Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/14/20
Area Forecast Discussion
National Weather Service Billings MT
216 PM MDT Mon Jul 13 2020
.DISCUSSION...
Tonight through Tuesday night...
700 mb front and frontogenesis were progressing SE through the
area this afternoon. So far, front was just producing a few
showers over SE MT and one thunderstorm near Red Lodge. While
there was little to no CAPE, thunder was still possible into
tonight due to steep lapse rates. Pieces of vorticity and the 700
mb frontogenesis will keep some precipitation going tonight.
Leaned on HRRR for tonight`s PoP forecast as it had a good handle
on shower location. Thus, had chance PoPs across the southern tier
through 06z, then had PoPs from S Big Horn County E and S later
at night. Any gusty winds will die out early this evening. On
Tuesday, cyclonic flow, vorticity and a weak cold front will bring
a chance of precipitation to SE MT and Sheridan County. Again,
CAPE will be lacking, but steep lapse rates will bring a low
chance of thunder. Temps will be similar to today`s readings and
humidities will be a little lower. Winds will be a bit gusty in
some areas. Tuesday night will dry out under NW flow. Arthur
Wednesday through Sunday...
Look for a warming trend through the work week as 500mb heights
gradually build at midweek. Pre-frontal warming will boost temps
into the 90s by Friday before a weather system moves across
Southern Canada. This system will drag a cold front over our
region late Friday with a chance of thunderstorms developing
along the front in the SE section of Montana.
Conditions behind the front for the weekend look cooler. Saturday
is generally dry, but a reinforcing upper trough crosses Montana
on Sunday for an increased chance of showers and thunderstorms
over the entire CWA. There could be some monsoonal moisture from
the south available for that system Sunday as well which could
lead to some heavy downpours. BT
&&
.AVIATION...
VFR will prevail through tonight and Tuesday. Isolated to
scattered showers, with a few thunderstorms, will affect mainly
southern areas, including KSHR, tonight. Cannot rule out MVFR
conditions in the precipitation. Tuesday will be similar with a
chance of showers and isolated thunderstorms over SE MT and the
KSHR area. Expect areas of mountain obscuration over the NE
Bighorns through Tuesday. There will be localized obscurations
over the Beartooths/Absarokas this evening. Surface winds will be
gusty over portions of the area on Tuesday. Arthur
&&
.PRELIMINARY POINT TEMP/POPS...
Tue Wed Thu Fri Sat Sun Mon
-----------------------------------------------------------
BIL 052/079 052/086 056/093 062/093 060/086 059/079 056/081
10/U 00/U 00/U 02/T 22/T 24/T 34/T
LVM 044/077 045/084 049/091 056/090 051/085 051/079 049/081
10/U 00/U 00/U 03/T 22/T 13/T 33/T
HDN 053/080 049/087 054/095 061/096 059/088 058/082 055/083
10/U 00/U 00/U 01/B 21/U 23/T 33/T
MLS 052/079 052/086 056/092 065/095 062/086 059/080 055/080
11/U 00/U 00/U 01/B 31/U 34/T 33/T
4BQ 053/078 052/086 056/092 064/097 061/088 059/081 055/080
22/T 00/U 00/U 01/U 21/U 34/T 44/T
BHK 049/077 049/084 053/089 062/094 059/086 056/079 052/078
11/U 00/U 00/U 01/U 21/U 43/T 33/T
SHR 051/078 049/087 054/093 060/097 058/090 056/084 052/082
43/T 10/U 00/U 01/U 22/T 24/T 44/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Dodge City KS
601 PM CDT Mon Jul 13 2020
...Updated aviation section...
.SHORT TERM...(This evening through Tuesday)
Issued at 312 PM CDT Mon Jul 13 2020
All of the convective allowing models drive a line of broken
convection into west central Kansas by around 23-00 UTC this evening.
The initial few hours may bring severe wind gusts well in excess of
60 mph, and hail locally in excess of 2 inches. There is no
impressive moisture transport signal, so the mcs will likely weaken
as it moves east across the area tonight with lightning and heavy
rain as main threats the farther east it gets (say past 283). The
best area for severe wind threat based on the HiRES and HRRR
output looks to be Garden City and points west. The overnight
cloud cover forecast will be a challenge as not all of the models
are in agreement on extent of low cloud cover. GFSLamp does show
potential for a period of low stratus as low as 100ft anywhere in
the outflow area with increasing potential toward sunrise Tuesday.
For Tuesday, the convection appears to develop over the Palmer
Divide region and feed into the instability axis characterized by
60s+ dew points funneling from west central Kansas into northeast
CO in the evening. The GFS models another widespread MCS across
our area. By contrast the convective allowing models
NMM/NAM4km/HRRR tend to develop discreet convection near a dryline
farther southeast closer to late afternoon, so a few leading
severe storms may impact the far southwest counties even earlier.
.LONG TERM...(Tuesday night through Monday)
Issued at 312 PM CDT Mon Jul 13 2020
By Wednesday evening, the ECMWF and GFS both model another
convective round as moisture/dew point pooling looks maximized east
to west across Kansas into southeast Colorado with weak upslope
surface flow. There should be multiple locations for convection to
develop on outflow boundaries by then as well. By Friday it looks
like the pattern shifts enough to have weak troughing near the
western state line and swrly winds and drier air working into sw
Kansas. That should end the series of MCS activity and lead to much
hotter temperatures again heading into the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 558 PM CDT Mon Jul 13 2020
Another round of storms will move through the TAF sites tonight
bringing periods of MVFR to IFR conditions. Otherwise expect
ceilings to remain at VFR. Winds will generally be light and from
the southeast with the exception of in and around the
aforementioned storms.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 93 65 88 / 50 10 40 10
GCK 66 91 63 86 / 60 10 40 10
EHA 69 95 65 89 / 50 10 40 20
LBL 67 97 65 91 / 50 0 40 10
HYS 69 87 63 84 / 30 10 40 10
P28 72 97 70 92 / 20 10 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Hovorka_42
Area Forecast Discussion
National Weather Service Duluth MN
1013 PM CDT Mon Jul 13 2020
.SHORT TERM...(This evening through Tuesday night)
Issued at 351 PM CDT Mon Jul 13 2020
An approaching cold front will lead to developing showers and
thunderstorms this evening. An upper level trough currently located
over eastern Montana will continue to work its way eastward, which
will help to provide additional lift. The combination of the cold
front and upper level trough is expected to lead to thunderstorm
development after 00Z this evening. The primary mode of these
storms is expected to be linear, as CAMs have been in decent
agreement. However, there is the potential for some discrete
convection, primarily in the southwestern portion of the CWA. A
few of these storms may be severe, particularly in the Brainerd
Lakes area. Main hazards include damaging winds, large hail,
isolated tornadoes, and very heavy rain.
Assessing the environment this evening, the ingredients for severe
convection are present. 0-6 km bulk shear values are forecasted to
be between 40-50 knots. MLCAPE values are expected to be between
1500-2000 J/kg. This amount of instability should help to maintain
the storms, but limit the ability for large hail development.
Moisture advection is expected to be plentiful as a lower level jet
from the south is expected to advect a moist airmass northward. PWAT
values around 1.5 inches could potentially lead to very heavy
rainfall. When assessing the potential for tornadoes, the Brainerd
Lakes have the most favorable environment according to SPC. 0-1 km
SRH from the HRRR has been quite impressive, with over 400 m2/s2
around the time of storm development. One potential limiting factor
towards tornado development would be the high LCLs, which are
currently forecasted to be above 2 km. Regardless, the risk for
tornadoes is still present and will be something to watch for in the
storms this evening.
For Tuesday, showers and thunderstorms are possible, particularly in
Northwest Wisconsin. A few of these storms may become severe in the
afternoon. SPC currently has most of NW WI under a marginal risk for
severe storms tomorrow. Looking at the environment, shear of 40-50
knots is possible, with MLCAPE values of 500-1000 J/kg. Possible
threats include damaging winds, large hail, and a few isolated
tornadoes. By Tuesday evening, the showers and thunderstorms will
exit the area, leading to dry conditions for Tuesday night.
Temperatures tomorrow are expected to feel much more comfortable,
with highs being in the mid 70s.
.LONG TERM...(Wednesday through Monday)
Issued at 351 PM CDT Mon Jul 13 2020
A progressive pattern will be in place for the extended period while
still maintaining above normal temperatures.
Overall, broadscale moisture is limited through the week, but a
large plume of rich PWAT air gets advected northward by the weekend.
This will set the stage for another good opportunity for stronger
storms - especially since shear becomes a lot more prevalent as
flow turns zonal. So, Friday through Sunday may be an active
period for storms.
Afterwards, a drier air mass moves in and a weak upper level ridge
tries to build to our west.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 657 PM CDT Mon Jul 13 2020
VFR conditions are currently in place with storms expected to
arrive this evening and bring deteriorating conditions. The best
chance for storms will be between 8PM and midnight and bring
periods of MVFR and perhaps IFR conditions as they move through.
Storms may be severe with damaging wind gusts and heavy rain as
the primary threats. Some fog is expected to develop during the
early morning hours with HIB being the most likely. A mix of MVFR
and VFR conditions are expected for Tuesday as showers linger
through the day. Winds will shift westerly overnight as a cold
front passes along with the storms.
&&
.MARINE...
Issued at 1013 PM CDT Mon Jul 13 2020
A cold front over western Minnesota this evening will progress
eastward during the next 24 hours. Thunderstorms are forecast to
move over western Lake Superior early Tuesday morning. Some may be
strong to severe. Winds will remain northeasterly initially and
will veer southerly by 12Z Tuesday. Another round of thunderstorms
is possible, mainly for the South Shore waters Tuesday afternoon.
Some of those storms may also be strong. The cold front is
forecast to pass over the lake during the morning hours and winds
will veer southwesterly by late morning and westerly by mid-
afternoon. Wind speeds will typically remain light, less than 12
knots, except locally stronger near thunderstorms. Weak high
pressure will build across the region in the wake of the cool
front for Tuesday night and Wednesday. Winds will remain
southwesterly at 5 to 12 knots through Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 62 73 54 81 / 90 60 0 0
INL 59 75 55 80 / 100 30 0 0
BRD 60 73 53 80 / 100 50 0 0
HYR 65 75 52 81 / 80 90 10 0
ASX 65 78 55 83 / 80 90 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement until 10 PM CDT this evening for WIZ001.
MN...Beach Hazards Statement until 10 PM CDT this evening for MNZ037.
LS...None.
&&
$$
SHORT TERM...Unruh/JJM
LONG TERM...Wolfe
AVIATION...BJH
MARINE...Huyck
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
626 PM CDT Mon Jul 13 2020
.SHORT TERM...(This evening through Tuesday)
Issued at 226 PM CDT Mon Jul 13 2020
Main concern in the short-term is the threat for severe storms this
evening. A few thunderstorms are already starting to bubble up
over the Nebraska panhandle, and these are expected to become more
numerous later this afternoon, especially in the vicinity of the cold
front draped across the Sandhills. SBCAPE in this area is around
4000J/kg, which will initially support threat for large hail, but
CAMs agree that these storms will evolve into more of a wind
threat as they organize into one or more cold-pool driven
clusters. Even so, there is certainly some uncertainty on how far
south and east the severe threat extends. Some models, especially
the HRRR, appear to weaken updrafts rather quickly as storms
enter central Nebraska. There may be a couple factors leading to
this. The first may be increased inhibition farther south and
east, and the second may be lackluster wind shear for overnight
MCS maintenance.
All that being said, the bottom line is that we should still be
prepared for the possibility of damaging wind, particularly for
locations northwest of a line from Cambridge to Grand Island to
Fullerton. Unfortunately, this certainly won`t be a widespread
rainfall producer. Rainfall amounts are looking pretty meager on the
latest HRRR runs. Many locations, especially south of I-80, will
stay dry or mostly dry.
A few showers or thunderstorms could linger into the morning hours
of Tuesday, but I expect it to be primarily dry. More notably, the
cold front will sweep through the area Tuesday morning ushering in
northerly winds and significantly cooler, drier air. The latest
model blend also hints strongly at some stratus building in behind
the front as well. Given this stratus and the timing of the front,
we will likely end up with a very large spread in temperatures.
Northern zones may only reach the low 70s, while the far south could
reach the low 90s just ahead of the front around midday.
.LONG TERM...(Tuesday night through Monday)
Issued at 226 PM CDT Mon Jul 13 2020
Despite the drier post-frontal airmass, chances for rain and
thunderstorms return Tuesday evening and overnight as a compact wave
rounds the base of the upper trough and we move into the right-
entrance region of a 100kt upper level jet. In fact, we could end up
with more widespread precip with this event than this evening. SPC
has kept the entire area in a marginal risk during this timeframe,
which seems reasonable given the RAP showing around 3000J/kg of CAPE
and 30kts of bulk shear.
Mild temperatures continue on Wednesday as surface high pressure
slides southward into the area. This should also quell any chance
for thunderstorms Wednesday or Wednesday night.
We will start to see warmth and moisture return on Thursday, and a
few thunderstorms are possible again Thursday evening and overnight.
The warmup continues Friday and Saturday, with highs expected to
push well into the 90s to low 100s by Saturday. Most areas will
have heat index values of at least 100 degrees, and some could top
105, especially on Saturday. Heat headlines will need to be
considered later this week. Despite the increasing heat/humidity,
700mb temperatures around 16C should keep us effectively capped
and dry during this period. A shortwave approaching from the NW
CONUS is then anticipated to bring the next chances for storms,
and possibly a minor cooldown in the Sunday or Monday timeframe.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday)
Issued at 624 PM CDT Mon Jul 13 2020
Thunderstorms will be moving in from the west during the evening.
KEAR will have better chances for thunderstorms than KGRI. MVFR
ceilings are expected behind a cold front that moves through late
tonight/early Tuesday morning.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...Mangels
LONG TERM...Mangels
AVIATION...JCB
Area Forecast Discussion
National Weather Service Marquette MI
800 PM EDT Mon Jul 13 2020
.SHORT TERM...(This evening through Tuesday)
Issued at 417 PM EDT MON JUL 13 2020
WV imagery and RAP analysis indicated a mid/upper level trough from
northern Alberta/Saskatchewan into the western portion of the
northern Plains with a downstream ridge from the southern MN and
northwst WI to James Bay. Tsra have increase over the northeast
corner of ND ahead of a shrtwv. At the surface, sse flow was
increasing through MN and western Wi ahead of a trough/front over
the eastern Dakotas. High pressure prevailed from Lake michigan
and eastern Lake Superior into northern Ontario. Abundant cu has
developed inland as lake breezes moved inland central and east.
As upstream shrtwv and front move off to the east and a 30-40 knot
LLJ develops, expect shra/tsra to increase in coverage through
northern MN and eventually move through western Lake Superior into
western Upper Michigan late tonight. MUCAPE values into the 500-1000
J/Kg could support some isold/sct thunderstorms. However, effective
shear values and diminishing instability as the storms move to the
east will be marginal to support more than small hail.
After a lull in the shra/tsra by late morning, shra/tsra coverage
should again increase during the afternoon as another shortwv and
sfc wave lift toward the area. With abundant moisture inflow, PWAT
values into the 1.5-2.0 inch range and potential for training with
the inflow aligned with the storm motion, locally heavy rain may
develop over the west half. Confidence in severe weather potential
is lower despite impressive deep layer shear and SRH, as clouds and
pcpn early in the day should limit heating enough to limit MLCAPE
values at or below 500 J/Kg.
.LONG TERM...(Tuesday night through Monday)
Issued at 346 PM EDT MON JUL 13 2020
Two things that will highlight this forecast period will be cold
front moving through Tuesday night into Wednesday and then a warmup
heading into the upcoming weekend with above normal temperatures
expected into next week.
Cold front will be slowly making its way across the CWA Tuesday
night into Wednesday as a line of showers, and a few thunderstorms,
over the west will move across the central and eastern UP. CAMS has
been consistently showing this line across the central late Tuesday,
slowly reaching the east by Wednesday morning and then lingering
over the east throughout Wednesday, while clearing over the west.
Best chances of potential thunderstorms will be over the south
central where MLCAPE values up to 750 J/kg. Don`t think any severe
weather will occur but can`t rule out an isolated gusty wind threat
with a LLJ moving through. Main threat of severe weather will stay
south of the CWA, in Wisconsin. Some locally heavy rainfall may
occur as well with PWAT values 1.5-2". WPC does have most of the UP
under a MRGL risk of excessive rain for this period so something to
keep an eye on. Precip finally moves out by early Thursday with dry
conditions expected into the weekend.
Upper-level ridging will begin to take control of our weather with
southwesterly flow returning. This southwesterly flow will bring in
warmer air across Upper Michigan. 850mb temperatures will likely be
in the 16-19 C range, resulting in mostly mid to upper 80s Thursday
and Friday across the UP, even along the lakeshores. Saturday is
still on track to be the warmest day of the period with upper 80s to
low 90s and more humid too with dewpoints mostly in the mid to upper
60s. Next chance of precip looks to be Saturday into Sunday but
still inconsistent with timing, so will keep low-end POPs into
Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 759 PM EDT MON JUL 13 2020
VFR conditions will prevail through tonight. An approaching cold
front will spread showers and possibly a thunderstorm into KIWD
later tonight, with chances increasing closer to daybreak.
Conditions at KIWD should fall below VFR near dawn as showers and
thunderstorms overspread the area. Conditions may become IFR from
noon onward at KIWD, however it will depend on rainfall rates from
the passing showers / storms and if any fog forms. Included LLWS
late tonight at KCMX as winds just off the surface really pick up
from the SW with the approach of the cold front / surface trough.
Conditions should then drop to MVFR as steadier showers move in
Tuesday morning. IFR conditions are also possible at KCMX as
well, given high enough rain rates from showers / storms and any
possible fog that may develop. KSAW will start having chances for
showers in the morning, with chances increasing into the afternoon
when the front moves through. Conditions at KSAW should stay at
VFR until the afternoon, when the heavier rainfall arrives.
Additional isold thunderstorms will also be possible. &&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 417 PM EDT MON JUL 13 2020 A surface trough will move through the area tonight.
Expect winds to become southeasterly at 15 to 20 kts. Winds become
breezy ahead of an approaching front with southerly winds 20 to 25
knots and gusts up to 30 kts on Tuesday over the eastern half of the
lake. Breezy conditions are expected across the west but not quite
as strong, mainly around 15 kts with gusts to 20 kts Tuesday. Could
not rule out some gale force gusts for higher platforms on Tuesday
over the east. A front will move across the area from west to east
Tuesday night into Wednesday, winds behind the front will shift
southwesterly at 10 to 15 knots. Winds look to remain southwesterly
and mainly below 15 kts for the rest of the week.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...JH
AVIATION...TAP
MARINE...TAP