Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/17/21
Area Forecast Discussion
National Weather Service Corpus Christi TX
642 PM CDT Wed Jun 16 2021
.AVIATION...
Showers and storms generally weakening this afternoon around the
VCT area. With outflow continuing to push southwestward, could see
another cell or two develop, but not expected to be in the
vicinity of any TAF sites. Mainly VFR conditions will persist
through the period, but could briefly see some vis restrictions
in the morning with fog. Winds will be fairly light through the
period. An isolated shower or storm will again be possible
Thursday afternoon, most likely around VCT, but coverage is
expected to be too small to include in TAF this early.
&&
.PREV DISCUSSION... /Issued 218 PM CDT Wed Jun 16 2021/
SHORT TERM (Tonight through Thursday Night)...
Some remnant showers may still be around in the early evening over
the Victoria Crossroads where CAM models have been showing a few
cells pass through the area like it has been the last few days.
Otherwise, dry conditions will dominate for all of South Texas
overnight as surface to mid-level ridging takes over. Short-term
guidances show an upper-level trough over the Texas Coast in between
the high pressure over the Four Corners and deep trough over the
east Atlantic coast that may allow for a few cirrus clouds to remain
present. Lows tonight will remain in the 70s across the area.
Thursday will contain another slight chance of showers and
thunderstorms over the Coastal Bend and Victoria Crossroads,
especially in the late afternoon into the early evening. Very
similar to the past few days where showers and storms developing to
the northeast progress southwestward towards the CWA, many times
weakening in the process. Wouldn`t be surprised to see a few cells
develop along the seabreeze along with surface heating and CAPE well
over 1000 J/kg. The RAP and NAM indicate CAPE ranging from 2500 to
3500 over the Coastal Plains and Victoria Crossroads with very
little to no CINH. Factors limiting convection potential include:
lack of mid-level energy (remains mostly to our south), building
high pressure from the surface to the mid-levels, and PWATs only
maxing around 1.5" (slightly below normal). Highs across South Texas
Thursday should remain in the 90s, with heat indices staying below
105.
CAM guidances are showing some convection from the HGX area to make
it into the northeast CWA. Knowing these type of models don`t
perform best at tropical disturbances, leaning against this
development. The disturbance should be moving northward through this
time period, staying east of the coast and keeping inland portions
on the dry west side. Lows in the 70s are expected through the
area.
LONG TERM (Friday through Wednesday)...
A mid to upper level ridge will begin to shift to the west
Friday, then persist west of the area through the weekend. Model
guidance and the NHC continue to highlight an area of disturbed
weather currently in the Bay of Campeche that is expected to move
north into the Gulf of Mexico and develop into a tropical depression
by late Thursday night into Friday, then move ashore by early
Saturday. As the potential tropical cyclone moves to the north, it
should remain east of our area thanks to the upper level ridge. This
doesn`t mean we are completely out of the woods for several reasons.
Firstly, the system has not developed so there is a lot of question
as to how strong it could become, what track it will take, along
with several other variables. Next, with a passing potential
tropical cyclone, increased swell and wave periods will lead to some
coastal effects. An increased rip current risk is expected by
Saturday and continuing into early next week. Minor coastal flooding
will also be a concern as increased swell and longer wave periods
push water ashore. At this point, inundation of up to 1 ft MSL is
expected but the forecast can and probably will change as the
potential tropical cyclone develops. The main concern for South
Texas will likely be rainfall. A slug of moisture will creep into
the area increasing PWAT values from around 1.5 inches to near 2.3
inches by Monday. Meanwhile, an upper level trough will dig in
behind the system, sending a cold front/boundary into the Hill
Country. This looks as though it will wash out by the time it
reaches our northern counties, but it will likely lead to some
isolated to scattered showers and thunderstorms. With PWATs this
high, it is not out of the question to have heavy rainfall,
particularly across the Victoria Crossroads and Coastal Plains. It`s
still too questionable to throw out any amounts, but this will
probably be considered in the next day or two. Generally diurnal
rain chances will then continue through the week as moisture
continues.
Otherwise, temperatures are likely to be hot and moisture is
expected to be high. A Heat Advisory may need needed for much of the
area each afternoon as the heat index values at many locations could
reach 110 to 114.
MARINE...
Weak easterly flow tonight will strengthen to moderate and shift
northeasterly Thursday. Moderate northeasterly to easterly winds
will persist through Thursday night. Isolated showers and
thunderstorms are possible through Thursday, increasing to scattered
Thursday night. Moisture will continue to increase Friday and
Saturday, lingering through the middle of the week. This will lead
to isolated to scattered showers and thunderstorms through the
middle of the week. Moderate to strong winds as well as increased
swell will lead to Small Craft Advisory conditions through
Saturday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 74 93 74 91 76 / 10 20 10 30 20
Victoria 74 94 73 93 74 / 20 20 10 20 30
Laredo 74 98 75 98 75 / 10 10 0 20 10
Alice 72 95 71 93 73 / 10 20 10 20 20
Rockport 77 93 77 94 77 / 10 20 10 30 30
Cotulla 74 98 75 98 75 / 10 10 0 10 10
Kingsville 73 93 72 92 73 / 10 20 10 30 20
Navy Corpus 79 91 78 91 78 / 10 20 10 30 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
PH/83...AVIATION
Area Forecast Discussion
National Weather Service Cheyenne WY
523 PM MDT Wed Jun 16 2021
.SHORT TERM...(Late this afternoon through Thursday night)
Issued at 225 PM MDT Wed Jun 16 2021
Upper ridge axis extended from the Dakotas to the Four Corners. A
surface front reached from north-central NE to along the I-80
corridor in southeast WY and southern NE Panhandle. Visible satellite
showed areas of moderate/towering CU from Cheyenne west to near
Arlington. CYS radar detected isolated high-based showers and a
few thunderstorms developing over the Laramie Valley and South
Laramie Range. The HRRR and NAMNest high-res models have performed
well with the convective initiation and coverage thus far. This
activity will spread east along I-80 in the southern NE Panhandle
through early evening. Brief wind gusts to 40 mph or higher will
be the primary hazard with the convection. Otherwise, the main story
has been the record/near-record heat with temperatures in the mid
90s to lower 100s east of the Laramie Range. Temperatures will
gradually cool this evening, with overnight lows in the mid 50s to
lower 60s.
Thursday will not be as hot as 700mb temperatures lower to the
mid and upper teens Celsius. Expect afternoon highs in the upper
80s and 90s. It will be breezy along and west of the Laramie Range
from late morning through the early evening. Hi-res models depict
isolated convection forming along the surface boundary near the
WY/NE/CO border late Thursday afternoon and early evening, and
over the northeast NE Panhandle after midnight.
.LONG TERM...(Friday through Wednesday)
Issued at 401 AM MDT Wed Jun 16 2021
Model solutions trend with the evolution of the cold front passage
transitioning into more of a stationary front with cooler temperatures
compared to previous days but still above normal prior to going
into the weekend with zonal to northwest flow. GFS has the 594 dam
high pressure center absorbed early Friday morning as approaching
shortwave and low level moisture provide a chance for isolated to
scattered showers and thunderstorms Friday afternoon. Guidance
pinpointing better precipitation chances across the NE Panhandle
and CO plains over the WY side.
Deepening trough axis late Saturday into Sunday provide WY a chance
for precipitation and cooler temperatures closer to our averages.
Ridging pattern sets in Monday morning as next system for next week
approaches the CA coast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 512 PM MDT Wed Jun 16 2021
VFR conditions will continue throughout the TAF period until 00Z.
Gusty winds up to 30kts will continue at southeastern Wyoming
terminals KCYS until 02Z and KRWL until 07Z. For the western
Nebraska Panhandle, gusty winds up to 30kts will continue until
04Z. SKC to SCT is possible across the region.
&&
.FIRE WEATHER...
Issued at 225 PM MDT Wed Jun 16 2021
Hot, breezy and mostly dry conditions will persist through Thursday.
Critically low humidities, winds and high Haines indices will maintain
high fire danger along and west of the Laramie Range. Fuels are conducive
to rapid fire growth in the Sierra Madre, Snowy and South Laramie Ranges.
A weak front will bring cooler temperatures and lighter winds Friday,
followed by warmer temperatures and gusty winds Saturday. A stronger
front will usher in much cooler temperatures Sunday and Monday, along
with scattered showers and thunderstorms.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Fire Weather Watch from Thursday morning through Thursday
evening for WYZ305-307-309.
NE...None.
&&
$$
SHORT TERM...MAJ
LONG TERM...WM
AVIATION...AW
FIRE WEATHER...MAJ
Area Forecast Discussion
National Weather Service Duluth MN
650 PM CDT Wed Jun 16 2021
.DISCUSSION...(This evening through Tuesday)
Issued at 359 PM CDT Wed Jun 16 2021
Summary: A more active and cooler weather pattern starts tonight
with several cold fronts and areas of low pressure affecting the
region. Scattered showers and storms will accompany a cold front
as it propagates eastward across Minnesota tonight. Storms may
refire ahead of the front central Minnesota into northwest
Wisconsin Thursday afternoon with dry and breezy conditions over
far northern Minnesota. Temperatures trend cooler Friday through
the weekend with several chances of showers and thunderstorms.
Warmer temps return again by the middle of next week.
Late this afternoon a broken line of showers and thunderstorms
stretched from southeast Manitoba to southwest Minnesota and
eastern South Dakota. Storms immediately to our west and northwest
seem to be well ahead of the cold front in an area of low to
modest CAPE values of 500 to 1000 J/kg. The area along the front
remains capped with a MLCAPE corridor of 1000 to 2500 J/kg over
eastern North Dakota extending south into eastern South Dakota
where greater instability existed. High-res models are struggling
with the convection ahead of the front and dont seem very
excited about convective potential along the boundary itself. Have
raised POPs a little since this morning, but still below 50
percent given uncertainty in coverage of the storms. Precipitation
amounts where storms occur of 0.10 up to 0.50 inches is possible
and a few locations may see even higher amounts. A stout 700 mb
cap is in place ahead of the front and is expected to remain in
place based on RAP soundings until around the time of frontal
passage. Im skeptical well see much activity with the front.
The nocturnal low-level jet is forecast to nose into central
Minnesota tonight and may provide a sufficient enhancement to
convergence for elevated storms tonight and early Thursday
morning. Should storms develop there will be a risk of large hail
and damaging wind gusts. Locally heavy rain isnt out of the
question, either as storms may train along the edge of the jet.
The front any any outflow from overnight storms is forecast to
stretch southwest Minnesota to northwest Wisconsin late Thursday
morning. Showers and storms may be ongoing through the morning
near the front and are expected to strengthen/redevelop along the
boundary during the afternoon. A few strong to severe storms are
possible. Breezy conditions are expected behind the boundary over
northern Minnesota where deep mixing will result in RH values of
20 to 30 percent in the afternoon. Winds will be westerly at 8 to
15 mph and there may be a few wind gusts in the low 20s. The dry
and breezy conditions will increase the fire weather risk,
especially if those areas dont receive any rainfall tonight.
Another cold front will move into the region Friday with a
surface low to move eastward across northern Ontario. A tight
pressure gradient will lead to strong and gusty winds Friday into
Friday evening. Cold air advection aloft should result in a robust
cumulus field with scattered showers and perhaps a thunderstorm
or two. Temperatures will trend cooler with highs in the 60s north
and the low 80s south. Temps will be in the low 70s to around 80
on Saturday.
A few shortwave troughs will move over the region late Saturday
night through Monday and will push temps below normal with chances
of showers and thunderstorms. Tuesday and Wednesday will start
trending warmer once again and a few showers and storms are
possible on Wednesday and Wednesday night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 643 PM CDT Wed Jun 16 2021
An area of thunderstorms were moving into north-central Minnesota
this evening, well out in front of a cold front that was still in
the Red River Valley. These storms were strong and may produce
hail, up to the size of pennies, as they continue east over the
next 2 to 4 hours. Ceilings and visibilities will drop as the
stronger storms move through, especially at KINL/KHIB. The storms
are currently expected to weaken by late evening and may dissipate
altogether with time. However, the cold front will be moving east
and could initiate more storms but confidence in that occurring is
low so we only have the evening mention of storms in the TAFs
except at KHYR. There were some indications some lower
ceilings/fog could form as the gradient weakens and winds diminish
later tonight. However, the RAP shows the drier air prevailing and
we did not bite on the lower ceilings/fog at this time. More
thunderstorms may form Thursday as the cold front continues to
move east, mostly likely over portions of northern Wisconsin.
&&
.MARINE...
Issued at 359 PM CDT Wed Jun 16 2021
A cold front over the eastern Dakotas this afternoon will move
eastward with time tonight and Thursday. Showers and a few
thunderstorms are expected ahead of the front. A few storms may be
strong with wind gusts to 40 knots and small hail. Winds will
turn westerly behind the front for Thursday and may become gusty
in the afternoon and evening. West and southwest winds will
continue on Friday as an area of low pressure moves east across
far northern Ontario and pulls another cold front across Lake
Superior. Sustained winds of around 15 knots are possible and
there may be gusts as high as 25 knots, which would create
conditions hazardous to smaller vessels Friday into Friday night.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 57 83 59 73 / 50 10 0 10
INL 58 83 53 67 / 50 0 0 50
BRD 63 86 60 78 / 50 20 0 0
HYR 61 84 56 79 / 50 30 10 10
ASX 58 85 58 77 / 50 30 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
DISCUSSION...Huyck
AVIATION...Melde
MARINE...Huyck
Area Forecast Discussion
National Weather Service Des Moines IA
702 PM CDT Wed Jun 16 2021
...Updated Aviation Discussion...
.DISCUSSION.../Tonight through Wednesday/
Issued at 258 PM CDT Wed Jun 16 2021
Take Home Points:
*Hot tomorrow/Thursday - HI approaching 100-105 deg F for C/W/S IA
*Scant chances for storms tonight, severe threat remains Thursday PM
*Best widespread precipitation opportunity remains Sunday, uncertain
chances next week
Discussion:
Overall it was another quiet day across the area with only a few mid
to high level clouds stream across the area this afternoon. With the
thermal ridge remaining centered west of the state, the hottest
temperatures remained mostly W of the Missouri River, but will
arrive in earnest tomorrow. Highs today remain on track to reach the
upper 80s E to the mid 90s deg F. W and will remain tolerable with
dew points mostly in the 50s to low 50s deg F.
Looking into the forecast, let us start with temperatures. Thursday
will be the hottest day of the forecast period and hottest day of
the season for that matter. Thermodynamically, the pieces will be in
place, including 850mb temps into the mid 20s, modest SW flow, and
likely ample sunshine. That last item touches on a caveat that could
prevent some areas from reaching into the upper 90s to low 100s.
Anticipated scattered convection tonight may fester into the morning
and resulting debris clouds could delay peak heating and suppress
MaxTs a couple of degrees. Currently do not anticipate overnight
convection to be a major issue with best chances to the E of areas
with the best heat setup. More on the convection potential latter
though. As it sits, Widespread upper 90s/around 100 deg F MaxTs are
forecast from roughly Ames/Des Moines and areas to the S and W.
Another note, models have struggled with Td, too moist, which lends
to the forecast continuing to reside around the 75th percentile in
model certainty. It is also possible the forecast remains a degree
or two too low, especially if convection is a non-issue and Tds
remain lower than forecast. Regardless, it will be hot and have gone
with a heat advisory in the above mentioned area with heat index
values around 100 to 105 deg F expected. Please take the necessary
precautions if working or enjoying the outdoors for any prolonged
periods of time. After Thursday, conditions ease a bit but remain on
the warmer end of normal for this time of the year as large scale
flow turns northwesterly to zonal. Additional cooling should be seen
later Sunday on the heels of a frontal passage.
Turning to shower/storm/precipitation, there remain multiple
opportunities in the forecast but many areas of the state may not
receive substantial relief to current dry and drought conditions.
Tonight, theta-e advection ahead of the surface boundary will
continue and in conjunction with the LLJ should spark some
convection. Unfortunately, the warm mid-levels may prevent much
activity from initiating in the area and may end up relying on
storms in MN streaming S. The threat for severe remains low, but
elevated storms with dry low levels would suggest damaging winds as
the primary threat and hail secondary. Activity should wane in the
morning hours and clear out/yield sunshine for the hot day Thursday.
For Thursday afternoon/Thursday night, there remains a SPC Slight
Risk for portions of central into northern and northeast IA.
Perusing forecast sounding, consistency remains in quite a large cap
to overcome throughout the forecast area. The cap is less robust as
you work into S MN, and will be the likely location for initial
convection in the mid-late afternoon as the boundary approaches and
shortwave moves through. Large MUCAPE 2000+ J/kg, increasing shear
profiles to around 50 kts 0-6km, and the dry low levels point
towards a large hail and wind threat for early storms, including
supercells possible. Of note, 18z extended HRRR does suggest that a
couple of supercells may track across N IA while most larger scale
guidance suggested initiation and track further N. Evolution into
the evening remains likely that additional convection will congeal
into a progressive MCS with the main severe threat damaging winds as
the LLJ increases. The overall track also continues likely be mostly
N and E of the forecast area, following mean flow across southern MN
and then turning SE into S WI. Backbuilding to the SW will be
dependent on both the strength of outflow and the LLJ. Even so,
confidence is not great that significant expansion will be seen into
central Iowa at this time. As the boundary sags southward Friday AM,
additional decaying activity may be seen from storms streaming in
from prior LLJ activity in NE. Most activity Friday/Saturday should
remain south of the state as the boundary settles into MO.
After Thursday/Thursday PM, next opportunity will be Sunday with
synoptics remaining in fair agreement on fairly widespread
precipitation along/ahead of a cool/cold front and larger upper
trough passage. Any strong/severe potential remains difficult to
hone in on and will be hashed out in the coming days. Beyond Sunday,
chances remain in flux with the 12z deterministics trending dryer
than previous runs. Ensembles too look to have trended drier next
week, unfortunately.
&&
.AVIATION.../For the 00Z TAFS through 00Z Thursday evening/
Issued at 700 PM CDT Wed Jun 16 2021
Expecting VFR conditions for the majority of the TAF period. There
is the potential for some convection later tonight into the
overnight hours. If a storm does happen to pass over a TAF site,
there is the potential for visibility restrictions with some
decent rainfall. High LCLs tonight thought should keep ceilings
VFR.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 1 PM to 8 PM CDT Thursday for IAZ033>036-
044>048-057>061-070>075-081>086-092>097.
&&
$$
DISCUSSION...Curtis
AVIATION...Podrazik
Area Forecast Discussion
National Weather Service Gray ME
1032 PM EDT Wed Jun 16 2021
.SYNOPSIS...
High pressure builds into the region for the middle of the week
with seasonable temperatures and a dry westerly flow.
Temperatures start to increase by the end of the week. A cold
front crosses Saturday with a chance for showers and
thunderstorms. Sunday and Monday look dry and warm as high
pressure builds in again. A more unsettled period is likely by
Tuesday and Wednesday of next week with more showers and
thunderstorms.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
1030 PM Update...No changes to the going forecast. Isold showers
are just about dissipated and temperatures are dropping as
forecast.
640 PM Update...Just a few very minor adjustments to the going
forecast at this time. Isolated showers near the Canadian border
will continue for the next couple of hours then dissipate.
Otherwise, mostly clear skies for the rest of the region with a
westerly breeze gradually diminishing.
Previously...
The latest HRRR continues to indicate a few scattered showers
for the rest of this afternoon over the northern mountains.
This precipitation rotating around the periphery of the upper
level low pressure system will continue into this evening before
finally dissipating during the overnight hours.
Otherwise, dry conditions with low dew points in place tonight.
These dry conditions and a marginal westerly gradient should
prevent fog from forming in most areas. It will be chilly with
overnight lows in the 40s across the interior and lower 50s
along the coast.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
The stubborn to move, upper level trough will finally begin to
exit the region on Thursday. This will leave most of the area
with mostly sunny skies. Over far northeastern portions of the
forecast area, expect more in the way of cloudiness in a region
of best cyclonic flow aloft.
High temperatures will be once again in the 70s in most areas,
with the exception of the higher terrain where readings will
hold in the 60s.
Temperatures will drop back into the 40s Thursday night as much
of the warm air across the country remains backed up to our
west. A southwesterly gradient will develop, however it will
most likely hold off until Friday morning.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
High Impact Weather Potential:
* Some potential for severe thunderstorms on Saturday.
* Additional shower/storm risk next Tue-Wed...with some
potential for significant precipitation.
--Pattern and Implications--
The pattern across North America early this afternoon shows longwave
troughing along the east coast of the United States...with what has
been a longwave ridge across the west becoming more SW/NE oriented
given shortwave energy pulling into the northwestern US.
Teleconnection indices continue to show a -EPO with a weakly
positive AO and not much in the way of other significant signals.
The -EPO indicates the west coast blocking which doesn/t allow for a
clear path for Pacific energy to move into the western US with
impressive /and record heat-causing/ ridging firmly entrenched over
the southwest. Going forward...longwave ridging strengthening over
western Canada north into Alaska will allow energy over the arctic
to dive south into central Canada which will act to initially erode
the troughing along the east coast through this weekend and causing
the longwave trough position to retrogrades to the central portion
of North America. This will direct a southwesterly flow over our
region before this trough then advances east to end the forecast
period. Thus...an initial warming trend is expected into the
weekend and early next week with the initial shortwave kicker
responsible for eroding the eastern trough bringing our first chance
of sensible weather. Beyond this a warm and increasingly humid
early week before the approaching longwave trough from the west
brings our next potential precipitation event to end the long term
period.
--Daily Details--
Friday: Building heights with backing mid and upper level flow as
troughing lifts east of the region. T8s move to near +13C...a solid
5C warmer than on Thursday which should allow southern areas to warm
to above 80 with highs in the upper 70s to around 80 in the
mountains under partly/mostly sunny skies and moderate southwesterly
breezes.
Saturday: Substantial northern stream trough will move north of the
region through the day with a warm front crossing the region in the
morning followed by the cold front Saturday night. Mid level wind
field is robust and suggests a conditional risk for severe weather
given enough instability. That is uncertain as morning convection
along the advancing warm front may limit daytime heating. At this
range...there/s not enough predictability to say confidently that
there will be severe, but it appears rather likely that most areas
will see rainfall and continue to nudge PoPs upward consistent with
recent NBM guidance. Clouds/precipitation could have a
significant impact on temperatures...but with T8s roughly 1C
warmer than on Friday..it won/t take much in the way of breaks
for southern areas to move into the 80s with 70s in the
mountains.
Sunday-Monday: Cold front will be offshore Sunday morning which will
yield a slightly drier airmass...but little change in temperature. A
weak secondary front nearing the international border may spark an
afternoon shower...but expect ample sun and temperatures in the 70s
in the mountains and lower to middle 80s to the south. As the flow
turns more southwesterly into Monday the heat begins to build as T8s
move above 15C likely allowing our warmest locations over southern
NH to make a run at 90 with 80s elsewhere. There are some
differences in the timing of shortwave energy out ahead of the
advancing longwave trough...so there is the chance for an
afternoon/late day shower/thunderstorm.
Tuesday-Wednesday: Longwave trough moves into the region to end the
long term forecast period with a substantial cold frontal passage.
Deep southwesterly flow ahead of the arriving front/trough suggests
ample opportunity for showers and thunderstorms with an added
complication from the tropical disturbance now over the Bay of
Campeche. Much can change...but the potential exists for moisture
associated with this system to get drawn north ahead of the
advancing trough increasing heavy rain potential. High pressure and
somewhat cooler temperatures should arrive behind the advancing
front on Wednesday.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Short Term...The northwesterly gradient will relax after sunset
tonight. Otherwise, VFR conditions expected tonight through
Thursday night.
Long Term...VFR Friday with showers arriving Friday night
bringing the potential for MVFR restrictions. This will continue
on Saturday with an approaching cold front bringing additional
showers and thunderstorms before drier air arrives with VFR for
Sunday and Monday. Winds look to generally remain less than
15kts through the period.
&&
.MARINE...
Short Term...Latest guidance suggests swell up to 5 feet at
times across the outer waters tonight and Thursday from the
remains of formally known TS Bill. Coordinated with Caribou and
feel this might be a little overdone. Expect up to 4 footers
across the outer waters with no headlines in effect.
Westerly winds tonight will gradually back to the southwest on
Thursday and Thursday night.
Long Term...Strengthening southerly winds on Friday night and
Saturday will likely necessitate SCAs at least on the outer
waters lingering into Saturday night with headline-free
conditions likely for Sunday - Monday.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
NEAR TERM...Cannon/Ekster
SHORT TERM...Cannon
LONG TERM...Arnott
Area Forecast Discussion
National Weather Service Lincoln IL
834 PM CDT Wed Jun 16 2021
.SYNOPSIS...
Issued at 315 PM CDT Wed Jun 16 2021
Heat and humidity will return to central Illinois over the next
couple of days. High temperatures will reach the lower 90s on
Thursday, then will climb into the middle to upper 90s by Friday.
One round of potentially strong thunderstorms will be likely late
Thursday night along and north of the I-74 corridor, while
additional scattered strong to severe storms develop across the
region Friday afternoon and evening.
&&
.UPDATE...
Issued at 831 PM CDT Wed Jun 16 2021
Forecast is on track this evening with quiet conditions expected
through most of the overnight hours. Some of the latest model runs
including the 00Z HRRR show overnight convection glancing our
westernmost counties during the early morning hours Thursday. 20
percent PoPs will cover this possibility for now, with the best
chances remaining west of the forecast area.
&&
.SHORT TERM...(This evening through Thursday)
ISSUED AT 315 PM CDT Wed Jun 16 2021
High pressure extending from the Great Lakes to the Gulf Coast
will provide one more cool/dry night across central Illinois, with
lows ranging from the middle 50s near the Indiana border to the
lower 60s west of the Illinois River. As the high slowly moves
away, a frontal boundary across the Plains will shift eastward.
While upper support will remain weak, convergence along the
boundary will be sufficient to trigger scattered convection from
Minnesota southward into Iowa/Missouri tonight. Some of this
activity could spill into west-central Illinois toward dawn before
rapidly dissipating upon weakening of the diurnal jet by mid-
morning. Have included slight chance PoPs along/west of the
Illinois River Thursday morning accordingly. The rest of the day
looks to be dry and warmer with afternoon highs topping out in
the lower 90s.
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 315 PM CDT Wed Jun 16 2021
A cluster of strong to severe convection is expected to develop
across northeast Iowa into southwest Wisconsin Thursday evening in
advance of a short-wave trough. With a 40-50kt 850mb jet feeding
into the system, the storm cluster is then expected to track E/SE
across northern Illinois overnight. Model track solutions vary,
but consensus suggests locations along/north of I-74 are favored.
Have therefore bumped PoPs up to likely across the northern KILX
CWA late Thursday night...tapering down to just slight PoPs along
a Rushville to Mattoon line. If the MCS materializes as expected,
the potential exists for damaging wind gusts along/north of I-74.
Once the late night convection tracks into central/northern
Indiana, the trailing outflow boundary will serve as the focus for
additional thunderstorm development across parts of central
Illinois Friday afternoon. With temperatures soaring into the
middle to upper 90s and dewpoints hovering in the upper 60s to
around 70 degrees, SBCAPEs will exceed 3000J/kg. In addition,
0-6km bulk shear will increase to 30-40kt. Despite the highly
unstable and moderately sheared environment, a very warm mid-level
cap characterized by 700mb temps of 11-12C will likely inhibit
widespread convection. Most models suggest storms will become more
numerous further downstream along the outflow across Pennsylvania
into Ohio/Indiana. Even though storms will not be particularly
widespread, any cells that manage to break the cap and take
advantage of the high CAPE will be capable of very large hail and
damaging wind gusts. Think this will be most likely along/east of
I-57 where higher PoPs are warranted. After an uptick in areal
coverage Friday night, storms will become more widely scattered
Saturday/Saturday night as a frontal boundary remains draped
across the region.
After a hot/humid weekend, a vigorous short-wave diving southward
out of Canada will bring a significant pattern change by early
next week. As this feature digs a sharp upper trough over the
Great Lakes/Midwest, it will push a strong cold front through
central Illinois...resulting in high chance to likely PoPs Sunday
afternoon through Monday morning. After that, a much cooler/drier
airmass will arrive...with high temps dropping into the 70s by
Tuesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 620 PM CDT Wed Jun 16 2021
Mainly a wind forecast across the central Illinois terminals with
no significant weather and VFR conditions expected. Light winds
will be in place overnight, generally favoring an E to NE
direction but will be calm or variable at times. Winds will set up
out of the SE late tonight/early Thursday then veer to south
Thursday afternoon with some gustiness possible.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Deubelbeiss
SYNOPSIS...Barnes
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Deubelbeiss
Area Forecast Discussion
National Weather Service North Platte NE
635 PM CDT Wed Jun 16 2021
.SHORT TERM...(This evening through Thursday night)
Issued at 334 PM CDT Wed Jun 16 2021
Isolated thunderstorm chances are in place this evening across
small parts of swrn and ncntl Nebraska. These thunderstorms are
associated with very steep lapse rates aloft and are expected to
remain high based non-severe storms. There is a small chance for
sfc based storms across ncntl Nebraska but temperatures aloft-
14C-16C at h700mb would seem to make that unlikely.
The temperature forecast for Thursday uses the guidance blend plus
bias correction for highs in the upper 80s to around 90 north and
90s to near 100 south. This forecast is consistent with the expected
location of a cold front shown by the NAM and RAP models along or
just south of Interstate 80. A Heat Advisory will be issued for
Thursday across Chase, Hayes and Frontier counties where
temperatures and heat indices will be highest- around 100F. There is
a chance the advisory might need to be extend north a bit, perhaps
along I-80 if it appears the front will slow up as suggested by the
ECM guidance which gives North Platte a high of 100F Thursday.
Another rain chance develops late Thursday night as depicted by the
SREF, HREF, NAM and GFS. These thunderstorms will be post frontal
affecting nrn Nebraska and appear to be forced by a mid level
disturbance moving east through Wyoming. The SREF suggests midlevel
frontogenesis will be operating.
.LONG TERM...(Friday through Wednesday)
Issued at 334 PM CDT Wed Jun 16 2021
Today`s model runs of the GFS and ECM show the record setting
subtropical ridge retreating south toward Old Mexico and remaining
south of the Central plains Friday through Wednesday. This will
place wrn and ncntl Nebraska in a zonal upper level flow this
weekend which transitions to northwest flow aloft next week.
The models are perking up rain chances late this weekend into early
next week as mean column RH increases to 60 percent or greater at
times. Moisture appears to peak Sunday night or Monday and then fall.
WPC which tends to lean on the drier ECM suggested total rainfall of
1/4 inch or less during the next 7 days. Temperatures aloft at
h700mb will be quite cool, less than 10C, which could easily support
storm development and winds aloft at h500mb increase to 30 to 50
kts. It is surprising the models aren`t showing organized thunderstorm
development and the blended forecast suggests just isolated to
perhaps scattered storm development. This is probably because the
better focus, the h850mb front, will be located across the Srn
Plains or the Nrn Plains. It will be interesting to see what
happens across wrn and ncntl Nebraska as this front moves south
and north of the region.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 634 PM CDT Wed Jun 16 2021
Mostly quiet aviation conditions are expected through Thursday.
Winds remain at or below 10 knots at KLBF with slightly stronger
winds at KVTN behind the departing front. Dry conditions are
expected as well. A few isolated thunderstorms may develop to the
west, but shouldn`t impact either terminal.
&&
.HYDROLOGY...
Issued at 334 PM CDT Wed Jun 16 2021
Releases from Lake McConaughy have increased to around 1500cfs.
This should send the North Platte river level above action stage
at North Platte.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT /7 PM MDT/ this evening for
NEZ005>010-024>029-036>038-057>059.
Heat Advisory until 8 PM CDT /7 PM MDT/ Thursday for NEZ069>071.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Kulik
HYDROLOGY...CDC
Area Forecast Discussion
National Weather Service Phoenix AZ
523 PM MST Wed Jun 16 2021
.UPDATE...Updated Aviation Discussion.
&&
.SYNOPSIS...
Extreme heat will persist throughout the week as high temperatures
generally remain 10 to 15 degrees above average and flirting with
daily records. Excessive Heat Warnings are in effect across all
areas of southern Arizona and southeast California. Even higher
elevation areas will experience uncommon, and potentially dangerous
heat. Isolated afternoon thunderstorms are likely over southern
Arizona and the mountains of northern and eastern Arizona through
Friday, sending gusty winds and cloud cover into lower elevation
communities.
&&
.DISCUSSION...
While the extreme heat continues to be the main forecast concern
affecting all areas, daily chances for isolated thunderstorms
producing gusty winds and dust will also be a concern through
Friday. The upper level high center will remain parked over the Four
Corners area through Thursday providing easterly mid level flow
across the southern half of Arizona into southeast California. This
easterly flow continues to increase moisture in the mid levels, with
this morning`s KPSR balloon sounding showing a PWAT value of 0.87
inch, up from yesterday morning`s reading of 0.64 inches. This
morning`s sounding is also showing a somewhat strong/deeper layer of
mid-level easterly flow than what we saw yesterday. Low level
moisture levels have risen as well as southerly flow has pulled in
moisture off the Gulf of California. Surface dew points have risen
into the 50s across the Imperial Valley and much of Yuma County and
well up into the 40s across south-central Arizona. Once again,
latest 88-D radar imagery is showing the development of high terrain
showers and thunderstorms along the Rim and over the White Mountains
while GOES-17 WV imagery shows another PV anomaly rotating SE-ward
into eastern AZ. These showers/storms should once again propagate
westward during the evening hours while gradually weakening as they
move off the mountains. However, latest HREF and HRRR high-res model
output is indicating that less activity will make it into the lower
deserts than what we saw yesterday (with the 10% 30kt gust potential
contour only making its way to central Phoenix and the 30% contour
staying just outside (east) of the metro). At this point, given the
more favorable moisture/mid-level bulk shear levels, have hedged
POPS across the lower deserts towards the higher NBM values. Similar
to last night, the main impacts from any storms that form will be
strong outflow winds, localized blowing dust, and lightning. Also, g
given the fact that the afomentioned PV anomaly is forecast to
progress into SW AZ/SE CA later tonight, along with greater
available moisture across the region, have also trended with the
higher NBM POPS out there as well.
Latest NBM temperatures are similar to early this morning, with
today`s highs from around 115 degrees in Phoenix to 111-114 degrees
across the western deserts. This is likely due to expected lingering
lofted smoke from the Telegraph fire, scattered cloud cover, and
higher boundary layer moisture. The hottest days are likely to fall
on Thursday and Friday as some drier air filters in from the
southeast and less cloud cover is anticipated. Lofted smoke from the
Telegraph fire is still a bit of a wildcard and could reduce
insolation even through Friday, but for now the NBM (50th/75th
percentiles) continues to show 116-118 degrees for the Phoenix area
and 118-120 degrees for the western deserts Thursday and Friday. The
slight drying should also allow our storm chances to gradually lower
over the high terrain from Thursday into Friday, while weakening
steering flow further reduces the possibility of any convection
reaching into the lower deserts.
The upper level ridge is finally seen weakening starting Friday with
the center eventually shifting southwestward to over northern Baja
and southwest Arizona by Sunday morning. The lowering heights aloft
over the weekend will allow for a very gradual cool down with highs
likely lowering to 111-113 degrees for Phoenix on Sunday to 115
degrees across the western deserts. The shifting of the high center
will also bring mostly westerly dry flow across our area, likely
ending any high terrain convection by Sunday.
Model ensembles are in fairly good agreement a weak upper level
low will develop well west of southern California Sunday into Monday
before tracking to the northeast by the middle of next week. This
likely system should reinforce our west southwesterly dry flow aloft
while also pushing the ridge just to our east. This should further
bring some slight cooling to the region with highs likely falling
below excessive heat levels starting Monday. However, temperatures
are likely to remain slightly above normal through the first half of
next week.
&&
.AVIATION...Updated at 0022Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Westerly winds will prevail through the remainder of the afternoon
with a few gusts into the teens. Relatively low confidence in the
forecast going into the evening/nighttime hours in regards to any
potential convective impacts across the metro. Radar currently shows
isolated showers and thunderstorms across the high terrain well to
the north and east of Phoenix. Any isolated thunderstorm activity
making it into the Valley looks to remain low (< 10%) with perhaps a
few showers/virga making it into the lower deserts.
Confidence remains low in any potential outflows reaching the
Phoenix area later this evening with model guidance showing little
support for organized outflows making it into the Valley. Have not
made mention of outflows in the TAFs at this time given the low
confidence. There is still ~10% chance of erratic, gusty winds
originating from any lingering showers tonight. Wind component
may be from any direction depending on the location of showers
before eventually acquiring the typical late night easterly wind.
Otherwise, an elevated HZ/FU layer is likely to continue with
impacts to slantwise visibility, while SCT-BKN clouds aoa 15 kft
are expected late tonight through the overnight hours.
Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns are expected through the next 24 hours.
Winds at KIPL will favor the east/southeast through much of the
period while KBLH favors the south. Can`t rule out a few remnant
showers making it near KBLH overnight but confidence in this
occurring is low. Otherwise, expect SCT-BKN clouds aoa 15 kft at
times throughout the TAF period.
&&
.FIRE WEATHER...
Saturday through Wednesday:
Extremely hot temperatures across the region and slight chances
(~10-15%) for isolated thunderstorms producing very gusty winds and
lightning with little rainfall over the higher terrain of south
central Arizona will continue through Saturday. Even higher
elevation locations with active wildfires should see afternoon highs
above 100 deg F. Thunderstorm coverage and temperatures will
decrease on Sunday, with only very isolated thunderstorms expected
along the Rim and White Mountains. Temperatures 10-15 deg F above
the seasonal average will cool modestly to around 5 deg F above
average early next week. Isolated thunderstorms this week will
generally develop just outside the eastern districts with minimal
chances (~5%) for wetting rains persisting into the local zones.
However, an isolated strike and very gusty and erratic outflow winds
will be possible through Saturday. Otherwise, winds will generally
follow diurnal tendencies with the strongest non-thunderstorm
related gusts expected on Sunday. Afternoon minimum RH levels will
generally fall to around 10% each day, with overnight RH values only
recovering to a 15-40% range.
&&
.CLIMATE...
Daily Record Highs
Date Phoenix Yuma El Centro
------------ ------- ---- ---------
Wednesday 6/16 115 (1974) 119 (1917) 114 (1974)
Thursday 6/17 114 (2015) 115 (1981) 115 (1971)
Friday 6/18 115 (2015) 116 (2015) 117 (2015)
Saturday 6/19 118 (2017) 120 (2016) 119 (2016)
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Excessive Heat Warning until 8 PM MST Sunday for AZZ537-540>544-
546-548>551.
Excessive Heat Warning until 8 PM MST Saturday for AZZ530>536-
538-539-545-547-552>556-559>562.
Excessive Heat Warning until 8 PM MST Friday for AZZ557-558-563.
CA...Excessive Heat Warning until 8 PM PDT Sunday for CAZ562>567.
Excessive Heat Warning until 8 PM PDT Saturday for CAZ560-561-
568>570.
&&
$$
DISCUSSION...Percha/Kuhlman
AVIATION...Smith/MO
FIRE WEATHER...Percha/Kuhlman
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
742 PM EDT Wed Jun 16 2021
.FOR THE EVENING UPDATE...
Convection waning this evening, however a large area of stratified
light to moderate rain developing mainly south of the Sarasota
area to Fort Myers and extending over the interior. This will
likely persist for the next several hours before dissipating by
midnight.
W/V imagery continues to show a large plume of tropical moisture
over the eastern Gulf of Mexico and Florida peninsula. Atmosphere
remains quite unstable, and outflow boundaries from earlier
convection could initiate additional showers and possible
thunderstorms overnight. Most likely area would be where IR
imagery shows an east-west band of colder cloud tops across the
central Florida peninsula associated with an U/L shear axis. HRRR
also hinting at redevelopment by midnight vicinity the Tampa Bay
area and across portions of the nature coast. If redevelopment
does occur, main impact would be locally heavy rain. Another area
to monitor which is not being picked up well by the HRRR is a
strong outflow boundary pushing north northeast over the southeast
Gulf of Mexico toward southwest Florida. If it holds together, it
could bring another period of showers/thunderstorms with gusty
winds to the Fort Myers area around 830 to 9 PM. More likely the
fast moving boundary will weaken as it outruns its support and
moves into atmosphere that has already been worked over by recent
convection. Regardless, it will throw a boundary over southwest
Florida which should slow down and eventually stall over
southwest/south central Florida which could be a trigger for
additional convection overnight or early tomorrow morning as
atmosphere gradually recovers/destabilizes. Locally heavy rain
possible across the entire area should any training of cells
occur.
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...None.
Gulf waters...None.
&&
$$
UPDATE/AVIATION/MARINE...13/Oglesby
UPPER AIR...09/Rude
DECISION SUPPORT...09/Rude
Area Forecast Discussion
National Weather Service Las Vegas NV
832 PM PDT Wed Jun 16 2021
.SYNOPSIS...Dangerously hot conditions will continue through this
weekend as an expansive ridge of high pressure sits over the region.
Some mid-level moisture trapped under the ridge will spark isolated
terrain favored storms possible area wide Thursday and Friday. Not
as hot conditions return next week as the high pressure weakens but
&&
.UPDATE...Tack on another scorching day to this long duration
heatwave with new high temperature records set in Las Vegas, Bishop
CA, Barstow CA, Desert Rock NV, and Death Valley CA. We expect
many locations will set new record high minimum temperatures as
well Thursday morning as this heat event rolls on. Expect cloud
cover to increase overnight as debris clouds from thunderstorm
activity in Arizona today moves in from the east. The climate
section below was advanced a day to include Saturday temperature
extremes. The updated forecast will be out shortly.
&&
.PREVIOUSLY ISSUED DISCUSSION...
.SHORT TERM...through Friday night.
Excessively hot temperatures occurring across the region with 1 pm
values running on par or up to 2 degrees above this time yesterday.
Also, seeing more cumulus developing over the higher terrain of
Mohave County and the crest of the southern Sierra as mid level
moisture continues to gradually seep in under the ridge. HRRR
indicates ongoing storms between Flagstaff and Williams will
continue west this afternoon but weaken before reaching the eastern
Mohave County line. The only item to monitor would be outflow flow
winds reaching eastern Mohave County as the storm collapses over
Yavapai County.
Another round of debris clouds from convection over Arizona is
progged to drift west into the lower Colorado River and southeast
California late tonight. Again, due to the very dry air near the
surface don`t foresee any of this reaching the ground.
Models continue to show gradual moistening in mid levels tomorrow
and Friday. Not impressed by instability parameters tomorrow. Values
look slightly better on Friday for the mention of isolated showers
and thunderstorms primarily over the higher terrain. Not
expecting much rainfall from the storms.
.LONG TERM...Saturday through Tuesday.
The intense heatwave continue into the 4th consecutive day on
Saturday with new record high minimums expected to be set at several
locations. The latest NBM bumped Saturday`s high temp in Vegas up 1
degree to 114 which would tie the record for the day but high
temperatures elsewhere on Saturday are forecast to end up just shy
of records for the day. Temperatures fall a few degrees on Sunday as
high pressure weakens and is suppressed south by low pressure
shifting south out of Canada into the Northern Rockies/Plains.
However, there is not sufficient relief to call an end to the heat
event by Sunday and the Excessive Heat Warning may need to be
extended for one more day based on the duration of the event and the
minor temperature falls. Next Monday and Tuesday, weaker high
pressure is forecast over northern Mexico extending into Arizona and
southern New Mexico with an low pressure area off the west coast.
This is expected to result in more tolerable temperatures than we
have been experiencing but still around 5-7 degrees above normal.
Once the somewhat enhanced mid level moisture is flushed out over
the weekend, very dry conditions are forecast next week as
&&
.AVIATION...For McCarran...Easterly winds are forecast to shift to
the southeast late this afternoon and early this evening with
upticks in speed to 8-11 knots between 02z-04z. After 04z, southwest
winds will settle in with continued speeds of 8-11 knots through
midnight. Isolated showers and storms are possible over the higher
elevations of Clark County after 18z Thursday. Any activity could
produce erratic, gusty winds which could impact the terminal. These
gusty winds are most likely to originate from the south or west
direction during the mid to late afternoon. Cloud heights look to
remain above 15k feet.
For the rest of southern Nevada, northwest Arizona and southeast
California...South to southwesterly winds around 10 knots will
prevail for most areas through this evening. Isolated showers and a
couple storms will be possible over northern Inyo and Esmeralda
counties through this evening which could push some stronger winds
up the Owens Valley. At KBIH, westerly winds around 15 knots gusting
20-25 knots look likely between 20z-01z. A southerly push of wind is
possible at KBIH between 00z-02z but there is lower confidence in
this switch. On Thursday, isolated showers and storms will be
possible over a larger area with KBIH and KDAG seeing the better
chances of a direct impact to the terminal. However, all terminals
&&
.FIRE WEATHER...Extremely hot conditions will persist across the
region into the weekend. Gradual moistening in the mid levels of the
atmosphere will lead to the potential of high based thunderstorms
with little rainfall Thursday and Friday. Higher coverage of storms
is expected Friday prompting the issuance of a Fire Weather Watch
&&
.CLIMATE...Listed below are a few climate locations showing both the
record high maximum and high minimum temperature for each location and
the year the record was last set for this Wednesday, Thursday and Friday.
LOCATION THU-JUNE 17 FRI-JUNE 18SAT-JUNE 19
(HIGH MAX) Record(year) Record(year)Record(year)
Las Vegas NV 113(1940) 115(1940) 114(1940)
Bishop CA 104(2017) 107(1985) 107(2015)
Barstow CA 110(2017) 112(1985) 115(2017)
Needles CA 120(1917) 119(2017) 123(2017)
Kingman AZ 108(1917) 109(2017) 111(2017)
Desert Rock NV 106(2017) 108(2017) 110(2017)
Death Valley CA 122(1917) 124(2017) 125(2017)
Laughlin NV* 113(2017) 117(2015) 117(2017)
Lake Havasu City AZ* 115(1985) 115(1985) 117(2017)
* Not climate sites, but state temperature record holders.
LOCATION THU-JUNE 17 FRI-JUNE 18SAT-JUNE 19
(HIGH MIN) Record(year) Record(year)Record(year)
Las Vegas NV 87(2008) 86(2017) 88(2017)
Bishop CA 65(2002) 69(2017) 67(2017)
Barstow CA 78(1971) 79(1971) 79(2017)
Needles CA 88(2000) 90(1988) 87(2017)
Kingman AZ 79(1949) 73(2000) 75(1945)
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
&&
$$
UPDATE...Salmen
SHORT TERM/FIRE WEATHER...Pierce
LONG TERM...Salmen
AVIATION...Guillet
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