Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/19/24
Area Forecast Discussion
National Weather Service Denver/Boulder CO
929 PM MDT Tue Jun 18 2024
.KEY MESSAGES...
- Cooler through Wednesday with scattered showers and a few
storms.
- Scattered thunderstorms Thursday into Friday
- Turning hot and drier this weekend through early next week
&&
.UPDATE...
Issued at 925 PM MDT Tue Jun 18 2024
There are a few light showers around this evening that are not
producing much in the way of rain or wind. These showers will
eventually end around midnight. Late tonight and into tomorrow
morning, there will likely be stratus that forms over much of the
plains. This will keep conditions cloudy and cool for much of the
day tomorrow.
&&
.SHORT TERM /Through Wednesday/...
Issued at 141 PM MDT Tue Jun 18 2024
Cooler temperatures have settled in across the forecast area
today after a cold front swept through the region earlier this
morning. As the troughing pattern continues over the western CONUS,
there is a slight chance we get some weak rain showers or an
isolated storm to develop over the higher terrain this afternoon.
Current water vapor imagery indicates low level moisture is lacking
at this time, but looking upstream, low and mid level moisture looks
to be heading our way.
The better chances for precipitation will be overnight tonight and
tomorrow as the trough shifts eastward and a 90 kt jet will be in
place to provide upper level support to northern CO. CAMs indicate
banded precipitation spreading across the plains and continuing into
tomorrow. Forecast soundings also show a dry to start moisture
profile becoming increasingly saturated as low level flow will be
from the southeast, allowing for moisture support from the Gulf.
With the increasing moisture in place, some lower level stratus
are expected to help keep Wednesday`s high temperatures on the
cooler side. Temperatures are forecast to be 10-20 degrees below
the norm and will likely struggle to reach the 70s across forecast
area.
&&
.LONG TERM /Wednesday night through Tuesday/...
Issued at 230 PM MDT Tue Jun 18 2024
Models are in very good agreement overall with regard to the
weather pattern.
With more moisture and higher precipitable water values,
scattered showers and a few storms will work their way eastward
across the plains through tomorrow evening. Most of these should
be ending by late evening in/near the mountains with some drying
aloft noted, but linger over the eastern plains with low level
850-700 mb theta-e advection.
For Thursday, the airmass should moisten a bit further across the
area with deepening southerly flow. There are indications a
little of this starts to peel off the easterly wave (broad
circulation around Potential Tropical Cyclone One) in the western
Gulf of Mexico. We`ll also be returning to warmer temperatures,
which gives us more instability and probably an area of 1000-1500
J/kg MLCAPE over the northeast plains. Thus, a couple stronger
storms would be possible, and perhaps an isolated pulse severe
storm.
By Friday, there`s a better chance some of this tropical moisture
spreads northward across the forecast area and onto the western
slope of Colorado. This would keep at least scattered shower and
storm coverage in the forecast in/near the mountains, along with
adding a threat of locally heavy rainfall. It appears an embedded
shortwave could be arriving a little late for higher storm
coverage, but something to keep an eye on for Friday afternoon and
evening.
For Saturday, the above shortwave will be passing to the east of
Colorado, resulting in drying and subsidence through the weekend.
Ensembles are in good agreement with that timing, and the
subsequent mid level ridging over the Central Rockies and Great
Basin into early next week. The combination of the ridge, drier
airmass, and westerly flow aloft all supports a return of hot
temperatures for the lower elevations, with mid and upper 90s
expected for the plains and I-25 Corridor for Sunday, Monday, and
Tuesday. There could still be enough moisture under the ridge for
scattered mountain convection, and isolated storms on the plains
each afternoon/early evening. But overall these would be high
based with gusty winds and mainly light rainfall.
Finally, depending on the fire intensity near Ruidoso, New
Mexico (it is flaring up again this afternoon), the HRRR Smoke
shows some smoke spreading across Colorado Thursday.
&&
.AVIATION /00Z TAFS through 00Z Wednesday/...
Issued at 541 PM MDT Tue Jun 18 2024
There will be a few showers in the vicinity of the terminals this
evening but they are not expected to impact operations. Any
ceilings that would form will be elevated and not significant.
Winds will not be the typical drainage but will be ESE at DEN and
APA.
Late tonight and into tomorrow morning, there will be better
moisture advected in from the east which may lead to status
development. The limiting factor that could keep stratus away from
the terminals would be the very dry air that is in place in this
post-frontal airmass. But given pattern recognition, there is
usually stratus that develops shortly after sunrise on setups like
this and the stratus can last for the entire morning.
The stratus will breakup around midday leading to some sunshine
and gusty SE winds at DEN and APA. There will be showers and
perhaps a couple thunderstorms tomorrow afternoon and evening. It
is unlikely these would produce much of an impact as they will be
elevated and likely won`t produce strong winds at the surface.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Danielson
SHORT TERM...Bonner
LONG TERM...Barjenbruch
AVIATION...Danielson
Area Forecast Discussion
National Weather Service Billings MT
754 PM MDT Tue Jun 18 2024
.UPDATE...
Rain continues at Baker, at the tail end of the wave departing to
the northeast, and this precip will end by 03z. To the west, we
are still seeing isolated to scattered showers in an area with
steep lapse rates and hints of PV advection west of Billings.
This activity may linger for a bit longer but overall it is
dissipating slowly. Have made a few pop/wx adjustments, including
the removal of TS for the duration of the night. The overnight
will be chilly and dry with mid 30s to around 40F for lows most
places. As previously noted, each of our climate stations has the
potential to reach a daily record for June 19. The other issue
tonight (remarkably for so close to the solstice) could be fog.
HRRR is hinting at it in our east and along the Musselshell. That
said, dewpt depressions are quite low, and in fact dewpts remain
in the low-mid 40s in our east as of 745pm. With clearing skies
and light winds, some valley fog seems plausible (we`ll give it a
20% chance for now). JKL
&&
.DISCUSSION...
Rest of Today through Thursday Night...
Satellite and radar imagery showed an upper trough axis across
eastern Montana with wrap around precipitation spilling into our
central and western zones while the southeast corner of MT was
being dry slotted. Precipitation coverage was greatest from
Billings south and southwest into the foothills aided by upslope
flow. The only lightning noted was in north central MT at this
time.
We may see a few isolated embedded lightning strikes over our
northern tier zones through evening, with enough instability still
out there to produce some groupel (Story, WY reported some) this
afternoon. Otherwise, as the upper trough slowly exits to the
Dakotas by evening we will see precipitation winding down. Some
trailing energy in the SW flow may produce some lingering showers
in our west until after midnight, but these should be hit and miss
showers at best.
For tonight, we should see partial clearing late. Overnight lows
will be in the 30s to lower 40s. Our current forecast is for
record lows...
Forecast Low Record Low
Billings 39 42 1946
Livingston 34 34 2007
Sheridan 34 36 1985
Miles City 37 41 2020
For Wednesday, relatively benign W/SW flow will mean mostly sunny
skies. We may see a few showers/thunderstorms develop in our
eastern border counties, as well as around the Belts and Snowies,
but for the most part dry conditions will prevail. The pattern
will favor a low level jet (850mb) developing Wednesday night
which may result in persistent isolated showers along the eastern
border counties overnight. Highs Wednesday will be in the upper
60s west to mid 70s east. Lows Wed night will be in the lower 40s
west to around 50 east.
Not much overall change for Thursday as southwest flow continues
aloft. We may see a few showers develop over the mountains by
midday, but more significantly, isolated showers and thunder
developing in a low level convergent zone (Rosebud County
vicinity) over the plains. MUCAPE may get over 500 J/kg in this
area with a 90% chance of effective bulk shear over 35kts. Thus, a
few strong storms are possible in the east Thursday afternoon and
early evening, though not a severe risk for now. Highs Thursday
will range from mid 70s west to lower 80s east. Showers could
linger again Thursday night over the eastern plains. Lows will be
in the 50s. BT
Friday through Tuesday...
Friday, the region will be ahead of Pacific troughing bringing
increased chances for precipitation early Friday morning through
Saturday morning. Models generally have forcing being the
strongest over northern MT, but our region still has a good chance
of getting at least a quarter inch of rain (50-70% Billings north
and east). SE flow in the low levels will stream in warm air and
moisture ahead of the frontal passage Friday night. PWATs will be
around 0.8-1.3 inches (highest in the east). This will give way
to good instability across the region and allow for thunderstorms
to develop. Ridging will build in the latter half of Saturday
through Sunday allowing for hot and dry conditions. Ensembles and
clusters then bring in slight troughing or westerly flow late
Monday into Tuesday, but generally keep most energy to the north
keeping PoPs at 20% or lower.
High temperatures will be in the 70s Friday, 70s/80s Saturday,
80s/mid 90s Sunday and 80s for Monday and Tuesday. TS
&&
.AVIATION...
Showers will begin to dissipate late this evening. Fog is likely
to form after 06Z for SE MT (KMLS and KBHK) dropping conditions
back down to MVFR/IFR. Fog is also possible for KBIL, but
confidence is lower. Conditions will clear up after sunrise with
VFR prevailing for most sites tomorrow. Mountain obscurations
will continue through the evening. TS/LT
&&
.PRELIMINARY POINT TEMP/POPS...
Wed Thu Fri Sat Sun Mon Tue
-----------------------------------------------------------
BIL 039/073 050/078 057/075 055/081 056/094 060/087 056/083
30/U 01/B 47/T 62/W 00/U 11/U 11/U
LVM 034/071 041/075 049/077 049/082 051/091 054/086 049/082
41/U 01/B 37/T 51/U 01/U 11/N 11/U
HDN 037/076 049/081 057/077 054/083 054/095 058/089 054/085
21/U 02/T 57/T 72/W 00/U 10/U 11/U
MLS 037/074 051/078 057/074 055/078 054/092 061/086 056/082
21/U 12/T 57/T 73/W 10/U 10/U 21/U
4BQ 036/074 052/078 059/077 057/079 055/094 064/088 057/084
02/T 22/T 56/T 72/W 10/U 10/U 10/U
BHK 035/072 050/075 054/072 054/077 051/089 059/087 053/083
32/T 22/T 57/T 73/W 10/U 10/U 21/U
SHR 034/074 046/080 054/078 052/080 052/094 058/089 053/085
21/U 11/B 46/T 62/W 00/U 10/U 10/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Charleston SC
1054 PM EDT Tue Jun 18 2024
.SYNOPSIS...
High pressure will extend across the region this week. A trough
of low pressure will impact the Southeast U.S coast Thursday
into Friday.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A narrow band of light showers continues to track westward across
portions of SE GA and adjacent waters as seen on KCLX radar.
As we head into the night, the current showers are expected to
dissipate before a second round of light showers arrive around
sunrise. The KCHS 00Z sounding observed a strong inversion
centered around 750 mb, beneath the inversion winds were E at 15
to 20 kt. Recent runs of HRRR indicated that low-level clouds
will move westward over the coastal areas overnight. The strong
observed inversion will likely trap moisture and will result in
increasing cloud cover near the coastline. The forecast update
included increasing cloud cover over portions of SE GA and the
SC lowcountry. Also, slight adjustments were made to PoPs and
weather.
The latest run of the HRRR forecast soundings indicate that the
strong 750 mb inversion through tomorrow and will result to
little to no deep instability. The forecast update also
included removing the thunderstorm potential for tomorrow. This
is in line with SPC`s Day 2 Convective Outlook.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Wednesday and Thursday: The southern flanks of the expansive upper
level anticyclone centered over the eastern United States will begin
to buckle just a bit as a well defined TUTT located north of the
Greater Antilles approaches the Southeast U.S. coast. The
operational GFS is has finally come in line with the rest of the
global guidance in keep any surface reflection of the TUTT as an
open tropical wave/inverted trough as it moves onshore late Thursday
night into the day Friday. Given a modest northeast low-level flow
is expected to continue ahead of the approaching tropical wave,
steering trajectories favor coastal Georgia for the best chances for
measurable rainfall. Still not seeing a strong QPF signal in the
various guidance for any concentrated areas of showers given the
development of deep convection seems unlikely with the degree of
subsidence noted aloft, but isolated to scattered low-topped showers
with a few tstms appear likely. Pops 20-40% were maintained for
mainly the coastal counties, highest along the Georgia coast. Highs
will warm into the upper 80s/lower 90s away from the coast both days
with lows Thursday morning dropping into mid-upper 60s well inland
to the mid-upper 70s at the beaches. Breezy to locally windy
conditions will also persist along the immediate coast and beaches.
Thursday Night and Friday: Rain chances will begin to ramp up late
Thursday Night and especially Friday as the approaching tropical
waves moves onshore. Shower coverage may lessen a bit Thursday
evening as subsidence ahead of the tropical wave spread in from the
east, but this will rapidly change as daybreak approaches Friday and
the primary wave axis pushes inland. The wave will be accompanied by
a ribbon of PWATS in excess of 2 inches. This coupled with some
forcing with the weakening TUTT aloft and the convergent/east side
of the westward propagating surface wave should be enough to support
scattered if not numerous showers with a few tstms. Pops were
trended up a bit to 40-60% (highest coast), but given the TUTT will
likely be rapidly dampening as it approaches the expansive upper-
level anticyclone, there is some hesitancy to go any higher with
pops at this time. Further adjustments will likely be needed. Lows
Thursday night will drop into the mid-upper 60s well inland to the
mid-upper 70s at the beaches. Highs Friday will range from the upper
80s/lower 90s away from the coast with cooler conditions at the
beaches.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
The tropical wave and associated TUTT aloft will quickly dissipate
over the weekend with the region positioned along the eastern flanks
of the large subtropical anticyclone. Despite the dissipation of the
TUTT, a broad weakness looks to remain through early next week.
This coupled with sea breeze influences and lingering deep-layered
moisture featuring PWATS in excess of 2 inches will support
scattered showers/tstms each day. The heat will also begin to build
through the weekend and especially Monday with highs warming into
lower-mid 90s Saturday with the mid-upper 90s into early next week.
The warmest day looks to occur Monday where a few spots far inland
could make a run for 100 before the onset of showers/tstms.
Dewpoints do not look to really mix out during this period with heat
indices expected to peak 100-103 Saturday, 102-105 Sunday and 105-
110 Monday, highest across the inland portions of the coastal counties.
Heat Advisories could be needed at some point with Monday being
the best day for reaching the Heat Advisory criteria of 108.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
0Z TAFs: Terminals are forecast to remain VFR through the TAF
period. The primary concern will be the timing of gusty east
winds at each terminal. Based on MOS, gusts are forecast to
return to 20-25kts by 14Z Wed. The gusty conditions are expected
to remain through the rest of daylight hours on Wednesday.
Extended Aviation Outlook: Brief flight restrictions are possible in
afternoon showers/thunderstorms Wednesday and Thursday, especially
at KSAV. Chances of flight restrictions increase at KCHS/KJZI/KSAV
terminals Friday and Saturday with lesser chances Sunday.
&&
.MARINE...
Tonight: A large and strong ridge of high pressure will encompass
the coastal waters, with a subtle inverted trough to form nearby.
The pattern will favor an enhanced pressure gradient across local
waters through the night, with easterly winds gusting upwards to 20-
25 kt. Favorable long duration onshore fetch will also allow seas to
build across local waters, eventually peaking between 4-6 ft across
nearshore waters and 5-7 ft across offshore Georgia waters. Small
Craft Advisories will therefore be in effect for all local waters
outside the CHS Harbor tonight, but a brief lull in winds is
possible this evening before 6 ft seas arrive across nearshore
waters around midnight.
Wednesday through Saturday: Gusty northeast winds will persist into
Friday as a tropical waves approaches from the east and a modest
gradient persists over the coastal waters. Northeast winds will
average 15-20 kt with gusts to 25 kt during this time. Seas will
remain above 6 ft through Thursday night within 20 NM and into
Friday evening for the waters 20-60 NM offshore. Small Craft
Advisories are in effect for these waters. Seas look to peak 5-6
nearshore waters and 6-8 ft in the offshore waters, mainly on
Thursday. Winds in the Charleston Harbor will be near advisory
thresholds, but are expected to hold just sky. The need for an
advisory there will be reevaluated Wednesday morning. Both winds and
seas will begin to diminish Friday night into Monday.
Rip Currents/High Surf: Tybee Island Ocean Rescue is flying double
red flags at all Tybee Island beaches where a number of very strong,
dangerous rip currents have been observed. The waters have been
closed here as a result. Expect the risk for strong and dangerous
rip currents to spread into all beaches Wednesday which will persist
into Thursday. A high risk for rip currents is being highlighted for
all beaches for both days. NWPS breaking wave guidance shows
breakers reaching 3-5 ft along the beaches on Wednesday and
Thursday, highest in the Folly Beach area. Given only spotty
instances of 5 ft breakers are being depicted, the situation for
Wednesday looks to marginal for a High Surf Advisory at this time.
&&
.TIDES/COASTAL FLOODING...
Surface high pressure will remain off the coast of New England with
a tight pressure gradient and elevated winds across the South
Carolina and Georgia coast. A full moon on 6/22 will also cause the
astronomical tides to slowly build. There is a chance that minor
coastal flood stage could be reach on the Wednesday and Thursday
evening high tides for Charleston Harbor.
Tides at Fort Pulaski are forecast to remain below minor flood
stage.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...High Risk for Rip Currents through Wednesday evening for GAZ117-119-
139-141.
SC...High Risk for Rip Currents from 8 AM EDT Wednesday through
Wednesday evening for SCZ048>051.
MARINE...Small Craft Advisory until 6 AM EDT Friday for AMZ350-352-354.
Small Craft Advisory until 11 PM EDT Friday for AMZ374.
&&
$$
NEAR TERM...ACD
SHORT TERM...ST
LONG TERM...ST
AVIATION...NED/ST
MARINE...DPB/ST
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
632 PM CDT Tue Jun 18 2024
.KEY MESSAGES...
- Hot and humid weather continues into next week.
- Thunderstorms expected in NW MO overnight Tuesday into
Wednesday, heightening flash flood concerns.
- Rain possible again on Sunday (~40%), but predominantly dry
next week.
&&
.DISCUSSION...
Issued at 430 PM CDT Tue Jun 18 2024
As has been the case for the past several days, hot and humid
weather will continue to dominate the forecast. Highs will
remain in the low/mid 90s, while lows will only drop to around
70. Diurnal cumulus is present across the area going into the
afternoon, but shower/storm activity is not expected to occur
with a lack of forcing at the lower levels to invigorate
convective activity before sunset. Gusty southerly winds will
diminish going into the evening.
A surface low in the northern Great Plains and its associated
cold front will bring a line of storms to NW MO overnight. These
storms have already been observed on satellite/radar firing
along the cold front. This cold front is expected to move into
NW MO by Wednesday morning. Some CAMs are suggesting that the
front will stall over NW MO. With this solution, more
concentrated rainfall over NW MO may increase concerns for
flash flooding. The HRRR, on the other hand, suggests a more
transient frontal passage protruding further east into MO,
which may limit the residency of rainfall in NW MO. In turn,
this would expand coverage of showers and storms, minimizing
flash flood concerns for NW MO. Current analysis between
guidance and reality suggests that the HRRR has a better handle
of the current storm activity out west, so more confidence can
be placed in the timing of the HRRR forecast for storms later.
However, as the event evolves, more concise evaluation can be
given to intensity and location. All guidance suggests that
there may be an isolated strong to severe storm or two
overnight into early Wednesday morning, with primary threats
being high winds and hail. Going into Wednesday afternoon, the
presence of upper level divergence and embedded shortwaves
could encourage additional rain showers across central MO.
Following the cold front and associated rain, highs for
Wednesday will fall slightly, remaining around the mid to upper
70s for far NW MO while areas towards central Missouri will
continue to see highs hovering around 90. Unfortunately, though,
this "reprieve" will not last into the following days. A ridge
will build into the central CONUS on Thursday, bringing with it
continued heat and humidity into Saturday. A shortwave trough
ejecting from the west will bring back the chance for
precipitation on Sunday (~40%), but higher probabilities remain
towards the northeast. After Sunday, a ridge will build back
into the area and keep conditions dry for the remainder of the
forecast period.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 626 PM CDT Tue Jun 18 2024
An area of showers and storms will move into area this evening.
This may bring periods of MVFR to IFR visibility and ceilings.
It looks like showers and storms will be in the vicinity then
for pretty much the remainder of the forecast as a front stalls
in the area. With the front over the area, ceilings will likely
(<60%) become MVFR with light winds prevailing.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.
&&
$$
DISCUSSION...HB/Pesel
AVIATION...CDB
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
327 PM PDT Tue Jun 18 2024
.SYNOPSIS...Dry weather is expected for the foreseeable future.
Interior temperatures begin a slow warming trend through the work
week with temperatures approaching 100 degrees in some interior
valley locations Friday into Saturday.
&&
.DISCUSSION...Dry weather conditions are expected persist through
the foreseeable future as dry air remains in place within the
mid- levels of the atmosphere over Northwest California. Visible
satellite imagery shows cirrus (high-level) clouds spreading from
northwest across the area this afternoon, while stratus near
coastal Humboldt finally scatter out. Temperatures has been
running 5 to 10 degrees warmer compared with yesterday`s reading
as a weak high pressure builds over the area, with inland highs in
the mid 70`s to mid 80`s. Tonight, stratus are expected to
redeveloped around Humboldt Bay and vicinity. Light offshore flow
is expected again tonight into Wednesday.
Smoke from the Sites Fire in Colusa Co. is forecast to spread
over Lake County overnight through Wednesday morning. HRRR smoke
dispersion model indicates more waves of smoke from Sites Fire
spreading form east-southeast on Thursday.
Troughing the next couple days will keep temperatures over the
interior near normal through Wednesday. By Thursday the trough
will begin to break down and 850 mb temperatures will warm across
the interior allowing some interior valleys to approach 100
degrees Friday into Saturday. This will bring a moderate heat risk
for portions eastern Mendocino, Trinity and Lake counties. All
while this is occurring, northerly winds and increasing low-level
moisture at the coast will result in increasing chances of coastal
stratus through the week with temperatures remaining near normal
at coastal sites.
Ensemble cluster analysis and deterministic models shows the high
pressure flatten on Sunday as a upper-level trough moves toward
the Pacific NW. An associated weak, dry cold front sweep east-
southeast across Northern California. Thus, temperatures will
moderate a few degrees across the interior late in the weekend
into early next week but still remain several degrees above
normal. /ZVS
&&
.AVIATION...Stratus has been stubborn early this afternoon, but
is slowly diminishing. All terminals this afternoon will be VFR,
with NNW winds peaking at 15 to 20 knots. Winds are expected to
diminishing by sunset. Tonight, stratus is expected to make a
return and be more widespread than today`s. Stratus is expected to
develop around Humboldt Bay and ACV, then advect north to CEC,
bringing MVFR to IFR conditions. Stratus looks likely to stay
offshore most the day Wednesday, but the coastal terminals could
still be affected periodically. UKI is expected to stay VFR
through Wednesday. JB
&&
.MARINE...Northerlies will continue to ease into Wednesday.
However, moderate to locally fresh northwesterlies persist over
the outer waters. Afternoon fresh to locally strong northerlies
are expected south of Cape Mendocino on Wednesday. Generally
light gentle breeze is expected nearshore, with a period of
southerlies north of Cape Mendocino tonight. Fresh breeze spread
across the outer waters and early Thursday as a thermal trough
develops inland, with locally strong winds downwind Cape
Mendocino. Steep short period seas will continue to promote
hazardous conditions for small craft primarily in the outer zones
for the rest of the week. /ZVS
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory until 3 PM PDT Wednesday for PZZ455.
Small Craft Advisory until 3 AM PDT Friday for PZZ470-475.
&&
$$
Visit us at https://www.weather.gov/eureka
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https://www.facebook.com/NWSEureka
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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
744 PM CDT Tue Jun 18 2024
.KEY MESSAGES...
- Seasonably hot and humid weather will prevail this week. The
hottest conditions will arrive Friday into Saturday when air
temperatures climb into the middle to upper 90s and heat index
values peak at 100-105 degrees.
- Isolated thunderstorms will be possible from time to time over
the next few days...with a better chance for thunderstorms
arriving late Saturday into Sunday.
&&
.UPDATE...
Issued at 744 PM CDT Tue Jun 18 2024
Extensive cirrus shield remains in place across much of the
forecast area, though is more sporadic across the Illinois River
Valley. Rainfall has been next to non-existent so far, though a
few showers are lifting northward toward the I-70 corridor in
south central Illinois. Latest SPC mesoanalysis and HRRR forecast
sounding for Effingham show some capping in this area, plus
temperatures have been lower with the thicker cloud cover down
there. Currently thinking thunder potential is minimal due to the
weak instability, though a few showers remain possible in the
eastern CWA through evening as a weak upper disturbance lifts
northeast out of Missouri. Updated grids recently sent to reflect
these thoughts, plus the usual minor tweaks to incorporate latest
observational trends.
Geelhart
&&
.SHORT TERM...(Tonight through Wednesday Night)
Issued at 329 PM CDT Tue Jun 18 2024
Deep-layer moisture continues to flow northward from the western
Gulf of Mexico on the back side of a prominent upper high centered
over the Carolinas. The corresponding thick cirrus shield has kept
temperatures a few degrees cooler than they were yesterday and has
limited instability. 20z/3pm satellite imagery shows mostly cloudy
skies along/southeast of a Bloomington to Jacksonville line...with
sunny skies to the northwest. Cannot rule out a stray shower or
storm over the next couple of hours, but areal coverage will
remain scant. CAMs are suggesting isolated showers may re-develop
overnight across the Wabash River Valley...with showers/storms
becoming a bit more numerous further west across Iowa/Missouri in
association with a slowing cold front. Overall think most
locations will remain dry as low temperatures only drop into the
lower to middle 70s.
The cold front will become stationary from Iowa into southern
Wisconsin/northern Illinois on Wednesday. The strongest forcing
and thus the greatest areal coverage of diurnal convection will
remain focused just N/NW of the KILX CWA: however, the HRRR continues
to suggest widely scattered convection along a pre-frontal trough
perhaps as far south as I-72. Have therefore included slight
chance PoPs as far S/SE as a Springfield to Paris line...but have
focused better rain chances northwest of the Illinois River in
closer proximity to the boundary. Otherwise Wednesday will be a
hot and humid day with considerably less wind than has been
experienced lately. S/SW winds will generally remain in the
10-15mph range as afternoon highs top out in the lower to middle
90s.
Barnes
.LONG TERM...(Thursday through Next Tuesday)
Issued at 329 PM CDT Tue Jun 18 2024
As the upper high retrogrades westward and upper heights rise,
rain chances will decrease and temperatures will increase by the
end of the week. Latest guidance suggests the hottest period will
be Friday and Saturday when high temperatures climb into the
middle and perhaps upper 90s in a few spots. Corresponding heat
index values will peak at 100-105 degrees...just shy of Heat
Advisory Criteria.
As has been advertised by the models for the past several runs, a
significant short-wave trough is expected to traverse the country
and push a cold front into central Illinois this weekend. 12z Jun
18 GFS and ECMWF are in relatively good agreement, showing the
front arriving Saturday night. As a result, have included high
chance to likely PoPs (40-60%) Saturday night into Sunday. Once
the front departs, slightly cooler and less humid weather is
expected early next week as highs drop back into the upper 80s to
around 90 degrees by Monday.
Barnes
&&
.AVIATION... (For the 00z TAFs through 00z Wednesday Evening)
Issued at 615 PM CDT Tue Jun 18 2024
VFR conditions expected the next 24 hours, with ceilings near or
above 15,000 feet, primarily tonight. Gusty south winds will begin
to diminish early this evening with loss of daytime heating. A
gradual shift to the southwest is expected on Wednesday as a cold
front approaches the Iowa/Illinois border, but speeds should be
near or below 10 knots.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Indianapolis IN
957 PM EDT Tue Jun 18 2024
.KEY MESSAGES...
- Extended period of hot and humid conditions through this weekend
- Partly cloudy Tonight and Wednesday.
- Stray Shower or Thunderstorm possible through Thursday.
&&
.FORECAST UPDATE...
No major changes needed to the ongoing forecast other than to cut
the POPs in the near term through 09Z as it becomes more clear that
precipitation has wrapped up. There will be another subtle surge of
forcing towards daybreak which could produce an isolated shower
towards daybreak but coverage is not expected to be more than
isolated.
Another mild night is expected with widespread cloud cover and low
70 dewpoints not allowing for much radiational cooling. Clouds may
begin to clear towards the morning hours tomorrow, but think that
the bulk of drier air aloft won`t arrive until later in the day.
&&
.SHORT TERM (This evening through Wednesday)...
Issued at 227 PM EDT Tue Jun 18 2024
Surface analysis early this afternoon shows a large area of high
pressure in place just east of the middle Atlantic States. This was
resulting in warm and humid southerly flow across Indiana and the
Ohio Valley. Aloft, water vapor showed a strong ridge of high
pressure over the United States east coast, while a moderate through
was found over the western CONUS. Water vapor also showed a plume of
tropical moisture streaming from the Gulf of Mexico across the
Tennessee river Valley to Indiana, OH and MI. Radar this afternoon
shows an area of showers under the plume over southern IL and SW
Indiana. Surface winds were from the south and dew points were quite
humid, in the lower 70s.
Tonight...
The upper high pressure system to the east is expected to begin to
retrograde a bit west tonight. This will slowly start the western
progression of the tropical plume of moisture that has been our main
weather feature today. However, until that occurs, southerly winds
with high clouds will persist through the evening and overnight. As
daytime heating is lost, instability will be lost which should limit
shower chances, but due to the plume aloft and plentiful moisture
available, any weak disturbances within the plume could result in a
brief passing shower. HRRR continues to suggest very light
precipitation possible under the plume through the overnight.
Confidence on specific locations and timing is low, thus a large
blanket of low pops will be used across the forecast area. Again,
there will be many dry hours and any precipitation amounts will be
light. Given the warm and humid air mass in place along with the
expected cloud cover, lows in the lower to middle 70s will be
expected.
Wednesday...
The upper pattern will become more dominated by the large upper high
pressure system on Wednesday. The high will retrograde westward,
steering any upper forcing dynamics well north of Indiana, to
Ontario. This should also effectively begin to block the tropical
plume, leading to increased sunshine as these mid and high clouds
are lost. Forecast soundings start the day with some high cloud
present, but these are lost as the day progresses. Furthermore,
forecast soundings show attainable convective temperatures in the
upper 80s with CAPE near 1000 J/KG. Thus as high clouds exit and
stronger heating is achieved in the afternoon, CU development is
expected and brief diurnal showers and storms will be possible. Once
again will include chc pops across most of the forecast area, mainly
for the afternoon for these light, isolated and brief diurnal
showers and storms. Highs should be able to reach the lower to
middle 90s.
&&
.LONG TERM (Wednesday night through Tuesday)...
Issued at 227 PM EDT Tue Jun 18 2024
Wednesday Night through the Weekend...
An extended period of high heat will continue through the weekend,
and likely will redevelop again next week. Although the magnitude
may not reach extreme heat indices of greater than 105, the extended
duration and presence of very warm overnight lows will provide
hazardous heat conditions across central Indiana during the long
term.
This stretch of above normal temperatures will be initiated by the
eastward progression of anomalously high heights aloft over the Ohio
Valley. This will allow for greater atmospheric expansion and
therefore higher temperature values throughout the entire lower 5km
of the troposphere. Greater lower troposphere temperatures will
be accentuated early this weekend as the ridge axis positions
directly overhead, with highest temperatures expected to occur on
Saturday afternoon (93-97F).
In conjunction with this deep ridging aloft, there will be gradual
south/southwest flow due to surface high pressure to the east and
north. This will allow for elevated dew point temperatures to remain
over the Ohio Valley, generally in the mid to upper 60s. The
combination of highs in the 90s and dew points in the low 70s will
push heat index values into the upper 90s through Thursday and
possibly low 100s Friday and Saturday. As mentioned, this within
itself is not overly hazardous, but the fact this is expected over a
succession of 4 to 5 days with over night lows in the low 70s puts
an even greater risk to vulnerable populations.
There are a few potential mitigating factors for high heat and are
mainly related to the potential for increased cloud cover and
isolated rain chances over the middle of the week. If cloud cover
becomes greater than 70% over the afternoon hours, highs may be
suppressed lowering the heat risk. Still, overnight lows should not
be greatly impacted with dew points remaining in the mid to upper
60s. By Friday, the greatest moisture and lift axis should shift
eastward, lowering the threat of afternoon clouds and rain chances
for Friday through Sunday.
Forecast confidence decreases late this weekend through early next
week as a shortwave approaches from the north. High pressure over
the Carolinas should impede shortwave progression some, but there is
still high uncertainty in how far east a weak pressure trough and
associated lift/precipitation will reach. Even so, ridging will
remain aloft and any weak wave passage that does occur should only
briefly impact surface conditions before upper 80s to low 90s
surface temperatures return for the middle of next week. Even looking
at the extended range (>10days), the pattern continues to favor
general temperatures at or above normal for the next few weeks. With
this in mind, expect more 90+ degree days heading into early July.
One note about the HeatRisk graphics by WPC. This is an experimental
product and values in the current pattern are higher than
traditional criteria, and may not be perfectly calibrated to best
represent the risk at this time. Thus, we advise users to take this
into consideration when viewing the HeatRisk product.
&&
.AVIATION (00Z TAF Issuance)...
Issued at 652 PM EDT Tue Jun 18 2024
Impacts:
- Low potential for afternoon showers/storms tomorrow
Discussion:
VFR conditions expected through the TAF period outside of a low
chance for afternoon thunderstorms tomorrow which could bring brief
MVFR to IFR vsbys. Best chances to see convection will be at LAF
with even lower chances at HUF and IND. Otherwise the BKN to OVC
ceiling at 200 will gradually begin to clear after daybreak tomorrow
with light southerly winds of 5-10kts through the TAF period.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...White
SHORT TERM...Puma
LONG TERM...Updike
AVIATION...White
Area Forecast Discussion
National Weather Service North Platte NE
646 PM CDT Tue Jun 18 2024
.KEY MESSAGES...
- Cool conditions on Wednesday with high temperatures 10 to 20
degrees below seasonal values. However, temperatures quickly rebound
back into the 80s for the remainder of the week into the weekend.
- Near daily shower and thunderstorm chances continue across the
area each day through the rest of the week into the weekend. The
severe threat remains uncertain at this time.
&&
.SYNOPSIS...
Issued at 206 PM CDT Tue Jun 18 2024
Recent GOES-16 WV and RAP 500-mb analysis showed a dome of high
pressure centered over the east coast with a ridge extending north-
northeastward into northern Quebec. Southwest flow aloft continues
across the region as an upper-level trough swings across the
northern Plains. At the surface, low pressure was moving
northeastward out of eastern South Dakota into Minnesota. An
attendant cold front extended southwest into eastern Nebraska and
central Kansas to another area of low pressure centered over
southwestern Kansas. This front advanced through western and
north central Nebraska this morning allowing the strong
overnight winds to subside some and shift towards the
northwest. At 2 PM CT, temperatures ranged from 61 degrees at
O`Neill to 76 degrees at Imperial.
The aforementioned cold front has sagged a bit further to the
southeast than previously thought with convection initiating
along the boundary in our eastern neighbor`s CWA. This ongoing
development is occurring south and east of the local area and
should continue to move north and east as the afternoon and
evening progresses. The potential for a brief shower or
thunderstorm exists across far north central Nebraska, generally
areas east of Highway 183. Do believe the bulk of the severe
threat will reside outside of these areas, though cannot rule
out some hail or gusty winds should a stronger storm develop and
maintain itself. Anything that does develop should exit the
previously mentioned areas by 00Z this evening.
&&
.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 206 PM CDT Tue Jun 18 2024
Tonight... Thanks to the cold frontal passage, overnight lows will
cool back into the 40s and 50s across western and north central
Nebraska. Clouds will continue to back build over the region late
tonight with relatively light winds out of the north and east as
surface high pressure nudges south out of Montana. A shortwave
embedded in the flow aloft combined with outflow from the
storms to the south should be enough to trigger scattered showers
and non-severe thunderstorms to develop after 06Z across
southwest into portions of central Nebraska.
Wednesday and Wednesday Night... The activity from overnight
is expected to wane across the area through Wednesday morning
with a cloudy and cool day is in store for the area. High
temperatures will be in the mid 60s which is 10 to 20 degrees
below normal for mid-June. An upper-level shortwave ejecting out
of the central Rockies Wednesday evening will provide another
focus for showers and thunderstorms to develop, continuing
overnight. Given the cloud cover and cool temperatures,
instability will be meager (MLCAPE 300 to 500 J/Kg) with weak
deep-layer shear (20 to 30kt), thus anticipate non-severe
thunderstorms with this activity. These showers and
thunderstorms should bring some moisture to portions of
southwest and north central Nebraska, though generally 0.25 to
0.75" appears most likely. Locally higher amounts up to 1"+ may
be observed for areas generally east of Highway 83.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 206 PM CDT Tue Jun 18 2024
Thursday... Showers and thunderstorms are expected to linger into
Thursday morning, waning through the afternoon hours. Another upper-
level shortwave ejecting eastward out of Wyoming and Colorado will
provide a focus for isolated to scattered thunderstorms across the
Nebraska Panhandle Thursday afternoon and evening. Mid-level warm
air advection (WAA) will result in a capping inversion and when
combined with persistent cloud cover, convection may be limited
Thursday. With the position of a lee trough near the
Colorado/Wyoming border, southeasterly surface flow will increase,
helping amplify southeasterly low-level flow and moisture advection
across the area. In fact, both the NAEFS and ENS guidance
highlighting precipitable water (PWAT) values approaching the
99th climatological percentile, especially north of a warm front
expected to lift northward across the Panhandle into the
Sandhills. Despite this, details remain rather murky resulting
in uncertainty on the degree of the severe risk Thursday given
large spread amongst model guidance. Will continue to monitor
the severe potential during this period as CAMs get into this
time range.
Friday and beyond...The cool conditions felt on Wednesday will be
short-lived as temperatures warm back into the 80s as the upper-
level ridge retrogrades westward into the weekend. Continued
southwesterly flow aloft with additional northern stream
disturbances tracking across the region will keep the extended
forecast in a relatively active pattern. While recurring afternoon
and evening thunderstorm chances exists in the extended, the degree
of severe potential and coverage remains in question. A return to
above normal temperatures and drier conditions will be felt heading
into early next week as the upper-level ridge re-amplifies
across the Desert Southwest, extending north into the northern
Plains.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 641 PM CDT Tue Jun 18 2024
VFR conditions are expected over the next 24 hours. Winds will
diminish this evening out of the north to northeast around 10 to
15 kts. There is a chance for rain to move in during the
afternoon hours, but at this time coverage remains uncertain,
thus have left the mention out of the tafs at this time.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Viken
SHORT TERM...Viken
LONG TERM...Viken
AVIATION...Gomez
Area Forecast Discussion
National Weather Service Melbourne FL
837 PM EDT Tue Jun 18 2024
.UPDATE...
Issued at 840 PM EDT Tue Jun 18 2024
The East winds will decrease some over the interior this evening
and overnight but remain breezy/gusty along the coast with
isolated to scattered showers pushing onshore and well inland.
No lightning has occurred over land or the adjacent coastal waters
but a couple strikes have been noted well offshore (beyond 60nm)
so will keep the slight chance for thunder over the marine zones
as well as coastal counties overnight.
&&
.AVIATION...
(00Z TAFs)
Issued at 840 PM EDT Tue Jun 18 2024
The gusty east winds will subside over the interior terminals
tonight but remain 10-15 knots while coastal terminals remain
at 15-25 knots. Fast moving SHRA will push onshore and well
inland so will carry VCSH. On Wed, similar conds as today are
forecast with East winds 15-25 knots, gusting near 30 knots all
terminals with SCT SHRA pushing onshore. Will keep CIGs VFR but
ocnl MVFR CIGs are likely mainly assocd with passing SHRA.
&&
.PREVIOUS DISCUSSION...
Issued at 400 PM EDT Tue Jun 18 2024
Tonight...Breezy to gusty conditions are present across much of
the area this afternoon, especially around the Orlando metro and
along the immediate coast. RAP analysis shows a tightening
pressure gradient over the FL Peninsula, reflected in some of the
higher wind gusts in the last couple of hours. Observing sites around
Cape Canaveral to Cocoa Beach are reaching gusts of 35 mph and
briefly higher at times. A weak disturbance is moving onshore just
south of Melbourne and providing the focus for some heavier
shower activity. So far, no lightning has been detected in or
around these showers, but it cannot be entirely ruled out along
the coast or just offshore through the evening. Locally higher
gusts to 40 mph at the coast may also accompany this feature as it
moves ashore.
Wind gusts will persist tonight along the coast, reaching 25 to
30 mph at times, but decreasing to 15-20 mph inland. Isolated to
scattered showers are expected to continue with a very low chance
for lightning at the coast and over the Atlantic waters.
Temperatures will gradually fall into the 70s, staying slightly
warmer east of I-95.
Wednesday-Thursday...Mid level ridging remains in place through
tomorrow but begins to flatten as a weak trough of low pressure
approaches the southeast U.S. This is the same feature highlighted
by NHC for a low chance of developing tropical characteristics in
the next few days. At this point, model guidance does very little
with it, other than to provide another wave of moisture and
associated shower activity somewhere along the FL/GA or Carolina
coastline Thursday afternoon into early Friday. Models remain in
some disagreement with regard to the placement and timing of this
feature, but an increasing trend to high chance/likely PoPs is
forecast Wednesday into Thursday. Brief, localized heavy rainfall
is possible as a result, though the QPF remains near 1.20" or less
for most locations through Friday morning. Temperatures each day
will remain near to slightly below normal with overnight lows
ranging through the 70s. A couple of warm low records may occur at
coastal sites due to the persistent onshore flow. Gusty winds are
forecast to continue, reaching 25-30+ mph at times, especially
along the immediate coast.
Saturday-Monday (modified previous)...Upper level high pressure
centered across the Deep South on Saturday will slowly shift
westward through the time, with the axis remaining over the
Florida peninsula. Surface high pressure in the western Atlantic
will build southwestward over the Florida peninsula through the
period. Locally, winds will generally be around 10 mph, with E/SE
winds forecast on Saturday before becoming S/SE on Sunday and
Monday. The east coast sea breeze is expected to form each
afternoon and push inland. Rain chances will remain elevated
through early week, with rain chances persisting into early next
week. For now, kept likely PoPs out of the forecast due to
variability in model solutions. Afternoon highs will be in the
upper 80s to low 90s across the immediate coast, and low to mid
90s across the interior each day. Overnight lows will generally be
in the low to mid 70s.
&&
.MARINE...
Issued at 400 PM EDT Tue Jun 18 2024
Tonight...Hazardous boating conditions will continue as easterly
winds 20-25 kt and occasional gusts of 30-35 kt. A Small Craft
Advisory remains in effect for all of the adjacent waters through
at least Thursday evening. Seas will continue to build, reaching
7-8 ft offshore north of Sebastian Inlet tonight and 6-7 ft
nearshore. A stream of isolated to scattered showers is also
forecast, with a very low probability of lightning strikes. Some
of these showers could mix down locally higher wind gusts at
times.
Wednesday-Saturday (modified previous)...Poor to hazardous
boating conditions will continue through late week as a weak
trough approaches the Florida peninsula and southeast U.S. coast.
Onshore flow will persist with winds generally 15-20 KT in the
nearshore waters and 20-25 KT in the offshore waters through
Thursday. Winds will decrease to around 10-15 KT by late week and
into the weekend. Seas 6-8ft on Wednesday will increase to 7-9 ft
on Thursday, before beginning to subside on Friday with seas
decreasing to 4-6ft. A Small Craft Advisory remains in effect for
all the Atlantic waters on Wednesday, and has been extended in
time through at least Thursday evening. Scattered to numerous
showers and isolated lightning storms will be possible each day.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 76 87 76 87 / 30 60 50 60
MCO 76 88 76 88 / 30 50 30 50
MLB 77 87 77 87 / 50 50 50 60
VRB 76 88 76 87 / 50 50 50 60
LEE 77 90 76 91 / 30 40 20 40
SFB 75 89 75 89 / 30 50 40 50
ORL 76 89 76 89 / 30 50 30 50
FPR 76 87 76 87 / 40 50 50 60
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...Small Craft Advisory until 8 PM EDT Thursday for AMZ550-552-555-
570-572-575.
&&
$$
UPDATE...Kelly
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
704 PM CDT Tue Jun 18 2024
.KEY MESSAGES...
- Strong to severe thunderstorms are likely to develop this
afternoon and evening. Primary hazards are damaging winds and
a chance for a few tornadoes. Locally heavy rainfall is also
possible this afternoon into tonight.
- Additional rainfall of 0.50" to 1.00" through Wednesday
morning.
- Pleasant stretch with temperatures in the 70s Wednesday and
Thursday.
- Next chance for widespread rain arrives Friday into the
weekend.
&&
.MESOSCALE...
Issued at 406 PM CDT Tue Jun 18 2024
Update on this evening`s severe threat and tornado watch. So
far, the storms over western MN have been mostly struggling to
sustain themselves, although there`s been a recent uptick in
updraft growth. This is likely attributed to a lack of good
upper level jet support, which is better over northern MN where
storms are better organized and severe. The storms over our area
should continue to get a bit better organized over the next hour
or two as upper level support is forecast to improve somewhat,
but the big question is how much. It will have to improve quite
a bit in order to produce more organized/upscale storm growth,
and the associated cold pools that would be needed for a more
widespread wind and isolated tornado threat. Otherwise the
storms will be more pulse in nature with mostly brief wind/hail
threats and not much else. Latest runs of the HRRR prefer the
pulse mode with a limited severe threat, however some other
models are suggesting upper level support could improve just
enough for a more organized storm mode with more widespread
severe threats. If this were to occur, it appears most likely to
occur in the 5pm to 7pm timeframe as the storms approach the
I-35 corridor, and we will continue to monitor closely to see if
this indeed looks to happen.
&&
.DISCUSSION...
Issued at 232 PM CDT Tue Jun 18 2024
Today and Tonight... A busy stretch of weather is on tap for
this afternoon and evening. Current observations highlight the
tropical-like airmass in place. Temperatures are in the low to
mid 80s with dewpoint temperatures in the low 70s. Southerly
winds with gusts up to 40 mph will turn northwesterly and
decrease overnight behind the frontal passage.
Our attention turns to this afternoon`s severe weather set up. A
potent sfc low over the eastern Dakotas will lift northeast into
northern Minnesota this afternoon. A trailing cold front moves into
western Minnesota by early afternoon and will be the focus point for
convective initiation. Strong southerly low-level flow will result
in continued moisture advection through the afternoon hours. Ahead
of the cold front, we`ve seen moderate instability 2500-3500 J/kg
build into central and southern Minnesota. Effective shear remains
around 30 knots with nearly unidirectional shear aloft, limited by
weak flow aloft. Initial storm mode will be multicell with a
supercell or two possible but storms will quickly congeal into a
linear storm mode given the unidirectional shear profile aloft. Our
primary concern will be the potential of damaging wind gusts
convection moves through central and southern Minnesota and
western Wisconsin. KMPX VAD profile highlights impressive low
level SRH values between 200-300 m2/s2 and along with decent
speed shear in the lower levels. Given the enhanced low level
wind shear, a few tornadoes will be possible this afternoon.
This matches up with the SPC SWO update added a 5% TOR area over
our MN counties. Our 18z sounding highlights impressive
moisture in the lower levels with PWAT of 1.91". The wind
profile has some veering in the mid levels. Low level wind
profile is impressive with nice curvature in the hodograph. Most
importantly, the capping inversion has effectively eroded in
the 18z ob. Initiation should when better upper level support
arrives mid-afternoon, roughly 2-4PM, with a mixed convective
mode before turning more linear. Storms impact the Twin Cities
metro between 5 and 8pm. Heading into the evening hours, the
front becomes more progressive and will shift the showers and
storms into western Wisconsin with an overall diminishing trend
by mid to late evening.
Wednesday and Thursday... A brief break in the active weather
pattern on tap for Wednesday and Thursday. Both days will be dry
& pleasant with highs in the low to mid-70s, partly sunny
skies, and light winds. Rain chances return Thursday night into
Friday ahead of our next system.
Friday through early next week...Southwest flow aloft will return
and so will the moisture. This will support additional rain chances
Friday and Saturday, with an additional 1-2" of rain likely for most
locations, and 3"+ still possible where the strongest storms move
through. Guidance hints at a slow moving system as it moves into the
Upper Midwest on Friday. Placement of the surface boundaries will be
important due to the potential for heavy rain. Any additional rain
will contribute to additional rises in area rivers and streams for
exacerbate flooding concerns into next weekend and early next week.
Temperatures appear to warm back up during this period with highs in
the 80s.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 641 PM CDT Tue Jun 18 2024
Main issues for this TAF set are the timing of any TSRA into the
terminals and how quickly ceilings drop into MVFR/IFR levels
behind the storms. Western MN has already had the drop to IFR as
evidenced by AXN. The trend is to have those lower ceilings
spread east with the precipitation but confidence not quite high
enough to go IFR at all terminals so have held ceilings at other
sites in MVFR range, waiting to see how trends evolve. As for
precip, have backed off the prevailing mention of TSRA in favor
of a shorter-duration TEMPO wording as convection does not have
the coverage as anticipated earlier. Still, certainly cannot
rule out TSRA at any terminal over the first few hours of the
19/00z TAF. Behind the convection, winds will diminish and shift
to W-NW with speeds around 10kts. MVFR ceilings will then hold
in place overnight through most of tomorrow. If anything, VFR
conditions may develop earlier than currently advertised.
KMSP...Best window for having convection across the MSP area
still looks to be 00z-03z as there are currently echoes near and
around MSP that can easily develop into taller thunderstorms.
The duration of any given storm will be relatively short, hence
the TEMPO mention instead of prevailing. Once the main line,
broken as it may be, moves through, wind speeds will diminish
and directions will shift to westerly while ceilings drop into
MVFR range. MVFR ceilings will then hold through late tomorrow
afternoon if not tomorrow evening before conditions improve to
VFR.
/OUTLOOK FOR KMSP/
THU...VFR/MVFR, chc -TSRA/-SHRA. Wind E 5-10kts.
FRI...VFR/MVFR, chc -TSRA/-SHRA. Wind S 10-15kts.
SAT...VFR/MVFR, chc -TSRA/-SHRA. Wind SW 10-15kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
MESOSCALE...DPH
DISCUSSION...BPH
AVIATION...JPC
Area Forecast Discussion
National Weather Service Pueblo CO
642 PM MDT Tue Jun 18 2024
.KEY MESSAGES...
- Non zero threat of thunderstorms and a few landspouts in Baca County
this evening.
- Widespread rain showers and thick clouds across the eastern
plains Wednesday, with some thunder over the mountains.
- Another warming trend late week into the weekend.
- Uptick in thunderstorms over the mountains late week as
southerly flow picks up some subtropical moisture.
- A return to around 100 degree readings across the plains early next
week.
&&
.UPDATE...
Issued at 641 PM MDT Tue Jun 18 2024
Quick update to the forecast database due to the expiration of
the Red Flag Warning for today. Incorporated latest HRR and
RUC model data as well as observations.
&&
.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 242 PM MDT Tue Jun 18 2024
Rest of Today...
Relatively quiet weather for the first part of today across the CWA,
with the front already moving to our south. High temperatures will
be cooler than yesterday, with mid-80s to low-90s over the southeast
plains and low-80s across most of the higher terrain. Winds will be
occasionally gusty but less than yesterday, and humidity over the
plains has increased behind the front enough to abate critical fire
weather conditions for now. However, the Red Flag Warning will
remain this afternoon over the San Luis Valley, as the humidity
values out there are still low and were mostly unaffected from the
passing front.
Our potentially more active weather will happen this evening, as the
front stalls out just south of our forecast area. The positioning of
the front will be crucial to how much activity we actually see, as
convective models show a line of thunderstorms forming along the
boundary and intensifying. The majority of models currently show the
convection initiating south of our area and largely staying there,
however a shift in position just a few miles north could put some
storms in Baca County. For any stronger storms that do manage to
form over our far southeast plains, enhanced heavy rain, some hail,
and even a few landspouts will be possible.
Tonight-Wednesday...
With post-frontal moisture and lingering convection, wet and
unsettled conditions will persist overnight and into early
Wednesday. Scattered showers and heavy rainfall will spread across
parts of the eastern plains, becoming more widespread the closer you
get to the KS border. A few stronger storms will be possible, mainly
over our far southeast counties. Precipitation will continue to
build west through the night and into the early morning hours, with
rain moving over I-25 around sunrise. Showers will start to decrease
in coverage closer to the mountains as we move into Wednesday, but a
low, thick cloud layer will last into the day.
High temperatures on Wednesday will be around 15 degrees cooler than
Tuesday, possibly even cooler in some areas thanks to extensive
cloud cover. The mountain valleys will not see the full impact of
the front, remaining in the high-70s to low-80s. Meanwhile, the
moist post-frontal airmass will remain in place with easterly
upslope over the plains. More stratiform-type rain showers will
spread over most of the eastern plains throughout the day, and
though there could be an embedded rumble of thunder, instability
will likely be too low. Southwest flow aloft should assist in some
weak thunderstorm formation over the mountains, with some locally
heavy rainfall being the main concern. Storms over the mountains
should stay sub-severe, though locally heavy rainfall could have
some impacts in more vulnerable locations.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 242 PM MDT Tue Jun 18 2024
Temperatures gradually warm again through late week as southerly
flow ahead of the next Pacific trough brings rising heights
aloft over CO. The warm up will be somewhat mitigated by an
influx in subtropical moisture as the H7-H5 layer specific
humidities increase to 6+ g/kg. This will bring an uptick in
thunderstorms to the mountains especially Thursday and Friday.
Day time humidity values will increase as well which should put
an end to critical fire weather conditions for a while, but
raise concerns for heavy rainfall on burn scars. Mean CAPE
values off national model blends are highest on Thursday ranging
from 500-1000 J/kg in the 50-75th percentiles and ranges. They
drop around 250 J/kg for Friday. Storm motions will be to the
north due to deep southerly flow aloft. A few strong storms will
be possible over the mountains where deep layer shears will be
around 30+ kts both days. Hail under 1 inch in diameter and wind
gusts up to 50 mph will be possible. Best forcing will be late
Friday as the dampening western U.S. upper trough ejects across
NW CO. This may keep some showers and isolated thunderstorms
going most of the night across the mountains though intensities
will be weaker with loss of heating during the overnight hours.
Drier and warmer weather returns for the weekend into next week as
the upper ridge aloft builds over the southern/central U.S. Rockies.
Temperatures will be back up to around 100 across the plains for
Monday and Tuesday. Probabilities for afternoon and evening showers
and thunderstorms gradually decrease though winds look to stay below
critical fire weather thresholds. -KT
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 548 PM MDT Tue Jun 18 2024
KALS: VFR conditions are expected over the next 24 hours. Winds will
remain relatively light overnight, and then start to increase during
the early afternoon. Mid level clouds will also start to increase
some during this TAF period, but dry conditions are anticipated
through tomorrow.
KCOS and KPUB: VFR conditions are expected through this evening,
with MVFR conditions developing overnight and persisting through
much of this TAF period, primarily due to low clouds. Speaking of
clouds, mid to low level clouds will develop overnight and remain in
place through much of this TAF period, with minor lifting/thinning
of clouds possible near the end of this TAF period. Along with that,
drizzle to light rain is expected as moist east to southeast upslope
flow prevails. Otherwise, pockets of light precipitation are
expected around both TAF sites through much of tonight and
tomorrow.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...MOORE
SHORT TERM...GARBEROGLIO
LONG TERM...KT
AVIATION...SIMCOE