST Tue Feb 7 2023
A strong upper level low pressure system will lift from Texas
into the Ozarks on Wednesday. Warm and humid air from the Gulf of
Mexico will build north through the Midsouth in advance of this
system. Scattered showers will develop early in the day, becoming
most numerous over northeast Arkansas and the Missouri bootheel.
By late afternoon Wednesday, thunderstorms will develop over
eastern Arkansas, and progress through most of the Midsouth
Wednesday evening.
There is a Slight Risk for severe thunderstorms Wednesday
afternoon and evening over the Mississippi River delta south of
Memphis, and over north central Mississippi. There is a Marginal
Risk over the remainder of the Midsouth. The primary severe
weather threats will be damaging winds. A few brief tornadoes
will be possible, especially over the Slight Risk area. Flash
flooding will be possible, especially over northeast Arkansas and
the Missouri bootheel, where rain will likely get an early start
to the day.
&&
.DISCUSSION...
(This evening through next Monday)
Issued at 345 PM CST Tue Feb 7 2023
GOES water vapor imagery shows a deep upper low near the NM
bootheel at 2045Z. A pronounced shortwave was evident along the
southwest periphery of the upper low. This system will track east
to west Texas by 18Z/Noon CST Wednesday, becoming neutrally-
tilted in the process. An elevated warm conveyer belt over the
eastern third of TX will extend northeast to Ozarks. The
operational NAM model depicts an east-west oriented 925mb warm
front over northern AR during the morning and early afternoon.
Persistent flow of higher theta-e air orthogonal to this slowly
lifting elevated front will lead to a potential of heavy rainfall
over far northeast AR and the MO bootheel through early afternoon
Wednesday. Although instability will modest, a plume of precipitable
water values nearing 1.5 inches should lead to efficient rainfall
rates. Following coordination with WFOs Paducah, Springfield and
Little Rock, a Flood Watch has been issued for far northeast AR
and the MO bootheel for Wednesday and Wednesday night.
Over the remainder of the Midsouth, Wednesday`s daytime storm
chances will be more conditional due to shortwave ridging aloft.
Expect some cloud breaks to allow surface temps to warm above NBM
guidance south of I-40. Dewpoints in this area will also warm to
the lower to mid 60s, yielding mixed layer CAPE of 500 to 1000
J/kg. NAM 3km soundings depict the presence of an elevated mixed
layer (EML), sufficient to cap surface based convection. As is
often the case, HRRR soundings don`t depict an EML. As such, the
HRRR is more prone to develop scattered storms along a northward
lifting warm front during the afternoon. It should be noted that
the 18Z HRRR has backed off the warm sector afternoon convection
slightly.
By 00Z Thursday/6 PM Wednesday, the southern lobe shortwave will
pivot around to the southeast perimeter of the upper low and eject
through AR during the evening. A 1001 mb surface low will track
just northeast of the main upper low, lifting into southern MO by
9 pm, where it become occluded. Nonetheless, the presence of the
ejecting shortwave and frontal reflection will likely maintain
strong frontal convergence through mid to late evening over the
Midsouth. If mixed layer CAPE of 500 to 1000 J/kg persists into
the evening south of I-40 to 03Z as the HRRR suggests, a damaging
wind and short-lived tornado threat will continue into midevening.
With 50 to 80 kts of 0-6km bulk shear, the kinematics with this
system are well-established. Cool season instability is difficult
to model this far in advance, and it is instability that will
determine the extent of the severe threat late Wednesday,
particularly past sunset.
The exit of Wednesday night`s system will be hastened by an
upstream northern branch trough dropping into the central and
southern Great Plains by Thursday afternoon. This trough will lift
into the Ozarks on Friday. Isolated rain showers will develop near
the upper low and extend into the Midsouth. Cooler temperatures
will follow for Saturday, before upstream ridging arrives from the
southern plains on Sunday. Sunday`s high temps should prevail
near normal. Temperatures should warm further early next week, in
advance of another upper level closed low.
PWB
&&
.AVIATION...
(00Z TAFS)
Issued at 552 PM CST Tue Feb 7 2023
A cold front is currently draped over MEM and MKL, where winds
have gone calm. The front will sag a little further south over
the next couple of hours with winds shifting to the northwest at
both MEM and MKL.
SHRAs will hang back behind the front with no impacts on station
through late tomorrow morning. The main story will be lowering
CIGs overnight behind the front, where they could go as low as
IFR. Some light fog is also possible. A warm front will lift back
north tomorrow afternoon and CIGs may lift back to MVFR or VFR
for a few hours before the main line of SHRAs and TSRAs arrive
after 09/00Z tomorrow.
AC3
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Flood Watch from 6 AM CST Wednesday through late Wednesday night
for ARZ009-018.
MO...Flood Watch from 6 AM CST Wednesday through late Wednesday night
for MOZ113-115.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...MJH
AVIATION...AC3
Area Forecast Discussion
National Weather Service Pueblo CO
313 PM MST Tue Feb 7 2023
.SHORT TERM...(This evening through Wednesday)
Issued at 309 PM MST Tue Feb 7 2023
Relatively quiet conditions are expected this forecast period. The
upper level system can still be seen slowly moving east, just to our
south. While this does remain close to southern CO, the drier air
which has been in place will continue to limit any precip
development across the CO and NM border, outside of a few possible
flurries. With the surface ridge in place, will see most places
across the plains fall well into the teens. Higher cloud cover over
the far southeast plains should keep these locations slightly
warmer. Similar temps expected Wednesday and given the strengthening
westerly winds, may be slightly warmer. Increasing cloud cover and
chances for snow very late in the afternoon/period, though not
really expected to increase until the evening.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 309 PM MST Tue Feb 7 2023
Key messages:
1) Snow will be possible over portions of southeast Colorado from
Wednesday night through Thursday. There could be some locally
heavier snow showers, and even a few snow squalls possible.
2) Very strong winds will be likely on during the day on Thursday,
with some gusts in excess of 60 mph possible over the eastern plains
during the afternoon.
3) A cold front will be moving in Wednesday evening with much colder
temperatures for highs on Thursday. Along with the winds will be
some low wind chill readings in the single digits or even less than
0F for areas of the plains tomorrow evening.
4) Temperatures will rebound quickly from Friday through Saturday,
with readings well above the seasonal average for most locations for
highs on Saturday.
5) There will be a gradual cooldown beginning Sunday through early
next week, with a chance of snow on Monday and Tuesday, mainly for
the southern mountains and plains.
Detailed discussion:
Wednesday night through Thursday...
A deepening major shortwave trough over Montana will move down over
the region through Thursday. There will be increasing clouds during
the evening on Wednesday, and some of the model guidance is starting
precipitation over Central Mountains and the Rampart Range/Palmer
Divide area as early as 9 PM. This system has a good amount of
dynamic forcing associated with it, however it lacks moisture.
Therefore, it could provide some good bursts of locally heavy
snowfall for some areas, while completely missing others. When
analyzing the CAMs (convective allowing models), the HRRR appears to
be the driest, especially over the plains. The ARW has only a
concentrated area of heavier QPF over Crowley and Kiowa counties
around midnight. Some of the other guidance suggests better amounts
for the plains, especially the NAM 4km Nest, which also reflects a
similar QPF to the ARW, with a micro-low embedded within the surge
of colder air over northeastern Otero County around 10 PM, providing
the extra lift needed for a heavier swath of snow around the US-50
in Bent and Prowers counties and northward. This heavier cluster
then proceeds to move over the southeastern plains through the early
morning on Thursday if the NAMNst verifies. Given the convective
nature of this with higher instability, there could be snow squalls
with this initial wave, even over the mountains.
In terms of the deterministic models, the GFS-20 does the best with
QPF over the Palmer Divide area, and the NAM12 also alludes to
higher amounts over the plains. The Canadian and ECMWF are more
sparse in terms of QPF over the plains, and keep the higher amounts
limited to more of the southern I-25 corridor where there is more of
an upsloping wind component to allow for better lift. The GFS does
favor higher QPF over the southern I-25 corridor and extending back
into the lower Arkansas River Valley between midnight and 5 AM on
Thursday morning. The models are in fairly good agreement with
better QPF sticking around over the southern I-25 corridor and Raton
Mesa area going into the early afternoon hours on Thursday. There
will also be some lingering snow showers continuing into the
afternoon hours over the central mountains, and then the snow will
continue to taper off and should be completely ended by the evening
hours with clearing taking place throughout the night.
The timing of the cold front also is relatively similar with all of
the model guidance, with winds switching to a northeasterly
direction over the plains at around 5 PM with an initial push of
colder air being the earliest with the HRRR. There is going to be a
stronger surge of colder air moving in later around midnight, which
will cause the increase in the northerly winds as the gradient
tightens from the deepening low to downstream over the Great Lakes
Region and the high builds in over the western states, along with
stronger winds moving in at the 700 mb level. Due to this, these
strong winds will help to draw in much colder air advection over the
CWA, with high temperatures being anywhere from 10 to 15 below the
seasonal average on Thursday. These blustery winds will also create
wind chill values mainly in the teens over much of the plains during
the day and then dropping into the single digits, or perhaps even
below 0F, for several locations by later in the evening. There will
also be much stronger winds over Kiowa, Bent, Prowers, and Baca
Counties which will likely reach High Wind Warning criteria from
around sunrise to the late afternoon hours. There could also be
some locations that potentially reach HWW criteria in eastern El
Paso County, as well as Crowley and Otero Counties, but more than
likely for a shorter duration. These winds do look to weaken by
around 5 PM and gradually decline going into the late evening
hours.
Friday through Sunday...
Winds will continue to weaken by early Friday morning as the trough
proceeds to move further north and allows for a ridge to move over
the region. This will allow for downsloping westerly winds to
provide a nice warmup back to around the seasonal average for most,
especially the plains, on Friday. Temperatures will even further
warm up significantly on Saturday as the strengthening and slight
positively tilted ridge moves over Colorado. Expect temperatures to
be well above the seasonal average for the plains, and even slightly
above average for the higher terrain. Temperatures will cool back
down on Sunday near the seasonal average as the ridge breaks down,
and another major shortwave trough begins to advance closer towards
the region, with extensive mid and high cloud coverage within the
baroclinic leaf moving overhead.
Monday through Tuesday...
Ensembles and deterministic models alike are generally displaying a
longwave trough moving in over the region early next week with an
U/L cut-off low over the southwestern CONUS, however, there is some
disagreement with the actual place of the trough will be between the
GFS and the ECMWF. The GFS puts the progression of the trough
further ahead than the ECMWF, and the Canadian is much more similar
To this. The location of the cut-off low is very close in agreement
between the GFS and Canadian. The ECMWF not only has the cut-off
located much further east, but it also keeps the trough further back
over Utah at the same time the other models has it over Colorado on
Monday afternoon, and also has the axis less positively tilted. If
the ECMWF verifies, it will be mainly dry over Colorado on Monday,
whereas if the GFS and Canadian resolve this better, there could be
some snow over the higher elevations. On Tuesday, the cut-off low
will progress northeastward and could provide a chance of precip for
southeast Colorado, especially over the southern half of the CWA.
This is where the GFS and Canadian diverge as far as the progression
of the cut-off low, where the GFS has it moving far south and not
providing any precip over southeast Colorado on Tuesday whatsoever.
-Stewey
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 309 PM MST Tue Feb 7 2023
VFR conditions and dry weather are expected to persist this period.
Winds will generally be light and diurnally driven, though do
anticipate increasing northerly winds at ALS very late with COS
possibly becoming more variable with an approaching boundary.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from late Wednesday night through Thursday
afternoon for COZ095>099.
&&
$$
SHORT TERM...RODRIGUEZ
LONG TERM...STEWARD
AVIATION...RODRIGUEZ
Area Forecast Discussion
National Weather Service Sacramento CA
148 PM PST Tue Feb 7 2023
.SYNOPSIS...
Mostly dry weather this week with chilly nights, near to slightly
above normal high temperatures, and areas of Valley fog. Light
precipitation possible Friday into Saturday, and again early next
week. Breezy northerly winds later this weekend into Monday.
&&
.Discussion...
Latest GOES-West visible satellite imagery shows a band of clouds
moving across interior northern California early this afternoon.
These clouds are associated with a shortwave trough that is
passing over the Pacific Northwest today. The upper level ridging
will flatten a little bit today as this shortwave passes to our
north, but the ridging will build back in on Wednesday and
Thursday. This band of clouds is expected to move out of the area
later this afternoon. Some clearing skies and light winds will
allow for the potential for fog development Wednesday morning.
HREF probabilities show about 50 to 80 percent probability for
less than a half mile visibility from Oroville southward. The HRRR
is also highlighting dense fog from about the Sacramento area
southward. With the increasing confidence in the return of dense
fog, a Dense Fog Advisory has been issued from 2 AM to 10 AM PST
Wednesday for portions of the southern Sacramento Valley,
Carquinez Straight and Delta, and northern San Joaquin Valley.
Motorists should drive slow and use low- beam headlights when fog
is encountered.
Relatively quiet weather is expected Wednesday and Thursday, with
some chilly overnight temperatures, near to slightly above normal
daytime temperatures, and generally light winds. Daytime high
temperatures in the Valley are expected to be in the 60s both
days. An upper level trough will approach the area on Friday,
bringing along chances for light precipitation Friday and
Saturday. At this point, minimal impacts are expected, as this
system does not have much moisture associated with it. The
National Blend of Models (NBM) has about a 10 to 25 percent
probability of observing a tenth of an inch of precipitation or
greater, mainly confined to the higher elevations of the foothills
and mountains. Snow probabilities range from 25 to 50 percent
chance of observing greater than an inch of snow in the mountains.
&&
.EXTENDED DISCUSSION (Saturday THROUGH Tuesday)...
Ensemble guidance is in agreement for the upper level low to push
southward across California over the weekend and into early next
week. Minimal impacts are expected with this trough besides some
light precipitation and breezy north to east winds. Some lingering
showers will be possible on Saturday as the weak weather system
moves through the area. Dry weather returns Sunday and into Monday
as ridging builds back in behind it. The Extreme Forecast Index
(EFI) highlights increased wind speeds and wind gusts over the
Sacramento Valley and Sierra Nevada later this weekend and into
Monday behind the passage of this system. An additional shortwave
trough early next week will bring chances for light precipitation
late Monday into Tuesday.
&&
.AVIATION...
Light and variable winds expected across the region through at
least Wednesday. Periods of SCT to BKN mid to high clouds aoa 12
Kft through 03-05Z Wednesday, then a brief period of mostly clear
skies tonight. MVFR to LIFR conditions possible for TAF sites from
the Sacramento Area to KMOD where fog development is likely
between 11Z-17Z Wednesday.
//Peters
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory from 2 AM to 10 AM PST Wednesday for
Carquinez Strait and Delta-Northern San Joaquin Valley-Southern
Sacramento Valley.
&&
$$