Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/14/25
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
604 PM MDT Thu Mar 13 2025
...New AVIATION...
.KEY MESSAGES...
Updated at 553 PM MDT Thu Mar 13 2025
- A potentially historical, multi-hazard spring storm system will
continue to impact the region through Saturday. Hazards include
widespread strong to damaging wind gusts, high to locally
extreme fire danger and blowing dust in the east, and minor to
moderate winter impacts that will favor the western and northern
mountains. One or more snow squalls may bring brief periods of
major impacts due to rapidly deteriorating road and visibility
conditions tonight.
- A second, less powerful system on Saturday will bring another
round of minor winter impacts and windy conditions. Blowing
snow and blowing dust will once again create hazardous driving
conditions for motorists.
- Winds ramp up Monday, then widespread strong to damaging winds
will return on Tuesday. Blowing dust and critical fire weather
conditions are expected each afternoon.
&&
.SYNOPSIS...
Issued at 250 PM MDT Thu Mar 13 2025
High impact weather is expected over the next 24 to 30 hours.
Strong winds today will only increase in intensity overnight and
into Friday. Widespread gusts between 50 and 80 mph are expected
through sunset Friday. These damaging winds may cause structural
damage, downed power lines and will create treacherous conditions
for high profile vehicles. Blowing dust will also reduce
visibility across southern and eastern New Mexico. High to
locally extreme critical fire weather conditions are also expected
across the eastern plains. Last but not least, there is moderate
to high potential for a snow squall along a cold front late
tonight across western and portions of central New Mexico which
could rapidly deteriorate road and visibility conditions.
Quieter, but still windy and wintry conditions expected on
Saturday. Tuesday looks to be another day with high winds,
critical fire weather conditions and widespread blowing dust.
&&
.SHORT TERM...
(This evening through Friday night)
Issued at 250 PM MDT Thu Mar 13 2025
...AN EXTREME MULTI-HAZARD EARLY SPRING STORM EXPECTED ACROSS
NORTHERN AND CENTRAL NEW MEXICO THROUGH FRIDAY EVENING...
A potent upper level trough is moving into the western U.S. this
afternoon with 500 mb heights as low as 538 dam over the Great Basin
of northern Nevada. An atmospheric river is being observed across
western Utah and Arizona ahead of the trough axis and on the leading
edge of the Pacific front. Meanwhile, over southern and western NM,
southwest winds are already gusty due to 40 to 50 kt 700 mb winds
already mixing down to the surface. A wind gust of 59 mph has
already been observed at KSRR as of 1455 LT and this is just a
precursor of what is to come tonight into tomorrow.
Let`s first talk about the winter weather side of this system. The
atmospheric river and strong band of rain and snow on the leading
edge of the Pacific front will move into western NM this evening at
around 8 to 9 PM. 700 mb temperatures will plummet quickly behind
the front to as low as -12 deg C come sunrise Friday, so rain will
quickly transition to snow resulting in a flash freeze. The HRRR
snow squall parameter is showing high probabilities in western NM
late tonight into early tomorrow morning, so snow squall warnings
will likely need to be issued for this band along and behind the
Pacific front. The snow squall will hold together as it moves into
the northern mountains just before sunrise, due to upslope flow,
resulting in brief higher snowfall rates there before drier westerly
flow allows it to weaken and taper off mid to late Friday morning.
The snow squall will likely dissipate across the middle and lower
RGV early Friday morning due to downslope westerly flow but could
get 1 to 3 inches across the peaks of the Sandia, Manzano and
Sacramento Mountains through mid Friday morning. Snow will mostly
taper off across the northern mountains by midday Friday. Expect
accumulations of around 5 to 10 inches across the peaks of the
southwest and north central mountains with generally around an inch
elsewhere across western and north central NM through late Friday
morning.
Now onto the more impactful part of this storm: the wind. The upper
trough will close off into a 535 dam 500 mb low as it moves over
northern NM early Friday morning. 700 mb winds will increase to 50
to 60 kts across central and southern NM come 12Z Friday. These mid
level winds will easily mix down to the surface due to subsidence
behind the Pacific front. Therefore, expect southwest winds to back
to a westerly direction and increase sharply behind the Pacific
frontal passage. Blowing snow is very likely across western and
north central NM. With the 500 mb low near the minimum values for
mid March, the presence of a 975 to 980 mb surface low over eastern
CO, and a very strong low to upper level gradient over the state
south of the low, very high to damaging west winds are expected
along and east of the central mountain chain Friday morning through
late Friday afternoon. MOS Guidance from the NAM and GFS is showing
sustained winds of 45 to 50 kts (50 to 60 mph) across the I-40
corridor of east central NM just south of the upper low circulation
mid Friday morning through early Friday afternoon as the mid level
60 to 70 kt speed max moves overhead. Wind gusts of up to 80 mph
will be possible across much of eastern NM. Additionally, with very
low min RH values critical to locally extreme fire weather
conditions are expected. For the RGV, there could be a little lull
in winds mid Friday morning before daytime mixing brings stronger
winds aloft down. Gusts of 45 to 55 mph are expected across central
NM west of the central mountain chain, but a few rogue gusts of 60
to 65 mph cannot be ruled out through the early afternoon.
Winds gradually taper off across the region Friday evening as mid
and upper level winds weaken. It will take the longest across the
east slopes of the central mountain chain and adjacent highlands. A
trailing disturbance moves into the Four Corners area Friday night
into Saturday morning brining another round of light snow showers to
western and north central NM. Accumulations with this round should
be minimal.
&&
.LONG TERM...
(Saturday through Wednesday)
Issued at 250 PM MDT Thu Mar 13 2025
A secondary disturbance will slide across the state on Saturday.
This will bring another round of light precipitation to much of the
state. H7 temperatures will be quite cold, especially to start the
state, in the -7 to -10C range, but do warm to -4 to -6C by late in
the afternoon. Thus, most of the precipitation will fall as snow,
though lower elevations may change over to rain late in the day.
Accumulations will be minimal, however. Even mountain areas will
struggle to get much more than an inch or two of the white stuff.
However, winds will be gusty yet again, though nothing compared to
Friday. Northwest wind gusts of 25 to 35 mph will be common with
locally higher gusts in northwest flow favored locales across
western and central NM. Areas of limited visibility will be
possible, particularly around Roswell, in blowing dust. A weak
boundary across northeast and east central NM should temper wind
speeds there. This system should slide out of NM Saturday night,
with precipitation lingering the longest over the Northern
Mountains.
Broad, but weak, ridging is in store for Sunday, but a few breezes
will still develop along and just east of the Central Mountain Chain
as a lee side trough gradually deepens. Temperatures will warm up 10
to 15 degrees on average from Saturday`s readings. The ridge will
slide eastward on Monday, resulting in stiff southwest flow over
NM. Widespread breezy to windy conditions will develop with
moderate mixing Monday afternoon. Temperatures will also rise 10
to 15 degrees from Sunday`s readings. In fact, all areas will be 5
to 15 degrees above normal sending RH values plummeting.
Winds aloft will only continue to increase through Tuesday as the
next upper level trough approaches and crosses the area. Another
potent cold front will race from west to east, but most of the
moisture will stay north of the NM/CO border. A few showers are
expected across the northern mountains, but amounts look to be
light once again. Rather, wind gusts may top 60 mph once again
along and behind the front, especially across eastern NM. Blowing
dust will again be a concern as well as widespread critical fire
weather conditions. There are some timing and strength
inconsistencies between models, but confidence is already moderate
to high that this will be another high wind event. That said, it
does not look to be as strong as Friday`s event.
Cooler conditions expected areawide on Wednesday with breezy to
locally windy conditions under northwest flow aloft. Most areas
will be 5 to 15 degrees below normal.
&&
.AVIATION...
(00Z TAFS)
Issued at 553 PM MDT Thu Mar 13 2025
Weather conditions will continue to deteriorate quickly this
evening through tonight and Friday as a low pressure system
approaches New Mexico. A north-south oriented Pacific front will
sweep into western New Mexico just before sunset, making its way
toward the Rio Grande valley by midnight. This will spread a
squall line (abrupt, brief, and intense rain and snow with strong
winds) across these western to central areas of the state this
evening with rapidly deteriorating visibility and ceilings. In
addition, winds will continue to strengthen in many areas through
the overnight and more-so into the morning hours, particularly
over highland areas (KAXX, KCQC, KSRR). Rain and snow will largely
fall apart as it reaches the east slopes of the central mountain
chain in the early morning, but some steady snow will persist over
the northern mountains through late morning Friday. At that point,
the winds, blowing dust, and mountain wave activity will be the
main aviation weather hazards with widespread gusts of 45 to 65
knots over the eastern half of New Mexico Friday. Widespread
visibility reductions to 1/2 to 2 miles in dust will be common.
&&
.FIRE WEATHER...
Issued at 250 PM MDT Thu Mar 13 2025
...CRITICAL TO LOCALLY EXTREME FIRE WEATHER CONDITIONS ACROSS
EASTERN AREAS FRIDAY AFTERNOON...
Southwest winds will continue to strengthen across central and
eastern areas for the rest of this afternoon and evening. This
combined with minimum relative humidity values below 20 percent will
result in rapid fire spread across this part of the state. A strong
Pacific cold front will enter and move across the state tonight
through tomorrow morning. A few to several inches of snow
accumulation mainly over the western and northern mountains behind
the front tonight. Additionally, very strong west and northwest wind
gusts of 45 to 80 mph will exist for most locations across central
and eastern areas late tonight through Friday afternoon before
trending weaker Friday evening. Temperatures will fall to below
average values on Friday. However, these high winds combined with
minimum relative humidity values in the low to mid teens and very
dry fine fuels will result in rapid and explosive fire growth across
northeast and east central areas Friday afternoon. Northwest winds
will remain gusty Saturday, though not as strong as Friday.
Thankfully, cool temperatures and higher humidities than Friday will
prevent critical fire weather conditions from developing. After
lighter winds and milder temperatures Sunday and Monday, another
high wind event looks increasingly likely for Tuesday. These high
winds combined with minimum relative humidity values in the upper
single digits to low teens will again result in critical fire
weather conditions for zones along and east of I-25.
&&
.PRELIMINARY POINT TEMPS/POPS...
Farmington...................... 32 46 28 48 / 90 30 30 30
Dulce........................... 22 39 16 43 / 100 60 30 50
Cuba............................ 24 39 21 42 / 90 40 50 50
Gallup.......................... 25 39 19 44 / 100 10 50 40
El Morro........................ 24 37 22 39 / 100 20 50 60
Grants.......................... 26 41 22 45 / 90 5 30 40
Quemado......................... 24 40 23 42 / 100 10 60 60
Magdalena....................... 28 45 26 46 / 80 0 20 30
Datil........................... 25 40 23 41 / 90 0 30 40
Reserve......................... 23 41 20 50 / 100 10 70 60
Glenwood........................ 27 43 27 50 / 100 20 70 70
Chama........................... 20 35 13 40 / 100 60 20 50
Los Alamos...................... 27 42 24 42 / 90 40 20 30
Pecos........................... 25 43 21 43 / 90 20 10 30
Cerro/Questa.................... 25 38 17 39 / 80 40 5 40
Red River....................... 19 30 12 30 / 80 40 5 40
Angel Fire...................... 22 35 14 35 / 80 40 5 50
Taos............................ 25 41 17 43 / 80 30 5 30
Mora............................ 24 41 18 42 / 70 20 5 40
Espanola........................ 31 49 25 50 / 90 30 20 20
Santa Fe........................ 26 44 23 43 / 90 40 20 30
Santa Fe Airport................ 28 47 24 47 / 90 30 20 30
Albuquerque Foothills........... 33 47 30 50 / 70 10 20 30
Albuquerque Heights............. 34 49 31 52 / 60 5 10 20
Albuquerque Valley.............. 35 51 31 53 / 60 5 5 20
Albuquerque West Mesa........... 34 49 30 52 / 70 10 10 20
Belen........................... 34 53 30 55 / 40 5 10 20
Bernalillo...................... 34 50 30 54 / 80 10 20 20
Bosque Farms.................... 34 52 30 54 / 50 5 10 20
Corrales........................ 34 49 30 53 / 70 10 10 20
Los Lunas....................... 35 52 30 54 / 50 5 10 20
Placitas........................ 32 47 28 49 / 80 10 20 20
Rio Rancho...................... 34 49 30 53 / 70 10 10 20
Socorro......................... 37 54 32 56 / 70 0 10 30
Sandia Park/Cedar Crest......... 28 42 24 45 / 90 10 20 30
Tijeras......................... 30 45 26 46 / 90 10 20 30
Edgewood........................ 28 46 24 48 / 90 5 10 20
Moriarty/Estancia............... 27 47 22 49 / 90 5 10 20
Clines Corners.................. 24 42 22 44 / 70 5 5 20
Mountainair..................... 27 45 23 47 / 80 0 10 20
Gran Quivira.................... 28 46 23 46 / 90 0 5 20
Carrizozo....................... 32 49 28 48 / 80 5 10 30
Ruidoso......................... 27 40 25 43 / 80 5 20 30
Capulin......................... 30 52 20 45 / 0 10 0 20
Raton........................... 31 54 22 47 / 5 10 0 20
Springer........................ 33 55 24 48 / 10 0 0 20
Las Vegas....................... 28 47 21 46 / 50 5 0 20
Clayton......................... 38 60 29 51 / 0 10 5 10
Roy............................. 34 55 27 48 / 0 0 5 20
Conchas......................... 39 62 31 54 / 0 0 5 20
Santa Rosa...................... 36 55 31 51 / 10 0 0 20
Tucumcari....................... 39 63 32 54 / 0 0 10 20
Clovis.......................... 36 59 32 55 / 0 0 5 20
Portales........................ 37 60 33 55 / 0 0 0 20
Fort Sumner..................... 37 59 32 57 / 10 0 0 20
Roswell......................... 42 66 34 63 / 10 0 0 20
Picacho......................... 34 55 31 54 / 50 0 5 20
Elk............................. 31 49 28 53 / 60 5 10 30
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from midnight tonight to 6 AM MDT Friday
for NMZ203-211-218.
Red Flag Warning until 8 PM MDT this evening for NMZ104-106-
123>126.
Red Flag Warning from noon to 8 PM MDT Friday for NMZ104-126.
High Wind Warning from midnight tonight to 6 PM MDT Friday for
NMZ212-215-221>225-229-232>239.
Winter Weather Advisory from 9 PM this evening to 6 AM MDT
Friday for NMZ202-205>208.
Wind Advisory from 6 AM to 6 PM MDT Friday for NMZ207-211-218.
High Wind Warning from midnight tonight to noon MDT Friday for
NMZ220-241.
Wind Advisory from midnight tonight to 6 PM MDT Friday for
NMZ219.
Winter Storm Warning from 9 PM this evening to 6 PM MDT Friday
for NMZ210-213-214.
High Wind Warning from 6 AM to noon MDT Friday for NMZ208.
High Wind Warning until 6 PM MDT Friday for NMZ226-240.
High Wind Warning from 6 AM to 6 PM MDT Friday for NMZ227-228-
230-231.
&&
$$
SHORT TERM...71
LONG TERM....34
AVIATION...52
Please note: The SYNOPSIS section will be terminated on or about Friday, April 4.
Area Forecast Discussion...Updated
National Weather Service Billings MT
809 PM MDT Thu Mar 13 2025
.KEY MESSAGES...
- Turning colder, a period of rain and wet snow, and brisk north
winds tonight and Friday; greatest chance of snow accumulations
over the mountains and foothills.
- Seasonal temperatures with low to moderate chance of
precipitation Saturday; warm and windy Sunday.
- Another potential weather system Monday into Tuesday next week.
&&
.UPDATE...
Cold front is currently from Musselshell County south to Carbon
County. Models indicate there is some weak instability of 0 to
200 J/KG of CAPE allowing some rain showers to pop up along the
line. RH values are still in the 20s and 30s to the east of the
line leading to virga until low level RH values increase along
and behind the front. RH values going down with the loss of
daytime heating will also help to moisten low levels. The front
has passed through Bozeman and Livingston with temperatures at
these locations approaching freezing.
Temperatures at Livingston dropped faster than expected,
therefore, snow amounts were increased to reflect current forecast
expectations. Some snow showers can be seen on Bozeman pass
webcams. This rain to snow transition will slowly spread east
overnight. Overall, snow amounts will be light with greatest
accumulations on grassy surfaces. Torgerson
&&
.DISCUSSION...
Tonight through Friday night...
Cold front was through KBZN at 2030Z and a few showers were moving
into the western mountains. Not seeing much in the way of CAPE in
Mesoanalysis, but lapse rates were steep. Soundings showed a
couple hundred J/kg of CAPE early this evening W of KBIL, so kept
in a mention of thunder. It was quite dry across the forecast
area with temps in the 60s and dewpoints in the 20s, so it will
take awhile for rain to make it to the ground in the lower
elevations.
N portion of splitting Pacific trough will move into
the area tonight and accompanying cold front will push SE through
the region. Weak to moderate frontogenesis will accompany the
front and jet divergence from the right-rear quadrant of an upper
jet will also provide lift. Decent PWAT`s of 0.4-0.6 inches will
provide moisture to the system. Snow levels will fall from W to E
across the area into Friday, so precipitation will begin as rain
and change over to snow through the night into Fri. from W to E.
Moderate to high PoPs will be common across the area into Friday.
Snow amounts will be limited to less than an inch over much of the
area due to the warmth of this system which will limit how much
lift gets into the dendritic growth zone.
Better dendritic growth with upslope snow will occur in the
foothills, S. Bighorn and Sheridan Counties as well as over S.
Rosebud County. Snow amounts will range from 1 to 4 inches in
these areas. For the Pryors and NE Bighorns, expect 5-10 inches of
snow. Cold front will usher in gusty winds with gusts in the 20s
and 30s through Friday and higher gusts near the MT/Dakotas border
and in S. Sheridan County. Winter Weather Advisories were issued
for the above areas for impacts from slushy roads and gusty winds
causing reduced visibility in patchy blowing snow. Added S.
Rosebud to the ongoing Advisories.
Bulk of precipitation will move E of the area Fri. afternoon.
However, influx of Pacific moisture will bring low chances of snow
to areas from KBIL W Fri. night. Temps on Fri. will be seasonable
with highs in the 40s. Bumped up wind speeds above the NBM tonight
and Fri. based on model guidance. Arthur
Saturday through Thursday...
The two main themes of the forecast after the initial system are
active and uncertain. Being that we are now two weeks into
Meteorological Spring, the mid latitudes are seeing consistent
active weather with a high amplitude trough-ridge pattern across
the Northern Hemisphere. Also, being that our Rossby Wave number
is 6 in the NH, these systems are moving pretty quickly.
As the end-of-week system pulls out of the area, a high amplitude
ridge builds in for the weekend. This will allow high
temperatures to return to 10-15 degrees above average across the
CWA with the SW flow. The main story with this ridge will be the
windy conditions that it brings with it. 700mb winds on Sunday are
forecast to be anywhere between 40-60kts depending on the model
run. This combined with the nearly 8C/KM lapse rates throughout
the layer Sunday afternoon, will make it very easy for these
winds to mix down to the surface. Areas in the Western Foothills
could see some gustier conditions with some downsloping and
gapping. Big Timber currently has the highest chance for seeing
the strongest wind gust with a 60% of winds gusting over 50mph per
the NBM. Although temps will be above average and winds will be
breezy, fire danger should remain minimal. Being that this is
coming on the heels of a decent rain/snow producer fuels should
be moist enough to keep things at bay. Additionally, the lowest RH
values throughout the period appear to occur in the SE part of
our CWA which is conveniently where our wind gusts will be the
weakest.
Monday there is some signal for a mountain wave in places like
Red Lodge and Sheridan. When looking at RAP and GFS forecast
soundings for both locations, the lack of any mountaintop
inversion is striking as lapse rates in the layer are forecast to
be greater than 7C/KM. Not to be ignored though is the strong
700-500mb winds out of the SW as well as ample subsidence on the
lee side of both the Absaroka/Beartooth and Bighorn ranges. When
looking at GFS forecast cross-sections for the aforementioned
locations at 18z, the downward motion is perfectly located for the
ridgetop winds to be forced down into the lee side foothills.
There is also a decent signal, when looking at the in-plane winds,
in this poorer resolution model that the ridgetop winds want to
dip below the ridgetop around 18z. Due to this I opted to include
some wind gusts of 25kts along the foothills in these locations.
It is certainly possible for higher gusts to occur, however,
confidence remains low at this time. If this does materialize, it
will likely be a quasi-mountain wave event.
As we move into the start of the week, all long range models have
a long wave trough moving ashore off of the Pacific early Monday.
While the models have come into more agreement in terms of timing
of this system, they have yet to agree in terms of the amplitude
of the trough. Interestingly enough, the ECMWF wants to dig the
trough deeper but also gives our CWA more precip as the trough
digs so deep that a split flow regime develops allowing a
shortwave trough to move directly through MT. The GFS, keeps most
of the energy south of the CWA for the duration of the event. This
will be a mountain snow and lower elevation rain event as temps
start to become more spring-like. Totals are still very uncertain
at this time.
WMR
&&
.AVIATION...
A cold front moving through the region will spread rain and snow
over the area, from west to east through the overnight. Rain and
snow will bring MVFR to IFR conditions. Gusty NW winds can be
expected with and behind the front, with gusts to 30 kts possible.
Precipitation will end from west to east Friday morning/afternoon
with conditions improving to VFR. Mountains will be obscured
through the period. STP
&&
.PRELIMINARY POINT TEMP/POPS...
Fri Sat Sun Mon Tue Wed Thu
-----------------------------------------------------------
BIL 036/048 029/050 032/055 039/060 036/045 030/049 030/055
93/S 22/S 22/R 34/R 66/S 31/U 01/B
LVM 029/040 025/041 030/048 038/049 028/037 022/042 026/044
82/S 24/S 44/O 47/R 76/S 31/B 13/S
HDN 033/048 025/049 029/056 036/063 033/045 027/048 025/056
85/S 11/B 31/B 23/R 66/O 31/B 01/B
MLS 035/043 021/043 026/051 031/059 031/043 024/045 026/055
25/O 00/U 11/B 21/B 33/S 20/B 00/B
4BQ 035/043 023/044 027/053 033/064 032/041 025/043 025/052
16/O 00/U 10/B 11/B 45/O 21/B 00/B
BHK 031/040 016/038 019/047 026/058 025/040 019/041 020/052
06/O 00/U 11/B 11/B 34/S 21/B 00/B
SHR 028/041 020/043 022/052 033/062 028/037 020/041 020/049
89/S 11/B 21/B 12/R 67/O 42/S 01/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect until 9 AM MDT Friday FOR
ZONES 56-64>66.
Winter Weather Advisory in effect from midnight tonight to
noon MDT Friday FOR ZONES 58-138-169.
Winter Weather Advisory in effect until noon MDT Friday FOR
ZONE 171.
WY...Winter Weather Advisory in effect from midnight tonight to
noon MDT Friday FOR ZONE 199.
Winter Weather Advisory in effect until noon MDT Friday FOR
ZONE 198.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Columbia SC
742 PM EDT Thu Mar 13 2025
.SYNOPSIS...
Warm temperatures and mostly dry through Saturday, with
increasing rain chances on Saturday evening. A strong storm
system will then push through on Sunday bringing rain, gusty
winds, the potential for strong to severe thunderstorms, and a
flood threat. Dry weather conditions return behind the front for
Monday with cooler temperatures. A warming trend then follows
for Tuesday and Wednesday.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
Key Message(s): Seasonably mild temperatures.
Upper low has worked its way into the western forecast area
early this evening, and should continue steadily eastward this
evening and head into the Atlantic. A few mid and upper clouds,
debris from earlier convection in central Georgia, should move
with the upper low and be out of the area by midnight, leaving
behind clear skies. Dew points in the mid to upper 40s portend
the expected low temps by morning.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Key Message(s):
- Calm and warm weather expected Friday and for much of
Saturday ahead of a strong front later in the weekend.
Ridging aloft will build into the region throughout Friday and
Saturday as we sit downstream of a strong upper level low to
west. Driving the ridging and height rises, strengthening
southerly component flow will develop below 500mb. So above
average temps and low level moisture are expected to steadily
increase throughout Friday and into Saturday. Friday will remain
dry, as PWAT`s have a long way to recover, but increasing
upslope flow and WAA ahead of the approaching front will bring
some low chance for showers or weak thunderstorm late Saturday
afternoon and evening, but only in the western Midlands. Rain
and shower chances will then steadily increase overnight into
Sunday morning (more on the front in the long term section).
Winds will also increaser throughout the afternoon, with some
gusts over 25 mph likely. Thanks to the warm advection and
extremely strong low level jet, near record high min temps are
possible Sunday as morning lows will stay in the 60`s.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Key Message(s):
- Strong front early Sunday will bring gusty winds, along with a
chance for thunderstorms and heavy rain.
The long discussed cold front will be pushing into the region
by Sunday morning with not too many changes in the forecast
thinking. Synoptically, the primary trough aloft is driven by
two prominent shortwaves, one occluding in the upper Midwest and
the other more progressive sliding across Texas. By Sunday
morning, the associated surface front will be dragging across GA
and into the forecast, but will be slowing down notably as deep
layer flow becomes more and more parallel. As such, the
synoptic forcing from this front and upper trough will generally
be weaker over our area than portions to our west, with only
modest height falls and PVA aloft despite very strong flow.
While the synoptic level forcing is not terribly impressive, the
moisture advection and wind field is quite impressive with near
record max throughout much of Sunday in the NAEFS in 850-700mb
winds and IVT; EC EFI continues to show a 0.7-0.9 event with
subtle shift of tails for wind and instability fields. Thanks
to the strong IVT, PWAT`s will climb above 1.6" by late Sunday
morning just ahead of the front. Modest mid-level lapse rates
and the diurnal timing looks to be the primary factors
mitigating a higher end severe event. But with the strong IVT
and seasonal climatology, between 25-750 J/kg of MU CAPE is
expected. So enough to cause to present the suite of severe
hazards, albeit somewhat low. The orientation of the front, deep
layer flow, skinny stretched CAPE, and PWAT`s over 1.5" point
to a low end flash flood threat as well. SPC and WPC have
continued a slight and marginal risk for SUnday for their
respective hazards.
Beyond Sunday, a cool and dry airmass will fill into the area
and linger through mid-week with high confidence in near average
temps and moisture. The next system and moisture return begins
late week.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
High confidence for VFR through 06z. Patchy fog/stratus
possible late tonight especially in the CSRA near AGS/DNL.
Higher clouds associated with a passing upper low should shift
east of the area overnight. Increasing low level moisture late
tonight with reasonably strong radiational cooling should result
in somewhat favorable conditions for patchy fog. SREF
probabilities are relatively high especially in the CSRA for
restrictions during the predawn hours through sunrise and HRRR
and NBM both in agreement showing low stratus and fog moving
into the CSRA and potentially impacting AGS/DNL during the
09z-13z time frame. Carried prevailing MVFR vsbys with tempo IFR
vis/cig at AGS/DNL at this time, meanwhile lower confidence at
the other terminals and only carrying tempo MVFR vsbys at
CAE/CUB/OGB from 11z-13z. Otherwise, generally light to calm
winds through mid morning then winds pick up from the southeast
after 18z around 5 to 8 knots with some increasing high clouds
ahead of the next system.
EXTENDED AVIATION OUTLOOK...Next chance of widespread
restrictions will be late Saturday into Sunday as a cold front
moves through the area. Numerous showers late Saturday night
into Sunday with scattered strong thunderstorms possible ahead
of the front.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.
&&
$$
Area Forecast Discussion
National Weather Service Charleston SC
957 PM EDT Thu Mar 13 2025
.SYNOPSIS...
A weak cold front will approach overnight into Friday, before
lifting back north as a warm front. A stronger cold front will
push through the region on Sunday. High pressure will return to
the region early next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Short-wave trough axis is pushing off the southeast coast this
evening. Earlier showers/thunderstorms moving through
central/southern Georgia with this feature have fizzled nearly
completely at this juncture. Thus shower/thunder mention has
been removed from the forecast with the mid evening update.
Skies will clear in wake of the short wave overnight, before
the development of fog and stratus moving in from the south-
southwest after 3 or 4 AM. These conditions look to advect in
from the south and west of the area, as shown by a variety of
guidance. This includes the NBM, LAMP, simulated satellite, etc.
This looks to result in locations mainly south of the
Charleston Tri-County district where the better condensation
pressure deficits overlap with greater low level moisture.
Fog wording has been nudged up a bit across southeast
Georgia...patchy-areas...but there is a chance for greater
coverage, and even a risk for dense fog. Overnight shift will
need to monitor conditions for possible DFA toward morning.
Winds will decouple shortly resulting in many places going
light or calm. Once the clouds with the short wave diminish,
this will result in decent radiational cooling. As such, lows
will drop into the middle 40s and lower 50s inland, with middle
50s near and along the coast.
There will continue to be smoke/haze in the skies due to a
considerable amount of wildfires in the Southeast. There have
been some indications of reduced visibility at a few sites, as
well as on webcams. The HRRR Smoke Graphics don`t show any
reductions in surface visibility, so we have not included it in
the forecast.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
A mid level ridge will build over the area on Friday and then will
shift offshore on Saturday in advance of the next weather system. At
the surface, a weak front lingering near the region will lift back
north as a warm front, with the forecast area becoming positioned in
between high pressure offshore and a cold front approaching from the
west. Models hint at a few showers possibly making a run for the
coast on Saturday, but probabilities remain less than 20%, so a dry
forecast prevails both days. A tightening pressure gradient will
lead to gusty south winds developing on Saturday into Saturday
night, and a Lake Wind Advisory for Lake Moultrie could be required.
Temperatures will be seasonably warm, especially on Saturday when
highs reach the upper 70s to lower 80s, perhaps even mid 80s in
spots, over most locations away from the immediate coast. Lows will
be in the mid/upper 50s Friday night, then only falling to the
low/mid 60s for Saturday night. Conditions could become favorable
for fog late Friday night into Saturday morning.
Most active day of the set will be Sunday as a strong cold front
impacts the region. Guidance is consistent in bringing a band of
showers with embedded thunderstorms through the area ahead of the
front. There remains a risk for strong to potentially severe storms
with deep layer shear increasing to 50+ knots. Instability progs are
not super impressive, with most indicating less than 500 J/kg CAPE,
though some places over southeast Georgia could exceed that.
Damaging wind gusts would be the primary threat, although an
isolated tornado cannot be ruled out. Rainfall totals for this event
are forecast to average in the 1/2 - 1 inch range. Otherwise, it
will remain gusty outside of convection, with gusts up to around 30
mph. Highs should peak in the mid to upper 70s.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
High pressure will build in on Monday behind a departing cold front
and remain the primary feature through Wednesday. Aloft, a trough
axis will exit east off the coast Monday, allowing heights to build
over the region. Quiet and dry weather is expected. Temperatures a
touch below normal on Monday will warm through the period.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
00Z TAFs: Overall VFR conditions will prevail at KCHS and KJZI
through 00Z Saturday.
For KSAV, VFR will generally prevail, although they do have a
greater chance of experiencing some fog and/or low stratus from
about 10-14Z Friday. 00Z terminal forecasts will have a brief
period of MVFR VSBYs between 10Z and 14Z along with a sct cloud
below 1K.
Extended Aviation Outlook: Flight restrictions are possible in
fog/stratus late Friday night into early Saturday morning, and then
in showers and thunderstorms Sunday associated with a cold front.
Gusty winds are likely Saturday afternoon into Sunday.
&&
.MARINE...
A weak cold front will approach from the north late tonight,
while Atlantic high pressure is positioned to our east, south,
and southeast. S and SW winds with sea breeze influences will
wane this evening, before they turn more SW, then eventually
toward the W late as land breeze circulations develop late.
Winds will be as high as 15 kt and gusty early on, dropping to
mainly 10 kt or less late. Seas will average 2 or 3 feet,
falling up to a foot or so before morning with the lighter
winds and offshore fetch.
Two items for mariners to consider: First would be the risk for
isolated t-storms between 10 PM and 12 AM over the nearshore
Georgia waters, as a short wave moves through. Secondly, some
fog is expected very late tonight into Friday morning, most
likely in the Savannah River/Port of Savannah. Dense fog could
occur. As winds turn westerly, some of the fog over land could
advect into the immediate coastal waters close to daybreak,
mainly south of the Edisto River. While we can`t rule out the
fog impacting the Charleston waters, including Charleston
Harbor, the probabilities are low enough not to mention in the
latest forecast.
Friday through Tuesday: East/southeast winds on Friday will turn
more southerly on Saturday with speeds and seas remaining below
Small Craft Advisory levels. Conditions will deteriorate Saturday
evening into Sunday ahead of an approaching cold front, with
Advisories expected over all coastal waters, including the
Charleston Harbor. There is a low-end chance for gusts to near gale
force. There should be improvement Sunday night into Monday
following frontal passage, with all advisories expected be down by
mid-day Monday. No additional concerns through Tuesday.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Des Moines IA
651 PM CDT Thu Mar 13 2025
...Updated for the 00z Aviation Discussion...
.KEY MESSAGES...
- Strong spring system on Friday brings strong winds, fire
weather concerns and the potential for severe thunderstorms.
Damaging winds remain the main concern with some hail and
minor tornado threats.
- Gusty winds persist into Saturday, with light rain/snow
chances (40-60%) primarily in the north and much colder
temperatures.
- Warmer into early next week with the next chance of
precipitation by midweek.
&&
.DISCUSSION...
Issued at 356 PM CDT Thu Mar 13 2025
A relative calm before an active day or so across Iowa with a multi-
faceted spring storm expected to move into the central United
States on Friday. Plenty of sunshine across the state today
with a tightening pressure gradient and increasing southeast
winds as warm advection intensifies. This continues into tonight
with an initial push of some moisture on an increasing low
level jet. This may lead to a few showers along the eastern edge
of the forecast area overnight with the small surge of theta-e
advection, however most locations remain dry overnight.
The upper low ejects into the central Plains from the southern
Rockies on Friday morning before lifting into western Iowa by mid
evening. Very strong southerly flow develops overnight and persists
into Friday as the surface low drops to around 975mb in southern
Nebraska by Monday afternoon. Mixing increases during the day
although the HRRR seems a bit overzealous trying to mix out to 550mb
with 66kts at the top of the mixed layer. More reasonable mixing
suggests 45kts or so at the top of the mixed layer and with being in
the warm sector and ongoing lift, the overall potential is not as
great as when compared to cold advection/subsidence events. The
current Wind Advisory appears sufficient to cover the expected winds
but have added a few counties on the northwest edge. A discussion
for fire weather concerns is located below.
Regarding severe weather, the amount of mixing will have a big
impact on the potential mode of severe weather. The deeper mixing
would lower surface dewpoints and CAPE along with raising the LCL`s.
This would continue to favor damaging straight line winds but
eliminate the tornado threat. Less mixing and more moisture would
provide the inverse conditions with a greater tornado threat along
with the wind threat remaining. Recent trends via the SPC HREF also
indicate an area of higher risk in west central Iowa just east of
the surface low and ahead of the approaching upper low where mid
level lapse rates are steep and may enhance convection and
severe potential. Once again, low level moisture will be the
main limiting factor in determining severe weather mode with
damaging winds remaining the main concern. Convection is
expected to begin in southwest to central Iowa around 3-4pm and
race north northeast at 50-60 mph in the strong southerly mean
wind, likely clearing the area by 9pm or so. A few lingering
showers remain possible near the core of the upper low as it
passes across central Iowa
Cold advection intensifies into late Friday night and Saturday as
strong northwest winds develop. Wind headlines may be needed once
again in the northwest on Saturday with gusts approaching 45 mph in
the strong cold advection. The wrap around precipitation has
trended a bit farther west but may still clip the far northwest with
some light rain or snow although any significant accumulations
appear to remain farther to the north and west. Thereafter, there
is a quick warmup into early next week before another system impacts
the state towards the middle of next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 638 PM CDT Thu Mar 13 2025
VFR conditions ongoing and expected to continue into midday
tomorrow with just some mid or higher level clouds. Winds out of
the southeast do continue to increase through the night and more
so Friday with a period of LLWS overnight at most sites, but
then gusts reaching 30 to 40 knots or more into Friday
afternoon. In addition, thunderstorms are expected to develop
through the afternoon into evening hours bringing the potential
for severe thunderstorms with damaging winds the primary threat
but some hail and a minor tornado threat as well, as noted
above. However, have not included thunderstorm mentions with
this issuance given the uncertainty of a storm occurring
directly within a 5SM radius of a terminal at this point 24
hours out. Will continue to assess guidance with mentions likely
added in future issuances as confidence in direct impacts to
terminals increase.
&&
.FIRE WEATHER...
Issued at 356 PM CDT Thu Mar 13 2025
A challenging fire weather forecast for Friday. Fire weather
partners on Wednesday indicated fire behavior more muted in the
areas that had snowpack last week, mainly across portions of western
into north central Iowa. However, expectations are that muted fire
behavior will be largely gone by tomorrow given our dry and warm
to near record temperatures today and tomorrow. So, fuels areawide
are expected to be critical and ready to burn on Friday. Winds
will also be near or above critical levels, particularly over
eastern and southern Iowa, with the sustained winds of 20 to 30
mph with gusts of 35 to 45 mph common. The main question - and
where the greatest uncertainty in the forecast lies - is the depth
of mixing and how low dewpoints and resultant RHs will fall. The
initial National Blend of Models (NBM) guidance would keep
dewpoints into the 40s or low 50s whereas the more mixed models
would suggest dewpoints at least 5 to 10 degrees lower. Our
forecast has favored some level of deeper mixing and thus lower
dewpoints with RHs currently forecast as low as 25 to 35%. We can
say with confidence that at least elevated fire weather conditions
will be areawide on Friday. With the uncertainty in mixing depth
potential and how low RHs will fall over southern into eastern
Iowa and in coordination with neighboring Iowa offices, have
issued a Fire Weather Watch for Friday afternoon for southern into
portions of central and eastern Iowa.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Friday afternoon through Friday
evening for IAZ038-039-049-050-060>062-072>075-081>086-092>097.
Wind Advisory from 1 PM to 10 PM CDT Friday for IAZ038-039-049-
050-060>062-072>075-081>086-092>097.
&&
$$
DISCUSSION...Cogil
AVIATION...KCM
FIRE WEATHER...Ansorge
Area Forecast Discussion
National Weather Service Quad Cities IA IL
650 PM CDT Thu Mar 13 2025
.KEY MESSAGES...
- Windy conditions on Friday with gusts up to 50 MPH(Wind
Advisory in effect).
- Warm temperatures and windy conditions will lead to critical
fire weather conditions across the area and a Fire Weather
Watch is also in effect.
- Late Friday afternoon and especially Friday evening, severe
thunderstorms are expected. Damaging winds up to 80 mph and a
few tornadoes are the primary threats. The Storm Prediction
Center has an Enhanced to Moderate Risk (level 3/4 out of 5)
across the area.
- Strong winds are possible again on Saturday.
- It will be blustery and colder Sunday with a warmup for Monday
and Tuesday.
&&
.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 302 PM CDT Thu Mar 13 2025
A deep trough is forecast to move from the Rocky Mountains tonight
and into the Plains during the day on Friday. A jet streak rounding
the base of the trough will lead to a rapidly deepening 500 MB
closed low as it rapidly lifts northeastward through the day and it
moves into southern Minnesota by 12 UTC on Saturday. The surface low
will follow a nearly identical storm track. The pressure gradient
will tighten through the day leading to an increase in winds across
the area.
Near Record Temperatures/Winds/Fire Weather:
Eastern Iowa, northwest Illinois and far northeast Missouri will be
in the warm sector with this storm system through the day on Friday.
High temperatures will be in the mid 70s along the Highway 20
corridor to the lower 80s along and south of of a Fairfield to
Galesburg line. These are near record high temperatures for this
date (see the Climate section below for more).
The wind and fire weather concerns are closely tied together. There
is a wind advisory from 1 PM Friday to 1 AM Saturday and a Fire
Weather Watch from 1 PM Friday to 8 PM Friday. The wind field will
steadily intensify through the day on Friday with a peak on Friday
night. 850 MB winds will be near 40 knots through 18 UTC but cool
morning temperatures will limit the gust potential. After 18 UTC
winds will rapidly increase after that with gusts over 40 MPH
through the afternoon. Winds at the top of the mixed layer by 00 UTC
on Saturday are in the 55 to 60 knots time frame with slightly
stronger winds during the evening hours with conceptual pattern of a
possible "sting jet". HREF guidance was showing a 70% chance of wind
gusts over 50 MPH late Friday afternoon and into the evening. The
current advisory still looks to be on track but this may need to be
upgraded to a warning in later shifts as winds strengthen on Friday
into Friday night.
Models have been showing deeper mix and rapidly lowering relative
humidities during the afternoon. The HRRR appears to be an extreme
outlier with relative humidity`s dropping into the 20s. For dew
points decided to do a blend of high resolution guidance to better
account for the potential for lower relative humidities. For these
reasons and very strong winds have decided to issue a Fire Weather
Watch for the entire forecast for Friday afternoon and early
evening.
Severe Potential:
Little has changed with the severe weather potential for Friday. The
background kinematic fields are very strong with gradient winds near
severe wind criteria during the evening hours. Intense deep layer
ascent is forecast to overspread the area in the 21 to 00 UTC time
frame Friday into Friday night. This will lead to storms developing
and moving into the area during this time frame. There continues to
be differences between the forecast models on the timing but the
best timing for severe thunderstorms moving into the area in the 5
PM to 11 PM timeframe. Based on forecast soundings, thunderstorms
may be able to tap into 70 knot winds higher up in the sounding
profiles via downdrafts and cold pool intensification. Soundings
have also been showing an inverted-V profile further increasing the
idea of damaging straighltline winds across the area.
There is the potential for embedded tornadoes as this line of storms
moves across the area with such strong 0 to 3 km shear increasing to
50 to 70 knots in the 00 to 03 UTC timeframe. Hodographs show strong
cyclonic curvature but lower dewpoints and the inverted V soundings
raising the LCL heights through the event. However model soundings
do show some lowering of the LCLs as the line approaches. The
tornado threat will be maximized where the 0 to 3 km shear vectors
are perpendicular to the orientation of the squall line, although
the magnitude is so strong it will be possible throughout the line.
So tornadoes are a threat but secondary, or lower confidence, to the
straighltline winds. Also, these storms will be moving very fast to
the northeast at speeds near 60 MPH. These will lead to conditions
deteriorating quickly. This may also lead to a narrow window for
severe as small as 3 to 4 hours as these storms move across the
area.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 302 PM CDT Thu Mar 13 2025
The 500 MB low will remain in the Upper Midwest into Sunday morning.
Temperatures will be significantly colder on Saturday with high
temperatures in the area in the 50s. Additionally. winds on Saturday
morning will be very strong with gusts approaching 50 MPH favored
especially in our northwest Illinois counties. We will continue to
monitor this for a wind headline, including possibly a warning, but
wanted to keep the headlines simple through Friday night with
everything going on in the Short term portion of the forecast.
Saturday night, as the closed low beings to move eastward into
Michigan, a deformation band of precipitation is forecast to move
across the area. If precipitation occurs, it will start as rain but
changeover to snow during Saturday evening. Precipitation is
expected to come to an end prior to daybreak Sunday. Low
temperatures on Sunday morning will be in the 20s to lower 30s.
Temperatures have warmed slight on Sunday with highs in the mid 40s
to lower 50s. Sunday will be breezy with gusts up to 30 MPH.
After Sunday, a gradual warm up will occur as high pressure builds
into the Plains once again. Another trough is forecast to move into
the Plains next week but there continues to be about a 24 hour
difference so there is the potential for precipitation Tuesday night
into Thursday.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 645 PM CDT Thu Mar 13 2025
A VFR period tonight into Friday morning, but with increasing
LLVl mechanical turbulence in the low to mid levels.
Southeasterly sfc winds will range from 8-12 KTs overnight,
while aloft an increasing south-southwest LLVL jet at 2K FT AGL
up to at least 40 KTs will make for LLVL wind shear into Friday
morning before the sfc winds start to get gusty. A low chance
tonight for an isolated elevated shower or even a thunderstorm
to develop in warm air advection(WAA) wing aloft, but the better
potential for thunder will be north of our area acrs WI late
tonight. Friday a windy turbulent day with sfc winds gusting up
to at least 40 KTs during the afternoon ahead of a very strong
low pressure storm system that will eventually sweep a line of
strong to severe storms with high winds acrs the area from the
southwest Friday evening.
&&
.CLIMATE...
Issued at 348 AM CDT Thu Mar 13 2025
Record highs March 13
Burlington.....77 in 2007 and previous years
Cedar Rapids...74 in 2007
Dubuque........71 in 2007
Moline.........77 in 2007
Record highs March 14
Burlington.....79 in 2012
Cedar Rapids...75 in 2012 and previous years
Dubuque........75 in 2012
Moline.........78 in 2012
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Fire Weather Watch from Friday afternoon through Friday
evening for IAZ040>042-051>054-063>068-076>078-087>089-
098-099.
Wind Advisory from 1 PM Friday to 1 AM CDT Saturday for
IAZ040>042-051>054-063>068-076>078-087>089-098-099.
IL...Fire Weather Watch from Friday afternoon through Friday
evening for ILZ001-002-007-009-015>018-024>026-034-035.
Wind Advisory from 1 PM Friday to 1 AM CDT Saturday for ILZ001-
002-007-009-015>018-024>026-034-035.
MO...Fire Weather Watch from Friday afternoon through Friday
evening for MOZ009-010.
Wind Advisory from 1 PM Friday to 1 AM CDT Saturday for MOZ009-
010.
&&
$$
SHORT TERM...Cousins
LONG TERM...Cousins
AVIATION...12
CLIMATE...McClure
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
653 PM CDT Thu Mar 13 2025
...New AVIATION...
.SHORT TERM...
(Tonight through Friday night)
Issued at 148 PM CDT Thu Mar 13 2025
Key Messages:
- Critical fire weather, breezy, and dry conditions across portions
of the area Friday
The low dew points and mostly sunny skies have allowed for warm
temperatures this afternoon, with highs forecast to top out in the
upper 80s to lower 90s for most locations, mid 90s along the Rio
Grande. Cirrus will continue to increase over the region this
evening, and could affect the lunar eclipse viewing late tonight.
Low stratus is also forecast to develop overnight across the Coastal
Plains around the time of the eclipse.
The next upper level low ejects out into the central Plains Friday
along with a powerful and deepening surface low. This will drag
another dryline into the area during the day on Friday, as far east
as the Coastal Plains before a developing sea-breeze pushes inland
in the early evening. A Pacific cold front also works into the
southern Edwards Plateau in the afternoon before slowing temporarily
in the evening. Behind the dry line, and especially the Pacific cold
front, effective mixing of higher momentum aloft downward to the
surface will result in breezy conditions, and when combined with the
low humidity will result in critical fire weather conditions. (see
fire weather section below) In addition, some blowing dust from
upstream in West Texas could impact portions of the Hill Country and
southern Edwards Plateau.
A secondary surge is forecast to push the Pacific cold front through
the region late Friday night into Saturday morning. There are a few
convective allowing and global models generating precipitation
overnight/early Saturday morning along the I-35 corridor near San
Marcos northeastward, in a region along the front intersecting the
low level moisutre temporarily recovering. Chances of this are low
(20%).
&&
.LONG TERM...
(Saturday through Thursday)
Issued at 148 PM CDT Thu Mar 13 2025
Key Messages:
- Critical fire weather likely Saturday with strong winds
- No rain continues; Additional fire weather next week
Fire weather conditions are likely to be critical again Saturday
across the area following another Pacific front. Winds will become
west-northwesterly at 20 to 30 mph with gusts up to 45 mph as a
secondary axis of wind shifts south into the region. More details in
the Fire Weather section below. Winds will decrease through the night
Saturday night. High pressure will shift to the east Sunday, and
winds will turn around to the south to southeast. This will lead to a
warming trend for the start of next week. Tuesday should be the
warmest day of the period with highs in the 80s to lower 90s. Tuesday
night/Wednesday morning the next cold front will move through our
CWA. This will turn the winds around to the north bringing cooler,
drier air. High temperatures will be down into the 70s by Thursday.
This will also bring another round of elevated to near critical fire
weather for Wednesday and Thursday.
&&
.AVIATION...
(00Z TAFS)
Issued at 647 PM CDT Thu Mar 13 2025
VFR conditions will continue this evening as plenty of high level
clouds move in from the west. Some low clouds are noted along the
middle TX coast and with a gradual increase in low-level moisture,
low clouds will likely move into the I-35 corridor early Friday. We
did opt to speed up the onset of low clouds slightly based on GFSLamp
and HREF data, but did not go quite as early as RAP forecast
soundings suggest. Based on this, MVFR cigs are expected between
08-14Z along I-35. The moisture will be shallow, so a quick return to
VFR is expected by mid-late morning. Attention will then turn to
gusty west winds for the afternoon hours. We will keep the forecast
VFR for DRT as low-level moisture looks to stay closer to I-35.
&&
.FIRE WEATHER...
Issued at 148 PM CDT Thu Mar 13 2025
Key Messages:
- Red Flag Warning for critical fire weather conditions Friday
- Fire Weather Watch for critical fire weather conditions Saturday
Another dryline and Pacific cold front are forecast to enter the
area on Friday, with critical fire weather conditions likely near
the I-35 corridor west to the Rio Grande. Sustained winds 15 to 25
mph with gusts near 35 mph coinciding with RH values of 5 to 15
percent are forecast Friday afternoon along the I-35 corridor west
to the Rio Grande, where a Red Flag Warning is now in effect. Wind
speeds are forecast to diminish after sunset Friday, with temporary
moisture recovery east of I-35.
Fire weather conditions are likely to be critical again Saturday
across the area following another Pacific front. West-northwest
winds of 20 to 30 mph with gusts up to 45 mph will develop as a
secondary axis of wind is expected to shift south into the region.
Similar to Friday, the minimum relative humidity levels, will
bottom out below 20%. We have issued a Fire Weather Watch for
Saturday afternoon and early evening for the entire area.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 62 87 55 78 / 0 0 20 0
Austin Bergstrom Intl Airport 60 88 55 78 / 0 0 20 0
New Braunfels Muni Airport 59 90 54 80 / 0 0 10 0
Burnet Muni Airport 61 82 53 74 / 0 0 10 0
Del Rio Intl Airport 59 90 56 79 / 0 0 0 0
Georgetown Muni Airport 62 85 55 76 / 0 0 20 0
Hondo Muni Airport 57 89 55 78 / 0 0 0 0
San Marcos Muni Airport 58 89 54 78 / 0 0 20 0
La Grange - Fayette Regional 61 88 54 79 / 0 0 10 0
San Antonio Intl Airport 60 89 57 79 / 0 0 10 0
Stinson Muni Airport 60 90 58 80 / 0 0 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
&&
$$
Short-Term...Platt
Long-Term...99
Aviation...Platt
Area Forecast Discussion
National Weather Service Hastings NE
936 PM CDT Thu Mar 13 2025
...Short Term Update...
.KEY MESSAGES...
- A strong upper level low pressure system will bring rain,
thunderstorm, and snow chances to the forecast area...along
with strong NW winds Friday into Saturday. A few severe storms
are not out of the question Friday afternoon for portions of
Nebraska mainly along/east of HWY 281 (area in SPC Marginal
Risk).
- Rain will switch over to snow Friday night into Saturday. Very
light accumulations (less than 1 inch) are possible across our
far northern areas...with a mix of rain and snow possible as
far south as I-80.
- Friday evening through Saturday, strong NW winds will spread
from west to east...sustained speeds of 30-40 MPH and gusts of
45-55 MPH will be possible. These winds, combined with even
light snow Friday night-Sat, could result in hazardous
conditions. A High Wind Watch has been issued for areas
roughly along and north of Highway 6.
- Widespread fire weather concerns return to the local area
Saturday afternoon, with at least near-critical fire weather
concerns likely. Additional fire weather concerns expected
across at least parts of the local area Sunday through
Tuesday.
- The next (cooler) system reaches the local area next Tuesday
night through Wednesday. Still lots of uncertainty in precip
type (although at least some minor snow accumulations look
possible) and wind speeds (although at least windy conditions
look probable).
&&
.UPDATE...
Issued at 935 PM CDT Thu Mar 13 2025
- Regarding the now-expired Red Flag Warning for today:
Allowed today`s Red Flag Warning for our entire forecast area
(CWA) to expire "on time" at 9 PM. As expected, the combination
of decreasing wind speeds and gradually-rising relative humidity
(RH)...currently no lower than 25-35 percent...has ended any
potential for critical fire weather conditions.
Unfortunately, a combination of satellite hotspot detection and
limited ground-truth reports confirmed that there were at least
5 wildfires within our CWA this afternoon, with a few of the
most obvious ones (per satellite imagery) occurring in far
northern Rooks County KS and also near the Sherman/Valley County
line.
&&
.DISCUSSION...
Issued at 348 PM CDT Thu Mar 13 2025
A warm, dry, and breezy day has been observed across the region
today. These conditions are creating dangerous fire weather
conditions, and a Red Flag warning remains in effect until 9 PM
this evening.
Later this evening, winds should relax some, but remain steady
out of the south at 10 to 15 mph, making for mild overnight
temperatures across the region. These southerly winds are ahead
of the anticipated area of low pressure across southern
California that will make its way into the central Plains
tomorrow afternoon. As this dynamic low emerges into the
plains, it will be rapidly deepening, bringing very strong winds
on its northern side as it crosses the area late Friday night
through Saturday.
Ahead of the low, however, the focus will be the chance for
strong to severe thunderstorms - which has increased over the
past 24 hours. What looked like questionable instability
yesterday looks much more promising with mesoscale models
attempting to develop a line of thunderstorms across the local
area Friday afternoon, and pushing them eastward by mid-evening.
With the proximity of the upper level low to the local area,
all forms of severe weather will be possible, although
marginally severe hail and 60+ mph wind gusts continue to look
like the primary threats. The 18Z HRRR is fairly aggressive
with thunderstorm coverage across the local area, but most
models are hinting at at least a similar scenario, so adjusted
pops and thunderstorm chances accordingly - extending the more
widespread thunderstorm chances into the early evening hours
Friday.
Friday night, rain could transition over to snow across our far
north, but this potential has trended downward - and we actually
do not have measurable snow in our current forecast for even our
most northern areas. That said, we do have a rain/snow mix as
far south as interstate 80, and any snow mixed in with the very
strong winds behind the rapidly intensifying area of low
pressure, could cause some visibility issues, so mentioned this
possibility in the High Wind Watch that was also issued earlier
today.
While significantly cooler air will filter in across the local
area Saturday, when high temperatures will likely only top out
near 50 degrees, drier air behind the low combined with the
very strong winds will bring a return to widespread fire
weather concerns. Additional fire weather concerns are expected
to start next week, with another upper level low possibly
impacting the plains mid-week. Still lots of uncertainty with
this system as the GFS is more of an open wave vs. the
closed/intensifying low depicted in the operations run of the
EC, but at this point there at least appears a decent chance for
some additional precipitation (maybe snow) and strong winds
late Tuesday into Wednesday of next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 723 PM CDT Thu Mar 13 2025
For KGRI/KEAR Airports:
- General overview:
This period will see the approach and eventual arrival of a
fairy classic/strong, early-spring low pressure system. The
primary concerns during the first 12 hours will be moderately-
strong low level wind shear (LLWS), while the main concern
during the latter 12 hours will be the possibility of some rain
shower/thunderstorm activity mid-late Friday afternoon. Aside
from any possible visibility reduction associated with
showers/storms, confidence is actually quite high in VFR
ceiling/visibility throughout. More element-specific details
follow.
- Ceiling/visibility/precipitation potential:
Very high confidence in VFR ceiling/visibility (along with
precip-free weather) through at least the vast majority of the
period, with only a gradual increase in mid-high level clouds.
However, mid-late Friday afternoon (mainly 20z and beyond), at
least isolated/scattered rain showers and perhaps some
(probably) non-severe thunderstorms could develop at any point.
For now, have introduced PROB30 groups to address this
potential. Unless a particularly heavy downpour happens to pass
overhead, would anticipate no worse than MVFR visibility/low-end
VFR ceiling.
- Winds (including LLWS):
- Surface winds:
Through the vast majority of the period, winds will remain
fairly consistent both in direction and speed, with direction
mainly southerly to southeasterly, sustained speeds mainly
12-16KT, and gusts mainly 19-22KT. However, very late in the
period Friday afternoon, a cold front will slice into the area
from the west-northwest, bringing an abrupt switch to west-
northwest winds and likely higher gusts. There is some question
whether the main wind shift will arrive before the end of this
valid period (especially at KGRI), with KEAR slightly more
favored to see this switch by 23-00Z.
- Low level wind shear (LLWS):
Although made some slight modifications to both duration and
intensity, have maintained previously-introduced LLWS groups for
this evening-overnight (now focused 03-08Z KEAR/04-10Z KGRI).
Both sites will experience moderately-strong LLWS during these
times as generally southerly winds especially between
1,000-1,500 ft. AGL ramp up to as high as 45-50KT, causing at
least 30-35KT of shear magnitude between the surface and this
level (even despite somewhat-breezy surface winds).
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...High Wind Watch from Friday evening through Saturday evening
for NEZ039>041-046>049-060>064-072>077.
KS...None.
&&
$$
UPDATE...Pfannkuch
DISCUSSION...Rossi
AVIATION...Pfannkuch
Area Forecast Discussion
National Weather Service Goodland KS
757 PM MDT Thu Mar 13 2025
.KEY MESSAGES...
- A High Wind Warning remains in effect for locations along and
west of Highway 83 for northwest winds gusting 55 to 65 mph.
- Blowing dust, potentially reducing visibilities to around 1-3
miles at times for most of the area is possible Friday. There
is also a low chance that a wall of dust develops ahead of the
rainfall favoring locations along and south of Interstate 70
which would lead to the potential for brownout conditions.
- A prolonged period of near critical to critical fire weather
conditions remains in the forecast for various parts of the
Tri-State area Saturday through Tuesday. Please use caution
if burning outdoors.
&&
.UPDATE...
Issued at 734 PM MDT Thu Mar 13 2025
Winds have decreased in strength significantly over the past
few hours as the low pressure system bringing tomorrow`s winds
is starting to take form across western portions of the area.
This along with an increase in RH values as the sun sets and
temperatures cools have ended any critical fire weather threat
for today so have ended the Red Flag Warning early.
Confidence has slightly increased as well in blowing dust for
tomorrow mainly along the rapid increasing pressure rises during
the late morning and into the early afternoon. Guidance is
showing very unstable lapse rates in the in 0-2km layer ranging
from 9-15C/KM and continued 2-2.5 km lapse rates around 4-6C/KM.
The GFS continues to be the most aggressive with the winds
showing significant surge in the low level wind fields up to 60
knots moving along and south of Interstate 70 starting around
17Z Friday. Some of the signals are similar to what was seen
when forecasting the December 2nd, 2022 haboob when the favored
office dust research parameters where moving along with the
cold front in that case. Should this end up being realized then
a haboob would have the potential to form given the decrease in
soil moisture over the past few days as the current NASASPORT
soil moisture in the 0-10cm level is showing mid teen to low 20
percent levels and even drier across Wallace, Greeley and Logan
counties. At this time giving haboob potential around a 10-20%
chance. Overall dust potential with visibilities around 1-3sm
around 30-40% chance of occurring but with some precipitation
and cloud cover on the back side think that these areas will be
localized. There also is the potential that no dust occurs at
all if enough wraparound moisture can occur helping to increase
rainfall potential as well.
Am also starting to see some signals of a secondary even
stronger jet pushing in from the northwest after 23Z which may
help keep the winds going longer across the current High Wind
Warning. May need to keep an eye on potential expansion east of
the warning if this jet continues to be seen as the pressure
rises and any showers (maybe storms) can help mix the winds of
this new jet which is around 50-55kts according to the 21Z RAP
to the surface.
&&
.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 225 PM MDT Thu Mar 13 2025
Across the region this afternoon, skies are sunny with a southerly
flow area-wide. Temperatures as of 200 PM MT are ranging in mainly
in the 70s, with a few isolated spots in the upper 60s in northern
Yuma county.
This afternoon/tonight...Red Flag conditions(warning) continue
across the region. RH values mainly in the lower to mid teens as
gusts have been ranging from 25-40 mph. There have been some
localized low 40 mph. The latest hourly LAV/NBH guidance continues
to show persistent gradient through about 00z Friday before tapering
off.
Friday/Friday night...the main concerns for this 24-hour period will
continue to focus on the storm system that passes south of the CWA.
Guidance still carries the upper low across the KS/OK border, with
the surface low further north, reaching into the area as it swings
through. It will be the passage of the low that will bring chances
for light rain, strong gusty winds and the threat for blowing dust.
Best chances for moisture to feed into the region will occur as the
system passes, allowing for moisture to wrap-around/pinwheel in from
the north. 60-80% chances for light rain showers during the day,
with highest chances in the northwest. Precip does lift out/taper
quickly to the east Friday night, with a low 15-20% chance for a few
light snow showers to mix with the exiting rain. Temperatures will
not be cold enough to allow for persistent snow, based on current
guidance.
The potential for high wind gusts to impact the region has remained,
allowing for the current High Wind Watch to be upgraded to a
Warning. Still looking for gusts in the 55-65 mph range, as model
soundings show decent mixing at least towards the 700-800 mb range.
Areas east of the warning could still see gusts to 50 mph. These
winds will also bring up the chances for blowing dust. The first
area will be the shift in direction/gradient along the passing low
and its associated front, mainly affecting the SE portion of the
CWA. The other area resides mainly in Colorado where guidance
continues to show the best chances for the strongest gusts to occur.
Patchy wording is in the forecast as a result. There is a low
confidence 5-15% chance, for an isolated rumble of thunder to occur
in the east as the low traverses. best instability resides east of
the area. Have left out for now despite SPC carrying general thunder
mention for portions of the CWA.
Saturday/Saturday night...the passage of the system from Friday will
open up the region to NW flow from the SFC to 500mb at least through
the afternoon hrs before a slow shift westerly during the
evening/overnight hours. Gradient still be tight on the backside of
the exiting system. Guidance still brings gusts potential up to the
30-35 mph range, but expected to taper through the day from west to
east. There is a weak shortwave continuing to push into/through
central Colorado that will bring increased moisture/clouds, mainly
in the west. The chance for clouds and the N/NW flow through the day
will hamper daytime highs especially in Colorado. Not expecting any
precip with this system at this time. There could be a 10-degree
range from west to east as a result.
Sunday/Sunday night...500mb ridge working east off the central
Rockies during the 24 hour period, allowing for NW flow aloft to
shift to zonal during the overnight hours. At the surface, looking
for a trough to set up over eastern Colorado. NAM/GFS do hint at
some weak ridging during the day, but overall a dry day is expected
with W/SW flow area-wide. The gradient will be tight w/ gusts at
least in the 20s area-wide, but locales closest to the trough
(Highway 27 and west) could see some gusts near 30 mph. The
downslope winds, combined with lack of low level moisture will
create RH values in the lower to mid teens. This will result in near
critical to critical fire wx concerns, especially along/south of I-
70 based on current wind criteria. If trend holds, a fire wx product
will eventually be needed. Highs expected to range in the lower to
mid 60s, with lows in the 30s.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
Issued at 100 PM MDT Thu Mar 13 2025
Ridging on Monday will transition to southwest flow on Tuesday
ahead of the next system. Both days will see above normal
temperatures and a fire weather risk. Monday will have south to
southwest winds gusting up to 25 mph east of Highway 25 and up
to 40 mph west of Highway 25, strongest in Colorado. Afternoon
relative humidity minimums will be 10-15% in the entire area.
Highs will be in the 70s and 80s with some record highs
possible. Tuesday, the front has slowed down compared to
previous runs which will result in warmer temperatures. Seeing
mainly a west wind in the morning and afternoon and not shifting
to northwest with the front until later in the day. There will
be slight risk for fire weather mainly south of I-70 where winds
will gust 30-40 mph and afternoon relative humidity minimums
are currently forecast to be 10-15%. The temperature gradient on
Tuesday may be rather large, ranging from the 60s and 70s in
southwest Nebraska to 70s and 80s south of I-70.
Main upper dynamics will move through Tuesday afternoon/evening
and Wednesday, bringing a chance for precipitation. Still seeing
major differences in the models with the upper feature
characteristics, track and timing. GFS showing a fast moving
open wave with just a glancing blow of light rain and light
snow Tuesday afternoon and Tuesday night. ECMWF is slower and
shows a closed low, with more precipitation, particularly more
snow, through the day on Wednesday. So confidence in
precipitation amounts/type is low at this time. The other factor
with this system will be the wind. Similar to the last couple
of systems, this one could produce a period of strong, gusty
northwest winds reaching warning criteria Tuesday night and/or
Wednesday depending on timing. Temperatures on Wednesday will be
below normal with clouds and precipitation possible.
Low amplitude ridging will return on Thursday resulting in
moderating temperatures, dry condition`s and less wind.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 514 PM MDT Thu Mar 13 2025
Winds are forecast to wane as the evening goes on for each
terminal remaining around 10 knots overnight. There is a less
than 10% chance some rain showers may come at least within the
vicinity of the Goodland terminal overnight but think these
will remain on the west side of the state line at this time. An
intense low pressure system is forecast to develop during the
day tomorrow leading to a difficult wind direction forecast as
many wind shifts will occur as the low will be over the region.
On the back end of the low winds will greatly strengthen
gusting 40-50+ knots across the area with the strongest
currently forecast at Goodland. There may also be some rain
showers in the area as well which may help mix down some even
stronger winds, confidence in the even stronger winds is less
than 20% at this time so will leave that out of the forecast.
There is also a conditional threat for blowing dust (less than
25%) for Goodland from 17-22Z with a 10-15% chance of a wall of
dust significantly reducing visibilities. At this time McCook
looks to be free of any blowing dust concerns due to the
position of the low.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...High Wind Warning from 10 AM MDT /11 AM CDT/ to 8 PM MDT /9 PM
CDT/ Friday for KSZ001-002-013-014-027-028-041-042.
CO...High Wind Warning from 10 AM to 8 PM MDT Friday for COZ090>092.
NE...High Wind Warning from 10 AM MDT /11 AM CDT/ to 8 PM MDT /9 PM
CDT/ Friday for NEZ079-080.
&&
$$
UPDATE...Trigg
SHORT TERM...JN
LONG TERM...024
AVIATION...Trigg
Area Forecast Discussion
National Weather Service Wilmington NC
844 PM EDT Thu Mar 13 2025
.SYNOPSIS...
Temperatures will remain above normal through the end of the
work-week and thru the weekend with high pressure mainly in
control thru Sat. A backdoor cold front will temporarily waver
into the area late tonight into Fri before lifting back north
for good later Fri. The next storm system is expected to affect
the region Sun into Mon with breezy to windy conditions and a
chance for strong or severe thunderstorms Sun. High pressure and
near normal temperatures will return for early next week.
&&
.UPDATE...
Forecast remains on track with the backdoor cold front about
half way through NC. Highest chances for fog towards dawn will
be for coastal SE NC. Updated 00Z aviation below.
&&
.NEAR TERM /THROUGH FRIDAY/...
An upper disturbance centered across Alabama will sweep eastward
and across the Carolinas this evening, moving off the coast
after midnight. This feature has led to showers and
thunderstorms across the Mid South region, now spreading into
southwestern GA. A pulse of Gulf moisture with precip water
values of 1.0 to 1.3 inches supporting these storms never
advects northeastward tonight, leaving steep lapse rates aloft
with insufficient moisture for any shower chances across our
area. The only direct effect of the disturbance should be
varying amounts of cirrus cloud cover this evening before it
clears offshore after midnight.
The feature of more importance is a backdoor cold front across
northeastern North Carolina. This feature surged south this
morning, but has temporarily stalled as daytime heating and
deeper boundary layer mixing is occurring out ahead of it. Low
pressure moving southeast of Cape Cod tonight should give the
front enough of a push to make it into our portion of the
Carolinas after midnight. A blend of HRRR and NAM guidance
suggests the boundary should reach Wilmington and Lumberton
around 2 AM, reaching Florence and North Myrtle Beach by 6 AM
Friday. Atlantic moisture advected southwestward behind the
front will cool over land due to radiational cooling, perhaps
forming areas of fog or low stratus across coastal southeastern
North Carolina into Horry County, SC. I`m including areas of fog
late tonight through about 10 AM Friday for these areas.
Forecast lows range from the upper 40s to around 50.
The backdoor front should stall south of the Santee River by
late Friday morning. North of the front light northeast surface
winds should turn easterly during the day, bringing a shallow
layer of cool, maritime air onshore. This will have significant
impacts on high temperatures which range from around 60 on the
beaches north of Cape Fear to the upper 60s along the Grand
Strand, all the way up to the upper 70s across the inland Pee
Dee counties.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
At the start of this period, a nearly full latitude, positive
to neutral tilt, upper trof situated across the West-Central
U.S. and Canada, will make some progress east this period, only
reaching the Mississippi River Valley by Sun daybreak. A 5h vort
or closed low will be riding NNE up the east side of this upper
trof reaching the Great lakes by the end of this period. It`s
attendant cold front and associated pcpn will translate east
ward, both features dampening out as it encounters the
Appalachians...and with the 5h ridge axis holding strong across
the Eastern carolinas or just off the coast. Will see residual
clouds Fri night into Sat but negated any POPs. The backdoor
front from the near term period will have lifted north of the FA
by the start of this period with light SE winds followed by
increasing S winds during Fri night. Nudged up Fri night min
temps from guidance with widespread 50s likely. Tightening
gradient Sat thru Sat night will result in increasing breezy
southerly winds. Max temps Sat should breach 80 degrees across
inland locations with upper 60s to around 70 at the beaches. Sat
night min temps may only drop into the 60s as an influx of
widespread 60s sfc dewpoints will have overspread the FA.
Onshore movement of SEA fog may become an issue Sat thru Sat
night with this rich low level moisture tracking across local
SSTs in the 50s
The next 5h s/w trof rotating thru the eastward moving longwave
upper trof, will reach the Gulf Coast States during Sat, lifting
NE to the Ohio River Valley by Sun daybreak. Line of convection
ahead of its attendant cold front will translate eastward,
reaching the spine of the Appalachians by Sun daybreak. A few
discrete showers ahead of this line may reach the far western
portions of the FA by Sun daybreak and may carry a POP.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
The eastward moving cold front and convection along it looks a
bit better organized in terms of the moisture accompanying it.
With south winds further increasing Sun, a sfc based marine
layer will have spread onshore and inland well before the
arrival of this line of convection and may be the delimiter of
SVR thunderstorm activity given the instability issues. Still
expect widespread 70s for Sun highs but with much of this
instability likely to be elevated and thus should be enough for
atleast tstorm activity. The 50+ kt low level southerly wind
field still being fcst by the models at the time when this
convection pushes across the FA. Areas from the I-95 corridor
westward will likely have the better chance of seeing strong to
possibly severe thunderstorm activity due to a shallower marine
layer this far inland. The convection will translate eastward
affecting the area from mid to late Sun morning thru Sun
evening, when it should slide off the Coast. Compared to
yesterday, this is slightly slower than previous runs. Onshore
movement again may be an issue for the immediate coast Sun but
confidence remains low at this point. Part of the reason is the
full latitude trof taking its sweet time pushing eastward.
Models indicate Mon midday thru Mon mid- afternoon, this upper
trof should slide off the SE States Coast. Could observe
isolated showers convection prior to its passage off the coast
if enough moisture avbl.
Later Mon thru midweek mid-level ridging will overspread the FA
with sfc ridging extending from the sfc high that will be
sliding along the Gulf Coast region beginning of the week to
offshore Atlantic off the SE States Coast by midweek. Cooler
temps, back to around normal, Mon with temps jumping back to
above normal Tue thru midweek as backside flow around the center
of the sfc high moving off the SE States Coast. &&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
There is high confidence VFR conditions will continue through
this evening. Seabreeze winds could increase to near 15 knots
near the beaches, but should diminish after 00-02z Friday.
Concern for fog and/or low ceilings begins to increase after
06z as a backdoor cold front arrives from the northeast. There
is moderate confidence that IFR visibility will develop at the
KILM and KCRE airports after 07z Friday, with low confidence
elsewhere. Surface winds will swing around to the northeast with
the arrival of this front Friday morning, but should remain
light in speed. Moderate confidence in IFR visibility continues
up through about 14z at KILM and KCRE before becoming low
confidence afterwards as the boundary layer begins to deepen
after sunrise. We expect VFR visibility to develop, however some
model guidance indicates low (IFR to MVFR) stratus or
stratocumulus ceilings may develop after 14z for the coastal
airports. Confidence in this scenario is very low at this time.
Extended Outlook...Additional patchy ground fog may develop
Friday night into Saturday morning, however confidence in low.
Better chances for flight restrictions will develop Sunday as a
cold front approaches. Temporary MVFR to IFR conditions are
expected Sunday afternoon/evening (moderate to high confidence) in
showers and thunderstorms. Conditions should improve to VFR
again on Monday as the front pushes offshore.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
High confidence in VFR through at least 06Z as a backdoor cold
front approaches the area. Behind this front, particularly close
to the northern NC coast, observations are showing clouds ~500
ft with some MVFR near IFR fog. Thoughts are that KILM will be
the target of harshest restrictions, and for now confidence is
higher with CIGs than VSBYs, but as that colder air comes in
with the front it`s possible that fog develops. VSBYs could drop
below 1SM, but thoughts are that this will be brief and near
dawn before clearing starts with sunrise, so have added to a
TEMPO. If low clouds hold together, they could also impact
KCRE. For now, timing of clearing is low confidence, but
thoughts are with daytime mixing restrictions should lift
through the morning. VFR is then expected through the rest of
the period.
Extended Outlook...Low to moderate confidence on fog development
Friday night. Increasing confidence for restrictions Sunday as
a cold front approaches. Temporary MVFR to IFR conditions are
expected Sunday afternoon/evening (moderate to high confidence)
in showers and thunderstorms. Conditions should improve to VFR
again on Monday as the front pushes offshore.
&&
.MARINE...
Through Friday...Seabreeze winds have increased to near 15
knots along the Grand Strand beaches and should reach 10-15
knots elsewhere through early this evening. High pressure near
Bermuda and low pressure across the western High Plains are
producing a wide swath of southerly flow across the eastern U.S.
A weak area of low pressure passing southeast of Cape Cod
tonight should nudge a backdoor cold front in northeastern North
Carolina south across our area late. High res models suggest
the boundary should reach Cape Fear a few hours before sunrise,
slipping southward across the Grand Strand beaches between
sunrise and 11 AM. Northeast winds behind the boundary should
veer easterly during the day in a combination of local seabreeze
flow plus the synoptic wind veering as the High Plains low
moves northeastward across Kansas and Nebraska. Local wind
speeds should remain 15 kt or less through the period with seas
2-3 feet.
Friday Night through Monday...
Increasing SE becoming S winds to dominate late Fri night thru
Sat as the sfc pg tightens and low level southerly wind fields
increase. Seas will be at their lull at the start of this
period, Fri night, followed by a building trend. For Sat night,
look for SCA threshold southerly winds...and short period seas
to further build, with steep waves breaching 6+ ft across all
zones by daybreak Sun. Solid SCA Sun into Sun night, with Gale
gusts possible. This in response to the tightened sfc pg ahead
of the approaching cold front with limited mixing from those 50+
kt LLJ due to the ocean based somewhat stable marine layer (with
local SSTs in the 50s). Mariners will see convection move off
the mainland later Sun afternoon into the evening with 1nm or
vsby in gusty showers/tstorms, especially experienced closer to
the coast. Will see winds veer to the SW at SCA levels, followed
by the actual CFP midnightish or pre-dawn Mon hrs with a further
wind shift to the NW and CAA surge combined at SCA levels. The
pg relaxes-some Mon and especially by Tue with winds
diminishing and wind driven seas subsiding. Sea fog could become
an issue later Sat into Sun with advection of 60s sfc dewpoints
across 50s SSTs. Confidence remains so-so with it`s possibility
but enough to mention here for now.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...None.
MARINE...None.
&&
$$
SYNOPSIS...ILM
UPDATE...LEW
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...LEW
MARINE...DCH/TRA
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
943 PM CDT Thu Mar 13 2025
.KEY MESSAGES...
- A Moderate Risk (level 4 of 5) of severe storms is still
expected Friday evening. The top concern is damaging straight-
line winds (potentially in excess of 75 mph), but a few brief
tornadoes (some of which could be strong) and large hail (some
greater than 2") are also still possible.
- Strong non-thunderstorm wind gusts, out of the south-southeast,
are expected Friday into Friday evening. Gusts of 35-45 mph will
be common Friday afternoon along and north of I-70, with a 40-50%
chance of up to 50 mph gusts late Friday afternoon into Friday
evening. A Wind Advisory has been issued for the entire area for
Friday PM.
- The very strong winds Friday afternoon into Friday evening,
combined with lower relative humidities down to 35% and very dry
fuels, will lead to the potential for any brush or field fires
to quickly spread. The main area of concern is along and north
of I-72, but the concern may have to include areas to the south
later. Therefore, a Fire Weather Watch has been issued for
Friday afternoon into early Friday evening and burning tomorrow
is not recommended.
- Near-record temperatures are possible on Friday. Forecast highs
are near 80 degrees, and record highs are generally in the low
80s.
- Additional strong wind gusts are expected from mid-morning
Saturday through early afternoon, out of the southwest. There is
a 40-50% chance for gusts up to 50 mph north of I-74, with
lower probabilities south of I-74.
&&
.UPDATE...
Issued at 943 PM CDT Thu Mar 13 2025
Temperatures late this evening remain mild with observations ranging
from the low to middle 60s. Overnight lows will bottom out in the
middle to upper 50s, with much of the area remaining underneath
broad WAA. A stationary/warm front is stretched from roughly Quincy
to Paris and will gradually lift north of here by sunrise. High
resolution CAMs still show some scattered shower activity developing
along the front late tonight, but a majority of it looks to stay
just outside of the forecast area in west-central Illinois.
Attention then turns to Friday with a potpourri of weather on
tap, including potentially record breaking warmth. Strong
southerly winds ramp up by late Friday morning into Friday
afternoon with the windiest period looking to be between 3-7 pm,
right before convection begins spreading in from the east. Wind
gusts during this period have the potential to approach or exceed
50 mph. This also brings a concern for fire weather since rapid
fire spread will be easily attainable with the strong winds, low
relative humidities (~30%), and dry vegetation. In addition, any
loose top soil from freshly touched fields could allow dust to
easily blow around and reduce visibility.
Storm chances increase Friday evening, with a line of strong to
severe thunderstorms anticipated to move into our west-central
Illinois counties between 7 and 9 pm. The line will then quickly
spread east and approach the Indiana border just after midnight. All
hazards are possible with the line of storms, though significant
(>75 mph) wind gusts appear to be the front runner. 0-3 km shear
vectors appear to be more parallel to the line of storms, which
typically wouldn`t favor a setup for embedded tornadoes. However,
with 0-3 km shear vectors of 50-60 kt we would have more range
off the 0-3 km line-normal vector (~57 degrees to be exact) to
support line-embedded tornadoes, especially where there is any
bowing or surges in the line. Modifications to PoPs were made this
evening to better time the arrival of storms, but otherwise the
forecast remains largely on track.
NMA
&&
.SHORT TERM... (Through Late Friday Night)
Issued at 313 PM CDT Thu Mar 13 2025
Earlier HiRes models continued to show isolated showers/storms
could possibly develop this evening in the southeast to southwest
parts of the CWA. Boundary and developing CU can still be seen on
vis satellite imagery in southeast IL slowly moving to the NW.
Already had slight chance of precip in the forecast and see no
reason to remove it at this time. The remainder of the night
should be dry with scattered clouds, so sky cover may be decent
for viewing of the lunar eclipse tonight. Overnight lows should
fall into the lower to middle 50s.
The big event will still be the strong system developing out west
through tomorrow afternoon. Newest HiRes CAMs continue to support
a strong squall line developing in central MO and central IA
tomorrow late afternoon and then moving toward IL in the early
evening hours. The 18z HRRR is about 1 hr slow than the 12z run,
but messaging remains the same. Arrival time into west parts of
the CWA looks to be between 8-9pm. The line quickly moves east,
but the individual cells will move northeast across the area. Line
and cell speeds still look to be around 50-60 mph. Wind dynamics
remain strong with 50-60kts of shear in the 0-3km layer. The
concern is the amount of moisture with the system. Dewpts only get
into the lower to middle 50s during the day, but temps will get to
around 80 across the area. This will keep RH values in the 35 to
40 degree range. Forecast soundings will be inverted V with steep
low level lapse rates. But they also show the moisture will be
quite shallow and will probably quickly mix out. So, thinking here
is that damaging wind event remains likely with possible bowing
segments which could produce brief tornadoes. Large hail is
possible with the colder air aloft, but think that is a small
threat due to the fast movement of the storms. Storms should move
through the entire CWA around midnight, but some CAMS indicating
that storms will start gusting out around I-55 with the threat
diminishing east of that.
Another items that was added with tomorrows weather is the
possibility of fire weather. With the very high winds, any brush
or field fire that develops tomorrow will likely quickly spread.
Adding to this is the RH values will be in the mid 30s and good
mixing will occur, bringing down those high winds. The winds will
dry out the fields quickly too. Do not think much tilling has
occurred, so do not think blowing dust will as bad of a problem as
in past years, but it is something we will be monitoring.
Auten
.LONG TERM... (Saturday through Next Thursday)
Issued at 313 PM CDT Thu Mar 13 2025
Showers will continue into Sat morning and afternoon in the east
and southeast, with only a small chance of a thunderstorm in the
far southeast. Most models push all precip out of the area with
nothing going on Sat. However, a few keep some form of precip in
the southeast on Sat afternoon. As the upper level system pushes
east into Sat night, light rain or snow showers will be possible
over parts of the CWA. Winds will remain gusty into Saturday, but
guidance suggests the winds will remain below the 45mph
criteria...though there may be a few gusts that reach that level,
but not long. However, if things change in later forecasts,
another wind advisory will have to be considered.
Cooler air will move into the area late this weekend, with some
areas seeing lows below freezing. However, this will be shortly
lived and temps will warm back into the 60s and 70s for Mon
through Wed. Then a mid week system will bring another round of
precip and cooler temps for the last part of the week.
Auten
&&
.AVIATION... (For the 00z TAFs through 00z Friday Evening)
Issued at 633 PM CDT Thu Mar 13 2025
VFR conditions are expected through the TAF period. The main
inconvenience to air travel will be strong winds, especially
during the day on Friday. Southeast winds will begin to ramp up
late Friday morning with gusts approaching 40-45 kts during the
afternoon hours. Winds will remain elevated beyond 00Z, with a
line of strong to severe thunderstorms expected to track east-
northeast across the area between 02-06Z Friday night.
NMA
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Friday afternoon through Friday evening
for ILZ027>031-036>038-040>051-053.
Wind Advisory from 1 PM Friday to 1 AM CDT Saturday for
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1112 PM EDT Thu Mar 13 2025
.KEY MESSAGES...
- Unseasonably warm weather will persist through Saturday.
- Near critical fire weather concerns will exist for Friday.
- A dynamic storm system is expected to bring multiple rounds of
showers, and some thunderstorms, to the area this weekend.
- There is a slight risk of severe storms for most of eastern KY,
with an enhanced risk of severe thunderstorms near Lake
Cumberland from Saturday afternoon into early on Saturday
night.
- Strong to damaging wind gusts and locally heavy rainfall are
the primary risks with thunderstorms late Friday night into
Saturday night.
- In addition to the damaging wind gust potential from
thunderstorms, strong environmental winds and wind gusts are
possible late Friday night through Saturday night.
&&
.UPDATE...
Issued at 1112 PM EDT THU MAR 13 2025
Have extended an area of elevated POP a little longer into
tonight, as a pesky band of convection is still slow to die.
UPDATE Issued at 1020 PM EDT THU MAR 13 2025
Convection fired further north in the forecast area, but is
refusing to die out. An outflow (visible in the night time fog
channel difference imagery) from earlier convection in our
southwest counties has traveled north to the band of convection
and enhanced it. Once this outflow pushes through and the
convection travels eastward, suspect that it will finally diminish
late tonight. In the mean time, have raised the POP for areas
affected by the northern convective band.
UPDATE Issued at 712 PM EDT THU MAR 13 2025
Thunderstorms have propagated northward out of TN into our
southwestern counties. Have raised the POP in the chance category
there for a brief time early this evening. Have followed a blend
of the latest HRRR and RAP for the POP as we head into the
evening, with a slight chance of showers/thunderstorms further
into our forecast area-- especially the north.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 305 PM EDT THU MAR 13 2025
Weak system moving across the area late this afternoon will help
to fire off some high-based showers and thunderstorms. Given the
surrounding drier low-level environment, gusty and erratic breezes
will be possible within and in the vicinity of these showers and
storms, but otherwise impacts will be limited to brief downpours
and some lightning where storms occur.
Skies clear overnight tonight with light winds. This will help to
promote significant ridge-valley temperature splits once again
tonight.
Southerly winds gradually increase through the day Friday as a
powerful low pressure system ramps up over the middle of the
country. The combination of increasingly gusty winds through the
afternoon and relatively dry conditions in part due to downslope
compressional warming/drying will present a near-critical fire
weather threat, especially east of the escarpment and downwind of
the highest terrain in far eastern Kentucky.
Winds continue to increase through the overnight Friday night,
with probabilities for wind gusts reaching or exceeding 34 kts
(or ~39 mph) starting to reach or exceed 50 percent after about
midnight along and just downwind of the higher terrain along the
Tennessee and Virginia borders, with these winds continuing to
increase into the morning Saturday. Will thus need to consider a
Wind Advisory beginning this period with future forecast packages.
Additionally, models suggesta a roughly linear area of showers
and generally discrete yet weakening thunderstorms approaching the
Interstate 75 corridor from the west shortly before or near dawn
Saturday. There is a Marginal Risk Severe Weather Outlook in
effect for this time period generally along and west of
Interstate 75 for the early morning hours Saturday.
.LONG TERM...(Saturday through Thursday)
Issued at 305 PM EDT THU MAR 13 2025
The period Saturday morning begins most likely with a weakening
linear area of showers and thunderstorms moving east across
eastern Kentucky. What CAMS that are available this far out
suggest the activity will continue to weaken and/or diminish while
moving east as they outrun better dynamic and thermodynamic
forcing to the west. The next potential round of showers and
thunderstorms then arrives in the afternoon as a powerful low-
level jet pushes a warm front rapidly north.
Heading into the evening, attention turns to an approaching upper
trough/disturbance with an intensifying meridionally-oriented
mid-level jet streak approaching from the west. Additionally, it
is possible a surface low will be moving northeast towards the
area from the Lower Tennessee Valley, and this will bear close
watching as to its strength as it approaches southeastern Kentucky
toward the evening and overnight. Models suggest a potentially
concerning environment supportive of a QLCS line of storms with
embedded supercells possible heading into the evening and/or
overnight given the exceptionally strong veering wind low-level
wind profile supportive of large hodographs. If the low-level or
surface low remains fairly discrete and deep, an environment
supportive of all severe weather modes will be on the table, but
particularly a damaging wind and tornado threat. The SPC continues
to trend more ominous with their outlooks into eastern Kentucky,
and we certainly believe this is warranted at this point. However,
there are still quite a few failure modes for this event to
materialize below its full potential, with the biggest question
being how much instability is available as the storms move into
eastern and southeastern Kentucky.
Other hazardous weather concerns for Saturday through Saturday
night will be environmental winds, particularly as the low-level
jet moves across the area Saturday and persists into Saturday
night, which will likely warrant at least a Wind Advisory for most
if not all of the area at some point soon. Additionally, the WPC
has issued a Slight Risk for excessive rainfall for all but far
eastern Kentucky, which seems prudent given the strength of the
warm advection and the intensity of the low-level jet and possible
moisture transport into southern and eastern Kentucky Saturday
into Saturday night. Given recent antecedent dry conditions, the
primary threat, at least initially, would be flash flooding
associated with any potential training of storms across the area.
The parent upper trough will be slowing as it approaches the area
Saturday night into Sunday, with trough passage not until the
afternoon hours even though the cold front will occur near or
shortly after the passage of the strong to severe storms Saturday
night. Until upper trough passage, will continue to keep cold
advection/upslope precipitation in the forecast into Sunday over
southeastern Kentucky, with breezy to perhaps windy conditions
also continuing. Temperatures will likely remain on the mild side
Sunday given continued southwesterly flow aloft, despite low-level
cold advection.
The final trough passage occurs late Sunday night into Monday,
ushering in drier weather but also more northwesterly flow aloft.
Despite this, highs Monday will only return to near normal values
(for mid-March) of around 60 degrees.
Dry weather persists into the middle of next week as warm
advection increases ahead of the next system which will likely not
reach the area until Wednesday night or Thursday morning, which
is at the tail end of the forecast period. Expect temperatures to
continue to rise back to above normal to well-above-normal levels,
with increasingly breezy south to southwesterly winds ahead of
the cold front arrival.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday EVENING)
ISSUED AT 712 PM EDT THU MAR 13 2025
Scattered showers/thunderstorms were present early this evening,
especially in an area bounded roughly by KSME, KLOZ, K1A6, and
KEKQ. Additional activity may develop further northeast this
evening, but all of it should eventually die out by around 04Z.
Will include a PROB30 group for TSRA at KLOZ and KSME this
evening, but the probability looks too low to include it
elsewhere. Once activity dies, quiet VFR conditions are forecast
through the remainder of the period. Although, winds will pick up
during the day Friday, gusting 20 kt or better at most places in
the afternoon.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...CMC
LONG TERM...CMC
AVIATION...HAL
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
910 PM CDT Thu Mar 13 2025
.KEY MESSAGES...
- A powerful spring cyclone will impact the area Friday
afternoon into Saturday and bring with it:
- Very windy and unseasonably warm Friday afternoon and
Friday night, wind gusts to 45-50 mph expected.
- Near critical threat of grass/brush fire spread Friday
afternoon.
- Fast moving line of showers and thunderstorms Friday
night, with a threat for severe thunderstorms.
- Very strong, possibly damaging winds, Saturday morning
through early afternoon with gusts over 50 mph likely.
- Elevated threat of grass/brush fire spread Saturday.
- It will be much cooler late Saturday night into Sunday with
widely scattered rain and snow showers possible, followed by
above normal temperatures quickly returning for Monday-
Tuesday.
- Precip chances will return by the middle of next week.
&&
.UPDATE...
Issued at 910 PM CDT Thu Mar 13 2025
Minor tweaks to forecast this evening, mainly to adjust temps a
little lower this evening before rising a few degrees again
toward morning. Also expanded the footprint of slight chance of
showers after midnight across north-central IL and IL/WI border
region west of the Fox Valley. Can`t rule out an isolated rumble
of thunder with this. Lastly, increasing thin cirrus from the
west may impact viewing of the total lunar eclipse overnight,
though it may be thin enough where the moon is still largely
visible.
Surface map depicts weak high pressure centered near James Bay
ON northeast of the Great Lakes, with lee-troughing east of the
Rockies resulting in a broad region of south-southeast low-level
flow across the Plains and Mississippi Valley. A warm front was
also evident from central MO into southern IL/IN. This warm
front will lift slowly north overnight in response to
strengthening southerly flow. Light east winds north of this
boundary, combined with clear skies and a dry low-level airmass
(surface dew points again in the upper 20s/low 30s along/north
of I-80) have combined to allow temps to dip quickly in spots
after sunset this evening, especially near/along Lake Michigan
where current readings are around 40. We`ll likely see late
evening/midnight lows in these areas before temps gradually rise
into the mid-upper 40s toward morning as the warm front
approaches.
00Z RAOBs from sites to our west/southwest depict rather dry
profiles, though various guidance continues to indicate the
potential for isolated to scattered elevated convective showers
to develop into northwest/north central IL west of the Fox
Valley after midnight tonight. RAP isentropic forecasts on the
300-305K surfaces depict this saturation developing out of
northeast MO as warm advection ascent persists aloft north of
the surface warm frontal zone, and indeed GOES IR satellite is
showing some altocumulus development across parts of eastern MO
at mid-evening with cloud bases in the 7-10 kft range (and now
seeing some patchy 7-8 kft bases developing into eastern IA).
Several CAMs bring elevated SHRA across roughly the SQI-RPJ/RFD
areas after 07Z (2AM), with varying footprint size. Current
forecast has slight chance pops which look good for that time
period, and did slightly expand across Boone into northwest
McHenry county by 09Z or so. Forecast soundings don`t indicate
much positive energy (and what exists doesn`t last long), though
steep mid-upper level lapse rates suggest isolated lightning is
not out of the question. Otherwise, an area of thin but
expansive cirrus is spreading into northern IL from IA at this
hour. This may impact viewing of the total lunar eclipse
overnight (totality from roughly 0630Z-0730Z or 130-230 am).
However, this deck may remain thin enough to still see the moon.
Ratzer
&&
.DISCUSSION...
Issued at 330 PM CDT Thu Mar 13 2025
Tonight...
A quasistationary front, currently arcing from near Topeka to St.
Louis and across downstate Illinois will return northward as a
warm front this evening and overnight. As this occurs,
dewpoints will start to increase with a near-surface hydrolapse
developing. Can`t rule out some patchy fog developing as a
result, but with a strengthening low-level wind field just off
the deck, forecast soundings suggest things may remain just a
bit too "mixy" for a widespread dense fog threat. Winds look the
weakest with eastward extent, so the fog potential may tend to
locally maximize east of I- 57 and into parts of northern
Indiana.
Guidance which had been developing some elevated showers and
thunderstorms north of the returning warm front appear to be
backing off from this scenario--at least with the degree of
coverage. That said, seeing some hints at cumulus developing
across central Missouri, and model guidance does show warm
advection ratcheting up significantly overnight as an
intensifying LLJ meanders eastward. 800-500 mb lapse rates also
increase, so if sufficient saturation occurs, WAA/forcing for
ascent could help lift elevated parcels to an uncapped LFC, in
which case there`d be a nonzero thunder threat. At this time,
the signal for convection isn`t high enough to carry a formal
mention of thunder, but will continue a slight chance mention of
showers mainly west of the Fox Valley late tonight. Most
locations look to remain precipitation free.
Carlaw
Friday through Saturday Night...
There are no changes in thinking regarding most of the key forecast
elements (temps, winds, Fri. night t-storm/severe wind threat)
through Saturday night. The biggest change pertains to fire
weather concerns on Friday. This is due to expectation of temps
nearing 80F away from the lake, the already strong winds, dew
points likely to mix out into the upper 40s to around 50F knocking
% RH values down into mid 30s, and very dry fuels. The dry fuels
have contributed to several out of control brush fires the past
few days, even with fairly light light winds. Therefore, in
coordination with neighboring WFOs and fire weather partners, a
Fire Weather Watch was hoisted this morning and is in effect for
the entire area from 1 PM to 9 PM CST. Additional information will
be provided in the forthcoming Fire Weather section.
Otherwise, the strong southerly wind forecast looks to be in good
shape and we continue to be concerned about damaging wind gusts
to around 60 mph on Saturday. No major changes were made to the
wind headlines in effect for Friday, with the minor exception of
extending the northeast Illinois to northwest Indiana advisory
segment until 4 AM Saturday. A High Wind Watch remains in effect
from 8 AM to 2 PM Saturday for all counties except Ford, Iroquois,
Newton, Jasper, and Benton.
Castro
The following will be mostly pulled from the previous AFD,
considering the continuity in forecast thinking.
Synoptic Overview:
Intense/rapid lee cyclogenesis will take over the central Plains
tonight into Friday morning, fostered by an incredibly intense
upper-level jet streak (120+ kts progged at 500 mb) and
corresponding left exit region fanning out across the central
Great Plains. A quasistationary front that`s been stalled out
well south of the area will begin lifting northward as a warm
front in response to pressure falls ahead of the developing lee
cyclone. Surface pressure falls on the order of 10 mb/6 hours will
support the quick development of a mid 970s mb low by midday over
western Kansas. This powerful low and associated negatively
tilted, sharp upper trough with an attendant closed mid-upper
level low will eject northeastward toward the upper Mississippi
Valley Friday afternoon into Friday night.
Friday Temps and Dew Points:
The aforementioned warm front from the overview section should
clear all but the Illinois north shore by mid-late morning Friday.
A buckling mid-upper level ridge over the region will send the
core of the upper level jet and associated cirrus north of the
area by late morning with skies becoming mostly sunny. The global
guidance continues to feature 925mb temps warming to near/around
20C by late afternoon, which given the mostly sunny skies should
allow temps to get at least into the upper 70s, with it looking
increasingly likely that some locations will tag 80 degrees Friday
afternoon (do have some explicit 80F highs in the grids). Thanks
to the backed south-southeasterly synoptic flow, it will take
much of the afternoon and possibly the early evening before the
warm front can finally reach the Lake County IL shore. As the
higher dewpoints meet the lake chilled air, some dense marine fog
is certainly possible along on the cool side of the front along
the IL north shore. Will let later shifts assess this item (fog
along IL North Shore) for possible inclusion.
Dew points starting the day in the 40s for most locales should mix
out into the upper 40s to around 50F in the mid to late afternoon
due to the shallow nature of the warm sector moisture profiles,
dormant vegetation, and a deepening mixed layer. With the strong
synoptic winds (described below), this will contribute to the near
critical fire weather conditions.
Friday Afternoon/Evening Winds:
A quickly tightening pressure gradient amidst the deeply mixed
boundary layer should set the stage for very strong southerly
winds Friday afternoon. By early/mid afternoon, bufkit soundings
over the western CWA continue to show boundary layer mixing up to
40kt winds, which given the sunshine should be able to mix to the
surface in gusts, particularly by late afternoon. The very strong
winds will likely continue into the evening hours, with strong
pressure falls and turbulent mixing likely keeping very strong
gusts going. If gusts ease a bit at sunset, they should ramp back
up during the early evening as 50-60kt low level jet around 1500ft
AGL overspreads the area.
This very strong low level jet and very little diurnal
cooling/decoupling should result in frequent gusts of 40-50 mph
Friday evening with a few gusts over 50 mph not out of the
question. The previously collaborated Wind Advisory for Friday
starts at noon for the western half of the CWA and 3 pm for the
eastern half of CWA. These start times may be a little early, but
it shouldn`t be too long after those start times that we start to
see advisory level gusts. The advisory level gusts should abate
in the wake of the fast moving convective line moving across the
CWA, which looks to exit out eastern CWA by 08-09z. Another
consideration for Friday night is that the advisory in effect and
expectation on non-convective gusts to 50 mph may allow for a more
targeted (severe t-storm) warning strategy.
Friday Night Storms:
Forecast reasoning again hasn`t changed much at all from the past
couple of days.
Vigorous thunderstorm development is expected Friday afternoon
across southwest Iowa arcing southeast and south across Missouri
as the main upper jet streak spreads across a sharpening
dryline. While a notable cross-boundary component to deep layer
shear vectors is forecast, which would normally tend to promote
discrete or semi-discrete storm modes, the significant nature of
synoptic scale forcing with this system looks to encourage a rapid
development towards a line of strongly-forced convection. This
activity will quickly become severe across central and eastern
Missouri and into Iowa.
The magnitude/expansiveness of the severe threat into our forecast
area remains uncertain. It appears likely that low level moisture
will mix out to some degree Friday afternoon across much of the
warm sector of the cyclone, including a good chunk of Illinois.
Assuming this occurs (and our confidence has increased in this),
it should keep instability confined to a fairly narrow ribbon
pooled moisture immediately ahead of the surging dryline. It
appears likely that this QLCS will outrun that narrow ribbon of
pooled moisture and instability as it matures and accelerates
eastward. During the evening as this QLCS moves east of the
Mississippi River it should be venturing into an increasingly
marginal/more hostile environment with respect to boundary layer
based instability. This should result in weakening trend in the
deep convection as the thunderstorms approach and/or move across
our CWA mid-late evening Friday.
As we`ve been detailing, how quickly that weakening trend occurs
will be a critical in determining both the magnitude and eastward
extent of the severe weather threat. If greater than expected
boundary layer instability persists well into the evening and/or
synoptic forcing help maintain the QLCS longer, then the threat
for significant winds gusts (65kt+) and QLCS type tornados will
increase in our area. In line with the latest (essentially
unchanged) SWODY2, it appears the highest severe probabilities in
our area will be across western and southwestern CWA with threat
decreasing with eastward extent. It is worth noting, that given
the extreme low level wind fields, even innocuous looking showers
could mix severe criteria wind gusts to the surface, so the wind
threat with the QLCS could persist longer than the lightning and
heavy rain threat!
Synoptic High Winds Saturday through Early Afternoon:
The potential for a period of damaging winds across portions of
the area remains evident. As the dry slot of this 970s mb cyclone
punches into the area, deepening mixing into very strong wind
field should promote increasingly strong and potentially damaging
wind gusts Saturday morning into the early afternoon. Bufkit
soundings from both the NAM and GFS show peak boundary layer winds
of 50-60kt and mean BL winds of 40-45kt from the south-southwest.
Given the propensity for very effective downward momentum transfer
within the dry slots of intense mid-latitude cyclones, it seems
likely that there will be a couple/few hours with some 50kt+
gusts. It`s also worth noting that in the 51 member ECMWF (EPS)
ensemble, the 10th percentile wind gusts on Saturday are roughly
in the 45-50 mph range! Meanwhile, the 90th percentile EPS gusts
are near/around 60 mph.
The strongest wind fields within this dry slot begin move east of
our CWA between 18-20z, so our likely window of strongest winds
appears to be 15-19z. Given the continued potential for occasional
damaging wind gusts on Saturday, maintained the High Wind Watch
for about the northern 2/3rds of the CWA. While the lack of
leaves on trees may very well mitigate tree damage (and power
outages) to an extent, there are numerous scheduled St. Patrick`s
Day celebrations on Saturday. This heightens concern for the
dangers posed to parade participants and onlookers by flying
tents, structures, and even debris (such as windows and
scaffolding from high-rise buildings). Regardless of the top end
magnitude wind gusts being 50-55 mph or 60 mph on Saturday,
confidence is high in the winds being strong enough to make
outdoor activities potentially hazardous/dangerous.
A cold front will sweep across the area Saturday night, resulting
in a breezy and colder conditions. Will have to watch for a
glancing blow from synoptic rain into our southeast CWA Saturday
night, along with the possibility of showery precip (rain to snow)
developing into northern Illinois overnight.
- Izzi/Castro
Sunday through Thursday...
Conditions will be substantially colder and blustery on Sunday
as the synoptic cold front associated with the Friday/Saturday
storm system sweeps through the area. There is a potential for
some lingering precipitation (mostly snow) Sunday morning
towards midday as a sharp mid-level trough axis pushes overhead.
There`s plenty of variability regarding the amount of moisture
availability, so for now haven`t made any changes from the NBM-
delivered slight chance PoPs. Any light snow doesn`t look overly
impactful with temperatures expected to rise through the 30s
through the morning. Blustery W/NW winds will occur through the
day, with some gusts to around 30 mph appearing likely. While
temperatures will be notably colder, very dry air is slated to
arrive, and this may end up dropping RH values under 30 percent
at times during the afternoon. Fine fuels will likely still be
recovering from Friday night - Saturday`s precipitation, so it`s
unclear what impact this will have on any fire weather
potential, but will continue to monitor this for a potential
slightly elevated fire danger.
A warming trend will commence on Monday and Tuesday as deep
south to southwesterly flow re-establishes itself across the
region as another sprawling area of low pressure begins to take
shape across the central plains. Depending on how warm things
get on Monday, this potentially could be another elevated fire
weather day with moisture transport still lagging and gusty
southerly winds expected to develop with increasing mixing.
For Tuesday night and beyond, models and ensemble guidance have
consistently been showing significant lee cyclogenesis taking
place to our west as another intense/positively-tilted trough
axis swings through the Great Basin and across the Continental
Divide. While there`s still a fair deal of spread in the
associated surface low tracks, the signal for a robust storm
system in the region during the Tuesday night-Thursday timeframe
continues to grow. Showers and thunderstorms, followed by a
potential changeover to a little snow on the backside appear
possible.
Carlaw
&&
.AVIATION /00Z TAFS THROUGH 06Z FRIDAY/...
Issued at 627 PM CDT Thu Mar 13 2025
Forecast concerns include...
Low level wind shear tonight.
Strong/gusty south/southeast winds Friday/Friday evening.
Line of strong/severe thunderstorms late Friday evening.
Easterly winds generally under 10kts early this evening will
become southeast tonight. Speeds will increase into the
10-15kt range after sunrise Friday morning with gusts into lower
20kt range expected. Speeds and gusts will quickly increase by
early afternoon when gusts into the 30-35kt range are expected.
Gusts will continue to increase into the 35-40kt range by late
afternoon and likely continue into the mid evening. Prevailing
wind directions are expected to remain south/southeast through
Friday evening, possibly becoming southerly late Friday evening.
Low level winds will steadily increase tonight, especially
across northwest IL where low level wind shear will be possible
and maintained mention with this forecast.
A fast moving line of thunderstorms is expected to move from
southwest to northeast across the entire area during the mid to
late evening Friday. This line may arrive faster than current
guidance suggests and tempo mention from 04z-06z seems
reasonable at this time for ORD/MDW. Wind gusts 45-50kts will
be possible with these thunderstorms. cms
&&
.MARINE...
Issued at 429 PM CDT Thu Mar 13 2025
A powerful area of low pressure will move from the central
Plains on Friday to near or over western Lake Superior on
Saturday. South-southeasterly winds will become increasingly
strong Friday afternoon and especially Friday evening. We`re
expecting a period of gale force (35-40 kt) winds through the
pre-dawn hours of Saturday, perhaps followed by a brief lull.
After daybreak Saturday, even stronger winds from the south-
southwest are then likely, with a distinct potential for 50 kt
storm force speeds/gusts. For the impending periods of very
strong winds, an unseasonably warm air mass will likely confine
the strongest winds to the first few/couple miles of the
Illinois and far northwest Indiana nearshore. A Gale Warning is
in effect from 4 PM Friday to 9 AM Saturday and a Storm Watch is
in effect from 9 AM to 3 PM Saturday.
Castro
&&
.FIRE WEATHER...
Issued at 429 PM CDT Thu Mar 13 2025
A Fire Weather Watch remains in effect for the entire area from
1 PM to 9 PM CDT on Friday, per earlier coordination with
partners and collaboration with neighboring WFOs. High temperatures
on Friday well into the 70s to near/around 80F away from Lake
Michigan will pair with strong south-southeast winds gusting up
to 45 to 50 mph from the mid afternoon through the early evening.
The very dry fuels, unseasonable warmth, and strong winds will
lead to an elevated fire danger. Despite minimum relative
humidity (RH) values possibly/likely remaining above the 25%
criteria in much of the watch area, the extenuating factors
(very strong winds, summer- like temps, and very dry fuels) may
still enable fires to quickly grow out of control and prompt
the issuance of a Red Flag Warning.
Strong southerly winds will continue through Friday evening out
ahead of a fast moving line of possibly severe thunderstorms
that will cross the area through the pre-dawn hours of Saturday.
Rain is expected areawide, though rainfall totals may only reach
one half inch. That said, the rain should moisten fuels going
into Saturday. Particularly if the rain under-performs though,
even stronger south-southwesterly winds gusting up to 50 to 60
mph and RH in the 40-50% range may dry out some fuels enough to
cause an elevated fire danger.
Castro
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Wind Advisory from noon Friday to 1 AM CDT Saturday for ILZ003-
ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-ILZ012-ILZ019-ILZ020-
ILZ021-ILZ032.
Fire Weather Watch from Friday afternoon through Friday
evening for ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039.
High Wind Watch from Saturday morning through Saturday
afternoon for ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ023-ILZ032-
ILZ103-ILZ104-ILZ105-ILZ106-ILZ107-ILZ108.
Wind Advisory from 4 PM Friday to 4 AM CDT Saturday for ILZ006-
ILZ013-ILZ023-ILZ033-ILZ039-ILZ103-ILZ104-ILZ105-ILZ106-
ILZ107-ILZ108.
IN...Fire Weather Watch from Friday afternoon through Friday
evening for INZ001-INZ002-INZ010-INZ011-INZ019.
High Wind Watch from Saturday morning through Saturday
afternoon for INZ001-INZ002.
Wind Advisory from 4 PM CDT /5 PM EDT/ Friday to 4 AM CDT /5
AM EDT/ Saturday for INZ001-INZ002-INZ010-INZ011-INZ019.
LM...Small Craft Advisory from 10 AM to 4 PM CDT Friday for the IL
and IN nearshore waters.
Gale Warning from 4 PM Friday to 9 AM CDT Saturday for the IL
and IN nearshore waters.
Storm Watch from Saturday morning through Saturday afternoon
for the IL and IN nearshore waters.
&&
$$
Visit us at weather.gov/chicago
Area Forecast Discussion
National Weather Service Memphis TN
939 PM CDT Thu Mar 13 2025
...New UPDATE...
.KEY MESSAGES...
Updated at 913 PM CDT Thu Mar 13 2025
- Multiple rounds of showers and thunderstorms are expected from
Friday night to Saturday night. Severe weather chances increase
during this time with all hazards at play. There continues to be
some uncertainty regarding the timing of these storms, so
continue to monitor the forecast for the end of the week.
- Dry weather returns to the Mid-South for Sunday through Tuesday.
Temperatures will cool on Sunday back to seasonal levels before
a warming trend bring highs into the low to mid 70s by Tuesday.
&&
.UPDATE...
Issued at 913 PM CDT Thu Mar 13 2025
Cirrus is starting to spill into the area from the west which may
affect viewing of the "Blood Moon" total lunar eclipse overnight.
The further east you are located the better chance of clear
skies. A steady southerly breeze will help keep temps in the upper
50s and lower 60s.
Friday will be windy and moisture will steadily advect into the
area ahead of the approaching system. The upper low will become
negatively titled with the main thrust pushing toward the Mid-MS
Valley. The severe threat across the Mid-South is more conditional
and dependent on the amount of forcing and the strength of the
CAP. The latest 00z CAMS are showing an uptick of convective
development east of the MS River after 10 pm Friday evening which
may indicate more lift across the Mid-South than previous runs.
The 3km NAMnest and HRRR show discrete cells developing across
West TN and perhaps even into NE MS. The model soundings look very
impressive with MLCAPES of 1500-1800 J/kg and 0-1km helicity
values of 400-500 m2/s2 across parts of West TN. This would
support strong tornadoes along with very large hail and damaging
winds.
This situation for tomorrow evening into the overnight is
especially concerning because we may be dealing with nighttime
tornadoes. Make sure you have a way to receive warnings at night.
&&
.DISCUSSION...
(This evening through next Wednesday)
Issued at 337 PM CDT Thu Mar 13 2025
Isolated thunderstorms are developing on radar as of 330 PM,
impacting portions of northeast Mississippi. SBCAPE values upwards
of 1500 J/kg are apparent in this region, but lapse rates remain
lack luster. Therefore, upscale growth of these storms is not
anticipated. Instead, expect storms to be capable of producing
small hail and gusty winds.
An active weather pattern will continue Friday as a large upper
level trough ejects out of the Rockies. This feature will take a
steep, negative tilt over Kansas by midday. Locally, the pressure
gradient will tighten and increase winds above 25 mph with gusts
up to 45 mph. As such, a Wind Advisory has been issued for areas
north of the TN/MS border through Friday night.
Also on Friday, severe weather parameters will be on the rise
underneath a strong capping inversion. High-resolution guidance
quickly erodes this cap after sunset as height falls increase. At
this point, the environment will house over 1500 J/kg of SBCAPE,
lapse rates in excess of 7.0 C/km, and bulk shear near 50 kts. The
main caveat to this forecast lies in storm initialization. If the
cap remains strong, storm development is not anticipated.
However, erosion of this inversion will result in a potentially
high-end severe weather maker with supercells capable of producing
all hazards. We would like to note: this severe setup will be
nocturnal. Nighttime tornadoes account for the majority of tornado
related fatalities each year in the United States. Therefore, we
emphasize that you and your loved ones ensure you have a way to be
alerted if you are asleep. Do not place your cellphones on do not
disturb.
Another round of severe weather is forecast Saturday as a longwave
trough quickly follows Friday`s disturbance, ejecting a cold front
towards the Mid-South. Moisture availability surges north early
Saturday with 60+ dewpoints overspreading the area. In addition,
SBCAPE values remain elevated in the morning: in excess of 1500
J/kg. Storms will have ample fuel and shear to work with, posing
another threat for all severe weather hazards. Saturday`s forecast
becomes tricky by midday as early morning convection contaminates
the warm sector. SBCAPE drastically decreases by this timeframe
for areas outside of northeast Mississippi. However, guidance
continues to recover the atmosphere along the Mississippi /
Alabama stateline by Saturday afternoon. Should this scenario
occur, yet another round of severe storms is expected. Storms at
this time will have elevated lapse rates near 7.5 C/km to work
with. In addition, long looping hodographs suggest potential for
long-lived cyclical supercells capable of producing strong
tornadoes (EF-2+).
Thunderstorms will wane on Sunday as ridging aloft resumes over
the Mid-South. Temperatures will warm into the mid 70s by Tuesday
with the next rain chances occurring Wednesday.
ANS
&&
.AVIATION...
(00Z TAFS)
Issued at 628 PM CDT Thu Mar 13 2025
VFR conditions will prevail through much of the period at
JBR/MEM/MKL. MVFR conditions are expected to move over TUP
overnight, behind today`s convection. South winds will gust up to
35 kts across all terminals beginning around 15Z as the pressure
gradient tightens ahead of an upper low. LLWS will impact
JBR/MEM/MKL starting tomorrow afternoon with this upper low
movement. Scattered thunderstorms will move over MEM beginning
around 00Z tomorrow. A lowering to MVFR conditions will be
possible with convection, but confidence is not high enough to
prevail in TAF.
AEH
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Wind Advisory from 10 AM Friday to 1 AM CDT Saturday for ARZ009-
018-026>028-035-036-048.
MO...Wind Advisory from 10 AM Friday to 1 AM CDT Saturday for MOZ113-
115.
MS...None.
TN...Wind Advisory from 10 AM Friday to 1 AM CDT Saturday for
TNZ001>003-019-020-048>051-088-089.
&&
$$
PUBLIC FORECAST...SJM
AVIATION...AEH
Area Forecast Discussion
National Weather Service Morristown TN
1050 PM EDT Thu Mar 13 2025
...New UPDATE...
.UPDATE...
Issued at 1045 PM EDT Thu Mar 13 2025
A new update to remove showers and storms from southeast
Tennessee. Also kept a small chance in Wise county next hour as a
complex of showers and storms move southeast toward the Virginia
and West Virginia border. Another complex moving from east central
Alabama into western Georgia will not affect east Tennessee. Skies
will be clearing for the rest of the night. Weakening shortwave
trough is about to move out and into the Carolinas and mid
Atlantic states with mid level ridging moving in through the rest
of tonight and into Friday morning. Temperatures cooling a little
slower where clouds formed with the convection but also dropped
where rain fell. Updated hourly temperatures and dewpoints.
Updated forecast sent.
&&
.UPDATE...
Issued at 900 PM EDT Thu Mar 13 2025
Updated forecast as showers and storms are decreasing in coverage
and intensity. Still some over the southern plateau and southern
valley at 900 PM but expect them to die down in an hour. Skies are
partly cloudy to mostly cloudy in areas still getting showers and
temperatures are in the upper 50s to upper 60s. Winds are generally
light across the region. Some areas received up to about an inch
or more of much needed rainfall in the southern part of the forecast
area. May see some fog in the rain areas but did not add to
forecast. Update sent.
&&
.SHORT TERM...
(This evening through Friday night)
Issued at 242 PM EDT Thu Mar 13 2025
Key Messages:
1. Warm temperatures, deep mixing, and gusty winds on Friday will
promote elevated fire danger levels.
2. High winds ramp up across the mountains Friday night. Gusts of
60-70mph likely overnight, before even stronger winds arrive in
the long term.
Discussion:
Some isolated showers and thunderstorms continue to
develop/persist across the region this afternoon. This seems
largely tied to combination of terrain (Cumberland plateau and the
Appalachians) and the northward advance of mid 50s dewpoints.
Will leave the widespread slight chance PoPs in the forecast
through the afternoon but I don`t expect there will be much more
coverage than what is currently on radar. That said, model
soundings show very steep lapse rates so some decently tall storms
capable of small hail and gusty winds if any develop. The window
of opportunity for any convection will persist through 03z or
thereabouts. Afterwards, dry conditions are expected through
Friday.
By late tonight, the upper low/shortwave responsible for the
isolated showers across the region will have shifted well to our
southeast. Heights will then rise ahead of the system that will
bring us severe storms on Saturday. As such, tomorrow should be
warmer than even today, with mid and upper 70s forecast for the TN
valley. Winds will begin to pickup as well on Friday. Model
soundings show that we mix out to nearly 7000 ft AGL tomorrow
afternoon, which will tap into some 25-30kt flow aloft and help to
promote gusty afternoon winds. This deep mixing is also going to
lead to low afternoon RH values once again. Will need to
coordinate with fire weather partners on whether any headlines
will be needed. I say that because while lower elevations won`t be
near advisory levels during the afternoon tomorrow, the wind field
aloft is going to strengthen considerably as we head into the
evening hours. To that end, we`ve gone ahead and upgraded the high
wind watch to a warning for the mountain zones. There could be
some overlap these stronger winds with the lower RH values which
would elevate fire danger levels for sure.
Friday night, winds will continue to ramp up in the mountains as
a strong H85 wind field begins to spread across the area in
advance of the severe weather event. Put gusts to 80mph in the
high wind warning. While those types of gusts should largely hold
off until the long term period, gusts of 60-70mph will certainly
be possible Friday night.
&&
.LONG TERM...
(Saturday through next Thursday)
Issued at 242 PM EDT Thu Mar 13 2025
Key Messages:
1. A very strong and dynamic system will impact the region Friday
night through early Sunday morning with a high-end, long-duration
mountain wave event likely across the mountains and foothills
through Saturday night.
2. A significant severe weather outbreak is likely across the region
with the greatest threat in our area being along the Cumberland
Plateau through southeast Tennessee and southwest North Carolina.
The greatest threat is for significant and widespread damaging winds
with tornadoes and large hail also possible.
3. Flooding of urban areas and flood prone locations will be
possible due to heavy rainfall rates Saturday night.
4. Drier and cooler conditions arrive Sunday night into Monday,
followed by a warming trend and another system by Wednesday.
Discussion:
Saturday morning, we will be under the influence of broad upper-
level diffluence with a potent shortwave vort max preparing to eject
from the longwave trough axis across the Arklatex region. An
occluding surface low will be across the Great Lakes region with a
trailing cold front across the Mississippi Valley. Due to an
increasing upper-level jet divergence, a subtle surface low feature
will develop along this cold front across the Lower Mississippi
Valley and race northeastward Saturday afternoon and night. This
will bring an increasing risk of a dangerous significant severe
weather outbreak for portions of the Mid-South and Tennessee Valley
across Mississippi, Alabama, and Tennessee. Supercell thunderstorm
structures capable of large, long-track tornadoes will be possible
as well as QLCS convection during the evening and overnight hours
with a continued high-end damaging wind risk and a continued risk of
tornadoes. Behind the front, cooler and drier weather arrive early
to mid next week. The following sections are grouped based on order
of occurrence and with respect to our area:
1. Mountain Waves/Fire Weather
A strengthening pressure gradient and increasing 850mb LLJ over 50
kt will result in mountain wave high winds increasing into Saturday
morning and during the day. The LLJ will increase to over 70 kt by
Saturday evening with intense high-end mountain wave high winds
expected. Based on extent of winds and dry conditions seen in recent
days, fire weather is of significant concern, especially in the
mountains and foothills. The High Wind Watch will be upgraded to a
High Wind Warning since we are now within 24 to 36 hours of the high
winds beginning and confidence continues to increase in these
intense winds for the mountains and foothills.
2. Severe Weather
As mentioned above, a new subtle surface low will be developing
beneath a region of upper-level divergence across the Lower
Mississippi Valley on Saturday morning. This low will move rapidly
northeast Saturday afternoon and evening with the cold front moving
eastward. With a strong SSW 850mb LLJ around 70+ kt and upper-level
500mb winds from the WSW at 80+ kt by Saturday evening, effective
bulk shear will be very strong across the Mid-South and Tennessee
Valley. 15Z RAP forecast soundings at CHA for 18z Saturday are
showing low instability and very high shear values. MLCAPE around
500 J/Kg with EBShear around 55 kt. ESRH between 300 to 500 m2/s2 is
very high, and the strong low-level shear is resulting in long,
curved hodographs favorable to tornadoes, including strong and long-
track tornadoes. The big limitation for Saturday`s severe convection
across our region may be morning showers and thunderstorms that
stabilize portions of the forecast area. This could stabilize the
boundary layer and limit surface based convection. However, it still
appears likely that strong southerly flow will lift this northward,
and at the very least, destabilize the southern plateau and southern
valley enough to support high-end severe weather. For this reason,
the highest risk of severe weather across our forecast area will be
counties along the southern Cumberland Plateau and southeast
Tennessee.
On Saturday afternoon, it is likely that Supercells develop along
the cold front or prefrontal trough across northeast and east-
central Mississippi and central and northern Alabama; these would
begin to track northeast through the evening. These storms would
most likely arrive in southeast Tennessee sometime between 23z and
04z Saturday evening with a gradual upscale growth into a QLCS with
embedded circulations as the night progresses. Storm motion will be
very fast, around 220/65kt. The fast movement and kinematic wind
profile will support severe thunderstorm damaging winds area-wide.
The main tornado risk, including the most probable significant, long-
track tornado risk, is likely to remain south and west of the
Knoxville area where better boundary layer moisture is present, but
there will at least be a low risk of tornadoes area-wide. There will
be a risk of large hail with Supercell thunderstorms, but the
overall hail risk is low to medium.
3. Flooding
Ahead of the approaching cold front, very strong 850mb moisture
transport moves into our area with PWATs reaching to near record
high values of 1.4 to 1.5 inches. This is around 3.5 sigma above
normal values which will support heavy rain rates. Due to heavy rain
rates, flooding of urban areas and flood prone locations is expected.
Sunday through Wednesday
Upslope flow keeps clouds and showers across the mountains on Sunday
with a chance of some light snow or rime ice on Sunday night before
dry air and clear sky conditions return on Monday. With troughing
early week, temperatures will be cooler early in the week before
ridging brings a return to above normal temperatures by mid-week.
&&
.AVIATION...
(00Z TAFS)
Issued at 730 PM EDT Thu Mar 13 2025
A possible thunderstorm near TYS and possibly CHA next hour before
dissipating so VCTS remarks. VFR flight categories however will
continue through the 00z TAF period. Winds will be light through
about 18z Friday, after which point the potential for gusts up to
about 20 knots begins to increase.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 52 76 61 73 / 10 10 50 90
Knoxville McGhee Tyson Airport, TN 48 78 60 73 / 30 0 30 80
Oak Ridge, TN 48 77 59 72 / 30 0 30 80
Tri Cities Airport, TN 45 75 54 74 / 10 0 10 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...High Wind Warning from 8 PM Friday to 2 AM EDT Sunday for Blount
Smoky Mountains-Cocke Smoky Mountains-East Polk-Johnson-
Sevier Smoky Mountains-Southeast Carter-Southeast Greene-
Southeast Monroe-Unicoi.
VA...NONE.
&&
$$
SHORT TERM...TD
LONG TERM....JB
AVIATION...TD
Area Forecast Discussion
National Weather Service Raleigh NC
1003 PM EDT Thu Mar 13 2025
.SYNOPSIS...
High pressure will extend across the Middle Atlantic coast and nudge
a backdoor cold front southwestward across NC tonight. The front
will become quasi-stationary over SC on Friday, then return north
across NC and VA as a warm front on Saturday.
&&
.NEAR TERM /TONIGHT/...
As of 1000 PM Thursday...
A shortwave trough over the Carolinas will move offshore tonight, as
will an accompanying canopy of 15-20 thousand ft ceilings evident in
the 00Z-observed GSO and MHX RAOBs.
At the surface, 1019-1020 mb high pressure centered along the srn
New England and Middle Atlantic coast will extend swd and continue
to shove a backdoor cold front swwd through cntl NC tonight. That
front was already well established at 02Z across cntl NC and evident
in regional radar and surface observational data from near NBT and
EWN wwd to HRJ, then nwwd to SCR, GSO, and MWK.
Nely flow and CAA behind the backdoor front will increase low-level
RH and contribute to the continued expansion of an area of post-
frontal, 500-1200 ft AGL ceilings from sern VA/nern NC swwd and
across cntl NC through 12Z Fri. Timing of the ewd-departing mid-high
ceilings and swwd-developing low overcast will favor areas from GSO
to RDU to GSB and points swwd for optimally clear viewing of the
total lunar eclipse at 3 AM EDT. Low temperatures should be mainly
in the 40s.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 311 PM Thursday...
Friday will be dry with temperatures 5 to 10 degrees above average.
The cold front that sagged to the south across central NC on
Thursday night, will retreat north as a warm front in the
afternoon. Southeasterly flow on Friday will result in another day
of above average temperatures with highs in the mid 60s NE to
mid/upper 70s SW. Overnight lows will be warmer than previous night
thanks to the WAA with lows in the upper 40s NE to low 50s
elsewhere.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY...
As of 300 PM Thursday...
* A strong cold front will bring strong winds and a threat for
severe storms/squall line Sunday...
* Unseasonably warm through much of the period...
Saturday: The eastward advancement of the strong upper trough into
the Central US and MS Valley will kick the mid/upper level offshore
early in the day. Strengthening southerly flow and associated
moisture transport between offshore Bermuda high pressure and the
upstream trough/cold front will result in some weak elevated
buoyancy and some isolated showers and/or sprinkles. Otherwise, it
should remain mostly dry. Becoming breezy and a few degrees warmer
than Friday. Highs in the mid 70s to lower 80s.
Saturday night and Sunday: A strong upper trough will advance east
into the region late Sunday and into the day on Monday. Strong deep-
layer southwesterly flow ahead of the trough, highlighted by a 100kt
H5 jet and a 60-70 kt wind maximum at H8, will move across the area
Sunday, preceding the passage of a cold front that will cross the
area Sunday night. This energetic system will bring a risk of
multiple hazards across central NC.
1) Strong non-convective wind threat: Confidence is highest with
this threat given the aforementioned strong background winds. Expect
sustained winds of 20 to 25 mph. Winds will gusts to 30-40 mph, with
some locally higher gusts possible late Saturday night across the NW
Piedmont, and then area-wide Sunday.
2) A lead pre-frontal line of severe storms capable of producing
swaths of damaging gusts, with some isolated embedded tornadoes
possible. Forecast confidence is seldom high in HSLC environments,
and that is certainly the case here with there being quite a bit of
model spread in convective details/evolution(timing,intensity).
Weak destabilization is probable across the area as BL dewpoints
increase into the lower/mid 60s. Convective onset/timing will likely
play a critical role in how the lead convective line evolves as it
moves east through the area with an earlier onset likely to temper
or restrict severe chances to eastern portions of the forecast area.
Given, strong, cyclonic curved hodographs, swaths of strong to
severe gusts are possible along the line, with some isolated
embedded tornadoes possible. Additionally, the development of a
secondary band of showers/storms is possible along the actual cold
front as it moves east through the area Sunday evening/night.
3) Storm total rainfall of 0.50"-1" is expected, with some
isolated/higher amounts possible. Given the potential for training
and high rainfall rates within the convective line,
isolated/localized instances of minor flooding is possible, mainly
in urban/poor drainage environments.
Monday through Thursday: There remains a model signal for some
lingering ana-frontal rain across eastern NC on Monday as the upper
trough moves through the area. Otherwise, drying out from west to
east with temperatures briefly cooling to near normal Monday/Monday
night as a southern stream high builds in from the gulf coast
states/mid South.
Surface high pressure will move the SE Coast Tuesday with
temperatures quickly warming to well-above normal readings(75-80 F)
by mid week. The next chance of rain returns late Wednesday and
Thursday as another formidable mid/upper level trough advances east
into the region.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 820 PM Thursday...
A backdoor cold front currently extends from the NW Piedmont to the
central/southern Coastal Plain, separating S/SW winds ahead of it to
NE winds behind it. This front will move SW through the rest of
central NC this evening, bringing low-level moisture and a good
chance for widespread low MVFR to IFR stratus, which observations
show is already starting to develop over extreme NE NC and SE VA.
This low stratus should spread from NE to SW across central NC, and
while there are slight timing differences in the models, it should
begin around 05-07z at KRWI, 06-08z at KRDU, 08-10z at KINT/KGSO,
and 09-11z at KFAY. GFS soundings are quite a bit drier, but
considering it is an outlier compared to the higher resolution HRRR,
RAP and NAM, opted to discount it at this time. Some LIFR ceilings
and fog even can`t be ruled out in the late overnight and early
morning hours on Friday, with the best chance at KRDU and KRWI.
Ceilings will begin to lift and scatter out to VFR by early
afternoon in most places, possibly not until mid afternoon at KRWI.
Winds will be from the NE tonight once the backdoor front moves
through, before shifting E/SE tomorrow afternoon, remaining light (7
kts or less).
Outlook: Sub-VFR conditions are possible Saturday morning with light
showers moving into the region from the west Saturday afternoon. A
better chance of sub-VFR ceilings is expected Saturday night into
Sunday as a line of showers/storms associated with a cold front
moves through from west to east. Very gusty winds and heavy rain
will also be possible. VFR conditions and dry weather will return on
Monday and Tuesday.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...CA
LONG TERM...CBL
AVIATION...Danco