Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/30/20
Area Forecast Discussion
National Weather Service Bismarck ND
947 PM CDT Mon Jun 29 2020
.UPDATE...
Issued at 947 PM CDT Mon Jun 29 2020
We cancelled the Tornado Watch for far southwestern ND with this
update behind the surface trough where westerly low-level flow is
ongoing behind the primary line of thunderstorms. We are keeping
the watch in the northwest for now given continued large values of
effective STP in that region and some signs of new development in
northeastern MT, however, going forward the greatest threat will
likely be along and east of a line from New Town to Dickinson and
Hettinger. Strong to extreme instability, but relatively weaker
deep-layer shear compared to further west will likely result in
mainly a multicellular convective mode going forward.
UPDATE Issued at 838 PM CDT Mon Jun 29 2020
Quick update to let the Heat Advisory expire as scheduled at 01
UTC, as slow cooling with the approach of sunset has allowed the
heat index values to drop below advisory criteria.
UPDATE Issued at 724 PM CDT Mon Jun 29 2020
Changes with this update were focused on updating hourly PoPs with
weighting toward time-lagged HRRR guidance, which appears to be
capturing observational trends well through 00 UTC. Convection is
expanding over western ND and will eventually shift into the
central parts of the state overnight. Otherwise, we will let the
Heat Advisory continue for now, but expect to let it expire at 01
UTC.
MESOSCALE DISCUSSION...Issued at 545 PM CDT Mon Jun 29 2020
Severe thunderstorm potential is rapidly increasing in western ND,
with an attendant risk of very large hail and tornadoes.
As of 2230 UTC, convective initiation is ongoing in the vicinity
of a warm frontal zone from Glendive toward Dickinson. That warm
frontal zone is lifting northward, with surface pressure falls and
low-level warm air advection per surface observations centered on
McKenzie and Dunn Counties late this afternoon. Billow clouds over
northwestern ND in visible satellite imagery provide evidence of
enhanced low-level SRH shown in RAP-based objective analyses, with
0-1-km SRH around 150 m2/s2 along and north of the warm front. The
thermodynamic environment is characterized by MLCAPE of 2000-3000
J/kg, though initial cells may be in an air mass characterized by
MLLCL heights close to 1500 m AGL. Right-moving supercell motion
vectors toward the north-northeast around 25 kt will eventually
take the initial storms, including the supercell in eastern MT,
into McKenzie and Williams Counties through 01 UTC, where MLLCL
heights are lower, while the partially-sheltered boundary layer is
still supportive of enhanced low-level shear in support of a risk
of tornadoes. Very large hail will also be an enhanced risk with
any sustained mesocyclones given steep midlevel lapse rates and
deep-layer shear on the order of 40 kt. Further south, along and
south of I-94 in southwestern ND, agitated cumulus and attempts at
convective initiation marked by orphan anvils are continuing, and
may result in an increasing severe-storm risk by 00 UTC, as well.
This may be further aided by confluence in the wind fields which
has recently been noted in the warm sector in southwestern ND, as
noted by southwest surface winds at Buffalo, SD, and southeast
winds at Hettinger, ND.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 308 PM CDT Mon Jun 29 2020
Multiple hazards are in effect, the Heat Advisory to cover the
oppressive heat and humidity, and a Flash Flood watch has been
issued for portions of western and north central ND for the
potential for flash flooding this evening through tomorrow
evening.
Currently, surface low pressure was situated over northwest South
Dakota with strong moisture convergence in southwest ND into east
central MT. An area of mid to high level moisture is streaming
into the south central this afternoon, and limiting our heating
potential for the Heat Advisory. Do expect we might see some
thinning of the clouds along the western fringes, plus we have
been as high as 98 degrees for a heat index at Bismarck. We may be
able to let go a little early, but will let it ride for the time
being.
Late this afternoon or early this evening still looks favorable
for thunderstorm initiation in western ND. Although we are not
quite as unstable as yesterday and there may be a larger area of
convective inhibition to overcome, there are still some areas of
strong pressure falls situated over west central ND, along with a
few areas of less CIN over southwest ND and parts of the far
northwest. The CAMs have been pretty consistent all day in
developing a N-S line of convection in western ND. The latest
CAMs may be a little farther west, and a bit later. But
nonetheless, there is a larger area of deep layer shear available
to storms that develop along the frontal zone. There is some
indication that the northern portion of the line may grow upscale
and race eastward into the north central. This was moreso on the
earlier iterations, but there is still some indication that this
could occur. Also, there is also a lot of directional shear over
west central ND, so any storms that fire along the boundary, could
become supercellular with the potential for tornadoes. Very large
hail would also be a possibility. So needless to day, all threats
will be in play today. In addition, areas of very heavy rain will
be possible with any storms that develop. CIPS analogs are pegged
at either the 99.5th percentile, or the Max of all models across
the far northern tier counties through Tuesday evening. WPC has
the northwest and north central within either a marginal or slight
risk of flooding this evening through Tuesday. We decided to
highlight this entire area with one watch through Tuesday evening.
Convection may also continue into the late evening and early
overnight hours, so some areas could see a couple rounds of heavy
rain tonight, and this does not take into account Tuesday and
Tuesday evening.
On Tuesday, the treat for severe weather shifts into central and
eastern North Dakota. Again, very warm and unstable will
atmosphere will remain along and east of wherever the surface
boundary ends up after tonights convection.
.LONG TERM...(Tuesday night through Monday)
Issued at 308 PM CDT Mon Jun 29 2020
We remains warm through the extended period. The main forecast issue
will be timing and placement issues with occasional thunderstorm
chances.
Except for Wednesday, which is a little cooler, Daytime highs
through the extended period will be in the 80s north to 90s south.
It still looks like a bit of a break from severe weather Wednesday
and Thursday with some drier air pushing into the forecast area.
However, we will remain situated along the southern periphery of the
westerlies so you can`t rule out a thunderstorm any day. Currently
our given model blend is showing mainly slight chances of
thunderstorms Wednesday daytime through Friday daytime, with chance
pops Friday night and through the weekend. This seems reasonable
and will stick close to our guidance.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 947 PM CDT Mon Jun 29 2020
Multiple rounds of showers and thunderstorms are expected across
western and central ND through the 00 UTC TAF cycle. The strongest
storms will produce local IFR conditions along with strong and
variable winds and possible large hail. Areas of stratus and fog
are also possible late tonight and Tuesday morning, but the 00
UTC TAFs did not emphasize that given uncertainty in the timing
and location of its development.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through late Tuesday night for NDZ001>004-
009>012-017>019-021-031-032.
&&
$$
UPDATE...CJS
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...CJS
Area Forecast Discussion
National Weather Service Cheyenne WY
611 PM MDT Mon Jun 29 2020
.SHORT TERM...(This evening through Wednesday night)
Issued at 233 PM MDT Mon Jun 29 2020
Quiet so far over the CWA with an upper low quite evident on
satellite spinning over Idaho. Latest HRRR showing some convection
firing over western areas late this afternoon and continuing this
evening while moving generally northward, but not reaching into
the Neb Panhandle. The southerly flow aloft would favor this and
have trimmed pops down over the Panhandle for tonight. Otherwise a
cold front will move across the CWA tonight while the upper low
drifts northward with convection continuing over northern parts of
the CWA after midnight ahead of a shortwave that will be over
central Wy.
Cooler Tuesday with some breezy conditions especially
over the plains. Dry air will hinder convection but a few showers
and storms possible in the afternoon as the shortwave moves
across. Rather cool by Weds morning with mins in the 40s common.
Warmer and still mainly dry Weds under a wsw flow aloft.
.LONG TERM...(Thursday through Monday)
Issued at 233 PM MDT Mon Jun 29 2020
Little change in the weather pattern overall through the weekend
with nearly daily chances for showers and storms as the CWA will
be under a swly flow aloft with weak disturbances lifting across
from time to time, especially Saturday through Monday when higher
moisture looks to advect over the area. Temperatures remaining
warm, being a bit above seasonal averages.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 558 PM MDT Mon Jun 29 2020
VFR conditions under a mostly cloudy sky this evening. Isolated
showers and thunderstorms will continue through about 30/06Z, with
gusty and erratic winds up to 45 mph the main concern. Breezy
conditions tomorrow out of the WSW across southeast Wyoming and
the WNW across the western Nebraska Panhandle beginning around
sunrise as a generally dry, strong cold front passes through the
region. Scattered showers expected generally between 30/21Z and
31/06Z across portions of the region. Gusty/erratic winds will be
the main concern once again.
&&
.FIRE WEATHER...
Issued at 233 PM MDT Mon Jun 29 2020
Isolated showers and storms are possible overnight as a cold
front moves east across the area with the best chance being over
northern districts. Tuesday will be breezy over much of the area
but cooler with higher min RHs. Warmer weather is then expected
for the rest of the week with isolated late day showers and storms
possible. Elevated fire weather conditions are also expected
midweek as min RHs lower into the teens.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...RE
LONG TERM...RE
AVIATION...AB
FIRE WEATHER...RE
Area Forecast Discussion
National Weather Service Des Moines IA
723 PM CDT Mon Jun 29 2020
.DISCUSSION.../Tonight through Monday/
Issued at 255 PM CDT Mon Jun 29 2020
Synoptic Overview:
Mid level closed low is moving eastward away from the New England
region while another strong PV anomaly sits over the western CONUS.
This places the central Plains and upper Midwest in area of weak
southwesterly flow. Ahead of the strong PV anomaly will be a few
waves of energy that will bring rain shower and thunderstorm chances
to various parts of the forecast area this week. In addition, with
flow remaining largely southerly the next few days, expect hot and
humid afternoons through the middle of this week. Overall, the flow
remains relatively weak, and thus the synoptic pattern does not
particularly scream any robust severe weather potential.
Today and Tomorrow:
Broad surface low sits over the High Plains under an area of
stronger CVA just ahead of the PV anomaly axis. This has kept flow
southerly across central Iowa overnight and through this morning,
and will remain that way through this afternoon. There is a
temperature inversion up to about 800 mb, and from visible satellite
is pretty clear moisture is being trapped underneath it with an
airmass characterized by 70 degree dewpoints. As a result, cloud
cover has been slow to break apart across the Missouri River Valley
and Central Iowa. This may keep high temperatures a bit lower this
afternoon than originally anticipated. On the mesoscale, the
remnants of a convective complex remain over central and southern
Minnesota. GOES-16 airmass RGB imagery shows what is likely an
outflow boundary that is moving southward into Iowa. This boundary
may be enough to generate some weak thundershowers this afternoon,
as the airmass it is pushing through is theta-e rich and unstable
with SBCAPE near 3500 J/kg. However, POPs will be kept relatively
low through most of this afternoon. CAM guidance does not depict too
much activity with this boundary moving through, only the HRRR has
been trying to depict a couple of isolated showers north of U.S.
Highway 20 after 19z. With weak flow, there is not any notable
vertical wind shear, thus looking at just a general thunderstorm
threat as there is not much for storms to organize and become
severe. Tonight, short-wave travels northward through the
Mississippi River Valley. This is expected to bring heavy rainfall
to eastern Missouri and western Illinois. The 12z GFS remains the
highest and most widespread on QPF with respect to the deterministic
suite of model guidance. This solution brings rainfall to the
southeast and extreme eastern portions of the forecast area early
morning Tuesday. However, CAM guidance, keeps the bulk of the
precipitation in Missouri and Illinois with this short wave.
Ensemble solutions also favor the greater impacts remaining south
and eastward of the forecast area, with the mean being less than a
tenth of inch for areas with POPs. Given the warm humid airmass,
will keep chances for rain showers and thunderstorms late overnight
and early into Tuesday morning, though the stronger forcing will
likely be confined south and east of the forecast area. Tuesday
afternoon, the GFS favors lingering rain showers in the far eastern
portions of the CWA, while NAM quickly dries out. One notable change
is that the 12z ECMWF has trended closer to the GFS with Tuesday
afternoon rain shower and thunderstorm activity. Thus for Tuesday
afternoon, have slightly increased POPs from NBM output to
incorporate the 12z ECMWF. This is also reasonable given weak
isentropic ascent with the warm airmass that is ahead of the PV
anomaly and surface low, which by Tuesday afternoon will be working
its way across the central Plains. As with Monday, not expecting a
severe threat given the lack of vertical wind shear. With respect to
temperatures, insolation may be hard to come by in the south and
east thus will limit high temperatures for Tuesday afternoon.
Wednesday into Thursday:
Trough associated with strong PV anomaly will begin to lift
northward into Canada as jet stream swings around to east side, and
will also push the surface low eastward into Iowa. While H5 height
falls will still occur, the magnitude will be much less compared to
the northern Plains. The mid-level trough separates from the surface
feature, with the latter taking a more east-northeast track than its
parent mid level feature. Wednesday morning, this will increase
convergence across the forecast area. With a warm humid airmass
already in place, this will allow for the development of rain
showers and thunderstorms early in the day Wednesday. Slightly
warmer air will attempt to move in, but its difficult to consider
this a warm front considering the airmass ahead of it is already
theta-e rich. However, behind the surface low will be a stronger
cold front, which will further enhance convergence across the
region. 12z deterministic solutions are in decent agreement about
widespread precipitation across the forecast area, and the bulk of
the ensemble members are also in agreement. With the loss of the mid
level support, the surface low propagation will slow as it crosses
Iowa. Thus, convergence is expected to linger into portions of
Thursday which will continue the chance for thundershower activity.
Yesterday, the SPC Day 4 outlook did have severe probs in the
forecast for Wednesday. However, as indicated in today`s SWODY3, the
lack of mid-level flow will leave wind shear very weak, with 25
knots being the greatest of any solution. Thus, once again,
thunderstorms will not have the environment needed for organization.
Wednesday and Thursday, just looking at a general thunderstorm
threat. The hydro picture will need to monitored closely, especially
across the northeast where rainfall has been plentiful over the past
week. Other parts of the state will be able to handle heavier
rainfall should storms not be overly progressive in nature, which
could be possible given the weaker flow. The dichotomy across the
state between wet and dry areas remains impressive as we prepare to
enter the month of July. With respect to temperatures Wednesday and
Thursday, weak southerly flow will help maintain the warm and humid
airmass, thus will be looking at higher temperatures as well as high
heat indices. However, rain showers and thunderstorms may provide
enough lingering cloud cover to bring some relief at times from the
heat.
Extended:
Heading into the holiday weekend, thermal ridge builds across the
central Plains into the middle Mississippi River Valley. For Friday,
there may be some convergence left from outflow boundaries or the
exiting surface low that that may generate a few rain showers. But
for the most part, expecting warm and humid conditions to continue.
With ridging in place, AVA looks to promote large scale subsidence
which would aid in building surface high pressure. In the coming
days, will better determine if there is any threat due to enhanced
heat indices, especially with increased outdoor activity.
&&
.AVIATION.../For the 00Z TAFS through 00Z Tuesday evening/
Issued at 655 PM CDT Mon Jun 29 2020
VFR conditions will persist at all sites until the early morning
hours Tuesday when CIGs will drop to MVFR conditions at most sites
with KFOD and KOTM approaching low MVFR. Isolated thunderstorms tomorrow
morning could drop CIGs at KOTM to upper IFR conditions for a few
hours but confidence is low to medium.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Krull
AVIATION...KCM
Area Forecast Discussion
National Weather Service Grand Forks ND
1017 PM CDT Mon Jun 29 2020
.UPDATE...
Issued at 1000 PM CDT Mon Jun 29 2020
Lingering showers and nearby thunderstorms in west-central MN
remain. Thunderstorms continue to to back build within Todd
County, and could see some build into portions of Otter Tail and
Wadena counties. Thus have added chance PoPs here through
midnight. Guidance remains persistent in slowly migrating forcing
east away from the area, although low confidence in this as
guidance keeps pushing it back in time.
QLCS in western ND continues trekking slowly eastward with a
bowing segment near Minot. Latest HRRR and HRRRX runs slow this
segment down as it runs into a more capped environment and loses
better forcing for ascent, although HRRRX hints at convection
making into the Devils Lake basin before dissipating after
midnight. Introduced chance PoPs here to account for this
possibility. Not expecting any convection into the CWA to be
severe with the anticipated weakening of wind shear and stout
convection inhibition, and anticipated weakening trend.
Otherwise could have some widely scattered sprinkles over much of
the CWA as widespread low stratus overcomes the region in
association with northward increase in low level moisture.
UPDATE Issued at 713 PM CDT Mon Jun 29 2020
Lingering scattered showers and thunderstorms near Wadena and
Otter Tail counties a result of moisture convergence and low level
WAA in the wake of a meandering, subtle shortwave trough. This
should continue into early evening before activity diminishes.
StratoCu starting to redevelop in the southern CWA as a result of
additional low level moisture trying to draw into the region
noted by increasing area of higher mixing ratios. On the leading
edge of this increasing moisture could be some scattered showers,
although a stout cap and lack of more robust forcing should keep
chance for thunderstorms quite low despite ample instability in
place.
Currently are not forecasting convection in western Dakotas to
make it east into the region overnight tonight, although is
something to watch for as some latest runs of hires models show
this scenario playing out. If this were to happen, not expecting
severe storms due to lack of wind shear and strong cap/nocturnal
inversion over the area. Should confidence increase, an amendment
will ensue.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 304 PM CDT Mon Jun 29 2020
Convective chances and strength will be the main forecast
challenges for the period.
Water vapor loop continues to show several upper vorts lifting
across the area, with one curly-cue lifting into Ontario from
northern MN, and another weaker vort over west central MN. That
second vort has helped set off some showers and thunderstorms into
west central MN where there has been some 500-1000 J/kg of CAPE.
Bulk shear is around 30 kts, so cannot completely rule out
something pulsing up quickly and coming back down but think severe
chances will be pretty isolated and minor if anything at all.
Better chances for severe will be well to the west tonight as the
negatively tilted trough over the Rockies approaches, with a lead
shortwave into western ND. CAMs and global models both continue
to show some activity from western and central ND starting to
impact the western Devils Lake Basin, so POPs remain reasonable.
Much on Tuesday will depend on how convection develops
overnight/early Tuesday morning, and how much clearing we get.
There will be plenty of moisture advecting into the area, and some
stratus coming along with it is not out of the question. However,
think there should be enough breaks in the clouds to bring some
pretty hefty ML CAPE by tomorrow afternoon as the surface trough
begins to move into central ND. Deep layer bulk shear is not very
impressive at all, around 15 kts or so, but could see enough local
effects to produce some decent effective shear. Could see some
strong to severe thunderstorms moving into eastern ND by Tuesday
evening as the cap weakens and we get the trough axis pushing into
our CWA. Confidence is not super high on convective mode but could
see a MCS of some sort moving into our area Tuesday night.
As for temperatures, moisture will keep overnight lows up in the
upper 60s to low 70s. Highs will be hot and humid, with exactly
how much dependent on cloud cover.
.LONG TERM...(Wednesday through Monday)
Issued at 304 PM CDT Mon Jun 29 2020
For Wednesday...some uncertainty is present with the upper level
features as the ridge weakens...and the main axis shifts east over
Minnesota. The surface front is forecast to push slowly east and
should provide sufficient lift to trigger convection. 700Hpa
temperatures cool off and will help with lapse rates. However...some
models indicate the surface boundary washing out over Minnesota but
some form of weak low level convergence may remain. Will continue to
monitor for changes and adjust the forecast accordingly.
Thursday through Sunday...the upper ridge reamplifies leading to
warmer temperatures. High temperatures throughout stay pretty
close to 90 with dew point readings in the 60s to around 70. This
keeps heat indices in the mid 90s in portions of the area every
afternoon. A few embedded disturbances propagating through the
flow across the ridge may provide enough instability to trigger
showers and a few storms.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 713 PM CDT Mon Jun 29 2020
Expecting widespread MVFR to IFR CIGs to develop tonight into
Tuesday morning, with KFAR already seeing MVFR CIGs. CIGs should
begin to lift after 14 UTC. Confidence is low in shower and
thunderstorm chances, although a general increase in chances will
occur Tuesday afternoon into evening. A few stray showers may pass
over sites between 05-14 UTC. Omitted mention of -TSRA or -SHRA
due to lack of confidence.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$
UPDATE...CJ
SHORT TERM...JR
LONG TERM...Hopkins
AVIATION...CJ
Area Forecast Discussion
National Weather Service Green Bay WI
1042 PM CDT Mon Jun 29 2020
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Tuesday
Issued at 242 PM CDT Mon Jun 29 2020
The latest RAP analysis and satellite/radar imagery show weak
shortwave energy/mcv activity lifting to the northeast over the
northern Mississippi Valley and western Great Lakes region early
this afternoon. Ascent associated with these shortwaves combined
with increasing instability and mid-level lapse rates of 6.5 to
7.0 C/km have contributed to scattered thunderstorms across the
region. One area of storms diminished across northeast Wisconsin
early this afternoon. Other clusters of storms are developing
along a warm front over southern Wisconsin to southern
Minnesota. Strong instability (3k-4k j/kg) exists south of the
warm front, while southerly flow is attempting to push advect this
instability northward into central and east-central WI. Although
the general trend is for storms to weaken as they move north, not
out of the question that strong storms could move into areas
south of Hwy 29 later this afternoon into early this evening.
Forecast concerns revolve around adding details to thunderstorm
trends over the next 24 hours.
Tonight...Getting a handle on convective details has been
challenging going into the forecast for tonight. Most convection
allowing models have the most prolific rainfall across northern
Wisconsin, along the southern periphery of shortwave/mcv activity.
However, given the instability over southern WI and potential for
further destabilization this afternoon, think there is potential
for strong storms and an isolated severe storm to move into
central and east-central WI late this afternoon into early this
evening. PWATs approaching 2 inches would also support potential
for heavy rainfall, particularly since storm movement will be
relatively slow. Large hail and strong, gusty winds in wet
microbursts will be the primary threats. As instability wanes this
evening, thunderstorms over central WI should diminish as well.
Otherwise, it will be a warm and muggy night with lows ranging
from middle to upper 60s.
Tuesday...Guidance generally shows shortwave energy lifting north
of the region. But a warm and humid airmass will continue to surge
into the region otherwise. Southeast flow will provide some
cooling to eastern WI. But away from the Bay and Lake, mixed-layer
capes of 1500-2000 j/kg are expected to develop with the heat of
the day. Given the low convective temps, could see isolated to
scattered storms develop in the afternoon. Weak shear under 15 kts
will keep any severe risk low, but cannot rule out a strong pulse
storm. Highs ranging from the middle to upper 80s.
.LONG TERM...Tuesday Night Through Monday
Issued at 242 PM CDT Mon Jun 29 2020
A warm humid airmass will be in place throughout the extended
period as daytime highs range from the middle 80s into the lower
90s. In addition, dew points will generally be in the 60s to near
70 at times, causing humid conditions on top of the hot
temperatures. Overnight there will not be much relief as overnight
lows only fall into the 60s, with some locations only falling to
around 70.
An omega blocking pattern will transition to a more zonal flow as
a large scale ridge develops across the southern plains and
stretches out over the western Great Lakes region. There will be
the chance for showers and thunderstorms at times through Thursday
as several shortwaves spin off the main low situated across the
high Plains. Any thunderstorms that form during this period could
produce heavy rainfall given the high PWAT values and abundant low
level moisture with the high dew points. Widespread severe weather
is not expected, however pulse-type severe cannot be ruled out if
enough instability can build up, especially during the afternoon
hours.
As the aforementioned ridge becomes entrenched across the western
Great Lakes late in the week and into the early part of the
weekend, a dry period is forecast across the region. Active
weather is then forecast to return for the second half of the
weekend into early next week as the ridge flattens a bit and
several shortwaves ride north along the periphery of the ridge.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1041 PM CDT Mon Jun 29 2020
Moist air near the surface and a light upslope wind could result
in low clouds west of an IMT to DLL line late tonight. VFR ceilings
are expected further east.
Any low clouds that form late tonight should dissipate by 15z Tuesday,
with mostly VFR conditions for the rest of the day. There is a small
chance of a thunderstorm across central and northcentral Wisconsin
in the afternoon.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Kurimski
AVIATION.......RDM
Area Forecast Discussion
National Weather Service Grand Rapids MI
836 PM EDT Mon Jun 29 2020
LATEST UPDATE...
Update
.SYNOPSIS...
Issued at 246 PM EDT Mon Jun 29 2020
- Building heat into the end of the week
- Small chance for a thunderstorm this evening
&&
.UPDATE...
Issued at 836 PM EDT Mon Jun 29 2020
I plan increasing the pop for the lake shore south of MKG this
evening for the convection heading this way. It should stay mostly
west of US-131 this evening.
The outflow boundary from the thunderstorms that were over
Wisconsin early this evening, has hit our lake shore near
Muskegon. Scattered storms continue to develop behind the outflow
boundary. Model sounding and the SPC meso-page show up to 3000
j/kg of surface based cape west of US-131 and south of I-96 at 8
pm. This instability does fade but even at midnight the models
like the RAP model have 2000 j/kg south of Holland through a good
part of the night. Both the HRRR and RAP show the showers holding
together. The 22z HRRR has up to 2" of rain in 3 hours in parts of
Van Buren County by midnight.
The instability says near the lake shore so whatever comes into
our CWA should mostly stay near and south and west of a MKG TO GRR
line tonight.
&&
.DISCUSSION...(This evening through next Monday)
Issued at 246 PM EDT Mon Jun 29 2020
- Building heat into the end of the week
Many locations have risen to well above normal temperatures this
afternoon...generally mid to upper 80s. Temps at 925 mb are up to
around 24 to 25 deg C. We stay there each afternoon for Tuesday
into Thursday. So highs should be in the 85 to 90 deg range. By
Friday...925 mb temps climb to 27 deg C which should solidly
support 90 degrees. We then stay at that level or higher through
the weekend possibly into early next week. Fortunately it does not
look like the high dewpoint airmass will move in through the
period. So Heat Index temperatures are forecasted to not stray too
far from the actual air temperatures. Near the lakeshore though
the dewpoints will be a few degrees higher than inland.
- Small chance for a thunderstorm this evening
ML CAPE values have risen to 1000 to 1500 J/KG along the lakeshore
south of Muskegon. This is in the area of the lake breeze that was
moving slowly inland. There is some subsidence in the mid levels
that may be limiting the formation of any showers or
thunderstorms. Toward 00z though...there is a little lift. We
could see an isolated shower or thunderstorm form along the front
before sunset. High Res models do not any strong convection so
uncertainty exists.
If there will be any afternoon showers or storms Tuesday
afternoon they would be west of Kalamazoo where some the better
instability is shown to be. Looking at the remainder of the
week...the airmass is shown to be relatively dry with little or no
lift. Thus we will keep it dry.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 653 PM EDT Mon Jun 29 2020
Overall I am thinking solid VFR conditions with winds mostly
under 10 knots from the east southeast through Tuesday night.
There were a few showers between MKG and GRR between 2130z and
2230z but they have dissipated. There is a much more significant
area of thunderstorms from just off shore of MKE to CHI that is
moving east toward the Michigan lake shore. These storms have
intense rainfall, frequent lighting, hail and gusty winds. If the
storms stayed together they would reach the lake shore around
130z but I am thinking the lack of surface instability over Lake
Michigan will dissipate them before they reach the shore line.
Still it is something to consider in the short term.
Once the storms dissipate skies should for the most part clear
overnight. I expect cumulus clouds to form around tomorrow like
they did today. I do not expect any convection tomorrow through.
&&
.MARINE...
Issued at 246 PM EDT Mon Jun 29 2020
The pressure gradient remains relatively weak for much of the
week. This no hazardous winds or waves are predicted. With water
temperatures rising to the upper 60s and low 70s...fog will likely
be a limited risk at this time.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...None.
&&
$$
UPDATE...WDM
SYNOPSIS...MJS
DISCUSSION...MJS
AVIATION...WDM
MARINE...MJS
Area Forecast Discussion
National Weather Service Gray ME
742 PM EDT Mon Jun 29 2020
.SYNOPSIS...
An upper level low will meander across the region through
Wednesday producing multiple rounds of showers and a few
thunderstorms. The upper low will lose its grip on Thursday
allowing for what looks to be a mostly dry and much warmer day.
A back door cold front then moves through the forecast area from
the northeast Thursday night and allows for a cooler weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
735 PM...Adjustments made to the forecast lean on the HRRR, but
use other meso models as well. The HRRR does show the break the
showers in the onshore flow that we are currently seeing on
radar. So, this trend will continue for a few more hours this
evening, with the shower moving out of ME and into NH, with a
drier period in ME. But, should see another wave of showers
moving in from the E, later this evening and overnight. The
expectation for this wave is a little less organized precip,
and a not as intense as rain today, but still some downpours are
possible. Overnight temps along the coast will pretty much stay
where they are while inland will drop a few degrees. Will see
more areas of fog later tonight as well.
Previously...At 18z a 1007 millibar low was centered south of
Cape Cod with a cool damp northeast flow to its north across
much of the forecast area. GOES water vapor showed an upper low
centered over southern New Hampshire with a plume of higher
precipitable water values...on the order of 1.5 inches across
northern and eastern sections of our area. Steadier light and
occasionally moderate rain continues over northern and eastern
sections this afternoon with scattered convection across the
remainder of the forecast area at moment. Some localized
flooding will remain possible through this evening...mainly
across southern and western sections where training and slow
moving convection is most likely to occur. Overnight...the upper
low will meander a bit further south. Convection will continue
to pinwheel around this feature...and with the moist onshore
flow it`ll be a damp night with areas of fog developing. Lows
tonight will be in the upper 50s to lower 60s.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
On Tuesday...the upper low meanders a bit further north.
Impulses pivoting around this feature coupled with some daytime
heating will once again cause convection to increase in coverage.
Slow moving cells and potential for training will once again
pose the risk for localized flooding. It`ll be a bit warmer on
Tuesday with highs in the upper 60s to lower 70s. Convection
diminishes across the area tomorrow evening with scattered
activity continuing overnight with the upper low remaining
nearby. Another damp night with some fog developing once again.
Lows will range from the upper 50s to lower 60s.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Upper low will still be overhead Wednesday and will weaken
throughout the day. This upper low will open up and get deflected to
our south Thursday by a short wave moving through the Canadian
Maritimes. This short wave will push a cold front north to south
through the area by Friday morning with mostly dry weather expected
Friday afternoon into the weekend. There will be low chances
for afternoon showers going into the weekend, although they are
not expected to be as widespread as we will see early this
week.
The upper low that will have brought beneficial rainfall will start
to weaken Wednesday. The weakening nature of this system will likely
allow for more solar heating during the day leading to decent
instability in the afternoon with pockets of MLCAPE in excess of
1000 J/kg across the interior. Shear will be limited leading to
pulse convective showers and these convective showers will
likely be slow movers bringing some hydrologic concerns with
antecedent rainfall. It will be fairly humid Wednesday with dew
points in the mid 60s and highs in the 70s.
Thursday will be fair with low chances for afternoon showers
and highs warming back into the 80s with more sunshine. A cold
front will drop south through the area Thursday night into
Friday dropping highs into the 70s for most with low 80s over SW
New Hampshire. Overall, the holiday weekend looks mostly dry,
although cyclonic flow aloft will be nearby over the Canadian
Maritimes bringing low chances of afternoon showers with the
best chances being Saturday afternoon. Highs will increase into
the mid 80s Saturday with further warming expected into early
next week.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Short Term /Through Tuesday Night/...Conditions lowering to IFR
this evening in low clouds and SHRA with isold -TSRA. IFR with
areas of MVFR on Tuesday in SHRA and sct TSRA. Conditions
lowering once again to IFR Tues evening in low clouds and SHRA
with isold -TSRA.
Long Term...Scattered SHRA and TSRA will likely bring
restrictions in heavier showers Wednesday. Mostly IFR Thursday
into the weekend with low chances of SHRA.
&&
.MARINE...
Short Term /Through Tuesday/...Northeasterly winds of 15 to 20
kt today with gusts near 25 kt have produced seas near 5 ft
on the ocean waters mainly from near Casco Bay to the New
Hampshire seacoast. I`ve extended the current SCA through
evening for the open waters...with winds and seas likely to drop
below SCA by then.
Long Term...Winds and seas are expected to stay below SCA
thresholds. Upper level low will bring chances of TSRA
Wednesday. A cold front dropping south Thursday night will bring
elevated northerly wind gusts to 20 kts Friday morning.
&&
.HYDROLOGY...
After a long period of drought, rain finally moved into the
region in the form of a closed upper level low. Still it remains
a game of the haves and have-nots. While most sections of our
area have seen at least some precipitation, the majority of the
region has seen under 0.50" - much less than our current
deficit. However a few locations have had storms linger, with
rainfall totals as high as 5" estimated by radar and supported
by both METARS and weather spotters. We`ll continue to see
convection pivoting across the area into Wednesday. Even in
regions with significant drought, these very intense rainfall
rates in convection may lead to localized flooding as the
rainfall exceeds the ground infiltration rate. This pattern of
scattered heavy rain persists over the next two days, and some
localized flooding is possible. However with river levels
running near record lows in some locations, and the scattered
nature of the rainfall no river flooding is expected.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ152-
154.
&&
$$
SYNOPSIS...
NEAR TERM...Cempa/Schwibs
SHORT TERM...Schwibs
LONG TERM...Schroeter
AVIATION...
MARINE...
HYDROLOGY...
Area Forecast Discussion
National Weather Service Wichita KS
627 PM CDT Mon Jun 29 2020
.SHORT TERM...(This evening through Wednesday night)
Issued at 243 PM CDT Mon Jun 29 2020
A weak PV anomaly is currently moving across central KS at this
time, with some sprinkles in central OK. Just ahead of this
feature, some showers and storms have developed over SW MO, where
slightly weaker inhibition has led to the cap eroding. As this PV-
anomaly shifts E-NE, warmer elevated mixed layer air over most of
the south central KS will keep any surface based showers/storms from
developing this afternoon. Latest RAP does show cap weakening over
extreme SE KS, which may lead to an isolated diurnally driven storm
developing in this area for the late afternoon, so will leave a low
pop in for this chance.
If any storm can get going, think if will be diurnally driven,
dissipating after sunset, with warm and humid air remaining over the
area overnight.
A shortwave is expected to swing northeast out of the Rockies and
into the northern plains on Tue. This will help push a weak low
pressure area across wrn KS into south central and central KS by Tue
afternoon. Much drier air will be pulled north with this feature,
allowing afternoon temps to soar into the 100-105 degree range
across portions of central and south central KS. As this drier air
pushes in, surface dewpoints will fall, which will temper apparent
temperatures some, even though surface temps will still be around
100-103. Heat indices will flirt with low end Heat Advisory
criteria, especially for areas along and east of the KS Turnpike, as
surface dewpoints arent expected to mix out as much in this area.
After collaboration with my neighbors, decided to go ahead an issue
a heat advisory with heat index values expected to be 105 to 107,
especially along and east of the Turnpike.
Not expecting any storm development underneath this weak low, on Tue
afternoon, as a very warm elevated mixed layer will be over most of
the forecast area.
More hot temps are forecast for Wednesday, but this time with a weak
surface boundary draped across the area. Again not expecting any
storm development as a very strong cap will likely limit any
convection from developing across the region.
Expect temperatures to remain above normal in the mid 90s to 100 to
102 across the forecast area for Wed, with the warmest temps and
highest heat index values expected to be over SE KS. May need
another heat advisory for SE KS on Wed, but will take it one day at
a time for now.
Ketcham
.LONG TERM...(Thursday through Monday)
Issued at 243 PM CDT Mon Jun 29 2020
The GFS and ECMWF differ somewhat on how they expect Thu into the
holiday weekend to play out. Latest ECMWF suggests that the upper
ridge will slowly retrograde back into the Rockies. GFS is similar
with upper level heights building over the plains. Not entirely
sure that this time frame will be completely dry, as there is a slim
chance for isolated afternoon storms for Thu and overnight isolated
storm chances going into the weekend. GFS pops and QPF are probably
overdone. But will keep some very small pops in for a few time
frames, mainly in the late afternoon and overnight time periods.
Ketcham
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 616 PM CDT Mon Jun 29 2020
Latest radar data showed broken line of towering cumulus and/or showers
approach KBVO associated with remnant low/shortwave moving
northeast. So far trend suggests the combo of cap and entrainment
of drier air is winning. Still think there is enough of a chance
to keep showers going for a couple of hours at KCNU, especially given
increasing 850MB warm air advection that is expected throughout
the evening. Otherwise winds should diurnally decrease a bit
overnight and increase Tuesday morning. Given depth of mixing
expected on Tuesday, bumped up winds a bit during the day. -Howerton
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 74 102 72 100 / 0 0 0 0
Hutchinson 74 102 69 97 / 0 0 0 0
Newton 74 101 71 98 / 0 0 0 0
ElDorado 73 98 73 99 / 10 0 0 0
Winfield-KWLD 75 101 74 101 / 10 0 0 0
Russell 72 103 66 94 / 0 0 0 0
Great Bend 72 104 66 95 / 0 0 0 0
Salina 75 103 70 97 / 0 0 10 0
McPherson 74 101 69 97 / 0 0 0 0
Coffeyville 76 94 76 99 / 20 0 0 0
Chanute 75 94 76 99 / 20 10 10 0
Iola 74 94 75 99 / 30 10 10 0
Parsons-KPPF 76 94 76 99 / 20 0 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from noon to 8 PM CDT Tuesday for KSZ049-051>053-
068>071-083-091>095-098-099.
&&
$$
SHORT TERM...Ketcham
LONG TERM...Ketcham
AVIATION...PJH
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1133 PM EDT Mon Jun 29 2020
.UPDATE...
Issued at 1133 PM EDT MON JUN 29 2020
Latest mesoanalysis still has quite a bit of instability across
our northern and eastern zones, but more limited in our southwest,
where earlier convection has died out. Main features to impact the
area overnight is a outflow boundary dropping south out of
southern Ohio which continues to generate additional showers and
storms as it has pushed south this evening. The other feature, is
the convection across central Kentucky. This convection is
starting to push east into the better instability. As these two
boundaries push east and south overnight, convection should
continue to develop and become more widespread with time. With
plenty of instability still in place and high PW`s, locally heavy
rain will continue to be a threat. Due to slow storm movement and
potential for colliding boundaries, the flash flood threat will
remain. Hesitant to expand the watch at this point, but will pass
along concerns to the oncoming shift to see if any expansion might
be needed. Updated pops to increase them across the north. Still a
tricky forecast given the amount of mesoscale features involved.
UPDATE Issued at 819 PM EDT MON JUN 29 2020
Colliding boundaries in our southwest has led to several flash
flood warnings and even a few SVR`s. Fortunately, area is getting
worked over fairly well now. We should start to see the heavier
activity settle down across this region, but we could still be
looking at another hour of potentially heavy rainfall. Latest HRRR
has much of the area staying quiet after this evening activity
burns out. This seems reasonable based on the trends. However, a
stray shower may still be possible through the overnight hours.
But will be adjusting pops downward for most areas through the
rest of the night given these trends.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 602 PM EDT MON JUN 29 2020
After a breif lull in activity, convection has refired,
especially to our southwest. Could not track down any reports of
flooding this morning, but that area has to be primed and it
should not take much in the form of additional rainfall for
problems to begin to crop up. MLCAPEs of 2000-2500 J/kg have
developed generally along and west of the I-75 corridor with the
help of a moist boundary layer and surface due points well into
the 70s. Relatively low storm motions (< 10kts) and a weakly
sheared environment (effective bulk shear of 10-15 kts or less)
portend slow moving pulsers, capable of producing heavy rainfall
and possibly some strong wind gusts. A few storms further
southwest of our area have already produced some damaging wind
gusts. Add that we continue to see the most robust development
along some type of surface boundary, most likely a residual
synoptic boundary of some type reinforced by cold pooling effects
of earlier convection. CAMs seem to highlight our southwest again
and portions of our Bluegrass over the course of the next 24
hours. NAM does show additional H850 convergence across our
southwest overnight with a 15-20 kt wind nosing its way into the
vicinity of the boundary, very similar to last night. This suggest
the potential of training cells and back building convection
similar to last night. Thus felt it prudent to expand and extend
the original flood watch that we had in effect for the
southwestern portions of our CWA. Otherwise, expect continued
isolated to at times scattered showers and thunderstorms across
the remainder of the forecast area. A few cells will be capable of
producing gusty winds and of course, locally heavy rainfall.
.LONG TERM...(Wednesday through Monday)
Issued at 445 PM EDT MON JUN 29 2020
The gloomy skies and persistent shower activity should finally
break for some drier weather heading into the the weekend.
Increasing sunshine will result in warming temperatures each
afternoon from Wednesday on into the weekend with afternoon
temperatures nearing 90 degrees by the 4th of July. Cloudier skies
with shower and storm chances could return during the second half
of the weekend and into early next week.
Model agreement is good through Saturday, then fair thereafter.
The 12z Wednesday model analysis continues to show an ~ 573 dam
cutoff low spinning over the Northeast US while an omega-type
blocking ridge remains anchored over the Central US, northward to
near the Hudson Bay. A large trough, with an embedded upper level
low, is situated over the western CONUS/western Canada. Meanwhile,
a surface cold front is draped over/near our area. During the day
on Wednesday, pieces of upper level energy will slip through a
weak spot in the blocking ridge and ride the upper level flow
between the eastern cutoff low and the upper level ridge, passing
across the Ohio Valley Wednesday afternoon and evening. Surface
high pressure and building heights build over the area on Thursday
as the cool front finally settles south of the Commonwealth.
While the upper level ridge becomes more firmly entrenched over
the Ohio Valley Thursday night, a digging trough captures the
cutoff low over the Northeast US. Some weakening in the ridge is
then expected by the second half of the weekend as some remnant
upper level energy, over the Deep South, develops into a cutoff
low and drifts back to the north. Much uncertainty remains with
this feature as the GFS lifts the low directly toward eastern
Kentucky while the Euro keeps the system well to the our east
along the Atlantic Seaboard.
Sensible wx will feature the continued threat for showers and
storms on Wednesday. The activity will then gradually diminish
from N-S Wednesday night and Thursday as the slow-moving cold
front finally settles south of the area. The most widespread
activity will likely occur as pieces of the upper-level energy
pass over the Commonwealth. By Thursday afternoon, the increasing
heights and surface high pressure nosing in from the north should
bring the shower or storm threat largely to an end. A few subtle
upper level disturbances could still spark an isolated shower or
storm on Friday or Saturday but the the dry air aloft and synoptic
scale subsidence should keep that threat very minimal. Thereafter,
the threat for any widespread shower or storm activity hinges on
the the development and potential track of the southern cutoff
low. Near to slightly above normal temperatures are expected
through the period. Afternoon highs in the mid 80 are expected to
start the period, warming to near 90 for Friday through Sunday,
then potentially cooling into the 80s on Monday. Meanwhile, night
mins are expected to range through the 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 819 PM EDT MON JUN 29 2020
Convection is starting to fade away this evening and will likely
set up a fairly tranquil overnight period. Its possible some MVFR
cigs could settle into the area, but confidence is not high on
these low clouds developing. If the clouds don`t develop, its
possible we could see some locally dense valley fog tonight. This
will be monitored for possible inclusion into the TAFs later on.
For now, will plan to keep the TAFs mainly VFR for most of the
night. Light winds should continue tonight.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Tuesday evening for KYZ050-058>060-068-
069-079-080-083>088-108-111>118.
&&
$$
UPDATE...KAS
SHORT TERM...RAY
LONG TERM...GEERTSON
AVIATION...KAS
Area Forecast Discussion
National Weather Service North Platte NE
623 PM CDT Mon Jun 29 2020
.SHORT TERM...(This evening through Tuesday night)
Issued at 333 PM CDT Mon Jun 29 2020
The temperature forecast tonight through Tuesday night leans on
the short term model blend. A strong Pacific cold front moving the
WY this afternoon will move into wrn Nebraska late tonight
presenting a well mixed atmosphere. The RAP model shows the
atmosphere remaining well mixed which supports warm lows tonight.
The cold front will continue to move through wrn Nebraska Tuesday
morning and arrive in ncntl Nebraska during the afternoon. The
latest temperature forecast Tuesday is a few degrees cooler for
highs mostly in the 80s.
The front and increasing winds aloft are the focus and forcing for
thunderstorm development beginning 21z-00z across ncntl Nebraska. A
very strong cap will be in place ahead of the cold front which could
easily delay storm development until 00z as suggested by the SPC day
2 outlook. In fact, the likely thunderstorm chances across ncntl
Nebraska Tuesday evening are post frontal which would most likely
represent a hail, wind and heavy rain threat. The prospect of a
weakening cap unleashing 4000-5000J/KG of MLCAPE is the main
convective weather concern and the models are in very good agreement
aiming a strong belt of warm air advection across cntl KS at cntl
Neb. This forecast would favor severe storm development across Holt
and Boyd counties late Tuesday afternoon or early evening.
The thunderstorm forecast uses the short term model blend which
places the best rain chance across ncntl Nebraska Tuesday evening.
Isolated thunderstorm chances are in place elsewhere across wrn
Nebraska during the day Tuesday associated with the progress of the
Pacific cold front.
.LONG TERM...(Wednesday through Monday)
Issued at 333 PM CDT Mon Jun 29 2020
A closed upper level low across the Pacific Northwest will lift
north into western Canada and then reform or build back south into
the Pac-northwest. The models are in very good agreement building
heights across Nebraska downstream from this upper low. This
should produce a modest rebound in the heat. H700mb drop about 10C
from 17C to 7C Wednesday and then rise back to around 11C
Thursday and beyond. Persistent south winds are shown by the
models Thursday through Monday supporting a return to modest heat
across wrn and ncntl Nebraska.
Mostly isolated thunderstorm chances are in place Thursday through
Monday. The high heights and warming temperatures aloft should
maintain a fairly stable environment. Winds aloft will become very
weak later this week also.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 623 PM CDT Mon Jun 29 2020
Wind is the primary aviation weather concern through the forecast
period across western Nebraska. Gusty southeast winds will
continue into the early overnight hours, then low level wind shear
conditions will arise. A cool front will result in a transition
to northwest winds early to mid morning. Stratus clouds will also
likely develop tomorrow morning over north central Nebraska (KONL)
with MVFR cigs possible.
&&
.HYDROLOGY...
Issued at 333 PM CDT Mon Jun 29 2020
The GFS and NAM soundings suggest a pretty good heavy rain signal
across ncntl Nebraska Tuesday evening. This rain will most likely
be post frontal but precipitable water rises above 1.5 inches and
warm cloud depth increases to 11kft as the sounding column
moistens. 2000-3000J/KG of elevated CAPE is shown in the GFS and
NAM models also. The WPC suggested training storms as a result of
deep southerly flow.
A Flood Watch is place across Holt and Boyd counties Tuesday night.
This area of ncntl Nebraska is on the southern fringe of a broad
area if deep moisture transport which extends north through the
Dakotas and into Canada.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Flood Watch from Tuesday evening through late Tuesday night for
NEZ007-010.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Snively
HYDROLOGY...CDC
Area Forecast Discussion
National Weather Service Midland/Odessa TX
624 PM CDT Mon Jun 29 2020
.DISCUSSION...
See 00Z aviation discussion below.
&&
.AVIATION...
Winds are the only concern for the TAF sites, diminishing in the
next couple of hours then increasing and becoming gusty again
tomorrow around 15Z.
Hennig
&&
.PREV DISCUSSION... /issued 245 PM CDT Mon Jun 29 2020/
DISCUSSION...
WV imagery shows a broad, upper trough over ID, and a ridge over the
Gulf of Mexico, leaving West Texas and Southeast New Mexico under SW
flow aloft. Diurnal mixing has brought some of the winds rounding
the base of the trough to the sfc in the Guadalupes, for a few hours
of high winds. These should fall under criteria late this
afternoon.
Latest sfc analysis shows the dryline over the ern zones, and this
will be the focus of convection this afternoon, w/the HRRR
initiating over the lwr Trans Pecos in a couple of hours. Afternoon
forecast soundings east of the dryline yield mucapes in excess of
3250 J/kg, dcapes over 1250 J/kg, and mid-lvl lapse rates of around
7 C/km, for the usual hail/wind threat. Deep lyr shear looks rather
anemic, so any cells that do develop should be short-lived.
SW flow aloft will continue thru at least Thursday, with the ridge
muscling west back into Texas. This will result in a chance of
convection each day, mainly over the SE where better Gulf moisture
is present, and a weak dryline sets up each day. Once the ridge
moves far enough west, Gulf moisture will surge west into the higher
terrain, and the convective focus will move to the mountains.
Through it all, however, chances will remain minimal.
For temps, thicknesses are forecast to increase over the next few
days as the ridge moves west, maintaining temps at many locations in
the triple digits. However, once Gulf moisture surges westward
later in the week, afternoon highs should moderate a bit, but stay a
few degrees above normal. Unfortunately, this will result in warm
overnight lows, as well. The dog days of summer are almost upon
us.
FIRE WEATHER...
Low RH`s hovering between 10-15% with elevated 20ft winds and
ambient dry conditions over the SE NM plains and adjacent mountains
will extend a higher chance for initial attack fires. With ERC`s
hovering between 55-70% for the plains, RFTI`s settled between 2-4
for the daytime hours. Recent precip will curb the threat of an Red
Flag Warning, but the elevated potential has lent to maintaining the
RFD for the afternoon for the above areas.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 75 103 75 102 / 0 0 10 10
Carlsbad 73 99 69 99 / 0 0 0 10
Dryden 76 100 76 100 / 20 20 20 20
Fort Stockton 74 98 74 98 / 10 10 10 10
Guadalupe Pass 66 88 67 88 / 0 0 0 10
Hobbs 69 97 67 99 / 0 0 0 10
Marfa 65 92 65 93 / 10 10 10 20
Midland Intl Airport 74 101 74 102 / 0 0 10 10
Odessa 74 101 74 101 / 0 0 0 10
Wink 73 101 72 102 / 0 0 0 10
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
99/99/10
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1011 PM EDT Mon Jun 29 2020
.SYNOPSIS...
A trough of low pressure will be centered across the interior
portions of the Carolinas today into Tuesday. Unsettled weather
will be the norm through the middle of next week as an upper low
becomes stalled over New England with several weak disturbances
moving across the Mid- Atlantic states.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 1010 PM Mon...Front is slowly pushing south and is helping
to spark some very weak showers mainly south of Highway 70.
Maintained slight chance PoPs for just a couple more hours to
capture this threat before the front ventures offshore.
Otherwise no other major changes to the forecast.
Prev disc...Radar remains mostly quiet this afternoon aside
from a isolated shower or two popping up. A few additional
showers may develop this afternoon along the sea breeze, but
otherwise, expect mostly dry weather through tomorrow morning.
Slight chc for some patchy fog development overnight, but
confidence remains low given the lack of ground level moisture
today, so have precluded fog mentions from the forecast for now.
Overnight temps in the low- 70s.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
As of 1010 PM Mon...Latest RAP soundings still indicate the
potential for marginally severe storms tomorrow afternoon with
isolated damaging wind gusts given DCAPE values ranging from
800-1000 J/kg and MLCAPEs easily exceeding 2000 J/kg. Storms
that form will also be efficient rainmakers with low and mid
level RHs exceeding 80% and PWATS hovering around 2 inches
during the afternoon.
Prev disc...A piece of shortwave energy will jettison off the
upper low over the Midwest and rendezvous with the trough of low
pressure extending off of the cut- off low in the Northeast.
Decent vorticity along the trough will invigorate storms late
Tuesday morning through the afternoon. MLCAPE values around 3000
J/kg with DCAPE values over 1000 J/kg with bulk shear around
20-30 kts insist on strong to marginally severe storms. Isolated
gusty winds in stronger storms will be the main threat. Storm
coverage will be decent with cells forming along the seabreeze
initially and propagate SE towards the coast through the
evening. Highs expected to reach the upper 80s to around 90.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
As of 315 AM Monday...The weather across the eastern United
States will be dominated by a closed upper low that will meander
over New England before finally moving offshore and away from
the US by later in the week. A moist and warm airmass will
remain in place. Better rain chances will occur Wednesday and
Thursday as significant shortwave energy will rotate around the
upper trough. Much of the rest of the period will feature daily
scattered convection along the sea breeze.
Wednesday through Friday...Closed upper level low will continue
over New England Wednesday before finally moving away from the
coast Thursday and Friday. Highest rain chances Wednesday and
Thursday as a couple of significant shortwaves rotate around the
mid-level closed low enhancing shower and thunderstorm
activity. With the upper low moving offshore, convection should
again be more widely scattered and diurnally driven. Daily high
temperatures will generally be in the mid/upper 80s with lows in
the low/mid 70s.
Saturday through Sunday...A general longwave trough pattern will
continue along the East Coast into next weekend, but convective
potential will be limited to sea breeze activity on Saturday.
Sunday looks to be a bit more active per long range ensembles.
Seasonable temperatures for mid June will continue.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Short Term /through Tonight/...
As of 740 PM Mon...VFR conditions prevail this evening and will
continue through the period with cumulus giving way to only some
thin cirrus aloft. Overnight winds are calm with clear skies,
but dry layer from the surface through the low-levels suggests
fog threat is minimal despite insistence from guidance. Opted
to keep BR mention out of TAFs this cycle.
Light winds continue tomorrow, gradually becoming light out of
the S/SE by late morning. Better chance of showers and storms
tomorrow afternoon as another lobe of upper energy approaches
the region from the west. Coverage uncertainty precludes mention
in TAFs this cycle, although best chance for associated
restrictions will be for OAJ/EWN after 17-18z.
Long Term /Tuesday through Friday/...
As of 130 PM Monday...Periods of sub-VFR conditions in
scattered to numerous showers and thunderstorms are likely,
especially on Wednesday and Thursday, with less convection
expected Tuesday and again on Friday. With very moist low-
levels, morning stratus and fog may occur in areas that receive
rain on the previous day leading to MVFR cats.
&&
.MARINE...
Short Term /through Tuesday/... As of 425 PM Mon...Seas will
start out around 2-4 feet and subside to 2-3 feet overnight
through tomorrow. Winds will be light swrly across srn waters
and become mostly calm overnight. Winds will become light from
the SE Tuesday morning and remain around 5-10 kts during the
afternoon.
Long Term /Tuesday night through Friday/...
As of 315 AM Monday...Winds turn S/SW on Wednesday into
Thursday before a weak front veers winds back around to N/NE
Friday. The good news is that wind speeds should be 15 knots or
less through the period with seas 2-3 feet, with perhaps a few 4
footers at times. No SCA conditions are expected through the
long term period.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...MHX
NEAR TERM...MS
SHORT TERM...MS/ML
LONG TERM...CTC
AVIATION...CTC/MS
MARINE...CTC/ML