Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/26/24
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
841 PM CDT Thu Apr 25 2024
.KEY MESSAGES...
- Winds will remain breezy out of the southeast with gusts of 35 to
near 45 mph, and slowly diminish from west to east into Friday
morning.
- Marginal risk for severe storms with strong winds over 60 mph
and small hail over portions of north central SD into this
evening.
- Weak thunderstorms will remain possible through Friday night.
Periodic soaking rains will continue into Saturday morning.
Another round of rain showers will move in Sunday, with a focus
over our southern and eastern counties.
&&
.UPDATE...
Issued at 839 PM CDT Thu Apr 25 2024
Have updated PoPs this evening to keep up with the latest trends
on radar. Rain should continue to push east and north through the
night, but especially on Friday as upper low gets closer to the
forecast area.
&&
.SHORT TERM /THIS EVENING THROUGH FRIDAY NIGHT/...
Issued at 401 PM CDT Thu Apr 25 2024
Elevated winds remain a concern over the next 1-3 hours, before
slowly diminishing. Several SD DOT and other locations have peaked
with wind gusts of 40-48 mph with a couple of locations briefly
around 50 mph. Winds will continue to be highlighted in our HWO and
other products through the evening hours.
Given the strong winds, the storms currently over
Meade/Perkins/Ziebach Counties (where winds are currently gusting
around 30 mph) will not take much to bring down near severe wind
gusts. We`ll continue to monitor the storms as they move into a less
favorable area. MLCAPE values near 1400J/kg will shift to central SD
by 00Z Thursday and diminish. While most storms will have a mainly
easterly component, any right moving supercells that could develop
would be shifting to the southeast. Bowing segments or outflows
still show up on the latest HRRR runs, and we will continue to
monitor for that potential with gusty winds pushing out away from
storms.
The main wave of precipitation, with embedded weak thunderstorms,
will shift overhead overnight. There is significant enough
differences in the CAMs and other models to reduce confidence in
overall rainfall totals. Friday may end up with significant dry
periods between the Missouri River and James River, especially
during the afternoon hours as rain bands rotate through. There end
up being a couple of maximums with this initial wave into Saturday,
over central SD and far eastern SD/west central MN.
Overall, the surface low will shift northeast from Colorado to
Kansas and Minnesota Saturday morning, pushing a wetting rain across
the region. The initial surge of rain showers will overspread the
area during the evening and overnight hours. While there will be
breaks in the showers they will continue through at least Friday
night. The rain showers may be accompanied by thunderstorms/mainly
just rumbles of thunder (after our initial storms this evening over
north central SD) through Friday evening.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 401 PM CDT Thu Apr 25 2024
This period kicks off at 12Z Saturday with one low pressure system
departing while the next one organizes right on the heels of the
first one to our southwest. Lingering rain shower activity will be
possible Saturday morning, especially across our eastern zones as
the upper low circulation and its sfc reflection lift northeast
across MN into the western Great Lakes. Any additional rainfall will
be minimal with up to around a tenth of an inch of accumulation
possible during the morning. Otherwise, our forecast area could
sneek in a period of dry conditions at least by midday and afternoon
before the next surge of moisture moves into the region. Daytime
high temperatures will be on the cool side as we`re expecting
extensive cloud cover and 950mb temps between about +5C and +10C.
During the course of the day on Saturday, the 2nd in the series of
500mb low pressure systems will be organizing across the Four
Corners region of the CONUS.
Deterministic and ensemble guidance has a fairly good handle on this
system. They prog it to track northeastward out into the Central
Plains by Saturday night. It will continue to take a northeastward
track into NE during the day Sunday and end up somewhere around the
eastern SD/western MN border region by Sunday night before lifting
across northern MN and Ontario on Monday. The sfc low is expected to
be somewhat more displaced farther southeast from the upper features
compared to the first system that moves through tomorrow and
Saturday. Guidance takes this system`s sfc low through the Omaha, NE
area and central IA by midday Sunday and Sunday afternoon and then
on up toward the Twin Cities and western Great Lakes on Monday. The
first surge of moisture with this system is forecast to make it
northward into our forecast area by late Saturday night/early Sunday
morning. This activity should become more prevalent and widespread
during the daytime as the upper wave circulation moves closer into
our region. It appears at this time our far southern and eastern
zones will have the greatest potential to see the steadier rain
shower activity and higher rainfall potential by the time this
system winds down early Monday.
NBM QPF probabilities for seeing a quarter of an inch or more in a
24-hour period ending at 12Z Monday range from 30-70 percent with
this highest values(>50%) from the James Valley and east into west
central MN. Bumping up the probs to at least a half inch or more
within that same time frame prog our eastern zones(James Valley and
points east) between a 40-50 percent range. Farther west,
probabilities drop off considerably to between 10-30 percent. By 12Z
Monday, most of the PoPs associated with this system will be exiting
our far eastern zones. A dry period can be expected thereafter until
late Monday into early Tuesday with another mid-lvl wave traverses
the region from west to east. Only light rain shower activity and
minimal rainfall is expected at this time. Drier conditions will
return for the end of the period by the middle of next week.
Temperatures will remain rather cool on Sunday with highs struggling
to reach 50 degrees. It will be brief however as a warming trend is
expected during the course of the first half of next week.
Temperatures at or above normal will be possible with daytime
temperatures in the 60s and 70s and overnight lows in the 30s and 40s.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 606 PM CDT Thu Apr 25 2024
Terminals KABR,KATY,KPIR,KMBG
As showers and thunderstorms gradually develop east and north
tonight, we can also expect lower cigs to form over the region,
likely becoming IFR after midnight. Showers may also bring
occasional MVFR vsbys.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...TDK
SHORT TERM...KF
LONG TERM...Vipond
AVIATION...TDK
Area Forecast Discussion
National Weather Service Boston/Norton MA
957 PM EDT Thu Apr 25 2024
.SYNOPSIS...
Sprawling high pressure over northeast Ontario moves southeast
over Southern New England through Friday, bringing clear skies
and chilly nights tonight and Friday night. Unsettled pattern
sets up for Sunday into early next week with shower chances.
Temperatures turn milder but there is a good deal of uncertainty
as to how warm Sun/Mon are.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Update: 10:00pm
No changes to the forecast as it remains in good shape. One area
made a minor adjustment was the CT River Valley, here T/Td have
been slow to cool, did blend in newer HRRR guidance, that seems
to handle the slightly warmer T/Td. Nevertheless, still expect
those locations will watch the mercury drop quickly over the
next several hours. Headlines remain the same. Please see the
prior discussion below.
---------------------------------------------------------------
Sprawling high pressure ridging in from northeast ON bringing
wall to wall sunshine, dry weather and light north winds
(seabreezes near the coast). It is a bit cool out with current
temps inland in the low to mid 50s, with cooler low/mid 40s near
the coasts.
Center of high pressure will continue to progress SE into the
Adirondacks tonight, and ridging to extend SE from it into Southern
New England. Expect any seabreezes near shore to shift to land-
breezes (southerlies) after sundown. Optimal radiational cooling is
likely to begin tonight under clear skies, light to calm winds and
very dry air in place. Thus low temperatures should reach
subfreezing levels in many areas in the 20s to around 30, with lows
32-35F at Worcester and near Boston.
With forecast temps, the Freeze Watch was converted over to Freeze
Warnings for northern CT, all of RI and eastern coastal and
southeast MA, which are where the frost/freeze program is active.
Opted to keep things simple as some of the immediate city areas such
as Boston, Hartford and Providence probably stay around or just
above freezing, and the best chance at seeing freezes is in the
outlying less urbanized areas. If you have planted crops in Southern
New England, take the necessary protective actions to prevent frost
or freeze related damage.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
330 PM Update:
Friday and Friday Night:
Friday is essentially a carbon copy of today, as high pressure
continues to slide southeastward into our southern outer waters.
After a chilly start, full sunshine and dry weather should allow
temperatures to rise into the 50s to lower 60s, with mid 50s along
the southern and eastern coasts as seabreezes get going. Will have a
bit of a southerly flow develop later in the day as high moves to
our southeast.
Friday night should again feature clear skies and favorable
conditions for radiational cooling. Temps should project to be a
couple degrees warmer than tonight`s lows, utilizing a heavy dose of
MOS guidance. That yields lows in the 30s, though a few areas which
radiate well such as around I-495 in MA and NW MA could see
subfreezing temps. The uncertainty in the forecast here revolves
around winds, and it is possible that winds could be strong enough
to preclude frost from developing. It`s very close but it is
possible that frost/freeze headlines could be needed again where the
frost freeze program is active; but the wind speeds make it a
tougher call.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Key Points...
* Remaining dry Saturday.
* Low chance for showers Saturday then again Tuesday through
Thursday.
* Warming trend into next week, but uncertainty remains high
Saturday...
Upper level ridge and surface high pressure remains centered over
the region through Saturday. With subsidence aloft and very dry mid
level air, skies look to remain clear with very little clouds until
late Saturday afternoon when high clouds ahead of a shortwave move
in. This will help moderate day time temperatures into the mid to
upper 60s Saturday. With a weak pressure gradient, local sea breezes
will occur again Saturday morning. However, winds begin to increase
out of the south Saturday afternoon, which could keep a true sea
breeze from continuing along eastern coasts.
Upper level ridge axis passes to the east by Saturday night with
some warm air advection ahead of the next shortwave trough. This
will lead to increased cloud cover and and isolated to scattered
showers. Lows stay warmer Saturday night in the upper 30s to low
40s.
Sunday and Monday
The center of the high pressure drops south to the Carolinas, but
the upper level ridge axis continues to stretch north in SNE. Being
at the top of the ridge axis, weak vort impulses, along with warm
air advection aloft bring high clouds and low chances for isolated
showers both Sunday and Monday. High temperatures Sunday and Monday
will be very dependent on a back door cold front working in. Latest
GFS and EURO is still bringing that back door cold front through
Sunday and again Monday keeping temperatures in the low 60s for
Eastern MA and RI, while western MA and CT stay warmer in the 70s.
However, if that cold front stays offshore Sunday, temperatures
could easily top the mid to upper 70s. NBM guidance still remains
significantly warmer then deterministic GFS and EURO guidance, so
again used a blend of warmer NBM guidance with cooler CONSALL
guidance. Temperatures Monday look to continue to warm for western
MA and CT with a 30-40% chance highs top 80F per GEFS. Eastern MA
and RI will still struggle to top 70F with the back door cold front
stalled over SNE.
Tuesday through Thursday
Upper level ridge axis again moves offshore to the east, but this
time, a weakening shortwave trough moves through the region, but
details on exact timing and coverage of precip remains very
uncertain. Given this is a week out, stuck with NBM for precip
chances, which shows 30-40% chance for showers through the middle of
next week. This seems reasonable given the weak forcing from the
weakening trough. A cold front looks to move through behind the
trough which could bring an isolated thunderstorms with it.
Southerly flow Tuesday should kick the back door cold front out,
however guidance remains very spread out on highs temps with
ensemble 25th-75th percentiles showing anywhere from the 50s to the
70s through Thursday.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
00z TAF Update:
Through Tonight: High confidence.
VFR. Light and variable winds
Friday: High confidence.
VFR. Winds become light SW for most, although with sea-breezes
near the coasts around 15-17z.
Friday night:
VFR: Light and variable winds.
KBOS TAF...High confidence in TAF.
Sea breeze should kick out shortly after 00z, with winds turning
to the southwest this evening and eventually north overnight
all under 10 knots. Sea breeze develops again tomorrow by
14-15z.
KBDL TAF...High confidence in TAF.
VFR with light and variable winds.
Outlook /Saturday through Tuesday/...
Saturday: VFR.
Saturday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Sunday: Mainly VFR, with local IFR possible. Breezy. Slight
chance SHRA.
Sunday Night: VFR. Slight chance SHRA.
Monday through Monday Night: Mainly VFR, with local MVFR
possible. Slight chance SHRA.
Tuesday: Mainly VFR, with areas MVFR possible. Chance SHRA,
isolated TSRA.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Tonight through Friday Night: High confidence.
Tranquil boating conditions are expected through Friday night as
high pressure gradually builds southeastward into the coastal
waters. Light north winds (easterly near shore) tonight and into
early Friday on all waters. Later Friday, winds turn southerly
around 10-15 kt. Seas 3 ft or less all waters.
Outlook /Saturday through Tuesday/...
Saturday: Winds less than 25 kt.
Saturday Night through Sunday Night: Winds less than 25 kt.
Slight chance of rain showers.
Monday: Winds less than 25 kt.
Monday Night: Winds less than 25 kt. Slight chance of rain
showers.
Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Freeze Warning from 2 AM to 8 AM EDT Friday for CTZ002>004.
MA...Freeze Warning from 2 AM to 8 AM EDT Friday for MAZ007-014>024.
RI...Freeze Warning from 2 AM to 8 AM EDT Friday for RIZ001>007.
MARINE...None.
&&
$$
SYNOPSIS...Loconto/KP
NEAR TERM...Loconto/Dooley/KP
SHORT TERM...Loconto
LONG TERM...KP
AVIATION...Loconto/KP
MARINE...Loconto/KP
Area Forecast Discussion
National Weather Service Cheyenne WY
915 PM MDT Thu Apr 25 2024
.KEY MESSAGES...
- Scattered to numerous showers and thunderstorms are expected
across southeast Wyoming and the western Nebraska Panhandle
today and tonight. A few storms may be strong to locally
severe, especially east of I-25. The primary hazards will be
large hail and damaging wind gusts, although an isolated
tornado or two will be possible. The potential will exist for
cold-core funnel clouds as well.
- An extremely active weather pattern persists through the
weekend with widespread stratiform rain w/ embedded thunder
likely for most areas from Friday through Sunday.
- Accumulating snow is expected at elevations above 8000 feet,
with the potential for 12+ inches in the Snowy and Sierra
Madre Ranges from Friday through Sunday. The I-80 Summit
between Laramie and Cheyenne will be very close to the main
transition zone between rain and snow. Travel impacts remain
possible, mainly from Friday night through Saturday.
&&
.MESOSCALE...
Issued at 245 PM MDT Thu Apr 25 2024
Latest GOES visible imagery shows numerous showers and
thunderstorms that have developed west of the Laramie Range
early this afternoon along with initiation along the dryline
positioned west of Cheyenne northeast through Chugwater. This
dryline has not propagated eastward as quickly as initially
forecast with the early clearing of morning cloud cover.
Additionally, early morning storms that tracked from western
Carbon Co up through Douglas has left an outflow boundary now
extending south through Goshen Co. This will lead to a potential
area of enhanced convergence in the North Platte River valley
near the WY/NE border for new storm development later this
afternoon right on the gradient of convective inhibition to the
east. Latest observations show dew points in the 50s near
Sidney up through Banner Co and points towards the northeast.
Based on latest CAM guidance, areas of concern will be from
Torrington through Scottsbluff and potential towards Alliance
areas late this afternoon into this evening. Forecast soundings
would support marginally severe hail likely around 1-1.5 inches
with the strongest cells with 500-700 J/kg of CAPE in the hail
growth region. Additionally, surface winds in the river valley
are modeled to by more east-southeasterly enhancing low-level
shear and short-lived tornado potential with any discrete
storms. However, stronger 0-6 km shear is present along the I-80
corridor in the NE panhandle as the core of 500mb flow aloft
has weakened over the last 24 hours per latest RAP analysis,
limiting stronger shear farther north in our CWA.
As better lift continues to arrive overhead, more widespread
storm coverage will continue with embedded stronger cells. Main
weather hazards overnight will transition towards heavy rainfall
and localized flooding, especially over the southern NE
panhandle that may see repeated rounds of precipitation with the
initial storm development in our area in addition to storms
closer to the surface low traversing north of the CO/WY border.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 402 AM MDT Thu Apr 25 2024
A highly complex & extremely active mid & upper level pattern is
expected to continue to evolve across the western and central US
over the next 24 to 48 hours, giving way to chances for multiple
hazards including severe convective storms, significant snowfall
accumulations above 7500-8000 feet elevation, as well as chances
for locally heavy rainfall for the lower elevations. The overall
upper-level pattern will remain characterized by expansive long-
wave troughing encompassing much of the western & central CONUS,
with two distinct pieces of energy pivoting across the 4 corners
region before ejecting northeastward across the southern/central
high plains. Overall, models are in excellent agreement with the
overall evolution of the pattern. However, there are a number of
notable complexities with potential outcomes highly sensitive to
the precise timing of disturbances and resulting interactions of
boundaries which eventually take place. Nonetheless, it is quite
likely that the majority of the CWA will see some sort of impact
from these systems.
The first notable short-wave disturbance will lift to the north-
east across the 4 corners this afternoon, contributing to strong
lee cyclogenesis over eastern Colorado with a sub-990-mb surface
low expected to develop by 21z. The resulting southeasterly low-
level flow should provide a sufficient fetch of moisture to help
maintain appreciable surface dew points in the lower 50s, mainly
across the western Nebraska Panhandle. The western extent of the
deeper moisture remains highly uncertain with a sharp cut-off in
the spread of HREF members along/southwest of a BFF-IBM line for
progged dew points indicating uncertainty regarding the eastward
progression of the dry line. The 10th %ile of the HREF ensembles
are in the mid 40s to the east of this line, but quickly drop to
the mid/upper 20s to the west. This may play a key role in storm
severity today w/ better MLCAPEs (1000-1500 J/kg) possibly being
focused more across our far eastern zones. Even so, there should
be good instability today as thermal profiles rapidly cool later
this afternoon as the mid-level cold pool approaches. Scattered/
numerous showers and thunderstorms should develop across western
areas by early afternoon, with a slightly delayed initiation for
the high plains closer to 21-00z given substantial inhibition w/
the initially warm, capped air mass aloft. High-res models would
suggest initiation occurring in the vicinity of the dryline near
the WY/NE border by 00z w/ numerous clusters developing through-
out the evening. Vertical shear will be more than sufficient for
organized, potentially rotating storms capable of large hail and
perhaps locally damaging wind gusts. The last several iterations
of the HRRR and NAMNest have suggested a few narrow UH tracks as
well, suggesting potential for a low-topped supercell or two and
the risk for a weak tornado or two. As thermal profiles cool, we
would not be surprised to see at least several cold-core funnels
develop in the early evening w/ numerous storm mergers likely to
be taking place during this time.
Dry-slotting on the back side of the rapidly maturing cyclone is
expected to limit convective coverage across western zones after
03z, with the primary focus shifting toward stratiform rain and/
or embedded convection over the western NE Panhandle through mid
day Friday. Brief short-wave dirty ridging should develop as the
first low departs. A weak, slow-moving disturbance will uncercut
this ridge over central Wyoming, resulting in a burst of notable
700-mb warm air advection across Carbon & Albany counties during
the afternoon and evening hours on Friday. As such, rain & high-
elevation snow should quickly re-develop as the next low deepens
and pivots northeast across the 4 corners from Friday night thru
Saturday. Yet again, lee cyclogenesis will result in substantial
wrap-around moisture in the TROWAL/deformation axis on the back-
side of a rapidly deepening cyclone over central KS. As a result
we should see deep/moist northeasterly low-level upslope flow as
well as favorable dynamics supporting widespread stratiform rain
and embedded convection over much of the CWA. PWATs of 0.5+ inch
will be near the 90th percentile of climatology, so would expect
some pretty impressive rainfall totals through Sunday. Localized
areas could see over 1.5 inches of rain over the next few days!
High-elevation snow will also be likely, as 700-hpa temperatures
fall to -2 to -4 deg C. A foot or more of accumulation will be a
good possibility for both the Snowy and Sierra Madre ranges with
this second wave, with more significant uncertainty below around
8000 feet elevation and potential impacts over the Interstate 80
Summit between Laramie and Cheyenne. Models continue to trend on
the cooler side for Friday Night & Saturday, validating previous
concerns of cold air damming along the front range favoring low-
tier percentiles of the model spectrum for temperatures. Decided
to populate snow levels with the 25th %ile of the NBM, which may
bring a brief rain/snow mix into Cheyenne but would restrict the
accumulations to the higher terrain to the west. The Summit will
be right near the transitional bubble, with the worst-case being
around 6-8 inches of heavy and wet snow. Ensemble means are near
2-3 inches using a 10:1 ratio. Will continue to hold off for now
on any headlines given lingering uncertainty. Daytime highs will
likely struggle to reach the middle 40s for many areas Saturday.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 402 AM MDT Thu Apr 25 2024
We will have an active weather pattern continue for the extended
forecast package. Near average temperatures for the weekend are
forecast, and gradually increasing through the week to be
approximately 5-15 degrees above climatological averages to round out
the last few days of April and into early May. At this time of
inspection, snow showers across the higher elevations will wind down
on Sunday and Monday, with rain showers and thunderstorms
anticipated daily for the entire cwa through the end of next week.
Saturday night into early Sunday, we will have a slow-moving upper
level low slowly propagating to the east-northeast, ultimately
ejecting out toward the Upper Midwest and Great Lakes region by late
Sunday. As this negatively tilted upper level system with an
attendant mid-latitude surface low propagates away from our region,
we will have wrap-around moisture coupled with CAA. 700mb
temperatures ranging from 0C to -5C along with scattered rain
showers in the lower elevations, and accumulation snowfall in the
higher terrain will slowly dissipate from Saturday night to late
Sunday afternoon. Isolated thundershowers are also possible, but sub-
severe. Areas of highest confidence for additional rainfall
accumulations in the lower terrain will be along and east of I-25
toward western Nebraska. Much needed rainfall is anticipated for
these areas.
The water faucet will be turned off for only a brief period as we
transition to a quiet weather setup for approximately 24 hours. A
shortwave trough will arrive from the Pacific Northwest by Monday
evening, bringing a renewed chance for showers and isolated
thunderstorms. This weak disturbance is anticipated to eject
downstream toward the Northern Plains and Great Lakes region
throughout the day on Tuesday, limiting our chances of rainfall from
that.
Tuesday is advertised by model guidance to transition to a more
quasi-zonal flow regime aloft, with weak shortwave disturbances
embedded within the H5 and H7 flow aloft. Diurnal convection is
signaled to be present as mid-levels will adiabatically cool from a
passing shortwave trough to our north, increasing the low-level and
mid-level atmosphere lapse rates. Not expecting severe weather from
this weak threshold of a disturbance, but lingering showers and
thunderstorms could persist overnight into early Wednesday morning.
Wednesday and Thursday will see an amplification of an upper level
ridge, with it originating across the Mexican Plateau, and advecting
warmer are northward across the Intermountain West. Weak shortwave
disturbances are forecast to propagate off a much larger longwave
trough from the Pacific Northwest on Wednesday, bringing another
opportunity for showers and thunderstorms during the peak heating
hours of the day. Thursday will have the aforementioned upper level
ridge axis positioned over the Central Plains. The potent longwave
trough will elongate and intensify across the western CONUS. This
trough is modeled to become negatively tilted by Thursday of next
week, with diffluent flow being coupled with moisture and
instability across the Central Rockies. We will need to pay
attention to this trend as it may be our next opportunity for
stronger, organized convection across the cwa to round out the
week.
&&
.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 905 PM MDT Thu Apr 25 2024
A storm system over central Colorado this evening will slowly
move to western Nebraska by Friday morning then to the Dakotas
by Friday evening.
Wyoming TAFS...Ceilings will vary from 4000 to 10000 feet with
occasional light rain and fog until 12Z reducing visibilities to
4 miles with ceilings near 2500 feet. Visibility will be near
5 miles in showers at Cheyenne from 15Z to 00Z. Winds will gust
to 32 knots at Cheyenne until 00Z, and to 30 knots at Laramie
from 15Z to 00Z.
Nebraska TAFS...Ceilings will range from 4000 to 10000 feet with
occasional showers reducing visibilities to 2 to 5 miles until
00Z, with occasional thunderstorms at Sidney reducing
visibilities to 4 miles until 08Z. Winds will gust to 35 knots
at Scottsbluff, Sidney and Alliance from 13Z to 00Z.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
MESOSCALE...MB
SHORT TERM...CLH
LONG TERM...BW
AVIATION...RUBIN
Area Forecast Discussion
National Weather Service Dodge City KS
535 PM CDT Thu Apr 25 2024
.KEY MESSAGES...
- CAP/EML has strengthened, severe storm coverage less than
previously thought and shifted NW.
- Northwest/north counties from Lakin to Scott City to Hays
still under a threat of severe thunderstorms tonight.
- Drier weather Friday.
&&
.UPDATE...
Issued at 345 PM CDT Thu Apr 25 2024
Mesoscale discussion
Towering cumulus along the dryline positioned from the west
Texas panhandle through southwest Kansas from Elkhart to Lakin
and north to the warm front along I-70 is increasing our
confidence of seeing some isolated thunderstorm development over
the next couple of hours. With the 19Z balloon at DDC showing
34 kt 0-6 km shear and 3200 J/kg MUCAPE and steep mid level
lapse rates we will have plenty of instability and shear for
thunderstorms to access once the break the strong cap that is
place. Hodographs are showing from the southerly flow at the
surface to the westerly winds aloft a mainly straight sounding
which would suggest a good environment for large to giant hail
with any discrete storms. We will also have to monitor for a
tornado threat after 7 pm with the low level jet forecast to
increase and the hodographs in the lowest 0-1 km becoming more
curved with height.
&&
.SHORT TERM /THROUGH FRIDAY/...
Issued at 333 PM CDT Thu Apr 25 2024
We did a special severe weather balloon (RAOB) launched at 1:30 pm
CDT. The cap/EML has strengthen over Dodge City. The 700 hPa temperature
on the special RAOB is 9.9C, up from 8.4C this morning. FYI, 8.6C
is at the 90th percentile for KDDC. This EML is quite strong/pronounced
across southwest Kansas. As far as warming up and breaking this cap,
that remains to be seen. Sfc temperatures have warmed into the mid
an upper 80s across far southwest Kansas. But this warming is associated
with some SSW downslope drier air advection, so this complicates
that scenario.
Sfc analysis shows a stationary boundary draped across southern Trego
county SE south of Great Bend. A sfc low pressure center is located
across east-central Colorado. A dryline is located just east of the
Kansas/Colorado state line. The most interesting/most severe storms
will be located at the intersection of the dryline and stationary
boundary. Right now, have the highest confidence of the most likely
chance of supercells in the Scott City area and a county of two surrounding
Scott county.
Where is the synoptic trof driving all this weather. Satellite water
vapor shows this feature was located just west of the four corners
region. The combination of the late arrival of the synoptic trof
and the strong cap clearly illustrates the concern that the severe
threat has probably shifted mainly to our NW counties and into NW
Kansas.
Taking a look at the models, the RRFS and FV3 are doing the worst
and were not considered. They are too cool/weak on the EML/cap, cooling
aloft and too aggressive on convective development. The HRRR and
the 3 km NAM seem to be doing the best at initializing the thermo
profile and were heavily biased to. WoFS was having technical problems
and was not updating anymore. The bottom line, do not be surprised
that at least 75% of the FA now seems less storm activity.
The main focus is from Lakin to Scott City to WaKeeney and Hays.
The cap holding strong looks like a more likely scenario for areas
SE of that area. As far as threats are concerned, this is obviously
driven down to the mesoscale and the analysis of it. Interests should
be focused on the intersection of those mentioned boundaries from
Sharon Springs, down to Scott City and over to Ransom. Our special
RAOB shows about 2000 to 3000 J/kg of SB/MUCAPE. 0-6 bulk shear was
34 knots, at the very low end of the spectrum for supercells. So
that is the current state of atmosphere, how about mid to late afternoon
and evening?
The stronger forcing associated with the synoptic UL trof is not
expected to strengthen until 00Z/7 pm tonight. Visible satellite
imagery shows a CU field currently located across eastern Colorado,
so that is the area to watch first. Storms mays also develop as moisture
and sfc convergence increases along the front up north. Again, there
are two significant fly in the ointments right now. A very strong
cap and a later arriving synoptic trof. Regardless of whatever a
CAM shows, you simply cannot ignore this meteorology.
As far as threats are concern, have the highest confidence of 2 to
3" hail across the NW counties should supercells develop. The tornado
threat should mainly be confined to the intersection of the dryline
and stationary front. The bottom line for tonight, it appears the
threats are shifting NW and that the cap will most likely win this
event with a reduced probability of severe thunderstorms for
the area outside of the area mentioned (not the NW counties).
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 333 PM CDT Thu Apr 25 2024
Dry air advection is expected Friday. The net result is a dry forecast,
continued drought, and warm highs. The next synoptic low/trof is
not expected until Saturday. Continue to see the trend that has been
with us for months... southwest Kansas getting dryslotted and missing
out on storm activity. Cannot rule out severe thunderstorms in
the far eastern zones near Pratt and Medicine Lodge Saturday evening.
The rest of the FA looks more doubtful. This weather pattern trend
of missing out continues. Our drought has gotten worse and unfortunately
it looks like very low chances for improvement with the brunt of
the thunderstorm action east of much of the FA. The rest of the long
term period looks fairly warm and dry.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 531 PM CDT Thu Apr 25 2024
Short term concern is watching storms developing west of the terminals.
Right now, have the highest confidence of KGCK being impacted by
tsra first, followed by KHYS. This is a formidable cap in place,
so it remains unclear how far east these storms will make it to KDDC
or KLBL. +TSRA with large gr and outflows winds > 50 kt cannot be
ruled out tonight with these storms. Otherwise, SE to S winds 15-25
kt will continue. For tomorrow, a boundary will move through with
the southerly winds becoming SW to W as the day continues.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM CDT /8 PM MDT/ this evening for
KSZ061-062-074-075-084-085.
&&
$$
UPDATE...Tatro
SHORT TERM...Sugden
LONG TERM...Sugden
AVIATION...Sugden
Area Forecast Discussion
National Weather Service Houston/Galveston TX
604 PM CDT Thu Apr 25 2024
...New UPDATE, AVIATION...
.UPDATE...
Issued at 547 PM CDT Thu Apr 25 2024
The past 06z/12z/18z HRRR runs have shown some general consistency
showing some iso-sct precip being a possibility as a few mid/upper
impulses move across parts of the area during the day tomorrow.
Went ahead and threw some low POPs in the grids down to about the
US59/I69 corridor just to get the mention in the fcst. 47
&&
.SHORT TERM...
(This evening through Friday Night)
Issued at 257 PM CDT Thu Apr 25 2024
If you`ve been outside this afternoon, then I`m sure you`ve noticed
that it`s a bit breezy out there. Latest surface analysis shows
surface low pressure beginning to develop on the lee side of the
Rockies, and the 12Z UA obs plot shows a LLJ developing out in
Central Texas earlier this morning. This LLJ will steadily slide
eastward and will make it over the Brazos Valley by later this
afternoon. It`ll start out as 25-35 kts this afternoon, then
increasing to 35-45 kts by tonight. This combined with the
tightening pressure gradient from the developing surface low will
lead to elevated winds prevailing throughout the short term period.
The main ridge axis will shift off to the east later this afternoon
as an upper level trough transitions from the Four Corners region to
the Central Plains. Embedded shortwaves within the ridge will
attempt to develop some isolated showers, but it`ll have a VERY
tough time doing so with a capping inversion aloft persisting. The
best chances of this occuring will be west of I-45 through this
afternoon. High temperatures today will reach the low to mid 80s.
Still expecting low temperatures tonight to drop into the low 70s
due to increasing low-level clouds and elevated winds persisting.
Southwesterly flow aloft is firmly established by Friday as the
upper level trough evolves to have an embedded upper level low.
Surface low pressure drifts northeastward on Friday causing the
associated frontal boundary to become quasi-stationary well to our
west. With increasing PVA and elevated PW values in the 1.4"-1.7"
range north of I-10 (90th percentile: ~1.61"), some showers/storms
are possible to develop along the tail-end of a convective line
advancing ahead of the front. Anything along this line will have to
battle a capping inversion to survive, but this cap is weaker over
the Brazos Valley. There is plenty of instability in place along
with steep 700-500mb lapse rates, so if anything manages to survive
long enough in our area there is potential for a storm or two to
maintain/become strong to severe. As a result, there is a marginal
risk of severe weather (level 1 out of 5) for northern portions of
the Brazos Valley/Piney Woods for Friday. With PW values exceeding
the 90th percentile, there is also a marginal risk of excessive
rainfall (level 1 out of 4) on Friday as well for portions of the
Brazos Valley/Piney Woods. This is all under the assumption that
storms can maintain themselves long enough in at least a slightly
capped environment...which is why it`s a marginal risk. As far as
temperatures go, expect another day with high temperatures in the
low to mid 80s with low temperatures in the low to mid 70s. This
will be another night where we may approach record high minimum
temperatures in some spots.
Batiste
&&
.LONG TERM...
(Saturday through next Wednesday)
Issued at 257 PM CDT Thu Apr 25 2024
With a weak surface boundary continuing to sit just to our north
(and thereby keeping rainfall out of the area for the time being),
the main story of Saturday will be the potential for some of the
warmest conditions we`ve seen across the area in many months. Robust
onshore flow will provide both steady WAA and low-level moisture
transport, helping to drive a further increase in high temperatures
to the mid/upper 80s while dew points sit just above 70. Resultant
WBGT values will reach around 80, which is mitigated somewhat by
elevated cloud cover and strong winds brought on by a very tight
pressure gradient given a deep surface low to the NE. Many locations
may in fact reach Wind Advisory criteria during the day on Saturday,
with winds reaching around 25 mph with gusts at times reaching in
excess of 30 mph.
Rainfall chances increase on Sunday as a midlevel low pushes into
the Central Plains while the surface boundary drifts back to the
south. Scattered showers and storms will become more widespread by
the afternoon, and while there remains a limited chance of a
stronger storm, severe weather chances remain best well to the north
of the area. Associated widespread cloud cover will diminish highs
slightly with most values in the low/mid 80s. Overnight lows remain
in the lower 70s through the duration of the weekend.
The weak boundary will remain stalled over the area through mid-
week, with passing shortwaves bringing a chance of showers and
storms each day through at least Wednesday. Highs should generally
remain in the mid 80s by this time with lows in the lower 70s.
Cady
&&
.AVIATION...
(00Z TAF Issuance)
Issued at 547 PM CDT Thu Apr 25 2024
MVFR ceilings should develop spread inland from the south fairly
quickly this evening. They`ll probably remain in low end MVFR
territory well into mid-late morning for most locations, and
might not lift much at all closer to the coast. Can`t rule out
some periods of high end IFR, but that should be the exception
moreso than the rule. Low level jet will increase overnight and
anticipate sustained surface winds in the 12-18kt range for most
areas. They`ll get stronger during the day Friday with mixing and
looking for frequent gusts in the 20-30kt range. There are some
models suggesting that a couple of upper level disturbances may
be capable for producing some shra, or even an iso tsra, as they
move overhead during the day Fri. Mid morning-early afternoon
chances should generally be better north of the metro area,
followed by slightly better chances along the I-45 corridor late
in the day. None of which should be impact makers...but just
something we`ll be keeping an eye out for going forward. 47
&&
.MARINE...
Issued at 257 PM CDT Thu Apr 25 2024
Elevated winds will build further heading into the weekend, with
sustained winds increasing from around 20 knots tonight to up to 25-
30 knots on Saturday. As this occurs, seas may reach as high as 10
feet at times, and an extended Small Craft Advisory is likely to be
required with conditions offshore remaining poor into the early part
of next week. Rainfall chances return by late Sunday, becoming more
isolated on Monday. Winds and seas will both diminish heading into
the early part of next week, remaining generally out of the
southeast.
Cady
&&
.HYDROLOGY...
Issued at 257 PM CDT Thu Apr 25 2024
Only one River Flood Warning remains in effect along the Trinity
River. The Trinity River at Moss Bluff (MBFT2) remains in minor
flood stage and is forecast to crest some time today. This site is
forecast to remain in minor flood stage through Monday. The Trinity
River at Riverside (RVRT2) and at Liberty (LBYT2) will remain in
action stage until further notice. Additional rounds of rainfall are
expected over the next week or so with the highest totals occuring
to the northeast of Southeast Texas. With some of the locally heavy
rainfall expected to occur along the Upper Trinity River, the
subsequent runoff may lead to an even longer period of action stage
to minor river flooding along this basin.
You can monitor current and forecast conditions at this weblink:
water.weather.gov/ahps2/forecasts.php?wfo=HGX
Batiste
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 71 83 72 87 / 10 30 10 10
Houston (IAH) 73 84 73 86 / 0 30 10 0
Galveston (GLS) 73 79 73 81 / 0 20 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Should Exercise Caution through Friday evening for
GMZ330-335.
Small Craft Advisory from 10 PM this evening to 7 PM CDT Friday
for GMZ350-355-370-375.
&&
$$
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1104 PM EDT Thu Apr 25 2024
.SYNOPSIS...
High pressure will gradually build into the Carolinas from the
northeast tonight, and will remain in control before sliding
offshore this weekend.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 11 PM Thu...Showers and isolated thunderstorms have
dissipated earlier this evening with loss of heating and expect
dry conditions through the rest of the overnight. Low stratus
is advecting in from the coast and has reached a line from
Greenville to Swansboro and will continue to spread across the
rest of the area over the next couple of hours.
Previous discussion...Eastern NC sits under broad upper level
troughing this afternoon in an increasingly amplified pattern as
ridging gradually builds over the central plains and makes its
way towards the eastern CONUS tonight into tomorrow morning. A
weak embedded s/w currently over the western Great Lakes is
expected to dive across the mid-Atlantic early Fri morning with
little fanfare. At the surface, cold front remains well offshore
but a reinforcing surge of northeasterly winds is pushing
across the northern Outer Banks and will continue to push
southwest through the tonight.
For tonight, confidence is increased in widespread low stratus
encroaching inland from the coast as onshore easterly flow
continues to pool moisture under the frontal inversion. Almost
all hi-res guidance shows low overcast conditions spreading at
least as far west as Highway 17, but about half the guidance
brings it across the coastal plain as well. Steady northeasterly
winds at around 5-10 mph (higher along the coast) will keep any
fog at bay. Did raise temperatures from the previous forecast
given insulating effect of low clouds and continuous low-level
mixing from the winds, favoring lows in the low to mid 50s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
As of 400 PM Thu...Low stratus will gradually break up tomorrow
morning with increased heating, with the first peaks of sky
likely around 9 am and rapidly giving way to mostly sunny
conditions while high pressure remains in control. With mid-
level ridge and associated subsidence shifting overhead no
precipitation is anticipated tomorrow allowing for a pleasant
mid-spring day. Highs will be a couple degrees cooler than
today, in the low to mid 70s inland but low to mid 60s along the
Outer Banks and immediate coastal areas.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
As of 400 AM Thursday...Fairly quiet stretch in the long term
with high pressure dominating the region.
High pressure will remain near the eastern seaboard through the
end of the work week, aided by omega blocking aloft. Low moving
through the eastern US in the weekend will encounter this
stubborn high, and some uncertainty remains if it will be
pushed north around the high, or if the high will give way. If
the low moves north, we will have less chances of precip in the
weekend. If the low is able to shift the high offshore, we will
see increased chances of precip. No mentionable PoPs with this
update for Saturday as high remaining stubborn looks to be the
most likely outcome. High will shift to our south in the
weekend, and easterly flow will gradually veer to become
southwesterly at the start of next week. Another frontal system
will be moving through mid week next week. How the high behaves
will play a role on how far south the higher moisture along the
cold front extends. As of right now, looks to be mostly dry with
higher precip chances expected in farther north than eastern NC.
Tuesday and Wednesday will be the warmest days of the long term
(mid-upper 80s inland), aided by SW flow with the surface high
to our east over the Western Atlantic Ocean.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /Through Friday/...
As of 11 PM Thursday...MVFR/IFR stratus continues to advect
westward from the coast which has reached a line from Greenville
to Swansboro. The stratus will continue to spread the rest of
the rtes by 04z and lowering to IFR around 06-07z. Status will
persist through much of the morning Friday, lifting to MVFR
around mid morning and VFR returning mid day. Winds will
generally be NE to E around 5-10 kt with gusts around 15 kt
inland while coastal sections will see 10-20 kt with gusts 25
kt.
LONG TERM /Friday night through Tuesday/...
As of 4 AM Thursday...VFR conditions will persist through
Monday with high pressure prevails over the region.
&&
.MARINE...
SHORT TERM /through Friday/...
As of 630 PM Thursday...Updated winds using HRRR model which
captures the stronger wind surge the best. Currently seeing N to
NE winds around 20-25 kt with gusts to near 30 kt. Strongest
winds will occur this evening, then diminish some after midnight
but gusts around 25 kt expected to continue through late tonight
and into Friday morning. Have adjusted the end time of the SCA
for the sounds and Alligator River accordingly. Continue to
leave the Neuse/Bay River zone out of the SCA but occasional
gusts to 25 kt will be possible near the mouth of the rivers
this evening.
Previous discussion...Advertised northeasterly surge this
afternoon is a bit stronger than anticipated this afternoon with
gusts already exceeding 25 kt over soundside waters and the
offshore waters north of Cape Hatteras. Seas across the far
northern waters are already starting to build in excess of 4
feet, while across Raleigh and Onslow Bays they remain at an
average 3-4 feet.
SCA conditions will continue through tonight as northeasterly
surge works its way across the waters. Latest guidance has the
strongest winds coming down a bit quicker soundside, ending just
before midnight, but still remaining at 20+ kt through tomorrow
as northeast to easterly flow remains in place. Did extend the
the SCA across the offshore waters north of Ocracoke Inlet as
local wave guidance tends to diminish seas too quickly in
northeasterly flow regimes.
LONG TERM /Friday night through Tuesday/...
As of 410 AM Thursday...Surface high pressure will shift off
the coast on Saturday allowing flow to become more easterly,
then eventually southeasterly by Sunday morning. A new surface
ridge will develop across the Southeastern states and shift off
the Carolina coast by Sunday afternoon, shifting winds
southwesterly and persisting SW through Tuesday.
May see SCAs persist until Friday evening for the central
coastal waters, Oregon Inlet to Ocracoke Inlet. Winds and seas
subside below SCA levels for the weekend into early next week
with generally good boating conditions anticipated.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement from 8 AM EDT Friday through Friday
evening for NCZ203-205.
MARINE...Small Craft Advisory until 5 AM EDT Friday for AMZ131-230-231.
Small Craft Advisory until noon EDT Friday for AMZ135-156-158.
Small Craft Advisory until 5 PM EDT Friday for AMZ150.
Small Craft Advisory until 5 AM EDT Saturday for AMZ152-154.
&&
$$
SYNOPSIS...MHX
NEAR TERM...SK/MS
SHORT TERM...MS
LONG TERM...DAG/RCF
AVIATION...DAG/SK/RCF
MARINE...DAG/SK/MS/RCF
Area Forecast Discussion
National Weather Service Marquette MI
806 PM EDT Thu Apr 25 2024
.KEY MESSAGES...
- Borderline elevated fire weather conditions continue this
afternoon with minimum relative humidities around 20-25
percent across much of the area and wind gusts remaining
mainly below 15 mph.
- Borderline to elevated fire weather conditions are expected
Friday as RHs dip into the mid 20 to 30%, temps get into the
mid 50s to low 60s, and S to SE`rly winds gust up to as high
as 25 mph over the higher elevations and downslope areas.
- Two low pressure systems, one this weekend and another into
early next week, bring rain showers and thunderstorms across
our area. More of the rainfall arrives with the second low.
- There is a marginal risk for severe thunderstorms Saturday,
with the greatest chances over the south central and east.
The severe weather threats are marginally severe hail and
winds.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 323 PM EDT Thu Apr 25 2024
RAP analysis shows the high pressure is currently centered over
southern Ontario, extending over the Great Lakes Basin with mid
level ridging over the Plains and a trough over the southwestern
U.S.. WV imagery shows a significantly dry air mass over the CWA
which is yielding clear skies and warmer than normal temps. With the
high pressure shifting east through tonight, southeast flow will
continue to keep the east cooler. An easterly wind component has
been observed along Lake Superior, resulting from the lake breeze
component, keeping those along the immediate lakeshore cooler. Highs
in the east are expected to peak in the upper 40s to mid 50s this
afternoon with low 50s to low 60s over the west; some mid 60s are
possible in the far west where there is downsloping flow. Mixing has
lowered RHs into the 20% range this afternoon save for areas with
onshore flow off Lake Michigan, but luckily wind gusts are expected
to continue mainly below 15 mph as winds aloft are also light. This
will continue borderline elevated fire weather conditions this
afternoon over the east and into the early evening hours over the
west. Be mindful of burn restrictions.
The trough over the southwest takes a negative tilt tonight as it
lifts northeast into NE/KS. With sfc high pressure and mid level
ridging still over the Great Lakes, the dry weather under clear
skies continues. While better subsidence will be located well east
of the UP, radiative cooling should bring lows into the mid 20s to
upper 30s with colder temps in the east. Light southeast winds
continue, stronger over the west where there is downsloping. Model
soundings indicate that the nocturnal inversion layer should prevent
stronger winds aloft from mixing down until late tonight/early
Friday morning over the far west, keeping gusts mainly below 20 mph
until Friday morning. Meanwhile, a low pressure system set to impact
the UP this weekend associated with the trough will be developing in
the lee of the central Rockies.
&&
.LONG TERM /FRIDAY THROUGH THURSDAY/...
Issued at 402 PM EDT Thu Apr 25 2024
The high pressure moves out Friday and gives way to a more active
period this weekend through next week, with rain showers and
thunderstorms moving into the far west as soon as late Friday
afternoon/early Friday evening. There is a marginal risk for some
severe weather Saturday as showers and thunderstorms continue across
our area while the low pressure system moves into Lake Superior.
Behind this low, a second low pressure system brings more showers
and thunderstorms back across the region early next week. While it
looks like we will receive a quick reprieve from rainfall come next
Tuesday, more shortwave lows look to impact our area by the end of
the extended period.
The dry weather continues into the first half of Friday as the high
pressure responsible continues to leave the area for the Atlantic
off of the New England coast. In it`s wake, a 986mb low over the
Central Plains lifts towards Lake Superior throughout the day,
increasing cloud cover across the U.P. by the afternoon hours. With
the sun being out even into the early afternoon hours over the west
though, and with the antecedent dry air conditions near the surface,
thinking the RHs will bottom out to the mid 20 percents to around 30
percent across the interior areas of the U.P. by early Friday
afternoon. In addition, with winds increasing from the south to
southeast ahead of the approaching low to 10 to 15 mph with gusts up
to 25 mph in the higher elevations and downslope areas, we could see
borderline to elevated fire weather conditions across the area
Friday as temps will be fairly similar to today. Therefore, follow
all burn restrictions put out by your local DNRs on Friday. As the
warm front of the low starts moving into the far west Friday
afternoon, we begin seeing some showers and thunderstorms
developing. As the antecedent dry air in the lower levels finally
gives way to the precipitation aloft, the rain showers and
thunderstorms spread into the rest of the U.P. from west to east
throughout the rest of Friday night. As the low`s center looks to
enter into far western Lake Superior Saturday morning, a dry slot
behind the warm front looks to move over our neck-of-the-woods. This
will reduce the shower and thunderstorm activity across the area
Saturday morning, and could even open up some spots of sunshine in
the cloud cover. Should we see some patches of sunshine in the
clouds Saturday, then expect the chances for severe weather to
increase, particularly across the south central and east. Currently,
most of the CAMs has severe thunderstorms missing our CWA to the
south and east of us. However, with MUCAPEs around 1000 J/kg in the
GFS and 2000 J/kg in the NAM, and with 0-6 km bulk shear being
around 50 kts, severe weather is certainly a possibility up here
Saturday (10 to 15% chance of seeing marginally severe hail and/or
wind). The only limiting factor will be the uplift; thus, if we get
some breaks in the clouds Saturday, expect our severe weather
chances to increase. In addition to the severe weather, we could
also see some heavy rainfall in some isolated spots, even though the
model consensus keeps the heaviest precipitation amounts out of our
area Saturday through Saturday night. Therefore, while it is
certainly not expected, there is a small chance (20 to 30% chance)
that some low-lying poor drainage areas could see some localized
flash flooding should multiple storms pass over.
A quick reprieve from the precipitation could (30 to 40% chance) come
early Sunday morning before more rainfall moves over the area the
rest of Sunday through Monday as a second low pressure system lifts
through the Upper Midwest. While bulk shear values are greater
Sunday, there is almost no CAPE to work with. Therefore, no severe
weather is expected Sunday through Sunday night as the warm front
passes through our area. That being said, the models do show higher
QPF totals, with many areas possibly receiving over an inch of
rainfall. Therefore, this second low pressure system is the one most
likely to bring a soaking rainfall to our area these next several
days. In addition, I`m thinking the chances for flash flooding will
be ever so slightly higher over the poor drainage areas. As we move
into Monday and Monday night, the cold front of the low moves
through Upper Michigan, bringing additional rainfall to the area.
Given that we would then be under the warm sector of the low ahead
of the cold front, with 0-6 km bulk shears near 45 kts and MUCAPEs
currently near 500 to 1000 J/kg, severe weather could (10% chance)
be a possibility Monday. The rainfall finally leaves the east Monday
night as weak ridging builds in from the west.
We look to get a quick reprieve from the rainfall next Tuesday as
high pressure ridging quickly slides through the Upper Midwest.
However, model guidance brings a shortwave low from the Northern
U.S. Rockies back across us come Tuesday night/Wednesday. As we look
ahead beyond the extended period, it appears that an active weather
pattern will continue, as the CPC still has above normal chances for
precipitation and above normal chances for temps for the 8 to 14 day
period.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 806 PM EDT Thu Apr 25 2024
VFR will prevail for the duration of the TAF period with high
pressure influencing the region. High clouds will increase tomorrow
morning ahead of the next system, but the main threats will be
LLWS at IWD and CMX with the associated low level jet. In
addition, south-southeast surface winds will be strong at all
TAF sites tomorrow morning with sustained speeds in the 15 to 20
kt range and gusts up to 30 kts.
&&
.MARINE...
Issued at 421 PM EDT Thu Apr 25 2024
Light winds of generally 20 knots or less continue the rest of this
afternoon through tonight before winds increase from the southeast
to 20 to 30 knots across the eastern lake Friday (east winds 20 to
25 knots over the western lake by the evening). The higher winds
continue into Saturday, with a few gale force gusts up to 35 knots
being possible over the far eastern lake near the international
border Friday evening and again Saturday morning. As a low pressure
moves into Lake Superior Saturday, expect the winds to calm down to
20 knots or less again. However behind the low, a second low begins
lifting towards the Upper Midwest. This causes winds to veer to the
northeast, with gales up to 40 knots being possible over the far
western lake Sunday afternoon and evening. As the low`s center lifts
through Lake Superior Monday, the winds veer towards the south as
they decrease to 20 to 25 knots. As the low`s cold front moves
through Monday and Monday night, expect winds to pick up from the
west to 20 to 25 knots, before dying down to 20 knots or less again
by Tuesday as weak ridging moves back over the area.
Thunderstorms are possible over the lake from Friday evening to
Monday night.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Jablonski
LONG TERM...TAP
AVIATION...TDUD
MARINE...TAP
Area Forecast Discussion
National Weather Service San Angelo TX
910 PM CDT Thu Apr 25 2024
...New MESOSCALE UPDATE...
.MESOSCALE UPDATE FOR SEVERE STORMS...
Issued at 903 PM CDT Thu Apr 25 2024
Starting to see convection develop well west near the New MExico
line, where pacific is now colliding with the retreating dryline.
Cap had held so far this evening, but with better convergence
along the boundary and lift being provided by a jet streak
overhead, cap is being weakened to the point that better
convection looks to develop over the next few hours.
The latest CAMs, the 00Z HRRR in particular, seem to have a
decent initialization with this developing convection and expand
it across the area between Lubbock and Midland through midnight
and then eventually towards the Big Country north of I-20 after
midnight. Some threat that as the pacific front reaches the Concho
Valley after 3 AM, more storms may develop.
Instability and decent shear remain in place. Once storms
develop, potential for them to reach severe levels remains
possible.
&&
.SHORT TERM...
(This evening through Friday)
Issued at 220 PM CDT Thu Apr 25 2024
...The main concern in the short term is severe weather chances
tonight...
A somewhat complicated forecast on tap for tonight with
potentially two areas of thunderstorms developing late tonight and
affecting much of the area. Currently, there is an upper level
low moving northeast from northern AZ that will make its way into
the northern central plains by Friday morning. Upper level
shortwave energy will rotate around this low through our area
tonight with an attendant 500mb speed max as well. In the lower
levels, a stout LLJ of 40 to 50 knots is expected to develop after
sunset. At the surface, we continue to have southerly winds
keeping the surface air mass moist and unstable. The dryline is
also expected to tighten up to our west this afternoon.
For late this afternoon, a few of the short range CAMs have
indicated the possibility of an isolated storm developing just
west of the Concho Valley, and moving east/northeast into the
western and northern Concho Valley this evening.
Later tonight (likely after Midnight), as the previously
mentioned upper level low and shortwave energy/speed max moves
east into our area, a Pacific cold front/dryline will also become
organized and move into our area. This should result in one or
two linear cluster of thunderstorms developing around midnight
tonight. There is higher confidence in a line of storms developing
along and north of Interstate 20 west of Sweetwater, and moving
east northeast through the Big Country, with the southern extent
of this line near the I-20 corridor. There is lesser confidence in
a second line developing in the western Concho Valley and moving
east through the Concho Valley and into the Heartland and
Northwest Hill Country areas. With either line of storms, all
modes of severe weather will be possible, including hail of up to
2.5 inches, damaging wind gusts over 60 mph, and isolated
tornadoes.
Storms are expected to largely move out of the area by 9 AM or
possibly a little earlier, with skies clearing from west to east
throughout the day. Temperatures will warm into the mid 80s to
near 90.
&&
.LONG TERM...
(Friday night through next Thursday)
Issued at 353 PM CDT Thu Apr 25 2024
...Severe thunderstorms possible again Saturday and Saturday night...
Low-level moisture will make a quick return across our area Friday
night, out ahead of another upper low and trough which will drop
southeast into the Four Corners area by Saturday morning. The upper
low will move east into southeastern Colorado by late Saturday
afternoon, with a trough extending south across New Mexico. The
approach of this system will bring a chance of showers and
thunderstorms during the day Saturday, but how much development is
uncertain. At this time, we have medium (40-60 percent) PoPs across
the Big Country in the morning, with these PoPs extending south to
the Brady and San Saba areas in the afternoon.
The area generally east of a line from Aspermont to Sweetwater to
San Angelo to Sonora will have a risk of severe storms Saturday and
Saturday night. The forecast instability and shear profiles will be
supportive of severe storms with damaging winds, large to very large
hail and some tornadoes. The tornado threat may increase Saturday
evening, with a potential for a strong tornado as the low-level jet
strengthens and low-level shear increases.
The dryline will be near our western border counties by mid-to-late
afternoon. Should have scattered thunderstorms develop on the
dryline and move into western parts of the Big Country and
possibly northwestern Concho Valley Saturday evening. The
aforementioned upper trough is forecast to lift northeast to near
the Colorado/Kansas/Nebraska border by daybreak Sunday, with a
trough extending south across the Texas Panhandle. With this setup,
weak Pacific front will overtake the dryline and move east into our
area Saturday night. Indications are for a extensive band of
thunderstorms to quickly develop along the Pacific front/dryline and
move east across much of our area overnight into early Sunday
morning. In addition to the severe weather threat, heavy rainfall
with a localized flooding threat will be possible.
The overall weather for Sunday looks similar to Friday, with the
weak Pacific front moving east of our area and a possible lingering
chance of showers and storms in our eastern and southeastern
counties in the morning. Skies will be clearing from the west with
warm and drier conditions in the afternoon and highs mostly in the
80s. Early next week looks warm with highs in the mid 80s to around
90 degrees Monday and Tuesday. Low-level moisture returns but should
have minimal rain chances. We have chances for showers and
thunderstorms Wednesday afternoon into Thursday, when an upper
shortwave trough may move northeast into the area.
&&
.AVIATION...
(00Z TAFS)
Issued at 613 PM CDT Thu Apr 25 2024
Veil of mid and high clouds continue to stream across West Central
Texas terminals early this evening. May still see an isolated
storm through mid evening and will monitor radar to see if any
updates to the terminals will be needed, but at this point will
hold off on mentioning anything in the terminal forecasts until
late this evening and into the overnight hours. Otherwise, MVFR
cigs will move back into the area overnight. As a pacific front
moves across the area late tonight, storm development becomes a
little more likely and will include at least some mention in the
forecast. Storms will push east with the front Friday morning,
clearing out the MVFR cigs and shifting winds around to the
southwest.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 82 63 86 63 / 10 70 10 10
San Angelo 83 64 89 63 / 10 60 10 10
Junction 87 68 92 67 / 10 30 20 0
Brownwood 82 66 87 65 / 10 70 60 10
Sweetwater 82 62 85 62 / 10 60 0 10
Ozona 81 64 88 65 / 0 40 0 10
Brady 82 67 87 67 / 10 50 30 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...07
LONG TERM....19
AVIATION...07
Area Forecast Discussion
National Weather Service Topeka KS
611 PM CDT Thu Apr 25 2024
.KEY MESSAGES...
- Several rounds of thunderstorms are expected to move across
the area through Sunday.
- There is a risk for severe weather each day, with the
greatest risk including tornadoes on Saturday.
- Multiple rounds of heavy rain could lead to isolated flooding.
&&
.DISCUSSION...
Issued at 249 PM CDT Thu Apr 25 2024
19Z water vapor imagery showed an upper trough over the Great
Basin with a shortwave lifting through the four corners region.
At the surface, low pressure was noted in southeast CO with a
warm/stationary front extending through southwest KS and north
central OK. Persistent moisture advection over this boundary has
maintained the elevated showers and thunderstorms across the
forecast area today.
The main focus of the forecast is on the potential for severe
weather in the coming days. 12Z model consistency is good with an
upper low lifting into central NEB Friday morning with a second
upper low coming out into the western plains Saturday night and
Sunday morning. The warm sector with dewpoints in the lower and
middle 60s is expected to lift into northeast KS by Friday afternoon
as the initial upper low lifts to the northwest of the forecast area
with a dry line developing by the afternoon. This warm moist airmass
remains over the area through Saturday night and becomes somewhat
modified by Sunday afternoon. Though there is still expected to be
some moisture lingering across northeast and east central KS Sunday
afternoon. Good environmental shear is progged with a strong wind
field forecast through the weekend and the setup for severe storms
just doesn`t move out of the area until Sunday evening.
The MCS this afternoon is expected to continue to propagate
southeast along the axis of MUCAPE that extends northeast of the
surface warm front. With this having worked over the environment a
little, think there may be a break from the deep moist convection
into the evening, but the CAMs hint at the redevelopment of showers
through the evening. The main point of uncertainty through the
evening is where new convection develops. The HRRR has been
consistent in thunderstorms developing more over northwest KS within
the low level convergence area northeast of the surface low. This
would tend to keep storms mainly north of the forecast area through
the late evening. However by the early morning hours, PVA with the
shortwave should cause development to become more widespread and
move east through the morning. These storms look to be mainly
elevated with a hail and damaging wind risk, but there does appear
to be a narrow axis of surface based instability advecting north
through the morning. If storms develop in this axis of surface based
instability, the risk for a tornado or two will be higher.
By Friday afternoon, forecast soundings from the NAM and RAP show
MUCAPE around 3500 J/kg just ahead of the dryline. Good turning in
the low level winds are progged to create SRH around 200 m2/s2. More
of the models are starting to show a signal for convective
initiation along the dryline in northeast KS though there remains
some uncertainty given the lack of convection from the HRRR this far
south. Supercell thunderstorms would be favored with the potential
for very large hail and perhaps a strong tornado into the evening
across northeast KS thanks to increasing SRH with the strengthening
low level jet. This risk may move east and north of the forecast
area by mid evening with shortwave ridging overspreading the area.
This should lead to a break in the thunderstorm activity heading
into Saturday with the dryline retreating west. The setup for
Saturday looks ominous with forecast soundings showing a capped
boundary layer with large amounts of CAPE (3000 to 4000 J/kg) within
the warm sector east of the dryline. Again good environmental shear
would support supercell thunderstorms and as the low level jet
increases in the early evening, SRH also increases to around 300
m2/s2. So the concern for Saturday afternoon and evening is for
tornadoes, some potentially strong. Shortwave energy is progged to
be lifting over the dryline through peak heating and could be the
trigger for thunderstorm development.
By Sunday, the upper low should be to the north of the forecast area
but a diffuse boundary may still be over eastern KS acting as a focus
for renewed convection. Models are not as strong with the instability
and deep layer shear looks to be a little weaker too. So severe
risks may be a little more marginal. Repeated rounds of heavy
rainfall could cause some flooding problems before the weekend is
over. But confidence in the location of the thunderstorms and where
heavy rain develops is a little to low to pinpoint with a watch at
this time. Right now the heaviest rainfall is forecast for parts of
east central KS, but this could change depending on the short term
evolution of the storms.
For next week, the pattern becomes a little more zonal with
shortwave energy passing through the plains mid-week. With a frontal
boundary in the area, there looks to be another chance for showers
and thunderstorms Tuesday through Thursday.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 611 PM CDT Thu Apr 25 2024
Scattered showers and thunderstorms will continue this evening and
overnight, most likely over the next couple hours and again in the
few hours before sunrise. Broken IFR to MVFR ceilings will continue
along with this activity, though thunderstorm bases will be more
towards 5 kft. Winds remain southeasterly around 15-20 kts
overnight, becoming southerly at 20-25 kts once the warm front
passes tomorrow morning. Isolated severe thunderstorm development
again becomes possible in the last few hours of the period
tomorrow.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Wolters
AVIATION...Reese